International Review of RESEARCH IN MENTAL RETARDATION VOLUME 7
Consulting Editors for This Volume Paul Weisberg UNIV...
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International Review of RESEARCH IN MENTAL RETARDATION VOLUME 7
Consulting Editors for This Volume Paul Weisberg UNIVERSITY OF ALABAMA UNIVERSITY, ALABAMA
Marvin S. Kivitz ELWYN INSTITUTE P H I W E L P H U , PENNSYLVANIA
International Review of RESEARCH IN MENTAL RETARDATION
EDITED BY
NORMAN R. ELLIS DEPARTMENT OF PSYCHOLOQY UNIVERSITY OF ALABAMA UNIVERSITY, ALABAMA
VOLUME 7
1974
(29
ACADEMIC PRESS New York San Francisco London A Subsidiary of Harcourt Brace Jovanovich, Publishers
COPYRXOHT 0 1974, BY ACADEMIC PRESS, INC. ALL RIQ?ITS RESERVED. NO PART OF THIS PUBLICAIION MAY BE REPRODUCED OR TRANSMITTED IN A N Y FORM OR BY A N Y MEANS, ELECTRONIC OR MECHANICAL, INCLUDMQ PHOTOCOPY, RECORDINQ, OR ANY INFORMATION STORAQE A N D RETRIEVAL SYSTEM, WIT€iOUT PERMISSION IN WRITINQ PROM THB PUBLISHER.
ACADEMIC PRESS, INC. 1 I1 Fiftb Avmw,
New York,New York loo03
United Kingdom Edition published by ACADEMIC PRESS, INC. (LONDON) LTD. 24/20 Oval Road. London NWI
LIBRARY OF CONQRBSS C A T m CARD NUMBER: 65-28627
ISBN 0-12-366207-9 PRINTED IN IME UNITED STATES OF AMERICA
Contents
.................................................. Prefuce ............................................................ Contents of Previous Volumes ......................................... U t of Contributors
vii
ix xi
Mediationai Proceues in the Retarded
JOHN G. BORKOWSKI AND PATRICIA B. WANSCHURA
. .................................................... ................................ III. Natural Language Mediation ...................................... IV. Conclusion ..................................................... I Introduction
.
I1 ThrccStage. Mdiational Paradigms
......................................................
References
1 7 26 49 50
The Role of Strategic Behavior In Retardate Memory
A”
L. BROWN
. . . .
I Introduction .................................................... I1. Developmental Theories of Memory and Their Implication for Retardation . III The Use of Memory Strategies by Retardates: A Brief Review .......... IV Specific Background to the Present Series of Studies .................. V. Specific Experiments ............................................. VI I m p l i c a t i ~for ~ Mucation ........................................ References ......................................................
55 56 66 77 79 100 104
Conrenation Rwearch with the Mentally Retarded
.
KEN M . WILTON AND FREDERIC J BoERSMA
.
I Introduction
....................................................
11. Studies of Conservation Development ............................... 111. Studies of Conservation Acceleration in the Mentally Retarded
.........
. V. Concluding Comments ............................................
IV Conservation and Other Aspects of Cognitive Functioning .............. References
...................................................... V
114 118 130 136 139 140
vi
Contents
Placement ot the Retarded in the Community: Prognosls and Outcome
RONALD B. MCCARVER AND ELLISM. CRAIG
. .
I Introduction .................................................... I1. Types of Studies ................................................ 111 Literature Review ............................................... IV. General Integration of Findings .................................... V. Suggestions for Future Research ................................... VI. Concluding Remarks ............................................. References ......................................................
146 147 149 180 194 199 199
Physical and Motor Development of Retarded Persons
ROBERTH. BRUININKS I. Introduction ................................................... I1 Definitions and Structures of Motor Proficiency ..................... 111. Physical Development ........................................... IV. Comparative Studies of Gross Motor Abilities ....................... V. Comparative Studies of Fine Motor Abilities VI. Comparative Studies with the Oseretsky Tests ....................... VII Training Studies ................................................ VIII. Summary and Conclusioas ....................................... References ....................................................
........................
209 210 216 220 226 228 231 248 253
..................................................
263
. .
Subject Index
Numbers in parentheses indicate the pages on which the authors’ contributions begin.
FREDERIC J. BOERSMA, University of Alberta, Edmonton, Alberta, Canada (113)
JOHN G. BORKOWSKI, University of Notre Dame, Notre Dame, Indiana (1) ANN L. BROWN,University of Illinois, Champaign-Urbana, Illinois (55) ROBERTH. BRUININKS, University of Minnesota, Minneapolis, Minnesota (209) ELLISM. CRAIG, Texas Department of Mental Health and Mental Retardation, Austin, Texas (145) RONALD B. MCCARVER, Northwest Louisiana State School for the Mentally Retarded, Bossier City, Louisiana (145) PATRICIA B. WANSCHURA, University of Notre Dame, Notre Dame, Indiana (1) KERIM. WILTON,University of Canterbury, Christchurch, New Zealand (113)
Vii
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This volume continues in the tradition established by the six previous ones. The aim is to present current reviews of behavioral research and theory as they relate to mental retardation and similar disorders. The focus has been on behavioral research, mainly psychological, with some attention to educational and sociological issues. A major portion of the contents has centered around basic research and theory rather than application. This reflects both an editorial value judgment and also the fact that the most research has been in this vein. During the past eight years, since publication of the first volume, there has been a dearth of applied research worthy of citation, and this seems unfortunate. Nevertheless, editorial policy for the series is steeped in the belief that the ultimate hope for amelioration of this social ill lies in basic research. Moreover, research of this type with the retarded will increase our knowledge of the normal human being. While most contributions to this series are by invitation, other manuscripts of high quality will be considered.
NORMAN R. ELLIS University of Alabama
ix
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Contents of Previous Volumes
Volume 1
A Functional Analysis of Retarded Development SIDNEY W.BIJOU Classical Conditioning and Discrimination Learning Research with the Mentally Retarded LEONARD E. Ross The Structure of Intellect in the Mental Retardate HARVEY F. DINGMAN AND C. EDWARD MEYERS Research on Personality Structure in the Retardate EDWARD ZIGLER Experience and the Development of Adaptive Behavior H. CARLHAYWOODAND JACKT. TAPP A Research Program on the Psychological Effects of Brain Lesions in Human Beings RALPHM. REITAN Long-Term Memory in Mental Retardation JOHNM. BELMONT The Behavior of Moderately and Severely Retarded Persons JOSEPH E. SPRADLIN AND FREDERIC L. GIRARDEAU Author Index-Subject Index
Volume 2
A Theoretical Analysis and Its Application to Training the Mentally Retarded M. RAY DENNY The Role of Input Organization in the Learning and Memory of Mental Retardates HERMAN H. SPITZ xi
xii
Contents of Previous VoIumes
Autonomic Nervous System Functions and Behavior: A Review of perimental Studies with Mental Defectives RATHEKARRER
Ex-
Learning and Transfer of Mediating Responses in Discriminative Learning BRYAN E. SHEPPAND FRANK D. TURRISI A Review of Research on Learning Sets and Transfer of Training in
Mental Defectives MELVINE. KAUFMAN AND HERBERT J. PREHM Programming Perception and Learning for Retarded Children MURRAY SIDMAN AND LAWRENCE T. STODDARD Programmed Instruction Techniques for the Mentally Retarded FRANCES M. GREENE Some Aspects of the Research on Mental Retardation in Norway IVAR ARNLJOT BJORGEN Research on Mental Deficiency During the Last Decade in France R. LAFON AND J. CHABANIER Psychotherapeutic Procedures with the Retarded MANNYSTERNLICHT Author Index-Subject Index Volume 3
Incentive Motivation in the Mental Retardate PAULS. SIEGEL Development of Lateral and Choice-Sequence Preferences IRMA R. GERJUOY AND JOHN J. WINTERS, JR. Studies in the Experimental Development of Left-Right Concepts in Retarded Children using Fading Techniques SIDNEYW. BIJOU Verbal Learning and Memory Research with Retardates: An Attempt to Assess Developmental Trends L. R. GOULET Research and Theory in Short-Term Memory KEITHG. SCOTTAND MARCIASTRONG SCOTT Reaction Time and Mental Retardation AND GEORGE KELLAS ALFREDA. BAUMEISTER
CONTENTS OF PREVIOUS VOLUMES
xiii
Mental Retardation in India: A Review of Care, Training, Research, and Rehabilitation Programs J. P. DAS Educational Research in Mental Retardation H. SPICKER SAMUELL. GUSKINAND HOWARD Author Index-Subject Index
Volume 4
Memory Processes in Retardates and Normals NORMANR. ELLIS A Theory of Primary and Secondary Familial Mental Retardation ARTHURR. JENSEN Inhibition Deficits in Retardate Learning and Attention LAIRD w. HEALAND JOHNT. JOHNSON, JR. Growth and Decline of Retardate Intelligence MARYANN FISHER AND DAVIDZEAMAN The Measurement of Intelligence A. B. SILVERSTEIN Social Psychology and Mental Retardation WARNERWILSON Mental Retardation in Animals GILBERTW.MEIER Audiologic Aspects of Mental Retardation LYLEL. LLOYD Author Index-Subject
Index
Volume 5
Medical-Behavioral Research in Retardation JOHNM. BELMONT Recognition Memory: A Research Strategy and a Summary of Initial Findings KEITHG. SCOTT
Contents of Previous Volumes
xiv
Operant Procedures with the Retardate: An Overview of Laboratory Research PAULWEISBERG Methodology of Psychopharmacological Studies with the Retarded ROBERTL. SPRAGUE AND JOHNs. WERRY Process Variables in the Paired-Associate Learning of Retardates AND GEORGE KELLAS ALFRED A. BAUMEISTER Sequential Dot Presentation Measures of Stimulus Trace in Retardates and Normals EDWARD A. HOLDEN, JR. Cultural-Familial Retardation FREDERIC L. GIRARDEAU German Theory and Research on Mental Retardation: Emphasis on Structure LOTHAR R. SCHMIDT AND PAUL B. BALTES Author Index-Subject
Index
Volume 6
Cultural Deprivation and Cognitive Competence J. P. DAS Stereotyped Acts ALFREDA. BAUMEISTER AND REXFOREHAND Research on the Vocational Habilitation of the Retarded: The Present, The Future MARCW. GOLD Consolidating Facts into the Schematized Learning and Memory System of Educable Retardates HERMAN H. SPITZ
An Attention-Retention Theory of Retardate Discrimination Learning MARYANN FISHER AND DAVIDZEAMAN Studying the Relationship of Task Performance to the Variables of Chronological Age, Mental Age, and IQ WILLIAME. KAPPAUF Author Index-Subject Index
Mediational Proaesses in the Retarded' JOHN 0. BORKOWSKI AND PATRICIA B. WANSCHURA UNIVERSITY OF NOTRE DAME, NOTRE DAME, INDIANA
1. Introduction.
.......................................
A. Mediation Defined. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B. Mediation in the Retarded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C. Paradigmatic Approaches to Mediation in the Retarded . . . . . . . . . . . . 11. Threeatage, Mediational Paradigms . . . . . . . . . . . . . . . . . . . . . . . . . . A. Experimentally Defied Mediational Paradigms . . . . . . . . . . . . . . . . . B. Mediation by Retarded Individuals in Threeatage Paradigms C. Retention and Transfer of Mediational Gains . . . . . . . . . . . . . . . . . . D. Conclusions and Future Research . . . . . . . . . . . . . . . . . . . . . . . . . 111. Natural Language Mediation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. An Overview of Natural Language Mediation in the Retarded . . . . . . . . . B. The Development of Natural Language Mediational Strategies. . . . . . . . . C. Retention and Transfer of Natural Language Mediation . . . . . . . . . . . . 1V. Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.........
1.
A.
1 1 2 4
I I 9 21 25 26 26 21 42 49 50
INTRODUCTION
Mediation Defined
Normal adolescents and adults rarely master a verbal learning task exclusively in rote fashion. That is, rote learning, which is the strengthening of the direct association between the internal representation of two events (e.g., a stimulus and a response in a paired-associate task), does not adequately describe the adult learning process. Indeed, language habits, syntactical structures, and cognitive strategies can singly, or in combina'This paper was supported, in part, by a training grant in mental retardation from the William Randolph Hearst Foundation to the University of Notre Dame. 1
2
John G. Borkowski and Patricia B. Wanschura
tion, influence even the simplest form of learning, and usually do. All represent higher forms of mental activity than is depicted by the label rote learning, and fit well under the heading cognitive structure representative (cf. Wickelgren, 1972). Cognitive structured learning occurs when a direct association occurs between two events, together with some additional, indirect association. The indirect association-perhaps a natural language associate-serves as a chain or bridge which links the two to-be-learned events more closely together. These indirect associations are commonly referred to as mediators (cf. Bourne, Ekstrand, & Dominowski, 1971) . In its most rudimentary form, a mediator can be represented by the implicit r-s association in the sequence, S + r +- s + R. In contrast to rote learning (S - R ) , cognitive structured or mediated learning involves an implicit, probably covert, response ( r ) to a stimulus event (S), which in turn produces an implicit stimulus (s) that leads directly to the terminal response ( R ) . Most instances of mediated learning fit the S + r +- s + R paradigm, though many require a complex elaboration of the internal, mediating events. Since language habits, syntactical structures, or cognitive strategies often provide mediating associations which facilitate or inhibit the learning process in normal and retarded persons, these mechanisms require further elaboration. Language habits include the natural associations a subject brings to the task, which can facilitate the learning process, such as the word “bacon” serving as an effective link between the stimulus event “bac” and the response “eggs” (cf. Dallet, 1964). The syntactical structure of language refers to the role of words, sentences, or paragraphs that might serve as aids in learning. For instance, Jensen and Rohwer (1963b) have shown that retarded children will learn the pair “shoe-clock’ if a short sentence “I threw the SHOE at the CLOCK” is given prior to the learning task. The term cognitive strategies acts as a broad umbrella covering such diverse phenomena as learning sets, mnemonic devices, and mental imagery (cf. Paivio, 1971). The variety of these higher-order mental activities provides a rich source of learning aids for both normal and retarded individuals.
B. Mediation in the Retarded 1. LURIA’SMEDIATIONAL DEFICITPOSITION Most prominent among the neurological deficit theories of mental retardation is that proposed by the Russian investigator, Luria (1961 ). According to Luria, the central deficit in the retarded child is a lack of development in the verbal system, such that a verbal response cannot serve as an adequate regulator or mediator of voluntary behavior. More specifically,
MEDIATIONAL PROCESSES IN THE RETARDED
3
Luria has observed the behavior of retarded children, who have clear signs of neurological damage, in simple discrimination tasks where the development of stable habits of responding, the child’s ability to switch response sets, and the role of language in mediating or regulating voluntary behavior are analyzed (cf. Zigler, 1966). Retarded children, like normal children of a much lower CA, experience considerable difficulty on discrimination tasks demanding verbal regulation of voluntary behavior. Luria ( 1961) has inferred that the major problem in the behavior of the retarded individual lies in the inadequate development of his verbal system and a “dissociation” of this system from external behavior. The “dissociation” hypothesis is at the core of Luria’s four stages of language development (cf. Spreen, 1965). At the earliest stage, an adult’s verbal commands can initiate or inhibit the child’s behavior. In the second stage, the child learns to accompany behavior with his own verbal descriptions and to activate or regulate his behaviors via verbal feedback. In the next stage, the discrimination function of language emerges (e.g., “press the blue button” promotes a specific behavior pattern). In the last stage, overt language becomes replaced by covert language (mediation) which serves to regulate behavior, especially voluntary actions. It is in the regulating functions of language where Luria postulates a verbal mediation deficit in the retarded. Much of the early mediation research in retardation seems to have originated in an attempt either to support or to refute Luria’s deficiency hypothesis. For instance, O’Conner and Hermelin (1959), Milgram and Furth (1963), and Rieber ( 1964) have claimed support for Luria’s position, while Balla and Zigler (1964) and Berkson and Cantor (1960) have provided contradictory evidence. It would seem that the imprecision of Luria’s theory makes direct, unequivocal assessment impossible. In fact, Zigler and Balla (1971 ) have pointed out that the conceptual ambiguity of Luria’s mediational deficiency hypothesis has resulted in antithetical predictions generated by different researchers. They conclude “one is tempted to argue that, in view of the negative and inconsistent experimental outcomes, the Luria formulation should be abandoned when interpreting differences in the performance of nonretarded and familial retarded children matched on MA” (Zigler &Balla, 1971, p. 412).
2. CURRENT PROCESS ANALYSES OF MEDIATIONAL DEFICIENCIES Although Luria’s theory has done much to stimulate mediation research with the retarded since the early 1960’s, recent research trends have assumed a more pragmatic orientation. Since mediation probably occurs in most learning tasks where complex language or conceptual processes are operative, it is not surprising to find that researchers have become increasingly concerned with the issue of how learning can be improved by media-
4
John G . Borkowski and Patricia B. Wanschura
tional activities, in lieu of a preoccupation with documenting a potential mediational deficit in the retarded person. Thus, much of the current interest in mediation is centered on the processes underlying mediational activity in the retarded. A process analysis of mediation separates the associative chain (S + r + s + R) into two distinct parts: S-r and s-R. A production deficiency is said to occur when the implicit mediator, r, is not evoked by event S, even though the mediator is a part of the language repertoire of the learner (Flavell, Beach, & Chinsky, 1966). A control deficiency is assumed present when the internal mediator, r, is present and elicits the internal stimulus event, s, but fails to influence the behavior under study, R (Kendler, 1972). Kendler has proposed that the term, mediutionaf deficiency, be reserved as a generic label to cover failures to mediate due to either production or control deficiencies. Process analyses of mediational activity permit a more precise pinpointing of deficiencies and have the capacity to bring about more effective application of remedial measures. A production deficiency is likely to occur when the stimulus (S) has a low probability of eliciting the mediator (r), presumably because the S + r association is low in the subject’s language habit hierarchy or has not been learned well during prior training. On the other hand, a control deficiency seems more attributable to the set, strategy, and/or expectation of the subject which influence his ability to utilize an available mediational chain. If a retarded child is shown to have a “mediational deficiency,” it is of importance to determine whether the deficit can be located in terms of control or production phases. Kendler ( 1972) has hypothesized that mediational activity and corresponding mediational deficiencies, as shown by control and production errors, evolve in three developmental stages. The first stage includes both kinds of deficiencies. In the second stage, children between the ages of 5 and 9 continue to show production deficiencies while control deficiencies decline rapidly. In the final stage, as control deficiencies are eliminated around ages 9 and 10, the influence of production deficiencies also begins to decline. However, Boat and Clifton (1968) and Brown and Scott (1972) have demonstrated that children as young as 3 and 4 years of age can mediate. Thus, the lower limit of Kendler’s stages can be questioned, leaving the rest of the formulation to be tested. C.
Paradigmatic Approaches to Mediation in the Retarded
1. AN OVERVIEW OF MEDIATION PARADIGMS
The broad definition of mediation-internal, associative events (r-s) in an S + r * s + R chain-has been operationalized in a wide variety of
5
MEDIATIONAL PROCESSES IN THE RETARDED
learning paradigms, Jensen (1971) lists 11 different tasks used to assess mediation, which we have ranked in terms of their frequency of usage with the retarded (see Table I). The paradigms range in diversity from discrimination learning and semantic generalization to experimentally acquired mediators (e.g., three-stage paradigms) and mnemonic elaborations. However, all refer to mental processes (mediators) that appear to intervene between stimulus and response events when the relationship between these to-be-learned associations cannot be attributed to simple, direct associative processing. Recent research has concentrated on the reliability and utility of the several paradigms that define mediation. The precision of each operational definition lies in the degree to which the internal r-s activity can be specified in terms of antecedent or consequent behaviors. For instance, Kendler and Kendler ( 1962), employing a discrimination learning paradigm, defined mediation in terms of the relative rates of learning for reversal and nonreversal shift tasks. Rats and children seemed to acquire reversal shifts, in contrast to nonreversal tasks, with more difficulty than adults, presumably due to limitations in mediational capabilities. However, the assumed mediational activity in the shift paradigms represents a rather remote inference from the actual task presented to the learner, simply a choice between several alternatives differing along various dimensions. That is, in the case of a reversal shift, the mediator is not directly manipulated by or under the control of the experimenter. In contrast, the paired-associate learning paradigm defines mediation in terms of relative rates of learning for mediated and nonmediated tasks. When mediators are supplied by the experimenter, the mediational process is under more external control. Although direct manipulation of internal events is not necessarily preferable, in a methodological sense, to more TABLE I MEDIATIONAL PARADIGMS: A RANKING ACCORDING TO FREQUENCY OF USE IN RETARDATION RESEARCH High frequency of usage (over ten studies) 1. Syntactical mediation and mnemonic elaborations 2. Associative clustering 3. Learning set formation 4. Reversal-nonreversal shifts 5. Experimentally acquired mediators 6. Labeling
Low frequency of usage (less than ten studies) 7. Extra-experimentally acquired mediators: implicit chaining paradigm 8. Semantic generalization 9. Cross-modal transfer 10. Far transposition 11. Verbal self-reinforcement
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John G . Borkowski and Patricia B. Wanschura
inferential mediational tasks in all cases, it does increase the probability of providing greater insights into the mediational process per se. Of the paradigms listed by Jensen (1971), natural language and three-stage PA tasks seem to allow a high degree of control of antecedent events so that the mediational (r-s) events can be directly manipulated.
2. NATURAL LANGUAGE AND THREE-STAGE MEDIATION PARADIGMS An inspection of natural language and three-stage paradigms indicates that both tasks require the learner, at one and the same time, to elaborate on the stimulus and simultaneously to reduce components of the stimulus event (Jensen, 1971) . For example, if “comb-glass” is the to-be-learned association and the experimenter has provided a sentence (“The comb is in the glass”) as a syntactical aid, then the stimulus “comb” is given novel, more elaborate properties which might compete with an erroneous old language association (e,g., comb + dresser + mirror). For the learner, which mediator, the new or the old, will become the functional mediator during PA learning? Restated, competing associations, evoked by the stimulus “comb,” must be reduced or eliminated if the sentence, “The comb is in the glass,” is to become the dominant mediational strategy. When the subject is asked to learn a pair of verbal items, designated A-C, he will likely find the learning of A-C easier if pairs A-B and B-C have previously been learned than if the prior learning consisted of the pairs A-B and D-C. In terms of such a three-stage mediational paradigm (A-B, B-C, A-C) the Occurrence of stimulus A in Stage I11 has a tendency to elicit B covertly, and the occurrence of B, in turn, tends to evoke C, the correct response (Horton & Kjeldergaard, 1961). The B mediator, which is not explicit during Stage I11 learning, has mediational properties ( r + s) in that it is elicited by A and evokes C. In three-stage paradigms, stimulus elaboration resides in the fact that each A-C pair is given an appropriate B mediator via prior experimentally developed associations. Stimulus reduction takes place when the learner uses the A + B + C strategy instead of alternative strategies, such as A + X + D or A + Y + E,which are likely based on preexisting language habits. In summary, syntactical and three-stage mediational tasks share several common features: (1) Both produce r + s mediators as aids to learning by way of experimentally defined manipulations, and (2) both require stimulus elaboration and stimulus reduction, if mediational processing is to occur in the manner intended by the experimenter. Our concern in this review is to understand more of the mediational capabilities and limitations of the mentally retarded based on data generated by syntactical and threestage paradigms.
MEDIATIONAL PROCESSES IN THE RETARDED
7
II. THREE-STAGE, MEDIATIONAL PARADIGMS
A. Experimentally Defined Mediational Paradigms 1. THECHAINING PARADIGM
One advantage of multi-stage, mediational paradigms is that the experimenter is able to develop and control, in a direct manner, the mediational chains used by the subject during learning. The simplest form of a multistage, mediational strategy is the chaining paradigm (Horton & Kjeldergaard, 1961). In the chaining model, three paired-associate (PA) lists (A-B, B-C, A-C) are presented sequentially. The ease of learning the pairs (generally, word or picture associations) of the third list (A-C) is assumed to be related directly to mediational links developed during the learning of two prior lists (A-B and B-C). That is, the occurrence of an A stimulus in Stage I11 has a tendency to elicit B covertly and the occurrence of B tends to evoke C, the correct response. The presence of A-(B)-C mediational associations in the chaining paradigm can be inferred when A-C learning for the mediation condition is superior to that for a nonmediation, control group (A-B, D-C, A-C) . In the control condition, laboratory-produced mediators are not available to aid A-C learning; only the effects of warm-up and learning-to-learn are present. 2. BOUNDARY CONDITIONS FOR MEDIATED FACILITATION
Although the chaining paradigm has been used extensively in mediational research with adults and normal children (Horton & Kjeldergaard, 1961; Jenkins, 1963; Goulet, 1968), it has not always resulted in a facilitation of PA learning. What seems to have emerged in this literature is a restricted set of conditions which seem to govern the presence of the mediational phenomenon (cf. Schulz, 1972). Among the more important factors that are responsible for producing mediated facilitation with normal adults in the chaining paradigm are: (1) the presumed mediator (B) must be readily available during Stage 111. Hence, it must be highly learned and discriminably different (semantically or structurally) from the A and C. (2) The association between A and C should be relatively difficult so as to encourage the use of the A-(B)-C strategy. Also, the A-C associations should not lend themselves to idiosyncratic, natural language mediators or direct language associations. (3) Schulz and Weaver (1968) have shown that the length of the test trial interval must be long enough to permit the “utilization” of mediators available to the subject. Intervals less than 5 seconds in duration are not conducive to producing mediated facilitation in PA learning for normal individuals (Schulz & Lovelace, 1964).
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John G . Borkowski and Patricia B. Wanschura
(4) In terms of Underwood, Runquist, and Schulz’s (1959) two-phase conception of PA learning (Phase 1 : response learning; Phase 2: associative or “hook-up” stage), mediation in the chaining paradigm is localized in the associative phase. By minimizing the role of response learning, mediation during associative learning can be more clearly assessed. For instance, the use of multiple-choice test trials in A-C learning prevents the possibility of a mediation chain being discarded because of a failure to remember the terminal response, C. Schulz (1972) has shown that an adherence to these four boundary conditions associated with list construction or procedural decisions in the chaining model almost invariably leads to mediated facilitation of PA learning with normal adults. It is important to keep in mind these “optimal” conditions, as multi-stage, mediational research with the retarded is reviewed.
3. TYPESOF MEDIATIONAL PARADIGMS The chaining model is but one type of several commonly used multistage learning paradigms. Other important paradigms are the stimulusequivalence (A-B, C-B, A-C) , response-equivalence (B-A, B-C, A-C), backward-chaining (B-A, C-B, A-C) , and the mediated-interference (A-B, B-C,, A-C) paradigms. The first three tasks involve a partial (stimulus- and response-equivalence) or total (backward-chaining) use of backward associations developed during Stages I and 11, as Stage 1111 learning occurs. The last paradigm, involving mediated interference, is constructed so that an inappropriate “repairing” of B and C terms during Stage I1 leads to an increased probability of mediational errors (e.g., Al-(Bl)-C5, rather than C,) during Stage I11 learning. Schulz (1972) has shown that under the appropriate boundary conditions all four paradigms provide evidence for the operation of mediational processes during PA learning. 4. INTERPRETATIONS OF MEDIATIONAL PROCESSING
Theoretically, most of the early mediational research was incorporated into a rather simple associationistic framework (cf. Jenkins, 1963; Schulz, Weaver, & Ginsberg, 1965 ) . More recent research has led to a widening of the theoretical perspective in which research on three-stage mediational paradigms is given interpretation. For instance, Schulz (1972) compares the chaining paradigm to a simple form of problem solving in which A-C is the to-be-solved problem, and A-B and B-C are previously acquired components, which, when properly integrated and utilized, lead to rapid learning or problem solving. A more cognitive view of mediation in the three-stage paradigms seems necessary when one considers that Stage I11
MEDIATIONAL PROCESSES IN THE RETARDED
9
learning often appears in the absence of A-C study trials. That is, if a subject is given only test trials during Stage III, he is likely to demonstrate mediational facilitation of the A-C associations based solely on the presence of A-B and B-C links developed during the first two stages (Schulz, 1972). In fact, performance on test Trial 1 is often considerably above chance level, even prior to the first opportunity to study Stage I11 pairs. Furthermore, research on the strength of A-B and B-C associations, as they relate to mediational activity during A-C learning, does not fit well into an associationistic framework. For instance, an increase in strength of A-B and B-C associations does not necessarily lead to an increased utilization of mediators (Schulz, 1972). In short, what appears to be emerging, at a theoretical level, is the possibility that mediational activity in the chaining paradigm, as well as in more complex mediational paradigms, involves higher-order, conceptual strategies dealing with the acquisition and employment of rules, as well as simple PA processes of an S-R or associationistic nature. This eclectic view of mediational processing has implications for our review of three-stage mediational research with the retarded, who are thought by some to possess higher-order mental deficiencies (Lipman, 1963; Luria, 1961). B.
Mediation by Retarded Individuals in Three-Stage Paradigms
1. MEDIATION IN
THE
CHAINING MODEL
Berkson and Cantor (1960) conducted the first mediational study with retarded children using the chaining paradigm (A-B, B-C, A-C). They found that a normal CA group learned an initial PA list of picture pairs more efficiently than a moderately retarded group, but that in Stage 111 (A-C), mediational associations facilitated PA learning for both the normal and retarded individuals in contrast to control subjects (X-B, B-C, A-C). One problem with the Berkson and Cantor (1960) study was that the mediational subjects had more exposure to the A stimulus during Stage I than the control subjects; hence, differential stimulus familiarity during A-C might have been a factor in producing the mediated facilitation observed in the CA and retarded groups. In order to further examine the effects of mediational associations on the PA learning of moderately retarded children and adolescents, Borkowski and Johnson (1968) again used the chaining paradigm. However, they employed a control group (A-B, D-C, A-C) in which the A and C terms were shown as frequently as in the mediation condition, in order to preclude possible differential effects of stimulus familiarity which had occurred in control and mediation conditions of the Berkson and Cantor
10
John G . Borkowski and Patricia B. Wanschura
(1960) study. In addition, Borkowski and Johnson ( 1968) compared learning rates for the retarded groups to those for equal CA and MA groups of normal subjects. The specific pictorial materials, designed for use in three-stage chaining (A-B, B-C, A-C) and control (A-B, D-C, A-C) paradigms, were constructed so that potential mediators would be highly available during List I11 learning (i.e., strong A-B, B-C associations). Furthermore, List 111 was designed so that the use of mediators would be the most “efficient” method of learning; that is, the A-C task was chosen so as to represent a rather difficult learning situation. These criteria were met by using highly associated pictures of common objects as the A and B terms, and colors as the C terms. The colored A stimuli and the black and white B stimuli were arranged in concept categories. The C colors were highly associated with B stimuli but not with A stimuli. For example, one set of pairs in the mediational lists was: girl(A)-dress(B), dress(B)-yellow(C), girl(A)-yellow(C). The control condition had pictures as D terms which were not associated with A or B, but were highly associated with C (e.g., giraffe-yellow). Six pairs were used in each of the three lists in both mediation and control conditions. It should be noted that these characteristics of the materials are in accord with Schulz’s (1972) suggestions for maximizing the chances of finding mediated facilitation: (1) Easily learned A-B and B-C links. (2) Distinctively different A, B, and C items. (3) A rather difficult A-C task, which did not lend itself easily to natural language mediators stronger than the experimentally produced mediators. Several features of the procedure used by Borkowski and Johnson (1968) deserve mention, as they may represent boundary or limiting conditions for producing mediation in the retarded. In the initial presentation of List I, the A and B terms were presented together on 3 x 24 inch cards, each pair for a 2-second duration (e.g., “the girl goes with the dress”). The first test trial involved recognition of the correct response from among the six possible alternatives. Incorrect responses were corrected and correct responses were restated. After the first study-test trial, the anticipation method was used to a criterion of two perfect, though not necessarily consecutive, recitations of the list. This criterion for mastery produced a high degree of overlearning for List A-B. Duration of presentation for recall and study intervals was 2 seconds. Pairs were randomized during 6-second intertrial intervals. Following A-B learning, list B-C was presented using exactly the same procedure as with List I, again to a criterion of two perfect recitations. A high degree of overlearning also resulted for List B-C. The study-test method of presentation was used for Stage 111. Study trials (S-Rpairs presented) and test trials (only S terms presented) were alternated until a criterion of two perfect recitations was reached, or to
11
MEDIATIONAL PROCESSES IN THE RETARDED
a maximum of ten study-test trials. Duration of presentation on study trials was 2 seconds per pair; a longer test trial interval (i.e., 5 seconds) was employed to allow for the utilization of the mediational chain. The only knowledge of results during the test trials for A-C learning consisted of “right-wrong” or “yes-no” feedback after each response. The multiple choice testing procedure ensured the availability of the terminal response (C) for each subject, thus reducing the memory load and restricting performance to the associative phase (cf. Underwood et al., 1959). In addition, the subjects had considerable time to analyze, integrate, and utilize potential mediators during the 5-second test period. The mean number of correct responses per trial as a function of mediation and control conditions for retarded, M A , and CA groups is presented in Fig. 1. In the D-C control condition analysis of the total number of correct responses over the first five trials indicated that A-C learning was equivalent for CA and M A groups, which both performed better than the retarded group. This finding is in accord with a considerable amount of data suggesting that with moderately difficult materials there is a deficit in PA learning for retarded individuals (Lipman, 1963). In contrast, a comparison of the mediation conditions showed that the CA group was superior to both the M A and retarded groups which were not significantly different from one another. When mediating links were provided, retarded individuals utilized these associations in Stage 111learning as well as the M A group, though not as efficiently as the CA group. These results indicate that the Low-IQ deficit (cf. Denny, 1964) often found in contrasting retarded and M A groups on moderately difficult (i.e., low meaningful) rote learning and discrimination tasks may be absent in three-stage mediational contexts. Such a suggestion is encouraging, since it indicates that certain learning
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FIG. 1. Mean number of correct responses during A-C learning as a function of type of paradigm and type of subject. (From Borkowski & Johnson, 1968.)
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John G . Borkowski and Patricia B. Wanschura
deficits of retarded individuals can be remedied by providing the appropriate mediational supports. Schulz (1972) has suggested that with normal subjects mediation effects occurring in the chaining paradigm are generally observed early in A-C learning, often in the absence of A-C study trials. In the Borkowski and Johnson (1968) study, the MA and retarded groups had exactly the same level of performance on Trial 1, where the effects of mediation were relatively free of the influence from specific A-C learning trials. Mediational opportunities seemed to be as effectively utilized by the retarded individuals as by MA controls. In contrast, the differences between retarded and MA subjects on Trial 1 in the D-C control condition were quite large and in agreement with other data obtained in a variety of PA learning tasks (Denny, 1964). It is possible that all mediation groups, including at least some of the retarded subjects in the mediation group, may have discovered a relationship or rule regarding the use of A-B and B-C as effective aids in anticipating the pictorial pairs making up Stage 111. Indeed, the rather high level of learning (66% correct) on Trial 1 suggests that more than an associative strategy may have been operative for retarded and normal subjects during the A-C task. Conceptual behavior, akin to problem solving, could have altered the task from the simple associationistic framework (as defined by the experimenters) to a combination of cognitive-associationistic strategies (as actually learned by the subjects). From a theoretical perspective, future research with the retarded might well be aimed at detailing those procedural conditions in the chaining paradigm, as well as subject characteristics, which change a mediational paradigm from associationistic to conceptual and, presumably, result in more rapid learning of the terminal PA list. Milgram (1968a) has also provided data supporting a conceptual rather than associative interpretation of mediated facilitation in the chaining paradigm (A-B, B-C, A-C) with retarded children and adults (both EMRs and TMRs ) . In his study, an explicit mediational strategy-sentence recitation-was used to strengthen the B-C associations and to test whether B-C associative strength, as reflected in Stage I11 learning rates, was solely a function of number of prior study trials. His four experimental conditions included one group receiving a standard chaining procedure in which A-B picture associations had strong extra-experimental connections while B-C and A-C picture pairs were weakly associated; two-sentence recital groups receiving the identical standard chaining paradigm, with additional instructions to repeat sentences containing stimulus and response terms during the initial B-C trial (in one group the sentences were meaningful and in another they were nonsensical) ; a control condition consisting of the stan-
MEDIATIONAL PROCESSES IN THE RETARDED
13
dard A-B, D-C, A-C paradigm. All lists, of lengths ranging from four (for TMRs) to six pair (for EMRs ) , were learned to a criterion of two perfect recitations; hence, many, if not all, pairs in each list were overlearned. Milgram’s (1968a) results indicated a clear superiority of the meaningful sentence recitation condition during A-C learning in contrast to the performance of the standard chaining as well as the control conditions. The effectiveness of the nonsensical sentences was also substantial when compared to the control or chaining conditions, although the differences were of smaller magnitude than when meaningful sentences were used. Only with TMRs did meaningful B-C sentences produce more evidence of mediational activity during A-C learning than nonsensical B-C sentences. Differences between the chaining and control conditions were significant, though smaller in magnitude than for the recitation and control comparisons. Analyses of Stage I1 learning showed that the meaningful sentence group learned the B-C list faster than the chaining group, with the nonsensical sentence group generally in the middle. Apparently, retarded adolescents and adults of widely different IQs were able to use explicit instructions related to B-C sentence recitation to increase mediation during A-C learning in contrast to a standard chaining group. This superiority in the sentence recitation groups was found in spite of the fact that the chaining condition had more B-C presentations and had learned the B-C associations to a high degree (i.e., a criterion of two perfect recitations of the list). Milgram (1968a) argued that his mediational results were attributed to a greater availability of B-C links during A-C learning for the sentence recitation groups and were not due to a transfer of learning strategy (sentence recitation) from Stage I1 to 111. Although in 1968 there were ample data suggesting that retarded individuals were unable to transfer a sentence strategy to a neutral list, more recent findings have demonstrated strategy transfer (MacMillan, 1972; Turnure & Thurlow, 1973; Wanschura & Borkowski, 1974). These findings argue for the inclusion of an A-B, D-C, A-C control group having sentence recitation during Stage 11, as a test for the possibility of strategy transfer during Stage 111 acquisition. In any case, both interpretations of Milgram’s ( 1968a) data suggest that higher-order, cognitive processing does indeed influence three-stage mediational activity. A simple S-R,associationistic view does not sufficiently account for mediation in the chaining paradigm by retarded individuals. 2. MEDIATIONAL DEFICIENCIES IN THE RETARDED?
Most of the studies using the three-stage chaining paradigm have indicated that mentally retarded individuals can improve PA learning via mediational associations acquired during earlier learning tasks. However, the
John G . Borkowski and Patricia B. Wanschura
14
results of two studies might tend to restrict such a generalization. Penney, Seim, and Peters (1968b) used a three-stage, mixed list, chaining task to test for a mediational deficiency in retarded children (1% = 61 ) relative to = 99.2). In their mixed list design, normal children of the same MA all subjects received both mediational (A-B, B-C, A-C) and control (A-B, D-C, A-C) pairs within the three tasks. The most important results, shown in Fig. 2, represent mediation scores, defined as the mean number of A-C trials required to reach a criterion of one correct recitation for D-C pairs minus a similar measure for B-C pairs, plotted as a function of type of subject and length of the anticipation or test interval. In other words, the mean CI facilitation scores in Fig. 2 represent the amount of mediation as indexed by the difference in learning rates for control and experimental pairs. With a relatively short anticipation interval (6 seconds), moderately retarded children were found to be mediationally deficient relative to normal children of the same MA. However, when the interval was lengthened to 12 seconds, mediation in the retarded group was facilitated (improving from approximately -.75 to .75 trials), whereas mediated facilitation was eliminated for normal children. Does the Penney et af. (1968b) study support a mediational deficiency position? Several aspects of the design and data suggest the answer is no. First, as the rate of testing became optimal (i.e., a 12-second anticipation
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FIG. 2. Mediated facilitation of A-C learning (D-C trials to criterion minus B-C trials to criterion) as a function of anticipation interval and type of subject. (From Penney et al., 1968b).
MEDIATIONAL PROCESSES IN THE RETARDED
15
period), the retarded group seemed to show increased benefits from mediational aids (A + B + C) during A-C learning. In fact, at the longer interval the retarded children were mediating more than the normal children. Second, the use of a mixed list design probably led to the adoption of “mixed” strategies, at least for some normal children. Hence, one explanation of the precipitous drop in mediation performance for the normal children as the anticipation interval increased could be based on their recognition of the difference between mediation and control pairs at the longer interval and a subsequent attempt to employ a unique, nonmediation strategy for control pairs. It should be noted that the 6-second test period for normals appears to be functionally equivalent, in terms of amount of mediational activity, to a 12-second test period for the retarded. In both instances, evidence for mediation is apparent; a mediational deficiency position does not seem tenable. Gallagher (1969) used the chaining paradigm to compare moderately retarded and normal children of the same MA, although he based A-B and B-C links on free-associative strengths (FAS) inferred from normative association data. In other words, rather than developing A-B and B-C associations in the laboratory, Gallagher manipulated the strength of these associations (high, low, and nonassociated FAS values) via natural language habits, requiring his subjects to learn only a single list, A-C. Within the A-C list, subjects were presented six pairs, two pairs each representing high, low, and zero FAS values; zero FAS was equivalent to a nonmediated, control condition. Significant main effects of FAS values and subject classification were found. That is, both normal and retarded subjects used natural language associations ( A + B + C) to facilitate A-C learning. However, contrary to the findings of Berkson and Cantor (1960) and Borkowski and Johnson (1968), normal M A control subjects made fewer errors than retarded subjects at all FAS levels. As Gallagher (1969) suggests, perhaps the natural language mediators based on two different sets of normative values were not as readily available to the retarded subjects. Three additional aspects of the design and procedure should be pointed out in assessing the mediational differences between the retarded and normal groups: (1 ) Study and anticipation intervals were both 2 seconds in duration. This represents a very rapid rate of presentation and testing, especially in view of the fact that the 2-second test period was filled with a stimulus probe and then a response. Schulz and Lovelace (1964) have pointed out that normal adults often require up to 5 seconds to utilize mediators available in their response repertoires. The use of a 2-second test period per A-C pair does not allow much time for mediational processing, especially in retarded individuals for whom natural language associations may be less accessible for retrieval. (2) The use of an aural presentation method is quite different from the visual presentation of pictures, which is common
John G . Borkowski and Patricia B. Wanschura
16
in much of the three-stage mediation research. Aural presentation is probably one major cause of differences in the mediational capacities of normal and retarded children. It would seem to constitute a more difficult task situation and the apparent success of the retarded group in utilizing high and low FAS words as mediators is encouraging. (3) Another possible difference in mediational performance may be related to Gallagher’s (1969) use of a mixed design in which some pairs lent themselves more readily to a mediational strategy. Did the retarded subjects employ separate strategies for the three sets of pairs? Were the strategies for normal and retarded children the same? Were the strategies recognized and developed at the same rate across trials? Some of these questions may be answered by probing each pair following A-C learning for the various units that served as mediational links. For instance, an A stimulus might be presented and the subject instructed to recall all words that were associated with A. Both the frequency and ordering (was B or C given first?) of responses might yield information about the various learning techniques used by both the normal and retarded subjects. In summary, the Gallagher (1969) study suggests that although retarded subjects can use their language habits as mediational aids during PA learning of word pairs, the extent of facilitation for the mentally handicapped may be limited by aural presentation, short test periods, and by mixed list designs, which perhaps require differential cognitive processing for rapid acquisition of the entire mediation list.
3. MEDIATION AS
A
FUNCTION OF INDIVIDUAL DIFFERENCES
a. Eflects of IQ There is not a wealth of data available on the effects of subject characteristics on mediation in the chaining paradigm with the mentally retarded. In 1960, Berkson and Cantor indicated that even low IQ retardates could profit from laboratory-produced mediators in improving PA learning. A more detailed analysis of the effects of IQ on mediated facilitation was performed in the Borkowski and Johnson (1968) study discussed in the preceding section. An inspection of mediational data for the highest and lowest IQ retarded subjects showed that those with the highest IQs (N = 8, 1% = 66.5) performed only slightly better than those with low IQs ( N = 9, = 45.9). That is, across five A-C trials on a six-pair list, the mean total correct for the high IQ subgroup was 27.4 and for the low IQ subgroup 25.3, the difference being nonsignificant. It is noteworthy that two of the three mongoloid children with IQs between 33 and 39 learned the A-C list to a criterion of two perfect recitations within five trials. Thus, the beneficial effects of mediation in the chaining paradigm do not appear
MEDIATIONAL PROCESSES IN THE RETARDED
17
to be restricted, in any obvious way, by intelligence level within the retarded group. These results lend some support to the conclusion of Berkson and Cantor (1960) that the degree of facilitation associated with mediation is not directly related to IQ.
b. M A Comparisons The effect of MA on the mediational abilities of cultural-familial, retarded children, and adolescents was found to be significant (Penney et al., 1968b). A low MA group (3.9-5.1 years) showed less mediation in a three-stage chaining paradigm than a higher MA group (6.1-8.7 years), although the low MA group experienced more improvement in mediated learning as the anticipation (or test) interval during A-C learning increased from 6 to 12 seconds. It would seem that at this point in time there is insufficient data to propose firm statements regarding the effects of IQ, CA, and MA on three-stage mediational processes in the retarded. However, the little data available does suggest that retarded children, within a rather wide range of I@, can utilize A-(B)-C chains to improve PA learning if procedural conditions are “optimal.”
c. Institutionalization The effect of institutionalization on mediation abilities of retarded children in the chaining paradigm was investigated by Penney and Willows ( 1970). Based on Zigler’s (1966) extensive work documenting the detrimental effects of institutionalization on learning processes, it was predicted that the longer a child was institutionalized, the more likely he would be to exhibit a mediational deficiency. Eighteen cultural-familial retardates who had been institutionalized for periods ranging from 5 months to 2 years = 63.8) were compared on a mediation task with 18 retarded = 61.7) who had been institutionalized for periods ranging children from 3 to 10 years. The task was a three-stage chaining paradigm (A-B, B-C, A-C) for one-half of the picture pairs with the other pairs representing a control paradigm (A-B, D-C, A-C). Contrary to expectations, the longer the institutionalization, the higher the mediation score. That is, a mediational deficit was found in children who had relatively brief periods of institutionalization. Several aspects of the Penney and Willows (1970) study preclude any firm conclusions concerning institutionalization effects on mediation in the retarded. First, a correlation of .73 between length of institutionalization and years in school suggests that some of the mediational advantage in the “long” institutionalized group can be attributed to prior learning experiences (e.g., learning sets) similar to the experimental conditions. Second, a noninstitutionalized, retarded group of the same MA and CA was not
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John G. Borkowski and Patricia B. Wanschura
tested; hence, a baseline for assessing the influence of institutionalization was not established. Third, the use of a mixed list design (half mediation, half control pairs per list) is questionable, from a methodological perspective, in mediational research with the retarded. That is, Schulz (1972) has shown that mixed list designs in three-stage paradigms encourage normal subjects to adopt a rather complex cognitive strategy; namely, a rapid discrimination on A-C Trials 1 and 2 of the differences between mediation (B-C) and control (D-C) pairs and a utilization of a mediational strategy (A + B + C) for some pairs but not for others. Whether or not retarded children can accomplish such a high level of discrimination is doubtful, especially early in A-C learning when mediation is normally most pronounced (cf. Schulz, 1972). In any case, the use of a mixed list probably leads to the utilization of varied strategies within a group and possibly between groups; certainly a mixed list does not present to the experimenter (let alone the subject) an easily analyzable task situation in terms of learning processes. It may well be that the higher IQ children who do discover a structural difference between mediation and control pairs within a PA list, and attempt to employ separate learning strategies for the respective pairs, are more hindered than helped by selective mediational strategies. In short, the effects of institutionalization on mediation in the mentally retarded require more detailed analyses before definite statements can be formulated. 4. COMPLEX THREE-STAGE PARADIGMS: BACKWARD ASSOCIATIONS
The chaining paradigm requires a subject to use forward associations (A + B and B + C ) if mediation is to occur during Stage I11 learning. Other three-stage paradigms are based on a subject’s ability to employ backward associations developed during Stages I and 11. Such paradigms make use of the fact that during PA learning of list A-B, both forward (A-B) and backward (B-A) associations are formed. For instance, if we present list B-A, B-C, A-C-referred to as the response-equivalence paradigm (Horton & Kjeldergaard, 1961)-a subject must use backward associations (A-B) if A + B + C mediational processing is to take place during Stage 111. Similarly, mediation in the stimulus equivalence paradigm (A-B, C-B, A-C) is based on the assumption that the backward link, B + C, developed during Stage 11, is available for A + B + C processing during Stage I11 learning. Both normal adults and chlidren have been shown to mediate in paradigms which rely on the utilization of backward associations (Palermo, 1962; Schulz, 1972). There are little data available on whether or not retarded children can mediate when more complex three-stage paradigms requiring the use of backward associations are employed. Only recently has the issue of associa-
MEDIATIONAL PROCESSES IN THE RETARDED
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tive symmetry-a comparison of the rates of development for forward (A-B) and backward (B-A) associations during A-B learning-been actively researched in the mentally retarded. Baumeister and Campbell (1971 ) found that backward associations did develop during the PA learning of retarded children, with the strength of backward associations being only slightly weaker than forward associations. Similarly, Borkowski, McGrath, and Doyle (1969b) used positive and negative transfer paradigms to demonstrate that backward associations in Task 1 influenced the rate of learning of Task 2 for both normal and retarded children. In their review of PA learning processes in the retarded, Baumeister and Kellas (1971) concluded that “bidirectional learning is a general phenomenon that occurs over a wide range of human development [p. 2651.” Can retarded children employ backward associations as mediational aids in three-stage paradigms? A recent unpublished study conducted by Kamfonik and Borkowski compared mediation in the stimulus-equivalence (A-B, C-B, A-C), response-equivalence (B-A, B-C, A-C), and standard control (A-B, D-C, A-C) paradigms. The materials in all three paradigms were picture pairs, similar to those used by Borkowski and Johnson (1968) designed to enhance the formation of backward associations in Stages I and 11. That is, the lists were constructed so that during Stage I11 learning, potential mediators would be highly available (i.e., strong A-B or B-C associations), and so that the level of A-C difficulty would prompt the use of mediators as the most “efficient” method of learning. An example of one set of pairs used in the stimulus equivalence list is: squirrel(A)tree(B), green(C)-tree(B), squirrel(A)-green(C). Six pairs were used in each of the three lists in both mediation and control conditions. It should be noted that identical performance has been obtained with normals when comparing A-C learning in the A-B, D-C, A-C control condition with A-C learning in A-B, D-B, A-C, and B-A, D-C, A-C control paradigms (Schulz, 1972); hence, only the A-B, D-C, A-C control group was used. The control group received pictures as D terms which were highly associated with C but not associated with the A or B terms (e.g., turtle-green). In order to compare the data with earlier studies involving the chaining paradigm, the procedures were identical to those used by Borkowski and Johnson (1968). The key features were multiple-choice test trials during A-C learning, with long ( 5 seconds) test trial intervals. The mean number of correct responses for the stimulus-equivalence (C-B) , response-equivalence (B-A) , and control (D-C) conditions is presented in Fig. 3. An analysis of variance of mean correct responses per trial indicated that the effects of trials and paradigms were significant, while the interaction between these two variables was not significant. Further analyses showed that the stimulus equivalence paradigm produced superior
John G . Borkowski and Patricia B . Wanschura
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3s 1 : : : : : : 1
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FIG.3. Mean number of correct responses during A C learning for stimulusequivalence (C-B ), response-equivalence (B-A) , and control (D-C ) paradigms. (From J. G. Borkowski & A. Kadonik, unpublished study.)
learning in comparison to that produced by the response-equivalence and control paradigms, whose performances were not significantly different from one another. A trials to criterion analysis yielded a similar pattern of results. Subjects in all groups were given a modified free recall task following A-C learning. Each child was presented with an A stimulus, both visually and orally, and asked to recall as many items as he could that “went with” each A stimulus. An analysis of the modified free recall data, which was designed to assess the strength of the B mediator following Stage 111 learning, tended to substantiate the fact that mediated facilitation occurred in the stimulus-equivalence paradigm. That is, B terms were recalled correctly 67% in C-By 52% in B-A, and 47% in D-C and were recalled first 32% in C-B, 28% in B-A, and 19% in D-C. These results reaffirmed the conclusions of Baumeister and Kellas (1971) and Borkowski et al. (1969b) that retarded children develop bidirectional associations during the course of PA learning. More specifically, in the stimulus-equivalence paradigm retarded subjects were shown to employ backward associations to produce mediated facilitation. However, the absence of mediation in the response-equivalence paradigm is not consistent with the findings of Horton and Kjeldergaard (1961) and Schulz (1972) who reported rather sizable mediational effects in this paradigm with college students. There are at least two factors which might have led to mediated facilitation in the stimulus-equivalence but not in the response-equivalence para-
MEDIATIONAL PROCESSES IN THE RETARDED
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d i p . First, the backward links in the C-B situation are temporally closer to the test stage (A-C) than in the B-A paradigm, where the backward links are learned during the first learning task. If there are differential rates of forgetting for forward and backward associations in the retarded, it is more likely to impede mediation in the response-equivalence paradigm. The second possible reason why mediation occurred only in the C-B paradigm is that the first link (A-B) may be more critical than the second link (B-C) in initiating or activating the A + B -+ C mediational chain. Perhaps the first link (A-B) is more difficult for retarded individuals to utilize during test trials when it is a backward rather than a forward association. Although backward links can be used in some situations by retarded individuals to mediate PA learning, the mediational process in paradigms requiring backward links does not appear to operate in identical ways for normals and retarded persons. One possible inference from existing data might be that normal individuals are more efficient at overcoming retrieval difficulties associated with the utilization of backward links than are the mentally retarded. However, it should be noted that the extent of mediated facilitation in the retarded with the stimulus-equivalence paradigm was identical to that previously demonstrated with the chaining paradigm (Borkowski & Johnson, 1968). In both situations, one involving the utilization of forward and the other backward associations during Stage 111, retarded subjects were able to report on the average five of six possible correct responses on Trial 1, when pictorial materials, welldeveloped mediation links, and a rather long test trial interval were used. Future research with more complex three-stage paradigms, such as the backward chaining paradigm (B-A, C-B, A-B), the mediated interference paradigm (A-B, B-C,, A-C), and the equivalence paradigms, should be aimed at testing the limitations of mediational processes in the retarded when backward associations or interlist interference are operative in PA learning. In addition, research programs dealing with mediation in fourstage paradigms are needed in order to extend our knowledge of PA learning in the retarded when the mediational chains are more complex in their formation and utilization. C.
Retention and Transfer of Mediational Gains
Most research in mental retardation with three-stage paradigms has focused on a documentation or refutation of mediational activity during the acquisition of a terminal PA list. However, other important issues in three-stage research concern the maintenance of mediational gains over time and the transfer of mediational strategies to new learning tasks. These recent issues in mediation research, while being of theoretical interest, have
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developed because of their obvious applied implications. For instance, can higher-order strategies be taught to retarded children in the laboratory and transferred to classroom assignments? Can problem-solving activities in the classroom be taught in terms of multi-stage paradigms with the expectation of strategy transfer to similar tasks? Borkowski, Ahearn, and Pearson (1969a) assessed the ability of mildly retarded children to store and utilize mediational associations in the chaining paradigm (A-B, B-C, A-C). Specifically, three groups of retarded children learned an A-C list 30 seconds, 20 minutes, or 24 hours after learning Lists A-B and B-C. A single control group learned List A-C 30 seconds after learning Lists A-B and D-C. The materials and procedure were similar to those used by Borkowski and Johnson (1968). Since the pairs were common pictures and the criteria for learning Lists A-B and B-C were extremely high, it was hypothesized that the retention interval would have minimal effect on the retarded children’s utilization of mediators during A-C learning. The mean number of correct responses for chaining and control paradigms as a function of the interval between Lists B-C (or D-C) and A-C is presented in Fig. 4. Orthogonal comparisons showed that A-C learning for the three chaining groups was superior to that for the control group and that the effects of retention interval (30 seconds, 20 minutes, or 24 hours) were nonsignificant. In other words, with highly learned, pictorial materials, retarded children were able to store mediational links up to 24 hours and then utilize these A + B + C chains during Stage I11 learning. 6e
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FIQ. 4. Mean number of correct responses for chaining and control paradigms as a function of the interval between lists B-C (or D-C) and A X . (From Borkowski et a!., 1969a.) Copyright 1969 by the American Psychological Association. Reprinted by permission.
23
MEDIATIONAL PROCESSES IN THE RETARDED
It should be noted, however, that the overall magnitude of mediation effect was rather small; the average superiority of the mediation group over the control was about one item per trial. The magnitude of the mediation effect in the Borkowski et al. (1969a) study (about 16% improvement under mediation conditions) is similar to that reported by Penney et d. (1968b) and Borkowski and Johnson (1968). Several studies have attempted to increase the magnitude of mediated facilitation by using transfer designs in which several paradigms are learned in succession. Penney, Peters, and Willows (1968a) used a mixed list, which included chaining and control pairs, to assess the mediational ability of mildly retarded children and adolescents = 60). An analysis of A-C learning during the mediational pretest showed that chaining pairs resulted in significantly fewer errors than control pairs over the first six trials. This finding is in contrast to results reported previously by Penney et al. (1968b) which indicated no mediation in the retarded group with similar materials and procedures, including a 6-second test interval in both studies. Two weeks following the mediation pretest, Penney et al. (1968a) gave subjects training in either a learning set or operant task, and then administered a mediation posttest. The learning set activity required the children to solve 50 consecutive two-choice discrimination problems, involving picture pairs presented for six trials each, or to reach a criterion of 14 out of 15 correct for any three consecutive problems. Subjects were tested over several days on the learning set task and were reinforced with marbles which could be redeemed for stickers. It was hypothesized that the learning set task would enhance the use of spontaneous mediational processing during the intervening training activity. The operant task was designed to minimize mediational activity (by requiring subjects to guess the position, left or right, of a series of pictures presented one at a time) and to provide reinforcement to the same extent as in the learning set condition. Five minutes following the learning set or operant tasks, the mediational posttest was presented. Both chaining and control pairs were included in the four-pair PA lists (A-B; B-C and D-C; A-C). An interaction was found between type of paradigm (mediation or control) and type of intervening activity (learning set or operant task). Learning set enhanced mediation, while the operant task depressed mediation scores. Penney et al. (1968a) concluded that the learning set provided an opportunity for the subject to organize behavior verbally and to use mediators in solving the discrimination problem. The mediational activity during the intervening phase presumably transferred to the mediation posttest and enhanced the children’s ability to employ A + B + C chains during Stage I11 learning on the mediation posttest.
(m
John G . Borkowski and Patricia B. Wanschura
24
Borkowski and Kamfonik (1972) attempted to generate transfer of verbal mediational strategies by presenting moderately and mildly retarded subjects = 62) two consecutive chaining or control paradigms separated by a 2-week interval. A major concern was whether or not the children could acquire paradigm-specific mediational habits which would later influence the learning of a second mediational task. If a subject became aware of the A-(B)-C associative strategy during the initial mediational session, would he utilize this strategy during a second mediational task? Postman (1968) has demonstrated that college students who have experience with the chaining paradigm on one occasion show improved performance on a second, unrelated chaining paradigm. In other words, exposure to successive mediational sessions results in a “learning-to-mediate’’ phenomenon. The mean number of correct responses per trial in Stage I11 (for the mediation and control groups) during both sessions is presented in Fig. 5. The main effect of the mediation-control comparison was significant, with the mediation group showing superior learning. The influence of the “learning-to-mediate” phenomenon was revealed in the significant Sessions X Groups interaction. An analysis of this interaction showed that the mediation groups were superior to their control counterparts in both sessions. In addition, the mediation groups were not different from one another during the two sessions whereas the learning for the control group during Session 1 was superior to that in Session 2, due to an increase in the difficulty of task two. In other words, the extent of the difference between the mediation and control groups increased significantly from the fist to the second session. A trials to criterion analysis yielded a similar pattern of results. Following A-C learning, presentation of the A stimuli in a modified free recall task requiring both the B and C responses indicated that B recall by mediational subjects increased from 85 to 95% from Session 1 to Ses-
(m
Session 2
TRIALS (Stage
m)
1 1 3 d 5 6 TRIALS (Stage
m)
FIG.5. Mean number of correct responses for A-C learning during two sessions by mediation and control groups. (From Borkowski & Kamfonik, 1972.)
MEDIATIONAL PROCESSES IN THE RETARDED
25
sion 2. In addition, recall of the B items first changed from 63 to 92%, suggesting a greater use of the mediational B link in Session 2 than Session 1. Thus, several aspects of the Borkowski and Kamfonik (1972) data suggest that moderately retarded children can “learn-to-mediate” when provided with successive experiences on three-stage mediational tasks. D.
Conclusions and Future Research
Most of the research on mediational processes in the retarded, defined in terms of three-stage paradigms, provides rather clear evidence for mediated facilitation during the terminal stage of PA learning. Given that the length of the test trial is sufficient to allow for the utilization of associative chains, mediation groups almost always perform superior to control groups when the learning materials are either pictures or words. When the mediational performance of retarded individuals is compared to normal individuals of the same MA, the normal group is likely to show greater mediated facilitation, especially at lower MA levels. However, it appears that the difference between normal and retarded individuals in learning a standard nonmediated PA list is considerably larger than the difference under mediation conditions. In other words, mediational processing can be used successfully by the retarded to remedy a portion of the PA deficit commonly found when the task is difficult (cf. Denny, 1964). Some of the more promising findings based on three-stage paradigms center on the ability of the retarded person to store and utilize mediational links over a long time span and to transfer mediational strategies when confronted with successive mediational tasks. Future research should be aimed at developing tactics which enhance the acquisition of mediational strategies and at assessing the transfer of strategies to nonmediated tasks. For instance, if separate groups of subjects are presented either the chaining paradigm or control paradigm for 3 days in succession (three lists per day) and then all are given a single, nonmediated PA list on Day 4, will the strategy developed over days in the mediation group transfer to the final PA list and result in superior learning? This type of research design will enable us to understand more of the retarded person’s capacity to maintain and utilize functional mediators in a variety of learning contexts. In addition, research on three-stage paradigms should be directed at examining failures to mediate in Stage I11 as a function of production deficiencies (the inability of A to elicit the B mediator during A-C learning) or control deficiencies (the inability to utilize an available A + B + C link during A-C learning). Such research efforts need to focus more carefully on a pair-by-pair analysis of mediated learning, rather than on molar
26
John G . Borkowski and Patricia B. Wamchura
response measures such as the number correct per trial or the trials required to reach criterion. Most likely a more microscopic assessment of Stage I11 learning would reveal that many retarded individuals consistently show mediation across trials for a portion of the items in a list, while never mediating on other items. If this is the case, techniques would then need to be devised to increase the generalization of mediational processing within a list, in terms of reducing or eliminating control and production deficiencies for retarded individuals. Ill. NATURAL LANGUAGE MEDIATION A.
An Overview of Natural Language Mediation in the Retarded
Natural language mediational processes in the mentally retarded have been actively researched only during the last decade. In an important study, Jensen and Rohwer (1963b) demonstrated that retarded adults could employ supplied sentence mediators to facilitate performance in a paired-associate (PA) task relative to control subjects who did not receive sentence mediators. This finding was contrary to the extant theoretical notion in the early 1960’s that retarded individuals were unable to use language, in its orienting, abstracting, and systematizing roles to mediate the formation of new connections (Luria, 1957). Following Jensen and Rohwer’s original report, several other studies replicated the facilitating effects of mediation on learning in the retarded, thereby restricting the generalizability of Luria’s (1957) deficit theory. More recent research has been aimed at delineating the types of mediators most easily employed by retarded individuals to aid PA learning. As we shall see in subsequent sections, sentence mediators have been compared with pictorial mediators; semantic and syntactic paragraphs have been contrasted with sentence and labeling mediators; and sentences have been examined in relation to prepositions and conjunctions in terms of their mediational effectiveness. Although most types of supplied mediators have been shown to facilitate performance, the ability of retarded individuals to generate their own mediators has been questioned. Researchers have compared learning rates with experimenter-supplied and subject-supplied mediators, and generally have found less facilitation for the latter condition, where performance sometimes fails to differ from a nonmediated control condition. Techniques and strategies have been sought to improve the production and utilization of self-generated mediators. These efforts include a fading technique with gradual removal of experimenter support, detailed instruc-
MEDIATIONAL PROCESSES IN THE RETARDED
27
tions to the subject for generating his own mediators, and the use of mixed lists to provide contrast and opportunity for mediational practice. Although techniques for developing an effective mediational strategy, as opposed to using experimenter-supplied mediators, have met with some success in terms of immediate learning, more permanent effects of mediation, as reflected in the retention and transfer of strategy, have generally not been found. What factors contribute to the development of an effective, lasting mediational strategy which can be utilized after a week or more with new learning tasks? In a general sense, sufficiency and consistency of mediational practice seem best to describe these necessary factors. Where sufficient training coupled with a consistent mediational strategy occurs, retarded children will likely demonstrate transfer of the strategy, to some extent, up to 2 weeks after training. Indeed, such findings represent a dramatic change from the mediational deficit positions formulated by researchers in retardation in the late 1950’s and early 1960’s. B. The Development of Natural Language Mediational Strategies
1. MEDIATION AND LANGUAGE STRUCTURES Jensen and Rohwer (1963b) conducted the first mediational study with retarded individuals who were supplied natural language mediators during a PA task. Designed to examine the effects of mediated facilitation on PA and serial learning tasks, Experiment I1 established that retarded adults could utilize supplied mediators to facilitate performance relative to nonmediated control subjects. On Trial 1, mediation subjects were provided with a sentence linking the PA items (e.g., “I threw the SHOE at the CLOCK”), while control subjects were required only to name the items. All subjects then learned a list of eight pairs of colored pictures at their own pace. Although Jensen and Rohwer (1963b) failed to report the analysis of simple effects based on the interaction of tasks and instructions, they stated that mediation groups made significantly fewer total errors and took significantly less time to learn than the nonmediation groups in the PA task. In a second study, Jensen and Rohwer (1963a) again found mediated facilitation for retarded adults supplied sentences for a PA list of six familiar objects. Here, retarded individuals were first required to name and recall the response items and then were provided with mediating sentences on Trial 1. Learning proceeded at the subject’s pace, with correction for wrong responses provided. The mediation group learned very quickly and significantly faster than the nonmediation group. In agreement with Jensen
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John G . Borkowski and Patricia B. Wanschura
and Rohwer’s (1963a, 1963b) findings, Milgram (1968a) found that retarded adolescents learned an A-C list in the three-stage chaining paradigm (A-B, B-C, A-C) significantly better when the B-C link was learned with sentence mediators rather than with standard PA instructions. Thus, the concept of mediational deficiency can no longer be considered synonymous with mental retardation. Since mentally retarded individuals can utilize supplied mediators to facilitate performance, their cognitive functioning cannot be characterized as control deficient (cf. Kendler, 1972). However, the possibility of a production deficiency and the spontaneous use of available mediators must still be considered. 2. MEDIATOR TYPE Once the mediational ability of retarded persons was established, researchers attempted to h d the types of mediators that resulted in maximal facilitation of PA performance. This search included experimenter-supplied, syntactic mediators (e.g., prepositions, sentences, and paragraphs) as well as pictorial mediators (e.g., interacting pictures). In addition, attempts were made to categorize subject-generated associative strategies and correlate their complexity with PA performance.
a. Experirnenter-Supplied Syntactic Mediators The simplest forms of syntactic mediators are prepositions. In an early study, Davidson (1964) found that prepositional mediators were as effective as sentence mediators, and significantly better than labeling (naming pairs) and control conditions for normal second graders of low and high PA ability. These results indicate that simple prepositional connectives are sufficient to produce mediated facilitation in PA learning. In addition, Davidson ( 1964) suggested that the equivalent performance with prepositions and sentences may have been due to the complexity of the supplied, nine-word sentences. A post hoc trial-by-trial analysis indicated that pictured sentences (i.e., a fifth condition in which pairs were joined by pictures interacting in a way described by sentences in the sentence mediation condition) led to significantly more correct responses on Trial 1 than all other conditions. Wanschura and Borkowski ( 1974) have also demonstrated that retarded children can use simple prepositional mediators to facilitate PA performance. Since their subjects were lower functioning than in most previously published research (MA = 4.9, = 39.9, CA = 12.6), the less complex prepositional mediators were chosen to minimize the effects of potential language deficiencies. Moderately and severely retarded children in the mediation groups were able to utilize the prepositions “in, on, and under” to significantly improve PA performance over nonmediation controls.
MEDIATIONAL PROCESSES IN THE RETARDED
29
Turnure and Walsh ( 1971) have extended syntactic mediation beyond simple prepositions, such as used by Wanschura and Borkowski (1974), and sentences, as employed by Jensen and Rohwer (1963a, 1963b), to two-sentence paragraphs. The EMR subjects learned a different list of four pairs of colored pictures in each of three sessions conducted at approximately 1-week intervals. Each subject learned under all three experimental conditions-Naming, Sentence, and Paragraph. On Trial 1 of each session, subjects were supplied with the appropriate mediator for the assigned condition. Learning proceeded via the anticipation method to a criterion of two consecutive perfect recitations or 20 trials. After criterion was reached, reversal of each PA association was tested by presenting the response term and asking for its associated stimulus item. Turnure and Walsh (1971) found that mediation conditions interacted with test days. On Day 1, Paragraphs required significantly fewer trials to criterion than Sentences, despite ceiling effects in the Paragraph condition. Sentences also required significantly fewer trials than the Naming control group. On Day 2, Paragraph and Sentence conditions performed similarly, although still significantly superior to controls. However, on Day 3 all groups were equal. Since only Day 1 was uncontaminated by transfer from other sessions and conditions, the superiority of Paragraphs over Sentences seems to be the most solid conclusion. That is, increasing syntactic elaboration produced greater mediated facilitation of PA learning in the retarded. The reversal data on Day 1 also indicated mediation in those conditions containing the most elaboration, since Paragraph and Sentence groups reversed well, with significantly less errors than Word mediation. Since the two-sentence paragraphs presented by Turnure and Walsh (1971) involved unbalanced placement of stimulus and response items for the various syntactic conditions, Turnure ( 1971) investigated the systematic placement of pair members within the elaboration. In one condition, Syntactic paragraph, the stimulus was embedded in the first sentence and the response term in the second. In the Semantic paragraph condition, the stimulus and response terms were both included in the first sentence, with the second sentence providing meaningful elaboration. Both Paragraph conditions were contrasted with Sentence and Word mediation (labeling) conditions. To avoid the ceiling effect present in the Turnure and Walsh (1971) study, mildly retarded subjects learned a PA list of eight pairs of colored pictures, It was found that all elaboration conditions required significantly fewer trials to criterion than the Word mediation condition. The two types of paragraphs did not differ, but they were significantly more effective than sentences. Thurlow and Turnure (1972) suggested that the equal performance of Syntactic and Semantic paragraph conditions in Turnure’s ( 1971) study
30
John G . Borkowski and Patricia B. Wanschura
resulted from an apparent ceiling effect. Hence, they administered three list lengths (8, 12, and 16 pairs) to EMR subjects in one of three elaboration conditions (Sentence, Semantic paragraph, Syntactic paragraph). In addition to their usual procedure of administering mediation training only on Trial 1, Thurlow and Turnure (1972) employed a drop-out procedure in which each pair correctly recalled one time was dropped from the list until the final trial. After completion of learning and a single reversal trial, five subjects selected randomly from each treatment condition were asked to recall the elaboration they had used during learning. The results indicated no overall effect of conditions, with list length contributing the only significant effect. However, a priori determined comparisons performed on the eight-pair list as a replication of earlier research indicated that the Semantic paragraph group made significantly fewer errors than the Sentence group, which did not differ from the Syntactic paragraph group. There were no significant differences in the trials to criterion measures. Thurlow and Turnure (1972) made a further comparison of syntactic mediators on a list of 24 pairs and found no differences in first trial errors of Sentence (9.14), Semantic paragraph (9.71 ), and Syntactic paragraph (9.28) groups. Not only do differences in syntactic mediators disappear with longer lists, but there is also a suggestion that the relationship among them starts to reverse. Perhaps the longer, more elaborate paragraphs become more of a memory load than a facilitator with more demanding tasks. b, Subject-Produced Syntactic Mediators In order to evaluate subject-produced mediators, a method must be established to categorize the myriad productions possible. Martin, Boersma, and Cox (1965) developed such a classification scheme for associative strategies employed by college students during PA learning. Combining the data from two experiments, they found a monotonically increasing relationship between their suggested ordering of strategy complexity and correct responding. Thus, Martin et al. (1965) felt that an ordinal scale underlay their categorization of strategy complexity and supported the notion that a quantified strategy score could be generated for each subject. To determine if this strategy score could be employed with retarded subjects, it was necessary first to assess whether or not mentally retarded individuals could verbalize the mediational strategies they used during learning. Therefore, Martin, Boersma, and Bulgarella ( 1968 ) provided practice on seven pairs of low meaningful stimuli and high meaningful responses for normal = 13.8, = 112) and retarded (FA = 14.2, = 72) adolescents. The normal individuals received three learning and test trials (LT, LT, LT), with retarded individuals having six learning and
(a
31
MEDIATIONAL PROCESSES IN THE RETARDED
three test trials (LLT, LLT, LLT). After the practice trials, during which normals made significantly more correct responses than retardates despite participating in half as many learning trials, subjects were informed of the strategies they could have used. Table I1 lists the various possible mediational strategies ranked from low to high level. A criterion task of six PA items was then presented to both groups for ten learning and five test trials (LLT, LLT, LLT, LLT, LLT). After the criterion task, subjects were asked to describe the “tricks” or “cues” they had used during learning. The results of Martin et al. (1968) indicated that the strategies described by retarded adolescents could be classified similarly by two independent judges. The reported strategies also reflected the fact that more correct responses were made by normal than the retarded subjects on the criterion task. Retarded individuals reported more low-level strategies (1 and 2 ) and fewer high-level strategies (6 and 7) than normals, with no difference TABLE I1 CLASSIFICATION OF ASSOCIATIVESTRATEQIES” Category level
Type of cue S reported using
Example of verbal report
Femur-Village: “I couldn’t think of anything here.” Flotsam-Keeper: “Just used straight memorization (repeated it over and over).” 3. Single letter S reported using a single letter Kaysen-Captain: “The second letter of both of them was cues in each of the dissyllables in an A.” making the association 4. Multiple letter S reported using multiple letWelkin-Kitchen: “Both words cues have a K and an I.” ters in each of the dissyllablea 5. Word formation S reported a word embedded Nimbus-Hunger: “I saw the word BUS and remembered in one or both of the dissylit went with Hunger.” lables and used the word in making the association. 6. Superordinate Welkin-Kitchen: “I thought of S reported selecting elements from each of the two disWeekend-Kitchen because syllables and connecting you use B kitchen a lot on them by relating them to the weekend.” each other in some way 7. Syntactical Kupod-Hewa: “Cupid is in S reported selecting elements from each of the two dissylHeaven.” lables and embedding them into a sentence, clause, or phrase. 1. No reported
associations 2. Repetition
S was not able to state how he made the association S reported rehearsing the pair
* Taken from Martin et al. (1968).
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John G . Borkowski and Patricia B. Wanschura
in intermediate strategies (3, 4, and 5 ) . It would seem that the poorer performance by the mentally retarded children may have resulted from their greater use of low-level strategies. However, strategy scores assigned to each subject according to Martin’s et al. (1965) procedure did not correlate with performance, although floor and ceiling effects probably influenced such a finding. Milgram ( 1 9 6 8 ~ )attempted to test the suggested relationship between strategy level or quality of subject-generated mediators and performance on PA tasks. Since he used both meaningful stimuli and responses, Milgram’s ( 1968c) strategies reflected only the higher-level syntactical strategies discussed by Martin et al. (1968) and required a different classification scheme. Milgram ( 1 9 6 8 ~ )compared sentences categorized as no response (0 pts.), nonsensical relationship ( 1 pt.), and positional relationship ( 2 pts.) with those showing functional ( 4 pts.) and novel or original relationships ( 5 pts.). There was no consistent relationship between sentence scores and learning trials. MacMillan (1972) also found no correlation between quality of sentence mediators and PA performance. Milgram and Riedel (1969) investigated the possibility that the low quality of retarded subjects’ produced mediators reflected an inability to describe the interacting pictures often used in mediation research. Both normal and retarded children were asked to describe interacting pictures, and their verbal responses linking the stimulus and response picture pairs were rated on the inclusion of both terms and context of the connection. The inclusion score included ratings for one term missing ( 1 pt.), both terms present ( 2 pts.), and both terms plus an additional element (3 pts.). The context score assigned values to position, unrelated actions, or missing terms (1 pt.); meaningful interaction (2 pts.); and novel or optimal relationship-e.g., “The TELEPHONE(R) is up in the BARN(S) so the cows can call other cows” ( 3 pts.). The data showed a significant effect of MA, with MA9 subjects receiving higher context and inclusion scores than MA7 and MA5 children, although MA7 and MA5 children did not differ from each other. In addition, normal children had significantly higher context scores than retarded children, but inclusion scores only approached significance. Since Milgram and Riedel (1969) gave only one point for positional relationships, which were shown to be effective mediators by both Davidson ( 1964) and Wanschura and Borkowski (1974), their results are difficult to interpret. The data on the utilization of experimenter-supplied sentences by the retarded also attest to the usefulness of positional relationships in improving PA learning (cf. Jensen & Rohwer, 1963b). Hohn and Martin (1970) felt there might be some effect of the quality of a subject-produced mediator on the effective use of experimenter-supplied mediators. Using normal fifth grade students, they presented 20 pairs
MEDIATIONAL PROCESSES IN THE RETARDED
33
of low meaningful paralogs and familiar words (e.g., DAVIT-VILLAGE) . The subjects were informed of different strategy “tricks” (cf. Martin et al;, 1965) and then asked to write which trick they would use for each pair. After the production patterns were determined (Simple: 1 and 2; Complex: 6 and 7; or Variable: no pattern), the children were assigned to one of three levels of experimenter-supplied mediators (Complex, Simple, or Control). It was found that the Complex treatment defined by the experimenter’s mediators led to significantly fewer trials to criterion than the Control treatment, which in turn resulted in faster learning than the Simple mediation treatment. In addition, high-level, complex producers performed significantly better than low-level, simple producers. Strategy scores reported after acquisition correlated negatively with trials to criterion. Perhaps the superiority of the Control over Simple mediation groups indicates that complex producers, who operate effectively with no instructions, tend to abandon their complex strategies for available experimenterdefined strategies, regardless of their simplicity or effectiveness. A similar study with retarded individuals might provide useful information on the strength of preexisting mediational habits and their interaction with experimentally produced strategies in PA learning.
c. Visual and Imagery Mediation Versus Syntactic Mediation Since syntactic mediation requires at least a minimal degree of language development, its use with retarded children has been compared with nonverbal, visual and imagery mediation. However, contrary to intuitive expectations, retarded individuals do not benefit more from visual than verbal mediators. In contrast to Paivio and Yuille’s (1969) adults, who report an imagery strategy most frequently, retarded subjects seem to perform as well or better with verbal mediators for concrete items. For example, Milgram and Riedel (1969) compared sentences ( verbal context) with interacting pictures (visual compound) at three MA levels. In Experiment I, trainable (TMR5:EA = 5.2, CA = 15.0) and educable (EMR7:KA = 6.9, CA = 15.6, E M R 9 : r A = 8.9, = 17.0) mentally retarded children learned two 6-, 9-, or 12-item PA lists of pictures. Comparisons with nonmediation controls are difficult, since experimental subjects participated in two lists and control subjects in only one. With this limitation in mind, the results suggested that the verbal condition was superior to the control condition at TMRS, verbal and visual superior to control at EMR7, and verbal greater than visual which was superior to control at EMR9. A comparison of EMR performance with that of similar MA, normal subjects from an earlier study (Milgram, 1967b) indicated that retarded individuals were equivalent to normal individuals under verbal and control conditions, but inferior under the visual condition. Milgram
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John G . Borkowski and Patricia B. Wanschura
and Riedel (1969) assert that the exact nature of the covert encoding of verbal and visual mediators is unclear. In an earlier study, Rohwer and Lynch (1968) employed both verbal and visual mediators in a study of PA learning efficiency in retarded adults and normal children of varying grades and social strata. They modified the standard procedures of using interacting pictures as visual mediators, by presenting black and white movie film sequences of the objects engaged in a short-action episode (e.g., a sequence showing a DOG walking to a GATE and closing it). Results showed that the two levels of visual depiction (Action and Still) and two levels of verbal mediators (Sentence and Name) interacted with school strata. An analysis revealed that the interaction occurred only in the lower-strata sample, but further simple effects were not reported. In comparison to all other groups, retarded individuals performed with significantly more errors. However, the lack of two- and three-factor interactions of Depiction and Verbalization with Subject Population (Retarded and Normal) indicated that retarded adults benefit from mediators in a way similar to normals. In addition, the mean correct for the retarded group suggested that all types of mediators (Names-Action = 11.29, Sentences-Still = 10.21, Sentences-Action = 10.62) were equivalent and significantly better than controls (Names-Still = 7.71 ) . Wanschura and Borkowski (1974) also found equal facilitation for three mediator types: Visual (interacting objects), Verbal (prepositional phrase), and Visual-Verbal (interacting objects and prepositional phrase). It would seem that verbal and visual mediators supplied by the experimenter cannot be consistently differentiated in terms of PA performance. Instead of providing mediators, Taylor, Josberger, and Knowlton (1972) instructed subjects in the production of their own imagery and = 70.2, verbal mediators. Before receiving instructions, subjects CA = 12.6) participated in a single study-test trial consisting of the auditory presentation of eight pairs of concrete nouns. A three-trial practice series was then presented during which instructional aid was gradually reduced. For example, the Imagery group saw interacting pictures on Trial 1 , with instructions to imagine separate pictures interacting on Trial 2, and no aid on Trial 3. The Verbal elaboration group received an experimenter-supplied sentence on Trial 1, with instructions to generate a sentence on Trial 2, and no aid on Trial 3. The Repetitioncontrol group participated in three trials during which the experimenter repeated the noun pairs over and over. After training, a list of twelve pairs was presented for a single study-test trial. Following two more practice trials, a third list was given for a single trial. Postexperimental questioning led to the discarding of two subjects who admitted not using the strategy. Taylor et al. (1972) showed that Imagery and Verbal mediation condi-
(m
MEDIATIONAL PROCESSES IN THE RETARDED
35
tions were significantly better than the Repetition-control on both Lists 2 and 3, but not different from each other. A subsequent study of five subjects trained in each mediation condition considered the types of elaborations given. The significantly greater use of the present tense in the Imagery condition and the past tense in the Verbal condition suggested to the authors a potential means of distinguishing between mediator types. However, no attempt was made to correlate reported elaboration and performance. Taylor et al. (1972) also discussed the fact that the tendency of Verbal mediation subjects to speak out loud may have confounded overt verbalization with elaboration training. In a study using only imagery elaboration, Yarmey and Bowen (1972) compared the effect of intentional and incidental imagery instructions in a 2 X 2 X 3 X 2 design consisting of the following variables: subjects (normal and EMR), stimulus materials (noun pairs and picture pairs), instructions (Intentional Imagery, Incidental Imagery, and Intentional Control), and presentations (one or four trials), After hearing an example, the Intentional Imagery group was instructed to make up images relating the pairs and to rate the ease of their formation on a scale from 1 to 5 . They were also told to learn the pairs for a later recall task. The Incidental Imagery group formed and rated images, but received no instructions to learn the pairs. The Intentional Control group was required to rate how recently they had heard the words or seen the pictured objects and also instructed to learn the pairs for later recall. The normal (1% = 110.5, F A = 8-13) and retarded (IQ = 71.3, CA = 8-13) children then rated a list of 16 PA items, consisting of eight noun pairs and eight picture pairs presented once or four times. Recall was tested by having subjects write the response to each stimulus. Since the response requirement of writing items was rather difficult, two scoring criteria were used: (1 ) Strict scoring-correct spelling or a close approximation; ( 2) Lenient scoring-strict scoring plus words with first two letters correct or a drawing substituted, It should be noted that since no instructions were provided concerning the Lenient system, it is possible that some subjects did not respond by guessing due to spelling difficulties, even though they had partial knowledge of the answer. In any case, with the Strict scoring system, there was a significant Subjects X Instructions X Presentation interaction. Analysis of simple effects indicated that Intentional Imagery equaled Incidental Imagery for retarded children, with both imagery conditions benefiting from four presentations. The Control group was inferior to imagery conditions and showed no effect of repeated presentations. However, floor effects in the performance of the Retarded group make interpretations difficult. In contrast, Intentional Imagery was significantly better than Incidental Imagery for normal children, and received
John G . Borkowski and Patricia B. Wanschura
36
no additional benefit from repeated presentations. In turn, Incidental Imagery was significantly better than controls, and both groups improved with more presentations. Thus, retarded children learned more with intentional and incidental imagery instructions than with control instructions, although the facilitation was not great. In addition, the superiority of normal over retarded children was diminished with the Lenient scoring system, under which Retarded-Imagery groups performed significantly better than normal controls. This finding is consistent with Gordon and Baumeister’s (1971) data demonstrating the facilitation of PA performance when response terms are made more available to retarded individuals.
d . Limitations of Mediator Type Research One basic problem with the research conducted on different types of mediational elaboration is the restricted range of materials used. Most of the studies cited have employed pictures, drawings, or common objects as stimulus and response items, the one exception, by Yarmey and Bowen ( 1972), compared noun pairs with picture pairs under imagery conditions. They found that picture pairs led to significantly more correct responses than noun pairs, when the Lenient scoring system was employed. There was also a significant Materials x Instructions interaction, with Intentional Imagery superior to Incidental Imagery for noun pairs, but not for picture pairs. Imagery facilitated performance relative to control for both types of materials. However, there has been no comparison of noun and picture pairs with different types of verbal elaboration. In the child literature, Rohwer, Lynch, Levin, and Suzuki (1967) found an interaction between type of mediator (conjunction, preposition, verb, or label) and type of material (nouns or pictures) at various age levels. For sixth graders verbs equaled prepositions, which were significantly better than conjunctions for printed nouns; in contrast, verbs were superior to prepositions for pictures, but prepositions did not differ from conjunctions. At the third-grade level, verb, preposition, and conjunction mediators were significantly different from each other for both nouns and pictures, but only verb strings were significantly better than nonmediation (naming) controls. Thus, the degree of facilitation from verbal elaborations seems to depend upon materials, as well as type of mediator. The range of materials used in mediation research with the retarded should therefore be expanded in order to assess the effects of mediator types on PA learning. 3.
PRODUCTION OF
SUBJECT-GENERATED MEDIATORS
For normal adults, supplied mediators do not seem as effective as selfgenerated mediators in the facilitation of PA learning. However, Schwartz
MEDIATIONAL PROCESSES IN THE RETARDED
37
( 1971) examined the possibility that experimenter-constructed sentences or yoked sentences, in which one person receives sentences generated by another (cf. Pelton, 1969), interfered with learning, because the supplied sentences are presumably unlike self-generated sentences. Schwartz ( 1971) developed PA materials (e.g., A-pie, D-cat) whose supplied mediators (e.g., apple, dog) were the most frequently generated mediators, when instructions to mediate were given. Analysis of only those items with identical mediators reported by both Supplied and Generated groups indicated that generated were indeed superior to supplied mediators. Arbuckle and Aznavour (1973) have recently noted that supplied mediators are as effective as self-generated ones for normals, if the method of presentation is auditory and the pairs contain a concrete stimulus and abstract response, together with a concrete retrieval cue. As with mediator type, materials and presentation conditions seem to limit the generalizability of a self-generated mediator superiority over experimenter-supplied mediators. In the area of retardation, Jensen (1965) suggested that the difference between retarded and normal subjects in PA learning may be due to a greater amount of spontaneous mediation by normals. In Kendler’s (1972) terms, retarded individuals would be considered to be production deficient. If this is true, it is reasonable to expect that the relationship between supplied and generated mediators in the learning of the retarded would be different from that found in normals. MacMillan (1970) compared the learning performance of EMR children (1% = 70.2) supplied sentence mediators (Experimental-Mediation) , instructed to generate mediators (Experimental-Control), or merely given verbal labels (Control). To minimize response learning during the PA task, subjects were required to name and recall the six response items prior to acquisition. During pretraining on two pairs, the experimental groups were supplied with short sentences linking the pairs. The learning session followed, with the ExperimentalMediation group receiving mediators and the Experimental-Control group instructed to generate sentences out loud on Trial 1. MacMillan’s (1970) results showed that the Experimental-Mediation group learned significantly faster than the Control group. However, the Experimental-Control group, though it did not differ significantly from Experimental-Mediation, also did not differ from the Controls in trials to criterion or errors. A floor effect was apparently operative, since 60% of control, 47% of Experimental-control, and 13 % of Experimental-Mediation subjects failed to reach criterion after 12 trials and were arbitrarily assigned a score of 13. Although the superiority of supplied over generated mediators is suggested for retarded subjects in the MacMillan (1970) study, the low level of learning limits the generality of this conclusion. In contrast, Gordon and Baumeister (1971) found no difference be-
John G . Borkowski and Patricia B. Wanschura tween supplied and generated mediators for EMRs learning a PA list of 16 items. MacMillan (1972) eliminated the floor effect in his 1970 study by allowing 18 trials to reach a criterion of one perfect recitation of the list. Both Experimental-Mediation and Experirnental-Control groups first learned two lists of nine pairs under mediation conditions and then one list under nonmediated, control conditions. The Control group learned three unaided lists. On Lists 1 and 2 it was found that the two mediation groups were equal and significantly better than controls on both trials to criterion and errors. However, only the Experimental-Mediation group was able to show positive transfer to an unaided list. The Experirnental-Control group equaled Control performance on List 3, for both trials to criterion and error measures. Although generated mediators operated as effectively as supplied mediators and significantly better than no mediators during training, they were still inferior to supplied mediators on a transfer task involving unaided pairs. Several techniques have been explored for enhancing the ability of retarded children to generate their own mediators. Milgram ( 1967a) has tried a fading technique in which subjects first received supplied mediators, then were required to generate mediators, and finally learned a list with only instructions to remember the earlier strategy. The retarded and normal children learned three PA lists of nine picture pairs. An analysis of trials to criterion by the retarded group on the first three lists showed a significant List x Condition interaction. That is, the Control group learned in significantly fewer trials on Lists 2 and 3 than List 1, whereas the Experimental group did not differ across lists. Since the Mediation group learned significantly faster than controls, the lack of significant change across lists implies that the training technique was successful in encouraging experimental subjects to generate their own mediators for the nonmediated List 3. In fact, normal and retarded performances were equal, with retarded individuals forming somewhat more complex sentences than normals on List 3. In another study, Milgram (1968b) spread his graduated training sequence across 8 days. On Days 1 and 2 a standard control procedure was followed. Lists on Days 3 and 4 were learned with supplied mediators, whereas self-generated mediators were used on Days 5 and 6. Days 7 and 8 involved noncommital instructions. Contrary to Milgram’s ( 1967a) earlier finding, a gradual sequence of training failed to facilitate self-mediation. In fact, Milgram suggests that his subjects may have been mediational deficient, since they benefited less from supplied mediators than normal children. However, this interpretation is tenuous since the retarded subjects did benefit from mediators relative to nonmediation controls. It would seem that low MA retarded adolescents have difficulty in developing a mediational strategy when it involves spontaneous utilization.
MEDIATIONAL PROCESSES IN THE RETARDED
39
Detailed instructions during practice trials have also been employed as devices to elicit self-generated mediators. This procedure differs from earlier methods in that actual mediation pairs are not involved in training. Taylor et al. (1972) found that EMRs could improve performance relative to controls, by receiving graded instructions (cf. Milgram, 1967a) on three practice trials in the use of verbal and imagery mediation. Yarmey and Bowen (1972) have also demonstrated that EMRs can learn to form imagery mediators in as few as four practice trials, such that performance of experimental subjects exceeded that of controls. However, the “high” IQs of the children in both studies (70.2 and 71.3, respectively) poses problems in extending the generality of these results to the retarded population as a whole. A third technique for developing subject-generated mediators involves the use of mixed lists of experimenter-supplied and control pairs. It might be expected that the juxtaposition of aided and unaided items would encourage the transfer of generated mediators to unaided pairs. Martin (1967) supplied normal fourth, sixth, and eighth graders with strategy aids for all eight PA items, for four of eight items, or for no items. He found that Total-Aid and Half-Aid groups were both significantly better than the Control group, and no different from each other. A comparison of unaided items in the partially aided list with the same items in the control list showed a significant superiority for those items juxtaposed to aided pairs. However, Martin (1967) rejected the interpretation that aided pairs provided implicit examples for producing subject-generated mediation. For the most part, there were no significant differences between strategy scores in the Half-Aid and Control groups, leading Martin to conclude that the half-aid condition merely reduced the size of the list by allowing rapid mastery of aided items. In this way, subjects had more time to concentrate on learning unaided pairs. However, since Milgram (1968c), Martin et al. (1968), and MacMillan ( 1972) have all reported no correlation between strategy level and PA performance with retarded individuals, the facilitation of unaided items in partially aided lists as a result of “strategy generalization” should not be disregarded solely on the basis of an absence of differences in strategy scores. Perhaps a more probing technique for assessing strategy utilization is needed. Wanschura and Borkowski (1974) tested the utility of partially aided lists in producing self-generated mediators in retarded children. They provided retarded children (MA = 4.9, 1% = 39.9, F A = 12.6) with prepositional mediators for all six items (100% aid), for three of six items (50% aid), or for no items (control). Although the Half-Aid group learned aided items as easily as the Total-Aid group, they failed to learn unaided items better than the Control group. Thus, the use of mixed lists
John G . Borkowski and Patricia B. Wanschura
40
with retarded subjects without further instructions did not facilitate subjectproduced mediators. Since these children were quite low functioning, the effect of explicit instructions to generate mediators should be examined before the mixed list techniques is discarded as a strategy for reducing possible production deficiencies. In summary, it would seem that retarded subjects who generate mediators do not surpass the performance of subjects supplied with mediators in PA learning. Indeed, retarded children sometimes fail to produce mediators and perform similarly to controls. Techniques for improving the selfgeneration of mediators have included a gradual reduction of the experimenter’s support as well as detailed instructions during practice. Although these methods have facilitated immediate performance, a long-term benefit from mediation is not evident. The use of aided and unaided pairs in the same list has also failed to improve mediational strategy. 4. MEDIATION AS
A
FUNCTION OF
INDIVIDUAL
DIFFERENCES
a. M A Eflects Contrary to Zigler’s (1967) contention that MA determines the rate of learning in most tasks, Jensen and Rohwer (1968) assert that both MA and IQ influence performance on learning tasks. The role of MA and IQ in mediated facilitation of PA learning can be studied by comparing the performance of retarded individuals with that of equal MA and CA control subjects. The three natural language mediation studies using an equal CA control group have reported the superiority of normal over retarded children (Martin et al., 1968; Rapier, 1968; Yarmey and Bowen, 1972). These data seem to suggest a low MA-low IQ deficit. The eight natural language studies using equal MA controls have found inferior retarded performance in four instances (Jensen, 1965; Milgram, 1968b, 1968c; Rohwer & Lynch, 1968) and performance equal to MA normals in the other four studies (MacMillan, 1972; Milgram, 1967a, 1968c; Milgram & Riedel, 1969). Those studies reporting the superiority of normal over equal MA retarded individuals tend to include low MA o r h w IQ subjects. For example, Milgram ( 1 9 6 8 ~ )found that CA4 normals were superior to TMRs (MA = 5.2) in learning a PA list with self-generated mediators. Milgram (1968b) reported that normals learned in significantly fewer trials to criterion than retarded children (MA = 4.6), when supplied and generated mediation conditions were combined. Thus, retarded individuals with an MA of 5 years seem to have more difficulty than normal children in utilizing mediators in PA learning. As MA level increases to around 8 years, the difference between normal and retarded groups disappears (Milgram, 1 9 6 8 ~ ) .
MEDIATIONAL PROCESSES IN THE RETARDED
41
To examine the influence of MA level on mediation independent of normal comparison groups, Gordon and Baumeister (1971) studied three levels of MA (6, 9, and 12). They employed a design consisting of MA level, Instructions (supplied, generated, or standard), and Response Availability (recall or recognition). Results showed that with standard PA instructions mildly retarded children (MA12) did not demonstrate a responselearning deficit, since the recognition procedure was equal to the recall procedure in terms of errors. However, MA6 and MA9 retarded children learned better with the recognition than the recall procedure. An analysis of MA and the two mediation instruction conditions showed a significant effect of MA, but no differences due to supplied or generated instructions. Thus, performance improved directly with increasing MA, although all MA levels benefited equally from supplied and generated mediators. The three MA levels showed a superiority of mediation conditions over control conditions. Contrary to Milgram’s (1968b) findings with the lowest MA group (MA = 4.5), Gordon and Baumeister’s (1971) lowest MA level ( 6 years) learned better under mediation than neutral conditions. Wanschura and Borkowski (1974) have also shown significant improvement for low functioning retarded children (MA = 4.9) receiving experimenter-supplied mediators. b . Institutionalization More than half of the studies reporting mediated facilitation in the retarded have employed noninstitutionalized subjects, usually EMR children enrolled in the public school system or adults in sheltered workshops. The remaining studies obtained subjects from institutions for the mentally retarded, often with no consideration given to length of institutionalization as a matching variable. Although Baumeister (1969) has shown that there is a significant correlation between months of institutionalization and trials to criterion on a standard PA task when IQ is statistically controlled, only one study has assessed natural language mediation in institutional and noninstitutional environments. Milgram ( 1968c) examined the sentence mediation performance of institutionalized EMR subjects (MA = 8.1, = 58, = 18.3) and noninstitutionalized EMRs (MA = 8.5, 13 = 77, CA = 11.9) enrolled in the public school system. He found that noninstitutionalized children learned in significantly fewer trials than institutionalized children. However, initial differences in IQ and age make the results difficult to interpret strictly in terms of institutionalization.
c. Socioeconomic Status In addition to MA, IQ, and institutionalization, there seems to be an interaction of IQ with socioeconomic status (SES) in mediation tasks.
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John G . Borkowski and Patricia B. Wanschura
Rapier (1968) has shown that normal children of high and low SES perform equally well, but that significant differences occur in the retarded population as a function of social class. It appears that low SES mentally retarded children perform as well as normal low SES children, but high SES retardates make significantly more errors than low SES retarded children. This latter result may be due to a greater homogeneity of etiology, probably organic in nature, in the upper class group.
d . Summary Mediated facilitation of PA learning in the retarded appears to be influenced by such subject characteristics as MA, IQ, SES, and perhaps length of institutionalization. Retarded children generally evidence a low MA-IQ deficit in comparison to normal CA controls, and sometimes show a low IQ deficit relative to normal MA controls. Although Milgram (1968b, 1968c) found inferior performance for low MA subjects, Gordon and Baumeister ( 197 1) and Wanschura and Borkowski ( 1974) both reported mediation effects with low MA levels. However, the range of reported IQs in the studies surveyed is restricted, with nine studies employing subjects with mean IQs of appproximately 70, four studies reporting IQs around 55, and three studies using IQs around 40. Thus, much of the mediation research using language associations has involved only mildly or moderately retarded EMR children. Little information is available on the mediation capabilities of low IQ, retarded children.
C.
Retention and Transfer of Natural Language Mediation
Although most researchers consistently report the lack of a mediational deficiency in retarded individuals, a durable mediational strategy usually fails to develop during training sessions. That is, subjects utilizing mediators during learning do not develop strategies which improve performance relative to controls on a subsequent nonmediated list presented at some future time, usually after 1 or 2 weeks. However, positive short-term effects from mediational training have been demonstrated (Milgram, 1967a; MacMillan, 1972), such that retarded children receiving mediation conditions learned significantly better than controls on a nonmediated list presented immediately after training. If the factors operating in these short-term successes can be isolated and expanded and those contributing to failure avoided, then the possibility of long-term mediational transfer can be enhanced.
MEDIATIONAL PROCESSES IN THE RETARDED
43
1. FAILURES IN RETENTION AND TRANSFER OF MEDIATIONAL STRATEGIES The long-term effects of mediational experiences have been studied by testing recall or relearning of mediated pairs or by comparing performance of Mediation and Nonmediation groups on subsequent nonmediated test lists. Jensen and Rohwer (1963a) found no effect of mediated learning on the relearning of six pairs 1 week later. However, ceiling effects in the Mediation group limited the possibility of improvement during relearning. Jensen and Rohwer (1963b) have also demonstrated that experience with a single mediated list of eight pairs did not facilitate performance on a control list given 10 to 12 days later. Rapier ( 1968) found similar negative results 1 week after her subjects learned a mediated, nine-item list. Milgram (1967a) replicated the failure of mediation subjects to show long-term benefits in learning two lists of 12 pairs 1 week after training. However, his mediation subjects did show short-term facilitation from the three-stage training sequence (supplied mediators, generated mediators, or no instructions). The major difference between those studies reporting no mediated facilitation and those obtaining short-term effects seems to be in amount of training in the use of mediational strategies. All three negative studies provided only one mediation experience, whereas Milgram ( 1967a) and MacMillan (1972) both provided two mediated lists before testing for immediate transfer. Although Milgram (1967a) later found no long-term transfer, his changing procedures might have produced a different strategy for each phase of his three-phase procedure. As a result, neither strategy may have been strong enough, due to only one training experience, to prevail over time. It would seem that a suficient amount of training coupled with a consistent strategy are essential in leading to the long-term transfer of mediational strategies.
TRANSFER OF MEDIATIONAL STRATEGIES 2. POSITIVE Although Martin ( 1967) reported significantly better recall by mediation than control subjects 1 week after learning, the failure to equate degree of original learning makes his results difficult to interpret. Turnure and Walsh ( 1971) found significant transfer of a mediational strategy to an unaided list learned 1 week later. In point of fact, Turnure and Walsh (1971) expected no transfer, so they assigned their experimental conditions (Paragraph mediation, Sentence mediation, and Word mediation) in three different orders. The EMR subjects learned four-pair lists under all three mediation conditions, each presented a week apart. It was found that the Word
John G . Borkowski and Patricia B . Wanschura
44
mediation group was significantly better on Day 3, after having participated in Paragraph and Sentence mediation conditions, than on Day 1. Turnure and Walsh’s (1971 ) finding supports the suggestion that sufficient training facilitates transfer, since their subjects had participated in two mediated lists, both of which involved experimenter-supplied mediators. Turnure and Thurlow (1973) have followed up the earlier study by Turnure and Walsh (1971 ) with an examination of the amount of training required for transfer. The EMR subjects learned a list of eight pairs each week for three successive weeks, under one of three treatment conditions: Group I-labeling only, then reversal on the last trial of the last day (LLLR) ; Group 11-paragraph, then labeling and reversal (PLRLR) ; Group 111-paragraphs twice, then labeling and reversal (PPLR). Two additional groups included to test for the effects o€ reversal did not differ from their no-reversal counterparts. The results presented in Fig. 6 indicate that mediation conditions performed significantly better than labeling on Day 1. On Day 2, the group receiving mediators only on Day 1 (i.e., Group
-- -
GROUP
1
QROUP
I1
---- -- - GROUP
0
(No elaboration)
(One elaboration)
111 ( T w elaborations)
t Day 1
Day 2
TESTING
Day 3
DAYS
FIG.6. Mean first trial errors for three treatment groups on three testing days. (From Turnure & Thurlow, 1973.)
MEDIATIONAL PROCESSES IN THE RETARDED
45
11) failed to differ from controls. Thus, one elaboration was not sufficient for transfer, as previous studies have also noted. On Day 3 first trial errors by the Two elaborations group (i.e., Group 111) differed significantly from the No-elaboration and One-elaboration groups, although trials to criterion did not differ. Sufficient practice (i.e., two mediated lists) together with a consistent strategy was effective in producing transfer of the strategy to an unaided list on Day 3. Ross (1971 ) has also found facilitation of PA strategy transfer through participation in a 6-week special music program. The principle and utility of mediational links were emphasized, while EMR children were presented a series of associative learning tasks (e.g., learn to clap loudly when one sees an elephant walking). Ross ( 1971 ) reported significant differences in pre- and postexperimental PA learning scores for the experimental children but no differences for children in the control, traditional music program. In postexperimental questioning, 16 of 19 experimental subjects reported using mediational links as compared to only 3 of 19 control children. Ross, Ross, and Downing (1 973) then tried to determine if intentional training was necessary for long-term strategy development, or if observational learning was equally effective. During a 5-week story, question, and table game program, Intentional-trained subjects were supplied mediational links for each game, then instructed to form their own links, and finally participated without mediational instructions. Observation learning subjects played each game with an adult model who exhibited mediational strategies, but they received no mediational instructions. Control subjects participated in the same story and PA game program, but received no direct or indirect mediational training. Ross, Ross, and Downing ( 1973) found that Intentional and Observation groups learned a posttraining PA task (adjusted for differing levels of pretraining performance) to the same number of trials to criterion, with Control subjects requiring significantly more trials. In addition, for Intentional and Observation conditions, observed and reported mediators increased from less than 1 % of the pairs in pretraining to 29% of the posttraining pairs. In contrast, control subjects frequently used a cumulative rehearsal strategy which tended to interfere with learning. Thus, a long-term mediational strategy was effectively developed by observation learning as well as intentional training programs administered over a relatively long period of time. However, several procedural and analytical problems seem to limit the interpretation of the (1973) findings of Ross et af. First, the failure to equate treatment groups on available pretraining PA scores leaves a doubt as to their actual equality before treatment, which cannot be erased through the simple expediency of adjusting posttraining scores. Second, pre-post
46
John G . Borkowski and Patricia B. Wanschura
comparisons might have more adequately taken into account pretraining group diflerences. However, if the Ross et al. (1973) results can be replicated with these minor procedural changes, they suggest exciting possibilities for training mentally retarded children in the development of mediational strategy solely through observational learning. Although long-term transfer of a mediational strategy has been reported by four investigators, the IQ range of the subjects involved has been very restricted (@ = 67.7; 78.9; 51-80; and 69.6). Examination of those studies failing to obtain mediational transfer (Jensen & Rohwer, 1963a; Rapier, 1968; Milgram, 1967a) reveals a much lower functioning individual (with m s generally around 50 to 5 5 ) , in all but one instance estimated at 71). Thus, it is difficult to assert that retarded individuals can transfer strategies, without restricting the statement to mildly retarded EM&. Wanschura and Borkowski (1974) attempted to address this issue by demonstrating that low-functioning retarded children (MA = 4.9, = 39.9, CA = 12.6) could, in fact, develop and transfer a mediational strategy. To maximize the amount of training, Wanschura and Borkowski departed from the normal procedure of providing mediators only on Trial 1. Instead, their subjects received supplied mediators on every trial of three successive PA tasks. In addition, three degrees of aid were provided, such that some children learned mixed lists consisting of both aided and unaided items (50% aid), whereas others received aid on all items (100% aid) or no items (control). Transfer was tested 2 weeks later on a nonmediated control list. Error data as a function of degree of aid and training and test sessions are presented in Fig. 7. It was found that the Total-Aid group learned the six pairs in the transfer list with significantly fewer errors than controls. The consistent 100% aid strategy showed significant transfer effects on Task 4, resulting in fewer errors than occurred in the other two conditions. The Half-Aid group failed to differ from controls during learning or transfer. One possible reason for the performance of the Half-Aid group is the lack of a consistent strategy during learning. That is, partial-aid subjects were provided with mediators for aided items, but no instructions were given for unaided pairs. This could have led to the development of two conflicting strategies-ne rote, the other mediational in nature. Sufficient and consistent training, both within and between training sessions, seemed necessary for the development of a mediational strategy strong enough to transfer to a nonmediated list 2 weeks later. It should be noted, however, that much of the mediational gain established by Task 3 in the 100% aid group had dissipated during the assessment of transfer of mediational strategy on Task 4.
(m
47
MEDIATIONAL PROCESSES IN THE RETARDED
Y
> a
1
2
3
4
T A S K S
FIG.7. Mean errors per trial averaged over the fist five trials as a function of degree of aid during training and transfer tasks. (From Wanschura & Borkowski, 1974.)
3. METHODOLOGICAL ASPECTSOF MEDIATEDTRANSFER One basic problem with the research on transfer of mediational strategies lies in the very definition of transfer effects. The typical paradigm provides some subjects with mediators and others with no mediators during a training period. After a retention period has elapsed, the performance of the two groups on a control list is compared. If mediation subjects perform significantly better than controls, a mediational strategy is assumed to be present. Although there are no a priori reasons to expect other factors to be operative, it would be reassuring to have additional measures of mediational activity. Postexperimental measures of mediator quality have been tried, but usually have failed to correlate with performance (Milgram, 1968c; MacMillan, 1972). Converging operations might be employed in the assessment of mediated transfer to bolster the assumption that such effects are truly operative (cf. Garner, Hake, & Eriksen, 1956). Turnure and his colleagues have tried reversal trials in which the response term is presented for recall of the
48
John G . Borkowski and Patricia B. Wanschura
stimulus item, after criterion is reached. Turnure and Walsh (1971) found that the mediation conditions were equal and significantly better than the control condition on the reversal trial. Thus, good reversal performance seemed equated with the effective use of mediators. Turnure and Thurlow (1973) showed that the reversal technique reflected the direction and significance of the transfer effects found in their study. However, Turnure (1971 ) found a significant Conditions X Sex interaction, such that the reversal technique failed to discriminate between Mediation and Control groups for male subjects. It would seem that the reversal technique has potential for discriminating the use of a mediational strategy in transfer tasks, but it needs further investigation to verify its effects over a wide range of conditions. Wanschura and Borkowski (1974) used a probe technique for determining the presence of mediators. After reaching criterion on the third list, subjects were asked to show how the pairs “go together.” Probe data reflected the significant differences between Total-, Partial-, and No-aid groups. It was found that the Total-Aid group recalled a mean of 4.8 out of 6 supplied mediators; this represents the best recall of prepositional mediators in any of the groups. A second probe required subjects to point to the picture depicting the mediational interaction. The correct picture was presented on a card with two other pictures, showing a noninteracting relationship or a touching relationship which was not explicitly positional. However, the Point probe data was not correlated with error scores during learning. In fact, a position bias developed, such that the left-bottom picture was pointed to significantly more often than either top or right-bottom ones, Unfortunately, Wanschura and Borkowski failed to employ the probes after the transfer task, so the value of the Show probe as an additional indicator of mediational transfer is yet to be determined. Thus, the current attempts at multiple measures fail to provide reliable indexes of mediational processing, beyond the traditional experimental-control comparison. The importance of mediation in cognitive functioning demands that more sophisticated and reliable methods be developed to act as converging measurement operatiops in documenting mediational processing in the retarded. The conclusion that retarded individuals can transfer a mediational strategy over time is qualified when one examines the data more carefully. Not only is the subject population extremely limited, but the degree of transfer is not large. For example, Turnure and Thurlow (1973) found approximately a 1.5 error difference between mediation and control conditions on Day 3 (the transfer task), but a 4.0 error difference between mediated conditions on Day 1 and the nonmediated control condition on Day 3 for
MEDIATIONAL PROCESSES IN THE RETARDED
49
the same subjects. Wanschura and Borkowski (1974) found a dissipation of mediated facilitation when comparing the performance for the Total-Aid group on Task 3 (final training session) and Task 4 (the transfer task). When retarded individuals employ a mediational strategy on a nonmediated, transfer task, it does not approach the strength or quality of a supplied mediational strategy used during training. It would seem that the ability of retarded individuals to produce a mediational strategy, though not lacking, is nevertheless deficient to some degree. Though transfer of strategy occurs across a wide range of M A levels, much of the positive influence of mediational transfer dissipates over time. It is necessary for researchers to determine the kind and amount of training that would remedy this “limited production deficiency.” We would expect that sufficiencyand consistency in training will be dominant in this search.
IV. CONCLUSION
Although most research with three-stage and natural language paradigms has been conducted during the last decade, there already exists a sizable literature on mediational processing in the mentally retarded. Under optimal experimental conditions, retarded individuals can use mediators in a wide variety of contexts to aid PA learning. These findings limit the generality of Luria’s ( 1961 ) mediational deficiency hypothesis associated with mental retardation. Apparently, there is little evidence to support a mediation control deficiency in the retarded. When r-s mediators are available during PA learning tasks, retarded children and adults are generally able to use covert mediators to influence rate of acquisition. However, most mediational findings indicate a limited production deficiency, especially with lower functioning retarded children. Production deficiencies become more obvious when tasks are designed to assess the transfer of mediational strategies. This is especially true when the mediational strategy has not been sufficiently or consistently formed during training. Future research in mediation will probably proceed in the same general direction as much of the current research in short-term memory, namely, at delineating the conditions under which learning strategies are most easily made available to and utilized by retarded individuals. Recently, Kellas, Ashcraft, and Johnson ( 1973) have shown that an experimenter-developed rehearsal strategy, in which cultural-familial retarded individuals shadowed the experimenter’s overt, cumulative rehearsal on a pretraining task, produced a dramatic alteration of the learning strategy which was, in turn,
John G. Borkowski and Patricia B. Wanschura
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correlated with accelerated rates of acquisition of the training task. Relearning measures, taken after a 2-week interval, continued to demonstrate the spontaneous use of the cumulative rehearsal strategy which appeared responsible for the retention superiority of those individuals who had been taught self-paced, rehearsal techniques. The next decade of research, in both mediation and memory, is likely to focus on the acquisition and maintenance of cognitive-structured, rehearsal and mediation strategies as means of ameliorating learning difficulties in the mentally retarded. REFERENCES Arbuckle, T. Y.,& Aznavour, L. Effectiveness of supplied mediators in relation to presentation modality and retrieval cue. Journal of Experimental Psychology, 1973, 98, 286-290. Balla, D., & Zigler, E. Discrimination and switching learning in normal, familial retarded, and organic retarded children. Journal of Abnormal and Social Psychology, 1964, 69, 664-669. Baumeister, A. A. Paired-associates learning by institutionalized and noninstitutionalized retardates and normal children. American Journal of Mental Deficiency, 1969, 73, 102-104.
Baumeister, A. A., & Campbell, C. Formation of backward associations in pairedassociates learning by normal children and retardates. Journal of Experimental Psychology, 1971, 89, 298-305. Baumeister, A. A., & Kellas, G. Process variables in the paired-associate learning of retardates. In N. R. Ellis (Ed.), Znternational review of research in mental retardation. Vol. 5. New York: Academic Press, 1971. Pp. 221-270. Berkson, G., & Cantor, G. N. A study of mediation in mentally retarded and normal school children. Journal of Educational Psychology, 1960, 51, 82-86. Boat, B. M., & Clifton, C., Jr. Verbal mediation in four-year-old children. Child Development, 1968, 39, 505-514. Borkowski, J. G., Ahearn, J. P., & Pearson, J. Retention and utilization of mediators by retardates. Psychonomic Science, 1969, 15, 96-97. ( a ) Borkowski, J. G., & Johnson, L. 0. Mediation and the paired-associate learning of normals and retardates. American Journal of Mental Deficiency, 1968, 72, 610-613.
Borkowski, J. G., & Kamfonik, A. Verbal mediation in moderately retarded children: Effects of successive mediational experiences. American Journal of Mental Deficiency, 1972, 77, 157-162. Borkowski, J. G., McGrath, R. A., & Doyle, L. T. Backward associations in the paired-associate learning of retardates. Developmental Psychology, 1969, 1, 470-473. (b) Bourne, L. E., Ekstrand, B. R., & Dominowski, R. L. The psychology of thinking. Englewood Cliffs, N.J. : Prentice-Hall, 197 1. Brown, A. L., & Scott, M. S. Transfer between the oddity and relative size concepts: Reversal and extradimensional shifts. Journal of Experimental Child Psychology, 1972, 13, 350-367.
Dallet, K. M. Implicit mediators in paired-associate learning. Journal of Verbal Learning and Verbal Behavior, 1964, 3, 209-214.
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Davidson, R. E. Mediation and ability in paired-associate learning. Journal of Educational Psychology, 1964, 55, 352-356. Denny, M. R. Research in learning and performance. In H. Stevens & R. Heber (Eds.), Mental retardation. Chicago: University of Chicago Press, 1964. Pp. 100-142.
Flavell, J. H., Beach, D. R., & Chinsky, J. M. Spontaneous verbal rehearsal in a memory task as a function of age. Child Development, 1966, 37, 283-299. Gallagher, J. W. Mediation as a function of associative chains in normal and retarded children. American Journal of Mental Deficiency, 1969, 73, 886-889. Garner, W. R., Hake, H. W., & Eriksen, C. W. Operationism and the concept of perception. Psychological Review, 1956, 63, 3 17-329. Gordon, D. A., & Baumeister, A. A. The use of verbal mediation in the retarded as a function of developmental level and response availability. Journal of Experimental Child Psychology, 1971, 12, 95-105. Goulet, L. R. Verbal learning in children: Implications for developmental research. Psychological Bulletin, 1968, 69, 359-376. Hohn, R. L., & Martin, C. J. Mediational styles: An individual difference variable in children’s learning ability. Psychonomic Science, 1970, 18, 348-349. Horton, D. L., & Kjeldergaard, P. M. An experimental analysis of associative factors in mediated generalization. Psychological Monographs, 1961, 75, No. 11. Jenkins, J. J. Mediated associations: Paradigms and situations. In C. N. Cofer & B. S. Musgrave (Eds.), Verbal behavior and learning: Problems and processes. New York: McGraw-Hill, 1963. Pp. 210-245. Jensen, A. R. Rote learning in retarded adults and normal children. American Journal of Mental Deficiency, 1965, 69, 828-834. Jensen, A. R. The role of verbal mediation in mental development. Journal of Genetic Psychology, 1971, 118, 39-70. Jensen, A. R., & Rohwer, W. D., Jr. The effect of verbal mediation on the learning and retention of paired-associates by retarded adults. American Journal of Mental Deficiency, 1963, 68, 80-84. ( a ) Jensen, A. R., & Rohwer, W. D., Jr. Verbal mediation in paired-associate and serial learning. Journal of Verbal Learning and Verbal Behavior, 1963, 1, 346-352. (b). Jensen, A. R., & Rohwer, W. D., Jr. Mental retardation, mental age, and learning rate. Journal of Educational Psychology, 1968, 59,402-403. Kellas, G., Ashcraft, M. H., & Johnson, N. S. Rehearsal processes in the short-term memory performance of mildly retarded adolescents. Anierican Journal of Mental Deficiency, 1973, 77, 670-679. Kendler, T. S. An ontogeny of mediational deficiency. Child Development, 1972, 43, 1-17.
Kendler, H. H., & Kendler, T. S. Vertical and horizontal processes in problem solving. Psychological Review, 1962, 69, 1-16. Lipman, R. S. Learning: Verbal, perceptual-motor and classical conditioning. In N. R. Ellis (Ed.), Handbook of mental deficiency. New York: McGraw-Hill, 1963. Pp. 391-423. Luria, A. The role of language in the formation of temporary connections. In B. Simon (Ed.), Psychology in the Soviet Union. Stanford, Calif.: Stanford University Press, 1957. Pp. 115-129. Luria, A. R. The role of speech in the regulation of normal and abnormal behavior. New York: Liveright, 1961.
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MacMillan, D. L. Facilitative effect of verbal mediation on paired-associate learning by EMR children. American Journal of Mental Deficiency, 1970, 74, 611-615. MacMillan, D. L. Paired-associate learning as a function of explicitness of mediational set by EMR and nonretarded children. American Journal of Mental Deficiency, 1972, 76, 686-691. Martin, C. J. Associative learning strategies employed by deaf, blind, retarded and normal children. Educational Research Series, 1967, 38, 1-158. Martin, C. J., Boersma, F. J., & Bulgarella, R. Verbalization of associative strategies by normal and retarded children. Journal of General Psychology, 1968, 78, 209-21 8. Martin, C. J., Boersma, F. J., & Cox, D. L. A classification of associative strategies in paired-associate learning. Psychonomic Science, 1965, 3, 455-456. Milgram, N. A. Retention of mediation set in paired-associate learning of normal children and retardates. Journal of Experimental Child Psychology, 1967, 5, 341-349. (a) Milgram, N. A. Verbal context versus visual compound in paired-associate learning. Journal of Experimental Child Psychology, 1967, 5 , 597-603. (b) Milgram, N. A. Effect of sentence recital on implicit mediation in paired-associate learning. Journal of Verbal Learning and Verbal Behavior, 1968, 7 , 714-721. (a) Milgram, N. A. The effect of verbal mediation in paired-associate learning in trainable retardates. American Journal of Mental Deficiency, 1968, 72, 518-524. (b) Milgram, N. A. The effects of MA and IQ on verbal mediation in paired associate learning. Journal of Genetic Psychology, 1968, 113, 129-143. (c) Milgram, N. A., & Furth, H. G. The influence of language on concept attainment in educable retarded children. American Journal of Mental Deficiency, 1963, 67, 733-739. Milgram, N. A., & Riedel, W. Verbal context and visual compound in paired-associate learning of mental retardates. American Journal of Mental Deficiency, 1969, 73, 755-761. O’Connor, N., & Hermelin, B. Discrimination and reversal learning in imbeciles. Journal of Abnormal and Social Psychology, 1959, 59, 409-413. Paivio, A. Imagery and verbal processes. New York: Holt, 1971. Paivio, A., & Yuille, J. C. Changes in associative strategies and paired-associate learning over trials as a function of word imagery and type of learning set. Journal of Experimental Psychology, 1969, 79, 458-463. Palermo, D. S. Mediated association in a paired-associate transfer task. Journal of Experimental Psychology, 1962, 64, 234-238. Pelton, L. H. Mediational construction vs. mediational perception in paired-associate learning. Psychonomic Science, 1969, 17, 220-221. Penney, R. K., Peters, R. De V., & Willows, D. M. The mediational deficiency of mentally retarded children: 11. Learning set’s effect on mediational deficiency. American Journal of Mental Deficiency, 1968, 73, 262-266. (a) Penney, R. K., Seim, R., & Peters, R. De V. The mediational deficiency of mentally retarded children: I. The establishment of retardates’ mediational deficiency. American Journal of Mental Deficiency, 1968, 72, 626-630. (b) Penney, R.K., & Willows, D. M. Mediational deficiency of mentally retarded children: 111. Effect of length of institutionalization. American Journal of Mental Deficiency, 1970, 74, 780-783. Postman, L. Studies of learning to learn: VI. General transfer effects in three-stage mediation, Journal of Verbal Learning and Verbal Behavior, 1968, 7, 659-664.
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Rapier, J. L. Learning abilities of normal and retarded children as a function of social class. Journal of Educational Psychology, 1968, 59, 102-1 10. Rieber, M. Verbal mediation in normal and retarded children. American Journal of Mental Deficiency, 1964, 68, 634-641. Rohwer, W. D., Jr., & Lynch, S. Retardation, school strata, and learning proficiency. American Journal of Mental Deficiency, 1968, 73, 91-96. Rohwer, W. D., Jr., Lynch, S., Levin, J. R., & Suzuki, N. Pictorial and verbal factors in the efficient learning of paired associates. Journal of Educational Psychology, 1967, 58, 278-284. Ross, D. Retention and transfer of mediation set in paired-associate learning of educable retarded children. Journal of Educational Psychology, 1971, 62, 3 22-327.
Ross, D. M., Ross, S. A., & Downing, M. L. Intentional training vs. observational learning of mediational strategies in EMR children. American Journal of Mental Deficiency, 1973, 78, 292-299. Schulz, R. W. Mediation. In C. P. Duncan, L. Sechrest, & A. W. Melton, Human memory: Festschrist for B. I . Underwood. New York: Appleton, 1972. Schulz, R. W., & Lovelace, E. A. Mediation. in verbal paired-associate learning: The role of temporal factors. Psychonomic Science, 1964, 1, 95-96. Schulz, R. W., & Weaver, G. E. The A-B, B-C, A-C mediation paradigm: The effects of variation in A-C study-and test-interval lengths and strength of A-B or B-C. Journal of Experimental Psychology, 1968, 76, 303-31 1. Schulz, R. W., Weaver, G. E., & Ginsberg, S. Mediation with pseudomediation controlled: Chaining is not an artifact! Psychonomic Science, 1965, 2, 169-1 70.
Schwartz, M. Subject-generated versus experimenter-supplied mediators in pairedassociate learning. Journal of Experimental Psychology, 1971, 87, 389-395. Spreen, 0. Language functions in mental retardation, a review. 11. Language in higher level performance. American Journal of Mental Deficiency, 1965, 70, 351-362.
Taylor, A. M., Josberger, M., & Knowlton, J. Q. Mental elaboration and learning in EMR children. American Journal of Mental Deficiency, 1972, 77, 69-76. Thurlow, M. L., & Turnure, J. E. Elaboration structure and list length effects on verbal elaboration phenomena. Journal of Experimental Child Psychology, 1972, 14, 184-195.
Turnure, J. E. Types of verbal elaboration in the paired-associate performance of educable mentally retarded children. American Journal of Mental Deficiency, 1971, 76, 306-312.
Turnure, J. E.,& Thurlow, M. L. Verbal elaboration and the promotion of transfer of training in educable mentally retarded children. Journal of Experimental Child Psychology, 1973, 15, 134-148. Turnure, J. E., & Walsh, M. K. Extended verbal mediation in the learning and reversal of paired-associates by EMR children. American Journal of Mental Deficiency, 1971, 76, 60-67. Underwood, B. J., Runquist, W. N., & Schulz, R. W.Response learning in pairedassociate lists as a function of intralist similarity. Journal of Experimental Psychology, 1959, 58, 70-78. Underwood, B. J., & Schulz, R. W . Meaningfulness and verbal learning. Philadelphia: Lippincott, 1960. Wanschura, P. B., & Borkowski. J. G. The development and transfer of mediational
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strategies by retarded children in paired-associate learning. American Journal of Mental Deficiency, 1974, 78, 631-639. Wickelgren, W. A. Coding, retrieval, and dynamics of multitrace associative memory. In L. W . Gregg (Ed.), Cognition in learning and memory. New York: Wiley, 1972. Pp. 19-50. Yarmey, A. D., & Bowen, N. V. The role of imagery in incidental learning of educable retarded and normal children. Journal of Experimental Child Psychology, 1972, 14, 303-312. Zigler, E. F. Mental retardation: Current issues and approaches. In M. L. Hoffman & L. W. Hoffman (Eds.), Review of child development research. Vol. 2. New York: Russell Sage Foundation, 1966. Pp. 107-168. Zigler, E. F. Mental retardation, technical comment. Science, 1967, 157, 578. Zigler, E. F., & Balla, D. Luria’s verbal deficiency theory of mental retardation and performance on sameness, symmetry, and opposition tasks: A critique. American Journal of Mental Deficiency, 1971, 75, 400413.
The Role of Strategic Behavior in Retardate Memory
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ANN L BROWN UNIVERSITY OF ILLINOIS. CHAMPAIGN.URBANA. ILLINOIS
I . Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 A . Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 B . Organizational Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 11. Developmental Theories of Memory and Their Implication for Retardation . . . . 56 A . Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 B. Structural Features and Control Processes . . . . . . . . . . . . . . . . . . . . 60 C. Mediational and Production Deficiencies . . . . . . . . . . . . . . . . . . . . . 62 D . Active and Passive Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 E . Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 111. The Use of Memory Strategies by Retardates: A Brief Review . . . . . . . . . . . 66 A . Rehearsal Mechanisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 B. Organizational Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 C . Processing Task-Relevant Information . . . . . . . . . . . . . . . . . . . . . . 74 D . Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 IV . Specific Background to the Present Series of Studies . . . . . . . . . . . . . . . . . 77 A . ChoiceofTasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 B. Choice of Subjects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 C. Interaction between Task and Subject Variables . . . . . . . . . . . . . . . . . 79 V. Specific Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 79 A . The Keeping-Track Task . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B . Recognition Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 C . Overall Summary of Specific Studies . . . . . . . . . . . . . . . . . . . . . . . 91 VI . Implications for Education . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
.
1
A
.
INTRODUCTION
Background
Efficient performance on a variety of memory tasks relies on the effective use of certain plans. schemes. or mnemonic strategies. By the appropriate 55
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exploitation of various strategies we organize and transform the random input of information into manageable information-rich units. Since it is as easy to remember a considerable amount of material in information-rich units as it is to remember a small amount of material in informationally impoverished units, it is economical to employ such strategies and plans in order to make the most effective use of a limited-capacity memory system (Miller, Galanter, & Pribram, 1960; Smirnov & Zinchenko, 1969). An examination of theoretical and empirical developments concerning the use of plans and strategies by young and retarded children is the principal focus of this chapter. Specifically, it is argued that the developmentally young are deficient in the spontaneous use of a number of strategic devices and, to the extent that efficient performance depends on the use of strategies, retarded and young children will perform poorly in comparison with more mature subjects. The corollary to this position is that certain memory tasks which do not require the use of deliberate mnemonics may not be developmentally sensitive (Brown, 1973a, 1973b). It is further argued that not only does the immature information processor possess a limited repertoire of specific plans or strategies but that the very intention to use such systems at all may be related to developmental level. That is, the “mysterious intent to learn” or the “plan to form a plan” (Miller et al., 1960, p. 129) is inadequate or absent in the developmentally young. B.
Organizational Scheme
First a description of general and developmental theories of memory, with specific relation to retardation will be described and the place of deliberate strategies, control processes, or organization schemes within these theories discussed. This will be followed by a brief review of empirical findings implicating a strategic deficit in a wide variety of tasks and situations. Next, two programs of research from our own laboratory will be described, the first examining a memory task which places heavy emphasis on strategic control and the second which does not appear to require deliberate strategies for its efficient execution. Finally, the implications of this research for educational practice will be examined. 11.
A.
DEVELOPMENTAL THEORIES OF MEMORY AND THEIR IMPLICATION FOR RETARDATION
Introduction
Theories of human memory in the last decade have been strongly influenced by information-processing models with their emphasis on flow diagrams and specific memory stores. A “modal model” (Murdock, 1967)
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embodying many of the essential features of such theories (Atkinson & Shiffrin, 1968; Waugh & Norman, 1965) will be outlined here. Incoming information enters a modality specific sensory store or register. This store has a large immediate capacity but information is rapidly lost unless the subject attends to specific features. Items thus selected for further processing are transferred to a limited-capacity short-term store (STS) where they are maintained by rehearsal mechanisms. From there they can be transferred to an apparently unlimited-capacity, permanent, long-term store (LTS). Thus the model is characterized by the transferral of information from store to store as it is progressively incorporated deeper within the memory system. Such models of memory have been and still are extremely influential as the resurgence of interest in memory processes can attest. However, like most simplified schemes, the modal model has encountered problems; problems usually remedied by the addition of new stores or boxes and additional transferral pathways. The main problem with such models is that certain assumptions are implicit concerning human memory, for example, that information necessarily flows from the sensory store via STS to LTS and that the system is discontinuous from one memory compartment to another. Historically this view has been countered by the theory that memory is better thought of as a continuum (Melton, 1963; Murdock, 1972). The utility of any theory of memory, however, must be measured in terms of the questions it raises and can answer. In a recent series of papers, Craik (Craik, 1973a, 1973b; Craik & Lockhart, 1972) has demonstrated that consideration of neither capacity, coding, nor retention mechanisms would necessarily lead to the assumption of specific stores or boxes following distinct laws. As an example, it is increasingly clear that distinguishing characteristics of the sensory store, STS and LTS depend heavily on the paradigm and the materials used, particularly when visual information is considered. As a consequence, although the multi-store models have been the basis of the resurgence of recent work with memory, there is a current trend away from these models toward a “levels of analysis” approach, typified by the work of Craik (Craik, 1973a, 1973b) but reflected in other recent theoretical papers (Paivio, 1971; Shiff rin, 1973). The levels of analysis approach suggests that incoming information is subjected to original analyses of physical features which are matched against “symbolic abstract and semantic features.” There is a hierarchy of levels of analysis ranging from the original physical feature stage through the semantic stage. Craik suggests that the memory trace is a product of these various analyses and that “trace persistence is a positive function of the depth of analysis.” The more analyses, and the more complex form those analyses take, the more durable the memory trace.
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Both the modal information processing model and the levels of analysis approach are, of course, far more complex than this superficial outline would suggest. However, sufficient detail is given here to illustrate the shift from a concentration on structural features and specific transferral patterns to an emphasis on the input processes or analyses performed upon the particular material at hand. This concentration on processing, coupled with a deemphasis on specific structural features, is the approach taken in this chapter. When developmental theories of memory, and specifically retardate memory, are considered it is again apparent that the influence of information processing models has been felt. The retention section of the recent Fisher and Zeaman (1973) theory borrows heavily from the Atkinson and ShifTrin (1968) model and the theory proposed by Ellis (1970) shares many of the essential features of the Waugh and Norman (1965) model. As in the area of adult memory, these theoretical formulations have proved their utility by the extensive experimental literature they have generated. Thus, the emphasis has been on specific memory stores and in the area of retardation this has been coupled with the search for the missing or defective store. Historically it has been the case that psychologists interested in retardation have searched for the structural feature(s) which can be found wanting. In the area of memory research the most commonly indicted culprit has been STS. It is in the status of short-term memory that the main differences between information processing models and levels of analysis approaches are highlighted. This controversy over the status of STS has particular relevance for theories of retardate memory due to the well-documented shortterm memory deficiency in these subjects (Ellis, 1970; K. G. Scott & Scott, 1968). Within an information processing model, STS is a structural feature of the memory system. In a levels of analysis approach, processes subsumed under the heading STS in information processing models are seen as the result of deliberate strategic devices employed by the subject. These strategies are deliberate attempts to maintain and prolong aspects of perceptual experience by continuing to attend to some salient aspects of the stimulation. Craik uses the term in the original James (1 890) sense of continued attention to the item, or keeping the item in consciousness. As these short-term memory strategies are optional they are “off to the side in the route taken from the environment to long-term memory and whether we maintain items at the STS level is very much an optional strategy rather than a structural feature” (Craik, 1973a). Thus the distinction made by information processing models is between STS and LTS, which are characterized as discrete compartments obeying separate laws. In developmental theories it has been traditional to describe
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retardates as deficient in the use of STS (K.G. Scott & Scott, 1968) but not necessarily LTS (Belmont, 1966). Thus the prediction which follows from this approach is that STS itself is in some way deficient and all shortterm memory functioning is implicated. However, if STS mechanisms are seen as optional strategies, then the retardate short-term memory deficiency can be seen as one example of a general pattern of inadequate exploitation of strategic plans to organize, maintain, and attend to relevant materials. Thus the STS-LTS distinction is deemphasized and the distinction becomes not whether a task is one of a short- or long-term nature but whether it demands strategic transformations for its efficient execution. It is not suggested here that a levels of analysis approach should replace an information processing approach, but rather that the different emphases could lead to alternative methods of attacking the problem of retardate memory processing. Indeed, it could be that the theoretical distinction is difficult to put to an empirical test, hence making such a distinction if not meaningless, at least of questionable value. In order to separate the two approaches experimentally it would be necessary to demonstrate normal-retardate differences on a short-term memory task which requires strategic behavior but not on a short-term task where such strategies are not typically employed. Such a demonstration might be difficult to provide because of the problem of determining the nature of a short- versus long-term memory task. The distinction has always been equivocal, involving both methodological and theoretical difficulties (Belmont, 1966). Surveying the literature, the author could find only one example of a developmentally examined short-term memory task which did not appear to require exploitation of obvious strategic plans. Belmont (1967) examined a perceptual short-term memory task where a delayed brightness comparison was required. It is difficult for the author to imagine a strategy (rehearsal, organization, etc.) which could be used to facilitate such a task. Belmont reported that the task was essentially developmentally insensitive. No evidence of a normal-retardate difference or an age-related trend in normal subjects was apparent. This could be taken as support for the contention that it is not a short-term memory deficit or structural problem, but a deficiency in the use of strategic devices which characterizes immature memory systems. When a short-term task which does not demand active strategies is involved, normal-retardate differences are not implicated. It is not the purpose of the present chapter to distinguish between the two approaches, rather, the rationale underlying the levels of analysis approach will be presented together with evidence to support the view that such an approach represents a viable alternative to current information-processing models. In this chapter the levels of analysis approach, with its deemphasis on structural stores and its emphasis on strategic processes,
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has been adopted for the reasons outlined above. Additional reasons are that it is possible to incorporate much of the existing literature on retardate memory processing under such a system. Second, such an approach, as typified by the work of Flavell (1970) in this country and many Soviet investigators (reviewed by Smirnov & Zinchenko, 1969), has already proved valuable in promoting our understanding of the memory processing of young children. An outline of these approaches to the development of memory follows, beginning with the structural versus control processes distinction of information-processing models, followed by a consideration of active versus passive strategies, and mediational versus production deficiencies. B.
Structural Features and Control Processes
From information-processing models comes a theoretical distinction of particular interest: that between the structural features of the memory system and its associated control processes. The distinction is relevant to both theories of memory, in general (Atkinson & Shifin, 1968) and to theories of retardate memory, in particular (Fischer & Zeaman, 1973). Structural features of memory refer to those aspects of the system which are not “programmable,” i.e., cannot be varied or changed due to some “structural” limitation of the organism. Control processes are seen as those aspects of the system which can be “reprogrammed,” i.e., altered through training. In terms of retardation, the distinction takes on added meaning, since we can substitute the word “remediable” for “programmable.~’As such, structural differences between normal and retarded subjects would be invariant differences which could not be eliminated and would serve to define retardation. Differences attributable to deficiencies in the use of control processes would, on the other hand, be subject to remediation. Thus, structural differences would be of particular interest to the psychometrician interested in a definition of retardation, while differences in control processes would be of particular interest to the educator, since such findings would indicate areas in which remediation was both necessary and possible. It has typically been the case that structural features of the memory system have been identified with specific memory stores (Atkinson & Shiffrin, 1968; Fisher & Zeaman, 1973). In keeping with the deemphasis on specific stores in this chapter, the structural features versus control process distinction will be maintained but in the limited sense that a structural feature is seen as any limited capacity within the system rather than being identified with a specific memory store. To further clarify the usage here, it should be pointed out that the term will be used in a different sense from that of Atkinson and Shiffrin (1968), who viewed structural features as fixed untrainable capacities which could not be modified. However,
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Atkinson and Shiffrin were concerned exclusively with adult subjects and did not consider developmental issues which are the focus of this chapter. Here, structural features will be equated with capacity limitations which may be modified by time but not by training. In this sense, the theory is consistent with more general developmental theories (such as that of Piaget) which allow structural changes with maturation. Consequently, while a structural feature at any point in time may be a fixed untrainable capacity, it is still the case that these structural features may change as a function of age and experience.’ There appears to be a problem with establishing a valid distinction between fixed-capacity restrictions and trainable control processes in that this would require that the effectiveness of a training procedure be independently evaluated. The problem is not acute if a particular training procedure is successful since it then would be possible to conclude that a trainable control process was involved and had responded to training. However, difficulty arises when training does not alter performance. Is this due to the presence of a structural capacity limitation which can not respond to training or due to the inadequacy of the training technique itself? It would be necessary to exhaust all possible training techniques before concluding that an untrainable structural feature had been discovered, surely a logically impossible task. In addition, the subjects’ performance on any one memory task may be the result of a complex interaction between his fixed structural capacities and his adequate use of strategic control processes. One example of such an interaction can be seen when rehearsal processes are examined. There is considerable evidence that although retardates and young children do not spontaneously rehearse in a memory task they can be trained to do so relatively easily (Belmont & Butterfield, 1969, 197 1 ;Brown, Campione, Bray & Wilcox, 1973; Ellis, 1970). The suggestion is that rehearsal is under the control of the subject and is a trainable process rather than a fixed untrainable capacity or structural feature of the memory system. However, there may be a structurally determined upper limit to the efficiency of rehearsal training, with this limit related to developmental level. Indeed, it has been shown that effective rehearsal training of young children is limited to those children sufficiently mature that they can rehearse fluently when trained (Kingsley & Hagen, 1969). Similarly, with retarded subjects, McBane (1972) has shown that the total number of items that can be effiAn example of structural features which change with age would be. the underlying semantic-conceptual organizational schemata which effect all stages of the memory process (see Piaget and Inhelder, 1973). As the child matures, his semantic memory also matures such that an adult’s storage and retrieval of a certain group of words, for example, would be different from a child’s because the former’s whole semanticconceptual organization would be qualitatively as well as quantitatively different.
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ciently rehearsed is related to the developmental level of the subject. McBane’s subjects were divided into a High-Level group (mean IQ = 74, mean MA = 10.8 years) and a Low-Level group (mean IQ = 50, mean MA = 6.2). The High-Level group “rehearsed” over twice as many items (4.8) as the Low-Level group (2.3). The tentative conclusion from McBane’s study is that there is an upper limit to rehearsal capacity, even following extensive training, and that this upper limit may represent a structural feature of the memory system related to developmental level. C.
Mediational and Production Deficiencies
Flavell (1970) distinguished between two major deficits the young or retarded child may bring to a memory task. The first is a mediation deficiency, where the subject is unable to employ a potential mediator even when he is specifically instructed to do so. The hypothetical case in question refers to situations where the potential mediator is produced but fails to iduence performance. Returning to the example of rehearsal mechanisms, a mediational deficiency would be said to exist if the subject could be trained to overtly rehearse items, but that this activity failed to improve performance. The second type of deficiency is that of production. A production deficiency is said to be operating when potential mediators are not produced and hence do not aid performance. Effective mediation naturally depends on adequate prior production of the would-be mediator. Thus, in our example, the subject would perform poorly on a memory task requiring rehearsal because he does not spontaneously employ the rehearsal strategy, although he can be shown capable of doing so if he were instructed. The two types of memory deficits have some correspondence with the structural features and control processes described previously. A production deficiency refers to an inadequate use of control processes, which can be remediated by adequate training of the required strategy. Once this training is accomplished the task will be mediated by the appropriate strategy and performance will improve. A mediational deficiency, however, is said to exist when the subject is trained to produce the required strategy but this does not mediate performance. This is in some ways equivalent to a structural limitation; the subject is insufficiently mature to benefit from the induced mediational strategy, presumably due to developmentally related structural limitations of his memory system. The difficulty of distinguishing between developmentally related untrainable components of the memory system and trainable processes, discussed before, is again a problem for the distinction between mediational and production deficiencies. Only if the subject can be trained to produce the re-
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quired strategy does a finer-grained analysis of the type of memory deficiency become possible. Thus, if having produced the strategy, performance is not significantly altered, then the deficiency is said to be mediational, i.e., the child does not use the strategy to mediate performance. If, however, performance is mediated appropriately once the strategy is produced, then the initial deficiency is termed a production deficiency. Therefore, if training works, the initial deficiency was one of production. However, a problem exists in establishing the presence of a mediational deficiency, for if training does not alter performance, is this due to a mediational problem or inadequate training? Flavell ( 1970) distinguishes between various degrees of deficient production, since the extent of the original deficiency and the degree to which it responds to training are both developmentally related. At certain stages in the developmental sequence the child may exhibit a production inefficiency (Corsini, Pick, & Flavell, 1968). The original production deficiency is not complete, or does respond to training, but due to some limitation to the child’s effective use of the strategy, his ability to benefit from its use is impaired. For example, moderately retarded adolescents (mean IQ = 58) were successfully trained in an overt cumulative rehearsal strategy (Brown et al., 1973). However, rehearsal was only accomplished easily for the first three items in a four-item list. Performance indeed improved on the first three but not the fourth item. Similarly, Kingsley and Hagan (1969) attempted to train preschool children to cumulatively rehearse aloud. Although most of the subjects understood what was required, “only a few actually had much success in consistently and correctly rehearsing. Often the subjects rehearsed the first two or three items relatively well, but found rehearsal of four or five items difficult” (Kingsley & Hagan, 1969, p. 45). The “magical number three” which haunted Spitz (1973) in his studies of retardates may have some generality as a capacity limitation for the developmentally young. D. Active and Passive Strategies
A memory task can be regarded as a problem-solving situation in which attempts at mnemonic mediation are equivalent to problem-solving strategies. As children mature they become increasingly strategic in their approach to memory tasks, as indeed they do in problem-solving situations in general (Spitz & Nadler, in press). Developmental differences between older and younger children and between retarded and normal children result from differences in the voluntary strategic behaviors applied to the task. Thus, the child with a production deficiency is one who does not spontaneously employ the appropriate mediator for a specific task. However,
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the concept of active versus passive strategies extends this by suggesting that the developmentally young not only fail to produce the appropriate mediator but generally fail to produce any mnemonic mediator in memory and problem-solving situations. Their behavior is characterized by a passive acceptance of the task. Little attempt is made to transform the input or in any way to deliberately attempt to memorize. Flavell ( 1970) has stressed this deliberate intentional characteristic of mnemonic mediation and in this context has distinguished between general and specific factors which affect the child’s use of potential mediators. Specific factors refer to the efficiency and sophistication with which a child may use a given mediational strategy or memory subroutine. However, Flavell also identifies a general factor, that is the ability or intention to plan performance in advance. This skill is not related to any particular mediational activity, but rather is relevant to the effective performance of all mediational activities-hence, the term general factor. In essence, the child facing the task of memorization must evaluate the task demands (Moynahan, 1973 ) and his repertoire of mediational skills (Flavell, Friedricks, & Hoyt, 1970) and select those which he believes will facilitate subsequent performance. There is, of course, an interaction between specific and general factors. If the child has no mediational skills, or fails to appreciate the need for such skills, then planned activity is unlikely. Similarly, if the child has a limited repertoire of skills he may engage in mediational activity which is somewhat less than optimal for the task at hand. For example, he may focus on an irrelevant skill simply because this is the only one available in his repertoire or because this is the most salient skill he possesses. Thus, the general factor described by Ravel1 refers to the voluntary intention to engage in some mnemonic activity while the specific factor refers to particular subroutines which he may engage. A similar distinction has been made by Soviet investigators (Smirnov & Zinchenko, 1969), that is, between voluntary and involuntary memory. The young child is dependent on involuntary memory, memory which is largely the result of incidental learning which accompanies his active exploration of his environment. Voluntary memory develops gradually as the child matures. In the first stage the child exhibits “no purposeful behavior in remembering. The process proceeds as it were with no active participation on the child’s part so that it seems less a matter of the children’s recalling material than that the material presents itself to them for recall” (Smirnov & Zinchenko, 1969, p. 476). The second stage is reached when the child attempts to memorize and “actively tries to carry out his intention even though he lacks the appropriate means to do this.” The final stage is reached when the child possesses the necessary methods which will facilitate recall. However, the child’s “stock of methods is still very slim and
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it mostly amounts to repetitions of words which the child names to himself, only in a few cases does he actually group material in any meaningful way.” Once the child has reached the level of actively attempting some recall strategy, further improvement takes the form of “an increasingly greater mastery of rational devices or methods of recall.” When a new device is initiated it often fails to improve performance significantly as the method itself demands considerable intellectual effort and cognitive strain (a production inefficiency) but gradually the child‘s repertoire expands to include more mnemonics which he can apply with greater efficiency and flexibility. This description of the gradual development from involuntary (passive) to voluntary (active) strategies obviously has marked similarity with the outline described by Flavell (1970) and, not surprisingly, both have led to similar types of experimental tests. The active versus passive distinction is well illustrated in a recent pair of studies by Flavell and his associates (Appel, Cooper, McCarrell, SimsKnight, Yussen, & Flavell, 1972). Preschool, first, and fifth grade children were tested under conditions where they were explicitly instructed to memorize pictures, or merely asked to look at them. Older children behaved differently under the two conditions. When instructed to memorize, they introduced deliberate mnemonic techniques, such as rehearsal and categorization and subsequently recalled more than in the perceptual (look at) condition. However, the younger children did not appear to differentiate the situations but remained passive in both. They failed to study differently in the memorize condition and subsequently their recall did not improve. Deliberate memorization strategies following instructions to remember were apparent only in the older children. A similar study with retarded children by the Soviet psychologist Pinskii was reported by Shif (1969). As with much of the Russian research the experiment was conducted in a school setting. Groups of retarded adolescents were given stories to read. One-half of the subjects were warned before reading the story that they would be asked to recall the story in their own words after reading it twice. The remaining subjects were not warned that recall would be required but merely told to read it through twice in order to understand the story. Subjects warned about the impending recall reproduced 46.6% of the “composite semantic units.” However, those who received no prior warning recalled almost as much (40% ) . When the same experiment was conducted with normal adolescents of the same age, prewarned subjects recalled 30 percentage points more than the .uninformed group. Thus, it appears to be the case that not only does a child’s repertoire of specific strategies expand and grow more flexible as he matures but that the general intention of using a strategy, or the “plan to execute a plan”
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(Miller et al., 1960), depends on maturational level. Obvously, this basic intention to use a strategy must underlie effective memorization; for it is often the case that a specific strategy can be used if it occurs to the child to do so, but spontaneous exploitation of strategic devices is atypical of the developmentally young. Indeed, a case could be made that, in many instances, it is the intention to use an appropriate strategy which is absent, not necessarily the ability to do so. Thus, a primary source of the memory inefficiency of young children and retardates may lie in their passive behavior in memory task situations, for without explicit instructions they fail to produce not only the appropriate strategy but any purposeful strategy at all. E. Summary
In this section the trend away from information-processing flow diagrams toward a levels of analysis approach as a feasible alternative theoretical framework was discussed. This trend is reflected in the concentration on memory processes rather than on specific structural stores and pathways. A variety of theoretical positions, arising from a diversity of backgrounds, have been examined. From these, certain common hypotheses emerged which are thought to have generality across a variety of tasks and situations. Thus, the general consensus of opinion is that a characteristic feature of the immature memorizer should be an inadequacy in the spontaneous use of control processes, active mediational devices, and strategic transformations of the input. Although developmentally related limitations to structural capacity (maturational level) may set a limit to the extent to which these strategies can be trained, the suggestion is that under certain favorable circumstances the use of higher level mnemonics can be induced. However, there is also considerable agreement that a general intention to exploit available plans must underlie the efficiency of memorization strategies and, as such, the generalizability of training may be restricted. For the intention to use strategic behavior whenever possible is a necessary prerequisite before specific processes can be flexibly employed over a variety of tasks and situations. In the next section the generality of the phenomena proposed by these theoretical positions will be examined. The problems encountered in training specific strategies will be discussed. The problem of training the intention to use any strategy is still largely unexplored. 111.
THE USE OF MEMORY STRATEGIES BY RETARDATES: A BRIEF REVIEW
No attempt will be made in this section to give a detailed or exhaustive review of the literature concerning strategic behaviors used by retardates
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under instructions to memorize. The intention here is to summarize, with a few critical studies, the data from a variety of memory tasks in order to establish that a deficiency in the intentional use of strategies is a widespread problem for retarded children. A.
Rehearsal Mechanisms
A deficiency in the use of rehearsal is one of the most firmly established cognitive characteristics of retarded children. Rehearsal as an active acquisition strategy has been extensively studied in a variety of tasks and situations. Primary sources of evidence that retarded children do not spontaneously rehearse have been the serial position effect (Ellis, 1970) and pause patterns (Belmont & Butterfield, 1969, 1971) found in response to a serial recall task. The typical serial position curve, characteristic of retarded children, lacks the elevated primacy portion found with rehearsing adults (Ellis, 1970). Accuracy on the 6rst few serial positions is approximately equal to that for items in the middle of the list for retarded children. Adults, however, commit fewer errors in the initial serial positions, a consistent pattern of accuracy which is referred to as the primacy effect. The presence of a primacy effect has been attributed to rehearsal of the first few items (Atkinson & Shiffrin, 1968; Glanzer & Cunitz, 1966) so that the conspicuous absence of primacy in the retardate curves has been used as evidence for a rehearsal deficiency in these subjects. Ellis (1970), in a previous chapter in this series, marshalled additional evidence to support the rehearsal deficit hypothesis. For example, the serial position curves of retardates were not affected by an increased study period of from to 2 seconds (Ellis, 1970). Adults, however, benefit from the increased study time allowed for rehearsal (Glanzer & Cunitz, 1966). A consideration of the serial position effect has been a fruitful source of retardate and normal comparative data. A second source of evidence implicating a rehearsal deficit has come from the research program of Belmont and Butterfield (1969, 1971). Using a task, similar to that of Ellis and his associates, they have concentrated on the patterning of pauses produced by subjects in the memorization period of a recall task. Specifically, Belmont and Butterfield measured the interitem pause time in a self-paced task. They found that the pause patterns of normal CA comparison subjects reflected the active acquisition strategy adopted. These patterns changed systematically in response to changes in recall response requirements (Kellas & Butterfield, 1971) , and changes in the amount of potential organizational structure of the material (Pinkus & Laughery, 1970). A typical adult pause pattern, called the “cumulative rehearsal, fast finish” strategy (Belmont & Butterfield, 1971; Pinkus & Laughery, 1970), is comprised of an initial phase, consisting of a
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series of brief pauses followed by a single long pause, and a terminal phase, consisting of a series of very brief pauses without the subsequent long pause. This modal pattern has been attributed to the two phases of the subject’s acquisition strategy when faced with a typical six-item list. For the initial positions, the subject rapidly views the items and then rehearses that set leisurely before progressing to the final series of rapid acquisitions which are followed immediately by a probe. The fast finish strategy is used consistently across lists of any length, while with increasing list length the initial phase is typically broken up into two or more sequences of short pauses followed by a long one. Belmont and Butterfield believe this typical pause pattern is a direct reflection of the strategy of filling up successive echo boxes (Waugh & Norman, 1965) or rehearsal buffers (Atkinson & Shiffrin, 1968) and rehearsing the contents of each before proceeding to the next. In contrast to these systematic adult patterns the pause times of retarded subjects remained relatively constant across the list of to-be-remembered items, suggesting that the retardates were not systematically organizing their study time as a function of an item’s position in the list. In fact, there appeared to be a conspicuous absence of any deliberate acquisition strategy. However, Belmont and Butterfield ( 1971 ) report that forcing retardates to mimic adult pause patterns improved performance particularly in the primacy portion of the curve. Considered together, the evidence for a rehearsal deficit in retarded children is quite convincing, although the generality of the deficit may depend on the particular task and situation. Both McBane ( 1972) and Glidden (1972) report some spontaneous rehearsal in their retarded subjects. However, in general, it appears that retardates fail to attempt active acquisition patterns of rehearsing and grouping the items in to-be-remembered lists. That training rehearsal strategies have met with success (Belmont & Butterfield, 1971; Brown et al., 1973; Brown, Campione, & Murphy, 1974b) however, suggests that this is a strategic deficit on the part of retardates. Since these children readily respond to training and performance improves once they do, the deficiency is one of production rather than a true mediational problem. As McBane (1972) has concluded rehearsal capacity may be a structural feature of retardate memory, but rehearsal use is a control process. 6.
Organizational Strategies
The role of organization strategies has received considerable interest from psychologists concerned with retardation. As extensive reviews of the literature predate this chapter only a brief outline will be included here. Three main lines of investigation can be cited: studies of associative clustering, mnemonic elaboration, and the use of redundancy.
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1. ASSOCIATIVE CLUSTERING The associative clustering technique, introduced by Bousfield ( 1953), was developed to investigate organizational strategies in free recall. The task consists of presenting a list of words drawn from several conceptual categories. The subject is required to recall as many words as possible. Both the total number of items recalled and the extent to which subjects organize items in recall are recorded. There is a tendency for adults to recall words from the same category (in clusters) even when the words are presented originally in a random sequence. Furthermore, recall of material based on conceptual or associative categories is superior to recall of control lists of conceptually unrelated items (Goulet, 1968). Retarded and young children have shown relatively limited tendencies to cluster during free recall (Bousfield, Esterson, & Whitmarsh, 1958; Gerjuoy & Alvarez, 1969; Gerjuoy & Spitz, 1966; Lawrence, 1966). Spitz ( 1966) reviewed the Johnstone Laboratory investigations into the relation between clustering and free recall performance in normal and retarded subjects. Four groups of subjects were tested: (1 ) a group of institutionalized retardates (mean CA = 14 years); (2) a group of equal MA normals (mean CA = 9.8 years); (3) a group of equal CA normals (mean CA = 14 years); and (4) a group of college students (mean CA = 21 years). All subjects were tested for free recall on a list of twenty items consisting of four conceptual categories of five items each. The list was randomly ordered and presented for five trials. Recall increased over trials for all groups. College and 14-year-old normal subjects’ recall performance was superior to that of the retardates and equal MA normals. College and 14-year-old normal subjects also showed increased clustering over trials, clustering that was significantly greater than chance. The retardates and equal MA normals showed little evidence of clustering above chance level and clustering did not increase over trials for these groups. Spitz also reported significant correlations between clustering and recall for the college and 14-year-old normals (.85 and .55, respectively) but not for the retardates (.30)and equal MA normals (.28). Recent evidence suggests that there are qualitative as well as quantitative dserences between the recall organization of the developmentally young and more mature subjects. Denney and Ziobrowski (1972) have shown that first grade children tend to cluster, if at all, according to complementary groupings, i.e., words are clustered together because they share some complementary interrelationship (such as, pipe-tobacco, baby-crib) . College students, however, cluster according to criteria based on conceptual similarity (e.g., king-ruler, cribbed). Similarly, Jensen ( 1970) has suggested that while normal children cluster by supraordinate categories, retar-
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dates show more “pair-wise coordinate groupings often of a complementary relationship.” Thus, the tendency is for the developmental young to cluster, if at all, according to idiosyncratic relations. However, various training procedures can be devised to increase the tendency to cluster more frequently and to cluster according to more adult criteria. Blocked presentation of all items in a particular category has been one method successfully used to induce clustering (Bilsky & Evans, 1970; Bilsky, Evans, & Gilbert, 1972; Gerjuoy, Winters, Pullen, & Spitz, 1969). An example of this training procedure can be seen in an early study by Gerjuoy and Spitz (1966). The stimuli were twenty words in four categories of five words each. Retarded subjects were tested under one of three conditions: (1) standard randomized item presentation and standard free recall instructions; (2) standard randomized item presentation with instructions prior to recall to cluster the items (i.e., “Tell me all the animals you remember from the list.”); and (3) blocking stimuli such that the five words of each category followed one another. In terms of total recall, subjects in Groups 2 and 3 showed significantly greater recall over five trials than subjects in the control conditions. There was no difierence in total recall for subjects in the requested clustering or presented clustered conditions. For the two experimental groups, clustering was significantly above chance on all five trials. In addition, on the fifth trial, there was a significant correlation between clustering and recall for subjects in the experimental conditions. Gerjuoy and Spitz concluded that inducing retardates to cluster or organize material by whatever means, facilitates recall. While it appears to be the case that young children and retardates can be induced to use organizational strategies, there also appears to be limitations on the long-term effectiveness of such training. Moely, Olson, Halwes, and Flavell ( 1969) trained young children to organize according to conceptual categories by inducing the subjects to sort items manually into appropriate groups and to label the categories and count the items in each category. The instructions were deliberately stressed throughout the training sessions. However, when the younger subjects were no longer reminded to organize and label, they reverted to their previous nonstrategic behavior. In view of this difficulty in maintaining the induced strategy within the same task it is not surprising to find that the prognosis for transfer of organization strategies across tasks has been relatively poor. Although Bilsky and Evans (1970) found that experience with blocked word lists facilitated retardates’ spontaneous clustering on subsequent randomly organized word lists retaining the same materials, this facilitation did not generalize to lists containing new verbal materials (Bilsky et al., 1972). Some generalization to new lists has been reported when extended training (15 days) is under-
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taken but again the effect was far more pronounced for the items used
in training than for new items (Nye, McManis, & Haugen, 1972). Thus a general pattern emerges, the developmentally young do not spontaneously adopt organizational strategies and even when induced to do so, the effectiveness of such training is limited. The pattern is one of a specific production deficiency compounded by the general factor, the absence of the intent to use the strategy when not specifically instructed. 2. MNEMONIC ELABORATION
Mnemonic elaboration as an aid to recall of both information and its temporal order is a memory strategy with both ancient origins (Bower, 1970; Yates, 1966) and reported efficiency in cases of exceptional memory (Crovitz, 1970; Luria, 1968). Interest in the use of mnemonic elaboration has recently revived and studies with adults have confirmed the e5ciency of such devices as the “method of loci” (Bower & Reitman, 1972; J. Ross & Lawrence, 1968; Winograd, Karchmer, & Tucher, 1970) and “pegword mnemonic” systems (Bower & Reitman, 1972; Paivio, 1971). Interest in similar phenomena in children has been reflected in the recent series of studies on verbal elaboration (Rohwer, 1970) and vivid associations (Holyoak, Hogeterp, & Yuille, 1972; Jones, 1973; Reese, 1972) in pairedassociate learning as well as memory for actional, locational, and series scenes (Brown, 1973b; Horowitz, Lampel, & Takanishi, 1969; Lampel, 1973). Considerable attention has been directed to the use of mnemonic elaboration in paired-associate learning.2An example of such a technique would be the creation of meaningful sentences in which to embed the to-beremembered pair, or to invent meaningful connective contexts or images (Jones, 1973) so that the pair of items can be more easily associated and hence recalled. Shif (1969) suggests that retarded children require specific instructions in the identification and utilization of such associates or contexts. Even when they are produced, they tend to be “superficial,” not productive of “high-grade recall of the materials.” Similarly, American researchers have suggested that the superiority of older normal children on such a task is attributable to their propensity for engaging in meaningful self-activated elaboration of the material. Younger and retarded children do not automatically use elaboration techniques to aid recall (C. J. Martin, 1967; Rohwer, 1968). However, these subjects can be induced to construct elaborative contexts with a subsequent improvement in their performance (Taylor, Josberger, & Knowlton, 1972). Similarly, several studies have demonstrated that supplying elaborative context in the form * For a detailed discussion of mediational processes and paired-associate learning, see the chapter by Borkowski and Wanschura in this volume.
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of sentences improves the paired-associate learning of retarded subjects (Jensen & Rohwer, 1963; Milgram, 1967; Turnure & Walsh, 1971). Retarded children are clearly capable of utilizing experimentally provided elaborations to mediate associations between noun pairs ( MacMillian, 1970; C. J. Martin, 1967), indicating that the deficiency in spontaneous elaboration is a production problem rather than an inherent mediational deficiency. Again, however, the spectre of a general factor is seen, for relatively little transfer of trained elaboration techniques to new paired-associate tasks has been found (Jensen & Rohwer, 1963; Milgram, 1967). However, in a recent paper, Turnure and Thurlow (1973) have demonstrated transfer to new lists following training on more than one set of stimuli. Subjects receiving one elaboration experience showed little evidence of transfer while those receiving two elaboration experiences revealed clear transfer patterns. Again the general pattern to emerge from these studies is a production deficiency in the voluntary use of mnemonic elaboration, a deficiency which responds to training. Extensive training is required, however, before transfer to new situations is achieved. As suggested previously (Campione & Brown, in press; Stoff & Eagle, 1971) the effectiveness of such training programs would be enhanced if subjects could not only be instructed to employ a certain strategy within a specific task but could also be trained in the use of that strategy in a variety of situations.
3. THE USEOF REDUNDANCY The use of elaborative contexts and categorical relations are both methods of organizing materials for efficient acquisition and retrieval. A third method of organization that facilitates recall is recognizing and using recurring redundant patternings in the to-be-remembered materials (Zeaman, 1968). Adults quickly discover redundant patterning and use this information to improve recall (Edmonds, Evans, & Mueller, 1966). By using redundancy we reduce the demand on information processing and storage requirements in a limited-capacity memory system. The general assumption made in this chapter is that the ability to organize material effectively, thereby decreasing the memory load, is related to developmental level. As such, the capacity for discovering and using redundancy should be developmentally sensitive. In a series of recent studies Spitz and his associates have investigated the recognition and utilization of redundancy by retarded children. Spitz (1973) has used lists of digits containing various degrees of redundancy. An example of 50% redundancy is the list 1 3 5 1 3 5. The first three digits give all the information necessary to recall all six digits. Under such circumstances, retardates, unlike adults, did not readily recognize the redundancy on the initial presentation, but when the redundancy was made
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more salient their performance improved dramatically (Spitz, Goettler, & Webreck, 1972). Similarly, repeated presentations of 50% redundant digit lists led to increased utilization of the redundancy and improved recall (Spitz & Webreck, 1972). Apparently both spontaneous discovery of the redundancy and externally cued discovery had the same facilitative effects and these facilitative effects were durable at least for a period of 7 days (Spitz & Webreck, 1972). The general finding is that retardates rapidly and relatively permanently learn to use the redundancy present in materials if the redundancy level is high (50% or more) and salient. However, there is some evidence which suggests that this facility may be restricted to digit series. For example, in paired-associate learning retardates do not make effective use of secondary, redundant cues contained in the stimulus items (Baumeister & Kellas, 1971 ) . Furthermore, when a simultaneous presentation is used to enhance the saliency of the redundancy, retardates are quickly swamped by the information load and the efficacy of providing redundant patterning is lost (Spitz, 1972). Apparently retardates are overwhelmed by the simultaneous presentation of the high information material and, unlike equal CA comparison subjects, are unable to find the necessary strategy to discover the presence of the redundancy. Thus, the work on redundancy tends to follow the same general pattern as that found for other organizational strategies. Retardates are less efficient at spontaneously recognizing and using information-reducing aspects of a stimulus to organize input and hence aid recall. Emphasizing the saliency of the redundant pattern in any way leads to spontaneous recognition and the use of the organization (Spitz, 1973); however, this is accomplished more easily with digits which contain a much higher level of “constraint redundancy” than with verbal materials. Indeed, the main difference between the use of digit redundancy and other organizational features is the relative ease and permanence with which digit redundancy is recognized. Spitz and Webreck (1972) suggest that in view of their data “the hypothesis that retardates have difficulty organizing material to reduce the information processing load must be tempered by a knowledge of the structure of the material.” Considered together, studies on a variety of organizational strategies demonstrate again the generality of the problem of strategic behavior in the memory performance of the developmentally young. In a variety of tasks and situations there is a deficiency in the spontaneous or voluntary ability to reduce information load by organizing, transforming, or elaborating the to-be-remembered materials. This inadequate use of organization or redundancy leads to chaotic input and as Spitz (1973) has declared “chaotic input makes for chaotic retrieval.”
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C. Processing Task-Relevant Information
1. DIRECTED ACQUISITION Hagen and his associates have studied incidental learning and selective attention in children (Hagen, 1967; Hagen & Sabo, 1967; Maccoby & Hagen, 1965). Drucker and Hagen (1969) suggested that the ability to focus on task-relevant information is not fully developed until early adolescence. Similarly, retardates’ difficulty with selecting relevant aspects of stimulation for attention in visual (Zeaman & House, 1963) and tactile (Brown, Scott, & Urbano, 1972) discrimination tasks, as well as more complex relational problems (Brown, 1970), has been well documented. Hagen, Meacham, and Mesibov ( 1970) have incorporated incidental learning tests into their studies of memory ability in young children. The subjects viewed a series of pictures each containing a pair of line drawings of an animal and a household object. The task was to remember only the animals. With increasing CA there was an increasingly negative correlation between recall of the central (animal) compared with recall of the incidental object. Recall of the central object steadily improved with age, while recall of the incidental object either remained constant or decreased with age (Hagen, 1967; Hagen et al., 1970). Hagen also reports that the central measure correlates positively with standard IQ measures while the incidental measure shows a slightly negative correlation or no association with IQ. Smirnov and Zinchenko (1969) support this view of the relationship between mental maturity and the ability to disregard irrelevant information. In a task similar to Hagen’s using numbers and objects, they also report a higher percentage of the younger children recalling the background stimuli to the detriment of the central relevant items. Brown, Campione, & Gilliard (1974a) have recently shown that young children generally fail to appreciate the importance or “payoff value” of incoming information. If efficient performance demands that they ignore irrelevant background cues, they fail to concentrate exclusively on relevant material and hence perform poorly (Hagen et al., 1970). However, it is also the case that if performance can be improved, or memory load lessened by attending to relevant background changes, young children fail to exploit this information and again perform inefficiently in comparison to older children (Brown et al., 1974a). These data provide strong support for the contention that as children mature they attend increasingly only to those features of incoming information that are critical for task performance. With the development of increasingly flexible and efficient strategies for problem solution the older child is free to ignore or exploit information of both central and background status in response to changing task de-
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mands. He becomes, in a sense, a more efficient information processor. He can ignore irrelevancy and exploit redundancy thus reserving his limited-capacity memory system for essential operations. Although Hagen’s work has been conducted with normal children, the impressive body of literature concerning retardates’ inability to focus on relevant dimensions (Zeaman & House, 1963), or exploit redundancy (Spitz, 1973), would seem to indicate that the ability to concentrate exclusively on essential information is a characteristic feature of mature information processors, an ability which is not typical of the developmentally young. 2. DIRECTED FORGETTING Rehearsal strategies and input organization are techniques used in order to remember essential information. An equally essential feature of an efficient memory system is the ability to forget, that is to disregard material which is no longer required. Positive forgetting, in this sense, is as much a necessary control process for efficient use of a limited memory capacity as positive remembering. If the ability to disregard irrelevant material is defective, the system would become overloaded, a problem which creates difficulties even for an adult with exceptional ability such as Luria’s mnemonist (Luria, 1968). The problem would be even more acute for the retardate with his repertoire of inadequate memory processes. Recent research with adults has shown that considerable control can be exerted over what to remember and what to forget (Bjork, 1970; Block, 197 1 ) , a strategy which serves to reduce the interference caused by retaining unnecessary information. According to Bjork (1970) the strategy used by adults consists of selective rehearsal and selective retrieval. If positive forgetting is a voluntary control process dependent at least in part on the strategic use of rehearsal it might be expected that retardates would be deficient in the use of this memory strategy. Evidence concerning positive forgetting in retardates is scarce but two recent sets of studies have examined both the spontaneous use of the strategy and the efficiency of training procedures (Bray, 1973; Brown, 1971). Brown (1971) adapted a keeping-track task (for details of the task see Section V, A) in order to investigate positive forgetting. On each trial retarded subjects were presented with one instance of each of four categories. On some trials the subjects were required to give the most recent instance from one of the categories, i.e., “What was the last animal seen?” However, the tests occurred in an unpredictable sequence and following many trials there were no tests. Keeping-track accuracy decreased as the number of consecutive no-test trials increased for retarded but not for adult subjects. The most efficient strategy in a keeping-track task is to rehearse the items on each trial until a test does or does not occur and then disregard (forget)
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these items in readiness for the next set of updated information. Retardates had difficulty concentrating exclusively on the current information, a difficulty which was reflected both in their declining accuracy between tests and in the number of intrusions from previous outdated sets. In a second study retardates were trained to use a signal to forget which was presented after half of the no-test trials. When the signal was presented accuracy remained high between tests suggesting the efficient use of the forget signal. However, the training did not generalize to those remaining trials where the signal did not occur but where intentional forgetting was obviously still the best strategy. Apparently, as with positive memorization strategies, positive forgetting is a strategy which can be trained but is neither spontaneously adopted nor generalized by retarded children. A series of three studies of positive forgetting in retarded children has recently been reported by Bray ( 1973). Following considerable pretraining moderately retarded adolescents were able to use the strategy of switching from the processing of unnecessary to the processing of necessary information, In an adaptation of the task used by Bjork (1970) with adults, retarded subjects were able to use a signal to forget to reduce interference from irrelevant items. The effect of the forget signal was apparent when both group and individual data were considered. Accuracy in a condition where the subject was instructed to forget the first two and remember only the last four items in a six-item list was essentially the same as when the subject was required to remember all four items in a four-item list and considerably better than when required to remember all six in a six-item list. The overall pattern of results from these studies was that retardates could be trained to use a signal to forget to improve performance. However, the same pattern emerges for positive forgetting strategies that is characteristic of positive remembering strategies; retardates can be trained to make efficient use of the mnemonic but do not spontaneously organize their performance in this manner.
D. Summary The common theoretical predictions outlined in Section I1 were evaluated in this section with reference to a wide variety of empirical tasks. A consistent pattern emerged, for it appears to be the case that the voluntary control of what to remember and what to forget, together with the strategic use of mnemonics to aid this process, is inadequate in young normal and retarded children. Thus the use of rehearsal, organizational strategies, and intentional nonprocessing of irrelevant materials are all strategic behavior patterns under the voluntary control of the subject. They can be induced with suitable training but there is some suggestion that this
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training may be limited in its ability to produce “broad transfer,” or “broad conceptual generalization of specific learning,” both criteria of Level I1 functioning (Jensen, 1970, see Section IV, C ) . Both a specific deficiency in the production of a variety of strategies and a general deficiency in the spontaneous production of any strategy are implicated in the general inadequacy of memory performance in immature subjects. Extended practice with a specific strategy in a wide variety of tasks, coupled with careful control of the similarity of training and transfer situations may be needed before we can assess whether flexible strategies can be trained (see Campione & Brown, in press, for a relevant discussion of processes controlling the probability of effective transfer). As yet, we do not know if extended practice of this kind will lead to the establishment of flexible strategies or whether there are developmentally related limits to the extent that stategic behavior can be induced. IV.
SPECIFIC BACKGROUND TO THE PRESENT SERIES OF STUDIES
In this section a series of studies from our own laboratory will be briefly described. Greater detail concerning each study can be obtained elsewhere. The general focus of the research program has been on both the efficiencies and inefficiencies of retardate memory. The major hypotheses follow from the background material discussed so far. First, it was assumed that retardates are deficient in terms of a number of control processes, or strategies. When performance on a memory task depends upon the use of these strategies, normal-retardate difference would be expected. Second, it was assumed that when a memory task did not demand that a deliberate strategy be used for efficient performance, no normal-retardate differences would be ~ b t a i n e d .The ~ distinction is, of course, the same as reviewed in the ‘ I t should be. pointed out that this hypothesis is at best an oversimplification for there is at least one major aspect of memory which changes with age, but is not of the voluntary, potentially conscious, control process variety. This is the basic underlying semantic-conceptual structure that influences all cognitive activity (as mentioned in footnote 2 ) . Changes in the conceptual-semantic basis of memory were not considered in this chapter, however, as pointed out by Flavell (personal communication), there are at least three major forms of memory processes: ( 1 ) aspects that do not depend on strategic processes and d o not reflect underlying semanticconceptual schemata and as such are developmentally insensitive, ( 2 ) aspects that change with the maturation of the overall semantic-conceptual organization, but are neither potentially conscious nor deliberately controlled by the subject, and (3) the type of voluntary, often reportable strategic processes which develop with age. The focus of this chapter is on points ( 1 ) and ( 3 ) , but the importance of (2) should not be overlooked.
Ann L. Brown
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previous sections, that is, between active and passive strategies and voluntary and involuntary memory processes. A.
Choice of Tasks
In order to put these hypotheses to the test, two basic paradigms were examined. The tasks were selected to meet the criteria that one would demand strategic behavior for adequate performance and the other could be performed without employing any of the obvious strategies so far described in this chapter. The first task selected was a keeping-track task which requires that the subject keep the current state of a number of variables or categories updated. This task was selected as it requires active cumulative rehearsal, a strategy which has been extensively examined with retardates. The advantages of this task over previous paradigms used to investigate rehearsal will be discussed later. In addition, intentional forgetting and adequate search strategies were thought to be involved in the keeping-track task. The second task selected was a recognition memory task, where it is not obvious that any organizational, search, or rehearsal strategies are used for efficient performance. In the keeping-track task the performance of mildly retarded subjects departs considerably from that of normal adults, both in terms of the overall level of performance and in terms of the pattern of results obtained. Evidence will be presented to support the hypothesis that these differences stem from an inadequate use of rehearsal mechanisms. In the recognition memory task the performance of mildly retarded children appears more comparable to that of adults. Evidence will be presented which suggests that this comes about because retarded children are able to use temporal cues and that these cues are sufficient for excellent performance. It is further suggested that temporal cues are encoded without any deliberate strategy on the part of the subject (Brown, 1973a, 1973b), thus accounting for the retardate efficiency on such tasks. Therefore, the two tasks seemed ideally suited to test the general hypothesis that it is in the deliberate use of strategic plans that a retardate memory deficit is implicated. 6. Choice of Subjects
Institutionalized children in the moderately retarded range (MA 7-9, mean IQ approximately 70) were selected, so that complex verbal instructions could be introduced in the recognition task and due to the necessity of training category responding in the keeping-track task. It was also a special feature of this program that the same children participated in both types of tasks whenever feasible so that it would be possible to determine if efficiency
STRATEGIC BEHAVIOR IN RETARDATE MEMORY
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on a memory task was dependent on the extent to which deliberate strategies were required and if this effect held up within, as well as between, subjects. C.
Interaction between Task and Subject Variables
Jensen’s ( 1970) distinctions between primary and secondary retardation and Level I and Level I1 abilities were considered in selecting both the tasks and the subject population examined in the research program. Jensen described two major types of ability. Level I abilities are characterized by relatively little processing or transformation of the informational input, but higher abilities (Level 11) are said to reflect increased utilization of transformation, organization, and elaboration of the incoming information. Primary retardataion refers to a deficiency in basic Level I functioning as well as Level I1 and subjects thus characterized were not considered in this research program. Secondary retardation, however, refers to a deficiency in higher Level II-type functioning. It is Jensen’s contention that in the subject population studied in the majority of tasks reviewed here, Level I ability should be intact. That is, in the mildly to moderately retarded range of ability (IQs in the range of 50-85), children can function quite adequately on Level I-type tasks. However, for these same subjects Level I1 processing is beyond their capacity or at least requires considerable training before it can be induced. As the focus of this research program was on the use of strategies the selection of secondarily retarded subjects was clearly dictated. For these children, Level I ability, in some sense the equivalent of passive nonstrategic performance, should be intact and it is this level of functioning which was assumed to be operating in the recognition task. However, Level I1 ability, that is active strategic use of mnemonics, should be deficient, and it is this level of processing which was thought to be tapped by the keeping-track task. Thus, the choice of tasks and subjects was the deliberate outcome of a consideration of the interaction between subject and task characteristics. V.
SPECIFIC EXPERIMENTS
A. The Keeping-Track Task 1. BACKGROUND A keeping-track task requires that the subject keep track of the present state of a number of variables (Yntema & Mueser, 1960). Questions which signal the subject to recall the most recent state of a particular vari-
80
Ann L. Brown
able (category) are interpolated within a sequence of messages updating the states of the variables. Not only would the ability to keep track of a number of things at once appear to be an important form of memory for everyday life, but the task provides an excellent vehicle for studying memory strategies such as rehearsal and controlled forgetting, since the ability to keep constantly changing material updated would seem to require both rehearsal of the present state of a variable and erasure of previous states. Morin, Hoving, and Konick (1970) adapted the keeping-track task for use with children. Their task included a number of variables each with a set number of states (e.g., either two, four, or six states). Thus, the six states of the food variable could be: bread, milk, apple, cake, pie, and corn. On each trial the subject was presented with four items (pictures) sequentially in an inspection set. One item came from each of the four variables. The subject’s task was to remember the most recent state of each variable, e.g., that bread was the last food seen, that dog was the last animal seen. The question “What was the last food seen?” can be answered by employing one of two strategies. The subject may answer after searching his memory of the inspection set and determining which item was a food. Alternately, he may reference the states of the food variable and determine which was seen most recently. Investigations of this type of task with adults have shown that performance is not affected by the number of states of each variable (Yntema & Mueser, 1962). The functional search set for adults appears to be the inspection set and not the states of the variable in question. Searching only this set provides all the updated information and alleviates the necessity of “time tagging” (Yntema & Trask, 1963) the items of the probed variable so that recency judgments can be made. However, this optimal strategy demands that the items in the preceding inspection set be maintained in memory until the probe occurs. The most efficient method of preserving the rapidly presented and constantly changing items in memory is to actively rehearse the most recent inspection set until the probe occurs. Unlike adults, the performance of preschool children is affected by the number of states of a variable (Morin et al., 1970). The number of errors increases significantly as the number of states of a variable increase. In answering the probe, the children must consider the states of the probed variable rather than concentrating exclusively on the items in the inspection set. Apparently, young children are forced to search the probed variable because they fail to keep the information concerning the inspection set “alive” until the probe occurred, due to inadequate rehearsal. The present series of keeping-track studies was designed to examine the performance of retarded children, a subject population also characterized as deficient in the use of rehearsal strategies.
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STRATEGIC BEHAVIOR IN RETARDATE MEMORY
2. STUDY 1 : KEEPING-TRACK PERFORMANCE ADOLESCENTS
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The first experiment in this series (Brown, 1972b) represented an attempt to replicate the developmentally related rehearsal deficit (Morin e? al. 1970) with retarded children. The subjects were institutionalized retardates from the Mansfield State Training School, Connecticut. Their mean MA was 9 years, their mean CA was 16 years, and their IQ range was 62-85, with a mean IQ of 70. Each subject received stimulus familiarization and pretraining sessions before beginning the study. The stimulus familiarization procedure was designed to train subjects to name and categorize all states and all variables without error. The pretraining procedure familiarized the subjects with the keeping-track tasks by gradually increasing the size on an inspection set from 1 to 4 items. Both procedures, which are described in detail elsewhere (Brown, 1972b) were common to all the keeping-track experiments to be described here. The basic design of the experiments was similar to the Morin et al. (1970) study with preschool children. There were four variables: animals, vehicles, foods, and clothing. For each subject one variable had two states, two variables had four states, and the remaining variable had six states. Each trial of the experimental session consisted of the sequential presentation of four stimuli in an inspection set. The inspection series always included one state from each variable, e.g., and animal, a vehicle, a food, and an article of clothing. The last stimulus in the array was followed immediately by a probe which indicated which variable was to be recalled. The mean adjusted4 proportions correct are shown in Fig. 1. It can be seen that accuracy decreased as the number of states increased and there is a marked recency, but no primacy effect in the serial position curves. Thus, the data from the first study provided a replication and extension of the results obtained by Morin et al. (1970) and indicated that retarded children perform in a keeping-track task in a manner more similar to preschool children than to adults. Performance decreased as the number of states of the variable increased, suggesting that the states of the variable ‘As guessing probabilities vary with changes in the number of states only, the adjusted error scores were considered throughout this series of experiments. The correction for guessing is based on the assumption that the subject either knows the answer and is correct or guesses and is correct with probabilty l/n, where n = number of states. When the number of errors is above the chance expectation, the adjustment gives an error score greater than the number of trials. When this happened, the subject was assigned an error score equal to the number of trials. As this happened only in the Nonrehearsal conditions when the probed variable had six states, this procedure makes the tests of the major hypotheses somewhat conservative, since it slightly decreases the number of errors in conditions where the most errors were expected.
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were considered when the answer to the probe was required. Furthermore, inspection of the serial position curves revealed a marked recency effect but no primacy effect, again a pattern of results similar to that found with young children (Morin ef al., 1970) but not rehearsing adults (Alden, Wedell, & Kanarick, 197 1 ) .
3. STUDY 2: THE EFFECTS OF TRAINING RETARDED ADOLESCENTS TO REHEARSE The data from the initial study indicated that retardates, unlike adults, do not spontaneously adopt the appropriate strategy of cumulative rehearsal in a keeping-track task. In the second study (Brown et al., 1973, Exp. 1 ) one group of retarded adolescents ( N = 10) was given rehearsal training on a keeping-track task and another group ( N = 13) received no rehearsal training. If the rehearsal deficit hypothesis is correct, accuracy should decrease as the number of states increases in the untrained group, replicating the previous study (Brown, 1972b). An effect of number of states might also be expected when latency of response is considered for it should take longer to consider a variable with six states than one with only two, However, if training were successful, we would expect both accuracy and latency of response to be relatively constant in the trained (re-
STRATEGIC BEHAVIOR IN RETARDATE MEMORY
83
hearsing) subjects who need not reference the state of a variable in answering a probe. The subjects were selected from the Lincoln State School, Lincoln, Illinois. They had a mean MA of 7 years 5 months, a mean CA of 15 years 10 months, and a mean IQ of 58. They were matched on their performance on the first 2 days of pretraining before being assigned to Rehearsal or Nonrehearsal conditions. All subjects were given two extra days of pretraining. The Rehearsal group received additional training in an overt rehearsal ~trategy,~ while Nonrehearsal subjects received no such instruction. In all other respects the procedure was identical to the previous study (Brown, 1972b). The adjusted proportions correct are shown in Fig. 2. In general, Rehearsal subjects performed better than Nonrehearsal subjects. Of greater interest, however, are the different patterns shown by the two groups. As can be seen, the performance of the Nonrehearsal subjects decreased as the number of states increased, replicating the data obtained by Brown (1972b) with MA 9 retardates, and Morin er al. (1970) with preschool children. However, the Rehearsal subjects were uninfluenced by the number of states a variable could assume. In addition, training subjects to rehearse should lead to improved performance, with the effect being greatest at the early serial positions; Fig. 2 shows that this was the obtained result. For the Nonrehearsal subjects, there was a clear serial position effect, indicating pronounced recency, whereas the Rehearsal subjects failed to show a serial position effect. Latency data were obtained for six Rehearsal and six Nonrehearsal subjects. The latency of correct responses are shown in Fig. 3. As can be seen, the Rehearsal subjects' latencies were uninfluenced by either number of states or serial position, but the Nonrehearsal subjects were influenced by both. The Nonrehearsal subjects took longer to respond to a probed variable which had many states than to one which had few. Both the accuracy and latency data provided strong support for the hypothesis that a rehearsal deficit is responsible for the poor performance of untrained retardates on a keeping-track task. Due to inadequate rehearsal, the items in the inspection set have faded from memory at the time of the probe. As a consequence, untrained subjects are required to reference the states of the variable in question in order to answer the probe, and both accuracy and latency measures reflect any increase in the number of states. However, when subjects are trained to rehearse, items can be maintained in the inspection set, enabling the subjects to search only this 'Special thanks are extended to Catherine Kolf for her patience and skill at collecting data and assisting in the development of the rehearsal training technique. (For full details of the technique, see Brown et al., 1974b.)
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set in response to the probe. As a consequence there is no need to search the states of the probed variable and the number of states a variable can assume is unimportant. As an additional point of interest, it was noted that two subjects in the Nonrehearsal group outperformed all but one subject in the Rehearsal group. One obvious suggestion is that these two subjects were rehearsing despite the fact that they were not instructed to do so. If this were the case, the latencies of these subjects should be independent of number of states. Their data (labeled Subject 15 and Subject 16) are shown in Fig. 4, along with the six subjects in the Rehearsal group and four other subjects in the Nonrehearsal group for whom complete latency data are available. As can be seen, their performance is identical to that of the Rehearsal subjects and markedly different from that of the remaining Nonrehearsal subjects. Thus, a consideration of the accuracy data suggested the likelihood that these subjects were rehearsing, and the latency data provide strong additional support. 4. STUDY 3: LONG-TERM RETENTIONOF THE REHEARSAL STRATEGY
Retardates do not spontaneously adopt a rehearsal strategy but can be induced to rehearse successfully. This suggests that rehearsal is under the control of the subject and is a trainable control process, rather than a fixed
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