Retrieval failure, rehearsal deficiency, and short-term memory loss in the aphasic adult

Studies show that aphasic patients typically are grossly impaired in short-term memory performance. Since aphasics generally experience difficulty in word retrieval, it is conceivable that short-term memory loss is partially the result of verbal rehearsal deficiency which, in turn, is caused by the word retrieval problem. This paper reports an experiment in which five aphasic adults were nonverbally to recall individualized lists of pictures they could easily name and lists of pictures they could not name. Final items in the two lists were recalled with equal accuracy; this was expected in that the recency effect usually reflects sensory rather than verbal storage. Initial items were recalled with greater accuracy than middle-list items in the nameable sets but not in the unnameable sets. This primacy effect suggests the aphasics rehearsed the nameable pictures, but both lists were recalled so poorly that rehearsal deficit was considered responsible for no more than a fraction of the aphasics' reduction in short-term memory.     

The interaction of semantic memory with storage and retrieval processes

A procedure for separating storage from retrieval (R. Chechile & D. L. Meyer, Journal of Mathematical Psychology, 1976, 14, 430–437) lead to the conclusion that memory development involves changes in both storage and retrieval. Nevertheless, these changes resulted from the interaction of storage and retrieval mechanisms with the age-related elaboration of the semantic memory system. This study shows that the memory improvement with age, between kindergarten and second grade, vanished when the meaningfulness of the materials were equated. The most plausible interpretation of the results is the hardware invariance hypothesis. According to that hypothesis, the memory apparatus for information processing is constant across ages, but the hardware is used more effectively if there is a better-developed semantic memory system.     

Verb semantic structures in memory for sentences: Evidence for componential representation

This research contrasts two hypotheses concerning componential storage of meaning. The Complexity Hypothesis assumed by Fodor (The language of thought, NY: Crowell, 1975), Kintsch (The representation of meaning in memory, Hillsdale, NJ: Erlbaum, 1974), and Thorndyke (Conceptual complexity and imagery in comprehension and memory. Journal of Verbal Learning and Verbal Behavior, 1975, 14, 359–369) states that a word with many semantic components will require more processing resources, comprehension time, and long-term memory space than a word with few components, and thus will interfere more with memory for surrounding words. This memory prediction was tested against an alternative prediction based on connectivity. The Connectivity Hypothesis views verb semantic structures as frames for sentence representation and states that memory strength between two nouns in a sentence increases with the number of underlying verb subpredicates that connect the nouns. Thus, the Complexity Hypothesis predicts that a verb with many subpredicates will lead to poorer memory strength between the surrounding nouns than a verb with few subpredicates, while the Connectivity Hypothesis predicts that verbs with many subpredicates will lead to greater memory strength between nouns in cases when the additional subpredicates provide semantic connections between the nouns.In three experiments, subjects recalled subject-verb-object sentences, given subject nouns as cues. General verbs, with relatively few subpredicates, were compared with more specific verbs whose additional subpredicates either did or did not provide additional connections between the surrounding nouns. The level of recall of the object noun, given the subject noun as cue, was predicted by the relative number of connecting subpredicates in the verb, but not by the relative number of subpredicates. This finding supports the Connectivity Hypothesis over the Complexity Hypothesis. These results are interpreted in terms of a model in which the verb conveys a structured set of subpredicates that provides a connective framework for sentence memory.     

Retrieval practice enhances the accessibility but not the quality of memory

Numerous studies have demonstrated that retrieval from long-term memory (LTM) can enhance subsequent memory performance, a phenomenon labeled the retrieval practice effect. However, the almost exclusive reliance on categorical stimuli in this literature leaves open a basic question about the nature of this improvement in memory performance. It has not yet been determined whether retrieval practice improves the probability of successful memory retrieval or the quality of the retrieved representation. To answer this question, we conducted three experiments using a mixture modeling approach (Zhang & Luck, 2008) that provides a measure of both the probability of recall and the quality of the recalled memories. Subjects attempted to memorize the color of 400 unique shapes. After every 10 images were presented, subjects either recalled the last 10 colors (the retrieval practice condition) by clicking on a color wheel with each shape as a retrieval cue or they participated in a control condition that involved no further presentations (Experiment 1) or restudy of the 10 shape/color associations (Experiments 2 and 3). Performance in a subsequent delayed recall test revealed a robust retrieval practice effect. Subjects recalled a significantly higher proportion of items that they had previously retrieved relative to items that were untested or that they had restudied. Interestingly, retrieval practice did not elicit any improvement in the precision of the retrieved memories. The same empirical pattern also was observed following delays of greater than 24 hours. Thus, retrieval practice increases the probability of successful memory retrieval but does not improve memory quality.     

The effect of pretraining and feedback on the reasoning of young children

Three experiments are reported in which kindergarten and first-grade children were given one-trial multidimensional reasoning tasks that were modifications of those used by T. C. Toppino (1980, Journal of Experimental Child Psychology, 30, 496–512). In the first two experiments, the nature of the stimulus compounds (partitioned or unitary) was varied in a series of tasks of increasing complexity. First-grade children (Experiment 1) and kindergarten children (Experiment 2) performed extremely well on all of the tasks presented. Experiment 3 was designed to identify factors that contribute to these high levels of performance, relative to those obtained under the conditions used by Toppino (1980). The results indicated that a combination of feedback information and preliminary experience with simple forms of the tasks are sufficient to produce the high performance levels, and that the verbal labeling of stimulus components is not an essential constituent of the training.     

A reexamination of the faithful subject role

Fillenbaum (Journal of Personality and Social Psychology, 1966, 4, 532–537; Fillenbaum & Frey, Journal of Personality, 1970, 38, 43–51) has proposed that a relatively large number of subjects within certain experiments will adopt a faithful subject role, that is, they will intentionally avoid basing their behavior on any suspicions they may have regarding the experimenter's hypothesis. However, examination of the studies on which this conclusion was based casts doubt on whether Fillenbaum's subjects were truly faithful or whether they may have become aware of the nature of the deception after all opportunity for awareness to influence their responses had passed. To test this hypothesis, awareness measures were administered to subjects either before they took an incidental learning test or (as in Fillenbaum's studies) after the test. As predicted, fewer subjects were classified as faithful in the first condition than in the second. It was concluded that, in fact, very few if any subjects are actively faithful. Discussion also concerned the problems associated with role analyses of subject behavior.     

Visual spatial memory in Australian Aboriginal children of desert regions

Visual spatial memory was investigated in Australian Aboriginal children of desert origin. The investigation arose from an environmental pressures hypothesis relating particular skills to survival requirements in a particular habitat, and follows one of a series of suggestions made by R. B. Lockard (American Psychologist, 1971, 26, 168–179) for research in the related field of comparative psychology. Aboriginal children, from 6 to 17 years, performed at significantly higher levels than white Australian children on the tasks. Item type did not affect scores of Aboriginal children, while for white Australian children familiar items were easier than less familiar, which, if potentially nameable, were easier than items unable to be differentiated by name. These indications of strategy difference between the groups were supported by overt differences in task behavior. Aboriginal children appeared to use visual strategies, while most white Australian children probably attempted verbal strategies. Extent of traditional orientation of their group of origin had little effect on the scores of Aboriginal children, who were superior performers whether they came from traditional or nontraditional backgrounds. The likely effects of differential child-rearing practices and interactions between learning and natural endowment are discussed.     

Center median "alerting" and verbal learning dysfunction

Previous data have shown that stereotaxic center median lesions alone or lesions in the amygdala, unilateral left and right and bilateral, do not impair verbal paired-word associates learning. However, “interactional” combined lesions in the amygdala and center median nucleus on the left side result in a significant decrease in test scores. Analysis of the types of errors made postoperatively by the six patients with this lesion combination indicates the persistence over trials of misnaming errors vs errors of omission. These findings are compatible with hypotheses of an alerting function performed by medial thalamic structures which, for effective learning, cosponsor attention to stimulus cues. Defective alerting is held to result in faulty labeling and subsequent mismatching (see Ojemann, 1975, Brain and Language, 2, 101–120, and Fedio &; Van Buren, 1975, Brain and Language, 2, 78–100).     

Effects of loss of freedom on subjects with internal or external locus of control

This study investigated the relationship between internal versus external locus of control of reinforcement and counter control or reactance in subjects in a verbal learning experiment. Internal and external controllers were given either a choice or no choice of material to be learned in a paired associate, anticipation task (after Monty & Perlmuter, Journal of Experimental Psychology, 1972, 94, 235–238). As hypothesized, the lack of freedom of choice was associated with counter control (decreased recall) in internals. Being able to choose material lead to faster learning for both internals and externals after first trial recall.     

Interference in memory for pictorial information

Subjects studied either faces composed from visual features or verbal facts composed from concepts. Recognition times were increased for both faces and facts when they were composed of elements that occurred in multiple study items. In Experiment 1 the interfering effect of other study items was much larger for verbal facts than for faces. This difference was largely eliminated in Experiment 2 where care was taken to control the features by which the faces were encoded. Experiment 2 also showed that verbal information could interfere with pictorial information and vice versa. However, this cross-modality interference was much weaker than within-modality interference. The data are consistent with the ACT theory in which pictorial material and verbal material are stored together in an abstract propositional network. The subnode model (Anderson, Language, memory, and thought, Hillsdale, N. J.: Lawrence Erlbaum, 1976) can account for the greater within- than cross-modality interference.     

The advantages of mathematical modeling over traditional methods in the analysis of category clustering

A mathematical model for the analysis of category clustering is developed and testd. The model, which can be applied to categories of any size, is an extension of a two-item statistical model developed by Batchelder and Riefer (Psychological Review, 1980, 87, 375–397), and is equivalent to their model when categories consist of two items. The model is based on a current theory of clustering which postulates that the learning of a list of category items occurs on different hierarchical levels. Two category list-learning experiments are presented, and the data from these experiments are analyzed using the general statistical model. The first experiment reveals that the probabilities of storing and retrieving a cluster increase with category size, while the learning of items as singletons decreases. The effects of within-category spacing indicate that the storage of clusters decreases while cluster retrievability increases with an increase in input spacing. In the second experiment, the storage and retrieval of clusters are shown to be unaffected by whether the presentation of items is uncued or cued with the name of the category. However, the association of items decreases and the learning of items as singletons increases with uncued presentation. In the final sections, the general statistical model is compared to other methods for the measurement of category clustering. The model is shown to be superior to numerical indices of clustering, since these measures are not based on any theory of clustering, and because unitary measures cannot capture the multiprocess nature of categorized recall. The model is also argued to have certain advantages over other mathematical models that have been applied to category clustering, since these models cannot account for situations in which a portion of the items are clustered while others are learned singularly.     

Procedural knowledge versus fact retrieval in mental arithmetic: A reply to Baroody

Based on a review of reaction time studies, a model of mental arithmetic performance which emphasizes the process of fact retrieval from organized memory representations was proposed (M. H. Ashcraft, Developmental Review, 1982, 2, 213–236). In contrast to this view A. J. Baroody (Developmental Review, 1983, 3, 225–230) proposes that most mental arithmetic performance depends on procedural knowledge such as rules, heuristics, and principles. While Baroody's idea is both intriguing and potentially important, its exposition is quite vague and speculative. Without concrete suggestions as to the nature of the proposed rules and heuristics, especially for routine problems like 4 + 3 and 8 × 5, Baroody's proposal appears to be pertinent only to special cases like N + 0 and N + 1. Lacking this sort of elaboration, the alternative does not provide a useful or compelling explanation of the existing Chronometric results, and seems, at best, to be premature.     

Selective attention and the processing of integral and nonintegral dimensions: A developmental study

In two experiments, first- and fourth-grade subjects (age 6 and 9 years) performed a speeded card-sorting task with either integral or nonintegral dimensions. The dimensions were so arranged that subjects sorted on three types of task: (1) single dimension, (2) correlated dimensions, and (3) orthogonal dimensions. Results of the first experiment indicate that both first- and fourth-grade subjects sorted integral dimensions in a manner not qualitatively different from that of the adult (Garner & Felfoldy, Cognitive Psychology, 1970, 1, 225–241). In comparison with single-dimension tasks, performance was facilitated on the correlated-dimensions tasks and interference was observed on the orthogonal-dimensions tasks. Performances with nonintegral dimensions revealed an age-related processing difference. Fourth graders sorted nonintegral dimensions like the adult; no differences in performance were observed between the tasks. In contrast, first-graders sorted nonintegral dimensions as if they were integral. Interference was consistently observed on orthogonal-dimensions tasks. On correlated-dimensions tasks, interference was observed on easy tasks and redundancy facilitated difficult tasks. In the second experiment, first graders showed consistent facilitation on the correlated-dimensions task; all other results were indentical to those of Experiment I. The results were interpreted as consistent with perceptual learning theory (Gibson, Principles of perceptual learning and development. New York: Appleton-Century-Crofts, 1969).     

Developmental changes in incidental memory as a function of processing level,congruity, and repetition

Second-, fifth-, and ninth-grade students (8, 11, and 14 years of age, respectively) answered acoustic and semantic questions about words which were either congruent or incongruent with the questions. Subsequently, students' free recall of the words was unexpectedly tested. For words presented once in the list, only orienting task and congruity main effects were found. For twice-presented words, grade level interacted with both variables in that older students' recall was better than younger students' only for semantically encoded, congruent words. This finding is consistant with the hypothesis that developmental increases in semantic knowledge enhance the potential for encoding elaboration, but is in apparent conflict with the results of M. F. Geis and D. M. Hall (Child Development, 1978, 49, 857–861) who found no such interaction for second- and fifth-grade children. The different age spans included in the two studies provides one resolution of the discrepancy in results. However, a second experiment tested the importance of a procedural difference between the two studies. M. F. Geis and D. M. Hall (Journal of Experimental Child Psychology, 1976, 22, 58–66; 1978) presented the question after the stimulus word while we presented the question before the word. For ninth-grade students, the question after condition resulted in an attenuation of the recall difference between semantic and acoustic questions compared to the question before condition. It was argued that the pattern of developmental differences in incidental memory that is obtained may be related to which procedure is utilized.     

Developmental aspects of the generation effect

Children from Grades 2, 3, 5, and 7 (7.6, 9, 11, and 13 years of age, respectively) were required to generate or study exemplars of semantic categories (semantic orientation) or rhymes to stimulus words (phonetic orientation). Each child then participated in one of three retention tests: free recall, standard recognition, and rhyme recognition. The results indicated that the developmental emergence of the “generation effect” (C. E. McFarland, Jr., T. J. Frey, & D. D. Rhodes, Journal of Verbal Learning and Verbal Behavior, 1980, 19, 210–225; N. J. Slamecka & P. Graf, Journal of Experimental Psychology: Human Learning and Memory, 1978, 4, 592–604) was dependent on both encoding orientation and the type of retention task employed. A substantial generation effect first emerged (7-year-olds) for standard recognition in the semantic condition. A similar effect for recall was evident for 9-year olds, but not for younger children. Internal stimulus generation became a strong memory facilitator for phonetically encoded items at age 11 for standard recognition, but not until age 13 for recall. The results of the rhyme recognition test indicated that internal generation facilitated “transfer-appropriate processing” (C. D. Morris, J. D. Bransford, & J. J. Franks, Journal of Verbal Learning and Verbal Behavior, 1977, 16, 519–533) only for seventh graders (age 13). The processes underlying this developmental pattern were discussed.     

Memory for verbal and nonverbal stimuli in learning disability subgroups: analysis by selective reminding

Memory for verbal and nonverbal stimuli was evaluated using selective reminding procedures in normal achieving children and four groups of disabled learners: (1) reading-spelling disabled (R-S); (2) reading-spelling-arithmetic disabled (R-S-A); (3) spelling-arithmetic disabled (S-A); and (4) arithmetic disabled (A). Each child received two analogous free-list memory tasks, one for verbal material (animal names) and the other for nonverbal material (random dot patterns). These tasks were administered using selective reminding procedures that permit separation of storage and retrieval aspects of memory by reminding children only of those words not recalled on previous trials. Results revealed that relative to controls, the A and S-A children had significantly lower storage and retrieval scores on the nonverbal task, but did not differ on the verbal task; the R-S children differed only on retrieval scores from the verbal task; and the R-S-A children on retrieval scores on the verbal task and storage and retrieval scores on the nonverbal task. Thus, results indicate that the memory performance of disabled learners varies according to (1) the type of learning problem (arithmetic vs reading), (2) the nature of the stimuli (verbal vs nonverbal), and (3) the aspect of memory being assessed (storage vs retrieval). This study provides external validation for the classification of disabled learners according to patterns of academic achievement, demonstrating a useful procedure for dealing with the intrasubject variability characteristic of disabled learners.     

Brain responses related to semantic meaning

Evoked Potentials from electroencephalogram (EEG) recording were averaged to many visually presented word stimuli whose semantic meanings were specified along Osgood's semantic dimensions of Evaluation, Potency, and Activity [Miron &; Osgood, 1966, in R. B. Cattell (Ed.), Handbook of multivariate experimental psychology, Chicago: Rand-McNally; Osgood, 1971, Journal of Social Issues, 27, 5–63; Osgood, May, &; Miron, 1975, Cross-cultural universals of affective meaning, Urbana, Ill.: University of Illinois Press]. Multivariate analyses classified the Evoked Potentials to six semantic classes with success rates more than twice chance expectation. The pattern of brain activity related to the six semantic classes was similar for (i) two sets of words, (ii) 10 subjects used to develop the analyses, and (iii) an added, new subject.