Encoding and retrieval processes in learning-disabled, head-injured, and nondisabled young adults

Using a multi-trial, free-recall paradigm (Rey Auditory-Verbal Learning Test; Lezak, 1983), the acquisition and retention by learning disabled (LD) young adults with a Halstead Impairment Index less than or equal to 0.3 (low LD) or greater than or equal to 0.4 (high LD) was compared with that of nondisabled and head-injured (HI) young adults. Significant group differences, particularly during the last three acquisition trials, confirmed the effectiveness of this method in revealing subtle learning and retention deficits. Analyses of Trial 1 recall showed group differences in the prerecency but not the recency portion of the serial position curve, thus implicating long-term but not short-term memory differences between the groups. Analyses of pair frequency (Sternberg & Tulving, 1977) data showed that the three clinical groups had difficulty organizing the to-be-learned material for effective retrieval. Following an interpolated task, retention was poorer for the clinical groups than for the nondisabled and varied inversely with the degree of neuropsychological impairment. Finally, during retention, the nondisabled and low LD groups retained and used the list organization established during acquisition whereas the high LD and HI groups did not.     

Information processing and speech lateralization in learning-disabled children

The relationship between information processing and speech lateralization was investigated in learning-disabled children. The Kaufman Assessment Battery for Children (K-ABC) assessed simultaneous and successive processing while a dichotic listening paradigm with free recall and directed attention conditions assessed speech lateralization. A three-factor ANOVA design conducted on the dichotic data revealed that normal children demonstrated stronger right ear advantage (REA); whereas learning-disabled showed weaker right ear advantage. Further, lambda analyses conducted on individual subjects revealed that the learning-disabled did not demonstrate the REA, were not biased attenders, and did not get more right ear than left ear items when attention was directed to one ear. Multiple-regression analysis was used to predict sequential processing from the dichotic data for both groups. Learning-disabled children demonstrated a substantial deficit in sequential processing as compared to normal children. These results indicate that learning-disabled children may not have adequate cerebral lateralization of receptive speech processes, shift their attention more readily, and are more inadequate in sequential processing that presumably subserves language functioning. Perhaps learning-disabled children have deficiencies of processor capacity of salient areas of the left (language) hemisphere.     

Accuracy versus speed in the generalized effort of learning-disabled children

Reinforcement of effortful performance in a given academic task has been found to increase the subsequent performance of other academic tasks. The learned-effort hypothesis assumes that individuals learn which dimensions of task performance are correlated with reinforcement of high effort, and generalize across tasks. Therefore, reinforcement of increased effort in a given dimension of one task should result in greater generalized effort in the same dimension of transfer performance than in another dimension. In accord with this view, preadolescent learning-disabled students who received points for high reading accuracy subsequently produced more accurate drawings and stories than did students whose points had been based upon high reading speed or upon mere completion of the reading task. Students who received points for high reading speed subsequently constructed stories more quickly than did children whose points had been based upon high reading accuracy or upon reading-task completion. Consistent with the more explicit and frequent feedback for accuracy than for speed in most academic tasks, generalized accuracy was much more durable than generalized speed.     

A developmental study of vigilance in learning-disabled and nondisabled children

To test the proposition that learning-disabled children manifest a sustained attentional deficit, the Continuous Performance Test was administered to learningdisabled and nondisabled children at three age levels. Children were tested on three task lengths (5, 10, and 15 minutes) and two modalities (auditory and visual) in which dependent measures were correct detections and false responses, d′ and B values. As expected, learning-disabled children made fewer correct detections and more false responses and were less sensitive (d') to critical stimuli than were nondisabled children at all ages. There was also evidence to indicate that learningdisabled children apply different response criteria across age when compared to nondisabled children. B values varied significantly across age, group, modality, and time on task; d′ remained relatively unchanged across time periods. The popular notion that learning-disabled and younger subjects start a vigilance task with the same capacity as nondisabled older children but show a decline in attention as time on task increases was not supported.     

The selective attention of learning-disabled children: Three studies

Three studies were performed to assess the selective attention of learning-disabled (LD) children. In the first study, 10 LD and 16 non-LD children were given the Speeded Classification task. LD children sorted cards more slowly than non-LD children, and children in both groups had trouble ignoring irrelevant information. Non-LD children became more accurate across trials, while LD children did not. In the second study, one group of 13 LD children was taught to accompany their Speeded Classification sorting verbally in an attempt to improve their performance; the other group of LD children (n=12) received no such instruction. The experimental group, however, showed poorer performance across trials compared with the control group. In the third study, the children from Experiments 1 and 2 were given the Central-Incidental Learning task. Older children learned more central memory items than younger children and, LD children learned more incidentally than non-LD children.The authors would like to thank James Merola, Lisa Hart, Donna Woods, and Leonne Paquette for their assistance in this project, and the headmaster, director, teachers, and staff who were so helpful. Parts of this paper were presented at the 1982 meeting of the American Psychological Association.     

Application of the verbal transformation effect with learning-disabled children

Verbal Transformations (VTs) are an illusory effect which results from hearing a tape recording consisting of one word repeated twice per second. VTs have been employed to ascertain auditory perceptual differences in normal subjects relative to chronological age. This research tested two groups of 10 male children (normal and learning disabled). Results showed a significant difference (p < .01) between the reported number of VTs per group, with normal subjects verbalizing more different words. LD results are compared to VT studies with geriatrics. A theory is presented to explain our findings based upon a defect in short-term memory.     

Considerations in the use of difference scores to identify learning-disabled children

Although difference scores are widely used in classifying children as learning-disabled, their psychometric properties are often not well understood. Such scores generally contain more error than single test scores. Reliability and standard error of measurement figures for several combinations of ability and achievement measures are presented. The rates and types of errors that occur when such scores are used to classify children as learning-disabled are discussed. Three recommendations for using difference scores are given: (a) combinations of ability and achievement tests that yield difference score reliabilities higher than .80 should be used when classifying children; (b) scores should be reported as a band of scores (± one standard error of measurement) to inform decision-makers regarding the amount of error estimated to be in the score, and (c) the criterion score for classifying the learning disabled should be set after consideration of the rate and types of errors likely to occur.     

A categorical analysis of the social attributions of learning-disabled children

The social attributions of learning-disabled and control children with either similar or higher social acceptance ratings were assessed within an open-ended interview format. In addition, measures of social self-esteem and expectation of social success were obtained. The learning-disabled group used luck more frequently and personality interaction less frequently as explanations for social outcomes than did the other two groups. Learning-disabled children also had the lowest expectation of social success and, like the low acceptance group, had a poorer social self-image. Possible explanations for the development of these attributions and the implications for holding them were discussed.     

Evaluation of behavioral group counseling for parents of learning-disabled children

The present study evaluated the effectiveness of a behavioral group counseling program for parent members of the Association for Children with Learning Disabilities. Twentytwo mothers were assigned to two treatment groups (N=5 and N=6) and a control group (N=11). Treatment-group mothers received a series of eight weekly 11/2-hour sessions in which they were taught basic principles and procedures of behavior modification which they could apply to specific childrearing problems. Multiplesuccess criteria (maternal reports, direct observation, frequency counts, and attitudinal measures) were employed to provide a broad-based measurement of outcome. Results indicated that treatment ratings of childrens' conduct and disruption and parental postbehavioral observations of mother-child interactions showed improvement for the behavioral-counseling groups while control-group ratings and behavior observations remained the same. All treatment-group changes were maintained at 3-month follow-up. Consistency of treatment-group data across measures and over time suggests the effectiveness of this approach as a training method. Implications for future research were discussed.     

Memory, acquisition, and category clustering in learning-disabled children.

In Experiment 1, single trial, immediate-free recall of learning disabled and nondisabled children was compared. The primacy effect in learning-disabled children was lower, suggesting that rehearsal or other types of elaborative encoding may be deficient in these children. In Experiment 2, acquisition of randomly presented categorical lists in a multitrial-free recall task was compared in learning disabled and nondisabled children. One-half of each group was required to learn the same number of words (34 per list), whereas list length for the other half exceeded the primacy effect of each child in immediate-free recall to the same degree. When the same number of items was learned, acquisition was slower in learning disabled than nondisabled children. When the number of items varied according to the primacy effect of each child, acquisition of both groups was similar. Clustering was lower in learning disabled than nondisabled children. In Experiment 3, multitrial-free recall acquisition of categorical lists was examined in a subject-paced task. When the number of words learned exceeded the primacy effect of each child to the same degree, trials to criterion were similar in both groups but, when the children learned the same number of items, learning-disabled children required more trials to criterion. Presentation rates were faster in learning-disabled children. Presentation rates were negatively correlated with trials to criterion and positively correlated with clustering and primacy in immediate-free recall, suggesting that study time may be taken up by clustering, rehearsal, and/or other encoding strategies. Deficient elaborative encoding may be responsible for the slower acquisition of learning-disabled children.     

Time sharing and dichotic listening asymmetry in normal and learning-disabled children

Time-sharing and dichotic listening techniques were used to examine cerebral lateralization for language function in 48 normal and 48 learning-disabled children. All subjects were matched according to age, sex, and handedness. An analysis of results indicated that both nornal and learning-disabled children demonstrated left hemisphere lateralization of language function on the time-sharing and dichotic listening tasks. However, no developmental trends were evident for either group. Differences observed in the performance of the normal and learning-disabled children may relate to how each group utilizes “verbal strategies” and processes simultaneous information in the left hemisphere. The results strongly question the notion that attributes learning disabilities to incomplete or delayed language lateralization and lend support to the notion that cerebral lateralization is not a developmental phenomena.     

Attentional deficit in learning-disabled children: evidence from visual half-field asymmetries

The structural theory of cerebral lateralization has been typically used to explain hemispheric asymmetries. However, the attentional model of brain functioning may help resolve some of the inconsistent findings with groups of learning-disabled children. To test this hypothesis, a visual half-field paradigm for word recognition was employed in a group of 26 learning-disabled and 26 normal children matched for sex, chronological age, and handedness. Three experimental conditions (unilateral, cued unilateral, and bilateral) and two word error types (visually and acoustically confusable words) were analyzed. The results indicated that normals produced the expected RVHF superiority under all experimental conditions, but the learning-disabled produced the expected RVHF superiority only under the cued unilateral condition. Learning-disabled children also made significantly more visually and acoustically confusable errors than normals and unlike normal children increased the number of acoustic errors in the RVF under bilateral stimulation. These results provide evidence that learning-disabled children may process information inefficiently and have brain activation patterns that are more susceptible to attentional effects.     

Physiological correlates of conduct problems and anxiety in hyperactive and learning-disabled children

Thirtysix learning disabled children (21 of whom were also classified as hyperactive) were subgrouped according to teacher ratings of tension-anxiety and conduct problems and then compared on measures of tonic and phasic autonomic arousal. The results indicated that children rated high on the conduct problem dimension evidenced smaller amplitude specific skin conductance responses, and that anxiety appeared to exert a moderating effect on physiological responses. When the hyperactive sample was considered separately, lower skin conductance levels were observed in children rated high on conduct problems than in hyperactive children rated low in conduct problems. These findings support the notion that hyperactive and learning-disabled children are heterogeneous at a physiological level and suggest that physiological differences previously attributed to hyperactivity may actually be correlates of the conduct problem dimension.     

An observational study of emotionally disturbed and learning-disabled children in school settings

It has been alleged that populations of learning-disabled (LD) and emotionally disturbed (ED) children are essentially indistinguishable on important intervention-related symptoms. To examine this claim, a direct observation study of social interactions during class, lunch, and recess settings in two public schools was conducted. Teacher ratings of school behavior were also collected. The results indicated that the ED boys exhibited significantly more nonphysical aggression and noncompliance than the LD boys across settings, and that the LD boys had significantly higher rates of physical and non-physical aggression and immature behavior than the LD girls. The correlations between the observations and teachers' ratings were modest but consistent with previous studies. The results are discussed with regard to their assessment and treatment implications.This study was supported, in part, by a grant from the National Institute of Mental Health (MH30058). The authors wish to acknowledge the assistance of the following individuals: Patricia Grayson, James Fogarty, Merrill Zusmer, James Burke, Elizabeth Mulvihill, and the teachers from the Sayville and Premm Learning Centers (L. Fass, J. Gould, K. Jones, C. Lacey, B. Licking, S. Ott, S. Palmer, J. Thorpe, C. Wangenstein, D. Wayne, and L. Wetter). We also wish to thank Michael H. Epstein and Jan Loney for their helpful comments on an earlier draft of this paper.     

Personality dimensions in two types of learning-disabled children: a Rorschach study

Children referred for psychoeducational assessment of learning disabilities (LDs) commonly receive the Rorschach test. yet little is known about the impact of LD on Rorschach response patterns. This study investigated Rorschach response patterns in two groups of 9- to 12-year-old children (n = 41) classified by their respective intellectual abilities. Another group of 9- to 12-year-olds (n = 143) served as a nonclinical comparison group. Rorschach variables indicative of personality dimensions failed to discriminate between the two LD groups. Compared to the nonclinical group, the LD group exhibited several Rorschach characteristics--including problems in perceptual accuracy, inefficient visual scanning and problem-solving strategies, and avoidance of affect-laden stimuli--having implications for successful socioemotional adaptation. Suggestions for further research are discussed.     

Encoding and incidental memory in children

First, third, and fifth graders (7.1, 8.8, 11.1 years old) performed semantic, acoustic, and orthographic orienting activities to different words in a list. Without forewarning, their free recall of the words was tested after the orienting activity. The semantic task yielded better recall than the acoustic or orthographic tasks, but the latter two did not differ. Age differences in recall were absent, and the effect of the three orienting tasks did not vary as a function of the child's age. The results support a direct extension of levels of processing theory (Craik, F. I. M., & Lockhart, R. S. Journal of Verbal Learning and Verbal Behavior, 1972, 11, 671–684) to children's memory. An obligatory-optional encoding distinction was suggested as a developmentally relevant addition to the levels of processing framework.     

Attentional deficits of learning-disabled children: Effects of rewards and practice

This study investigated the effects of rewards and practice on the attentional task performance of learning-disabled (LD) and normally achieving children. Contingent feedback and rewards resulted in faster but less accurate performance by the LD children. Despite the speed-accuracy trade-off, the LD children still responded more slowly than the controls. However, limited practice on the tasks resulted in significantly improved performance, such that the groups performed similarly. Poorer performance of LD children on their first encounter with laboratory measures of attention may be due to inefficient strategies rather than to actual deficits in ability to attend.This paper is based on the author's dissertation. I gratefully acknowledge the assistance of Nancy Ponzetti-Dyer, Susan Shapiro, and Duane Kemp in the data collection, and of Raymond Romanczyk and two anonymous reviewers for comments on a draft of this article.     

Response bias on a locus of control measure by learning-disabled children

Four experiments were conducted to clarify the relationship between internal locus of control and achievement in learning-disabled and normal boys. The initial study yielded only a weak relationship between achievement and locus of control. Two subsequent experiments found differences on internality, and experiment 3 confirmed a pattern of second response choice bias for low-achieving boys. In Experiment 4 a significant interaction of diagnosis and test form resulted. Overall the tendency of learning-disabled and low-achieving boys to choose second response alternatives may have resulted in the popular but unsubstantiated notion that disabled children are less internally oriented than normal children.