Causal learning across domains

Five studies investigated (a) children's ability to use the dependent and independent probabilities of events to make causal inferences and (b) the interaction between such inferences and domain-specific knowledge. In Experiment 1, preschoolers used patterns of dependence and independence to make accurate causal inferences in the domains of biology and psychology. Experiment 2 replicated the results in the domain of biology with a more complex pattern of conditional dependencies. In Experiment 3, children used evidence about patterns of dependence and independence to craft novel interventions across domains. In Experiments 4 and 5, children's sensitivity to patterns of dependence was pitted against their domain-specific knowledge. Children used conditional probabilities to make accurate causal inferences even when asked to violate domain boundaries.     

Reading deficits in learning disabled children

The purpose of this study was to determine whether LD children exhibited problems in the processes of attention, memory, or syntactical awareness when decoding written prose. Eighteen LD children and 18 normal controls were matched for initial word recognition skills. Subjects were then trained to read a list of individual words to criterion. Subsequently, they were tested on their ability to decode the same words in paragraph form, presented both immediately after training, and then again one week later. Half the children read paragraphs following standard English syntax, while the other half read a syntactically scrambled version of the same paragraph. The results indicated that a major contributing factor in the reading (decoding) difficulties demonstrated by the LD children derived from problems of acquisition and retrieval from long-term memory storage. The results were discussed in terms of their implications for the developmental lag theory of learning disabilities.     

Visual feature integration in learning disabled children

This study examined the ability of 7 learning disabled children to detect and integrate visual features in a complex display. While the learning disabled children performed more poorly over-all than 6 control children, differences between the two groups were most pronounced when subjects were required to conjoin or integrate visual features to make a decision about the presence of a target item. This finding is discussed with reference to automatic and attention-demanding components of visual perception.     

Variations in WISC-R patterns of learning disabled children

The WISC-R was administered to 19 learning disabled students at the time of diagnosis and following a period of time in special program placements. Group analyses indicated fluctuations between testing times in the Verbal and Full-Scale IQs and the V-P IQ discrepancies. Small but significant differences in Verbal, Performance and V-P scatter indices were observed at one or both testings in comparison to the normal standardization sample. Although the suggested group pattern for learning disabled children based on the Bannatyne categories was confirmed on both occasions, there was considerable variation for individual subjects.     

Syntactic decoding times of learning disabled children

Syntactic decoding reaction times of 20 learning disabled children comprising two groups of subjects (mean age of 8 and 13 yr., respectively) were compared to the responses of normal controls matched for age and sex. An analysis of variance procedure showed that the learning disabled children and their normal peers did not differ significantly in responses to the experimental stimuli. This held true regardless of linguistic complexity, suggesting that delays in processing elementary syntactic constructions are not a concomitant of learning disabilities.     

Symbolic representation across domains in preschool children

The study examines children's understanding of notational representation. Children 3 to 5 years old were shown a card containing a notation and told what it said. The children were asked to say what was printed on the card 3 times: when it was under a display named by the notation, when it was under a different display, and finally when it had been returned to the original position. In Study 1, the card contained a word or a picture indicating object identity or a numeral or an analogue indicating quantity. All the children could solve the problems containing pictures, numerals, or analogues, but the word condition was difficult and children believed that the word changed when the card moved to the new display. In Study 2, the comparison between object names and quantities was made more equitable by introducing easy and difficult versions of each condition. This time, there was little difference between cards indicating names and those indicating quantities but large differences in children's ability to solve the problem as a function of their familiarity with the notation that was written. The results point to weaknesses in children's understanding of how representations refer to meanings.     

Dynamic balance of learning disabled and nondisabled children

This investigation assessed a difference in the dynamic balance abilities of 30 learning disabled and 30 nondisabled children of elementary-school age. Only distance traveled across the beam, a novel task, was significantly different between groups; no other effects were significant. Nondisabled subjects traveled further across the beam before losing balance than learning disabled children.     

Vision and academic performance of learning disabled children

The purpose of this study was to assess difference in academic performance among myopic, hyperopic, and emmetropic children who were learning disabled. More specifically, myopic children were expected to perform better on mathematical and spatial tasks than would hyperopic ones and that hyperopic and emmetropic children would perform better on verbal measures than would myopic ones. For 439 learning disabled students visual anomalies were determined via a Generated Retinal Reflex Image Screening System. Test data were obtained from school files. Partial support for the hypothesis was obtained. Myopic learning disabled children outperformed hyperopic and emmetropic children on the Key Math test. Myopic children scored better than hyperopic children on the WRAT Reading subtest and on the Durrell Analysis of Reading Difficulty Oral Reading Comprehension, Oral Rate, Flashword, and Spelling subtests, and on the Key Math Measurement and Total Scores. Severity of refractive error significantly affected the Wechsler Intelligence Scale for Children--Revised Full Scale, Performance Scale, Verbal Scale, and Digit Span scores but did not affect any academic test scores. Several other findings were also reported. Those with nonametropic problems scored higher than those without problems on the Key Math Time subtest. Implications supportive of the theories of Benbow and Benbow and Geschwind and Behan were stated.     

The immediate impact of aggressive cartoons on emotionally disturbed and learning disabled children

The immediate impact of viewing aggressive cartoons on emotionally disturbed (ED) and learning disabled (LD) children's willingness to hurt another child was assessed. Fifteen ED and 23 LD children (M = 7.25 years old) viewed either an aggressive or a comparison cartoon and then played the Help-Hurt game. The children who watched the aggressive cartoon pressed the Hurt button for significantly more time than did those who were exposed to the comparison cartoon. Across cartoon conditions, the ED children pressed the Hurt button significantly longer than did their LD peers.     

Naming of object-drawings by dyslexic and other learning disabled children

On the Oldfield-Wingfield Picture-Naming Test, sensitive to subtle chronic dysphasia in adults, dyslexic children name fewer pictures correctly. Even when correct on words with less than 30 per million frequency of occurrence, they perform more slowly than do nondyslexic subjects suffering from minimal brain dysfunction (MBD) or normal controls. However, there is no evidence for “perceptual impairment” underlying dyslexic subjects' low scores and prolonged latencies, as the distribution of their errors is similar to that of normal children. Rather it is the nondyslexic MBD group which produces a high percentage of wrong names, suggestive of mistaking the pictured stimuli for other, visually similar, objects.     

Motor and cognitive proficiency of learning disabled and normal children

Motor and cognitive skills of learning disabled (N = 32) and normal (N = 32) boys were compared on the Modified Lincoln-Oseretsky Motor Development Scale and on the WISC-R Vocabulary and Block Design subtests. Eight learning disabled and eight normal boys were tested at four age levels from 8 to 11 years. All boys were of normal intelligence. Motor and cognitive skills of the learning disabled boys were significantly below those of the normal boys and below those of the normative group. Chronological age was not a significant factor in relationship to either motor or cognitive skills. Intercorrelations indicated that in the learning disabled group Block Design, but not Vocabulary, was significantly related to motor scores at the 8- and 9-year ages. These results suggest that a common factor relating to perceptual-motor coordination and efficiency may be involved on the Lincoln-Oseretsky and Block Design subtest for young learning disabled children but not for older learning disabled children or for normal children.     

Stability of WISC-R scores for a sample of learning disabled children

The study was designed to assess the stability of WISC-R profiles of 36 learning disabled children given the WISC-R two times. The mean time between tests was 2.5 yr. The pattern reported for learning disabled children on Bannatyne's categories was evident for the group at both times, however, this pattern was not found for the majority of subjects. Analysis indicated a decrease over time in Verbal IQs, Full Scale IQs, and Bannatyne's Conceptual category, confirming previous findings. Possible reasons for the changes in scores are discussed.     

Hyperactivity and related behavioral characteristics in a sample of learning disabled children.

64 learning disabled and 12 minimal brain-damaged children were evaluated by their teachers on 11 categories of behavior. Analysis showed that behavioral characteristics associated with hyperactivity did not differentiate among subjects. Teachers rated poor motor coordination as the outstanding trait of this sample.     

The generality of overselectivity in developmentally disabled children

A growing body of research suggests that low Mental Age (MA) autistic and retarded children show a unique stimulus control deficit, one that may cause many or most of their behavioral deficiencies. This problem, stimulus overselectivity, is evidenced when a child responds only to a restricted portion of the stimulus environment when compared with normal children. The purpose of this study was to assess whether this overselectivity is general across situations or whether it is restricted to certain stimulus/task conditions. Eight autistic children, who evidenced overselectivity on a preassessment task, and 8 normal children with similar MA levels participated. All children were trained on 3 tasks to determine if overselectivity varied as a function of different stimulus conditions. Each of the 3 tasks involved training a child to respond to (i.e., touch) a card containing a circle (S +) and to avoid a blank (S ?) card. In each case, the circle comprised a series of dots. The difference between the 3 circles (tasks) was the distance between the successive dots making up each circle. Also, in the minimal separation condition the dots were smaller in size and greater in number than in the larger separation conditions. Of concern was whether autistic children learned about the gestalt (i.e., the circle), which required attention to multiple cues, or whether children would overselect and respond to the dots. The results showed that (1) stimulus overselectivity was found not to be a generalized deficit in autistic subjects; instead, it varied as a function of the stimulus variables; and (2) the stimulus variables manipulated in this study similarly influenced the responding of both normal and autistic children. The implications of these data for a theory of overselectivity are discussed.     

Event-related EEG oscillations to semantically unrelated words in normal and learning disabled children

Learning disabilities (LD) are one of the most frequent problems for elementary school-aged children. In this paper, event-related EEG oscillations to semantically related and unrelated pairs of words were studied in a group of 18 children with LD not otherwise specified (LD-NOS) and in 16 children with normal academic achievement. We propose that EEG oscillations may be different in LD NOS children versus normal control children that may explain some of the deficits observed in the LD-NOS group. The EEGs were recorded using the 10/20 system. EEG segments were edited by visual inspection 1000ms before and after the stimulus, and only correct responses were considered in the analysis. Time-frequency (1-50Hz) topographic maps were obtained for the increases and decreases of power after the event with respect to the pre-stimulus average values. Significant differences between groups were observed in the behavioral responses. LD-NOS children show less number of correct responses and more omissions and false alarms than the control group. The event-induced EEG responses showed significant differences between groups. The control group showed greater power increases in the frequencies 1-6Hz than the LD-NOS group from 300 to 700ms. These differences were mainly observed in frontal regions, both to related and non-related words. This was interpreted as a deficit in attention, both to internal and external events, deficits in activation of working memory and deficits in encoding and memory retrieval in the LD-NOS children. Differences between groups were also observed in the suppression of alpha and beta rhythms in the occipital regions to related words in frequencies between 8 and 17Hz from 450 to 750ms. LD-NOS children showed shorter durations of the decreases in power than the control group. These results suggest also deficits in attention and memory retrieval. It may be concluded that LD-NOS children showed physiological differences from normal children that may explain their cognitive deficiencies.