Index

Visuospatial working memory (VSWM) and intuitive geometry were examined in two groups aged 11–13, one with children displaying symptoms of nonverbal learning disability (NLD; n?=?16), and the other, a control group without learning disabilities (n?=?16). The two groups were matched for general verbal abilities, age, gender, and socioeconomic level. The children were presented with simple storage and complex-span tasks involving VSWM and with the intuitive geometry task devised by Dehaene, Izard, Pica, and Spelke (2006 Dehaene, S., Izard, V., Pica, P. and Spelke, E. S. 2006. Core knowledge of geometry in an Amazonian indigene group. Science, 311: 381–384. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). Results revealed that the two groups differed in the intuitive geometry task. Differences were particularly evident in Euclidean geometry and in geometrical transformations. Moreover, the performance of NLD children was worse than controls to a larger extent in complex-span than in simple storage tasks, and VSWM differences were able to account for group differences in geometry. Finally, a discriminant function analysis confirmed the crucial role of complex-span tasks involving VSWM in distinguishing between the two groups. Results are discussed with reference to the relationship between VSWM and mathematics difficulties in nonverbal learning disabilities.     

Visuo-Spatial Working Memory Span: A Sensitive Measure of Cognitive Deficits in Children With ADHD

Working memory (WM) has been hypothesised to be impaired in attention-deficit/hyperactivity disorder (ADHD). However, there are few studies reported on tests measuring visuo-spatial WM (VSWM) in ADHD. Some of these studies used paradigms including episodic memory, others only used low memory loads. In the present study we used a VSWM test that has not been used previously in ADHD research. The sensitivity of the VSWM test and a choice reaction time (CRT) test was evaluated in a pilot study by comparing them to two commonly used tests in ADHD-research; the Continuous Performance Test (CPT) and a Go/no-go test, in children with and without ADHD. The groups differed significantly in performance on the VSWM test (P<.01) and CRT (P<.05) but not on the CPT (P>.1) or on the Go/no-go test (P>.1). The results from the VSWM and CRT tests were replicated in a larger sample of participants (80 boys; 27 boys with ADHD and 53 controls, mean age 11.4 years). The difference between the groups was significant for both the VSWM test (P<.01) and the CRT test (P<.01). The effect size (ES) of the VSWM test was 1.34. There was a significant age-by-group interaction on the VSWM test, with larger group differences for the older children (P<.01). Our results show that the VSWM test is a sensitive measure of cognitive deficits in ADHD and it supports the hypothesis that deficits in VSWM is a major component of ADHD.     

Social functioning using direct and indirect measures with children with High Functioning Autism,nonverbal learning disability,and typically developing children

Social perception is an important underlying foundation for emotional development and overall adaptation. The majority of studies with children with High Functioning Autism (HFA) or nonverbal learning disabilities (NLD) evaluating social functioning have used measures of parent and/or teacher ratings. The present study utilized parent and teacher ratings of behavior as well as executive functioning in addition to direct measures of social perception. Three groups participated in this study (control [n = 38] HFA [n = 36], NLD [n = 31]). Results indicated that the HFA group experienced the most difficulty understanding emotional cues on the direct measure while both the HFA and NLD groups experienced difficulty with nonverbal cues. Significant difficulties were reported on the parent rating scale for sadness and social withdrawal for both clinical groups. Executive functioning was found to be particularly problematic for the clinical groups. The direct social perception measure was highly correlated with the measures of executive functioning and reflects the contribution that executive functions have on social functioning. These findings suggest that the clinical presentation on behavior rating scales may be very similar for children with HFA and NLD. Moreover, it appears that measures of executive functioning are sensitive to the clinical difficulties these groups experience. The findings also suggest there is a commonality in these disorders that warrants further investigation.     

Visuospatial working memory for locations,colours, and binding in typically developing children and in children with dyslexia and non‐verbal learning disability

This study examined forward and backward recall of locations and colours and the binding of locations and colours, comparing typically developing children – aged between 8 and 10 years – with two different groups of children of the same age with learning disabilities (dyslexia in one group, non‐verbal learning disability [NLD] in the other). Results showed that groups with learning disabilities had different visuospatial working memory problems and that children with NLD had particular difficulties in the backward recall of locations. The differences between the groups disappeared, however, when locations and colours were bound together. It was concluded that specific processes may be involved in children in the binding and backward recall of different types of information, as they are not simply the resultant of combining the single processes needed to recall single features.     

Smaller splenium in children with nonverbal learning disability compared to controls,high-functioning autism and ADHD

The current study investigated morphological differences in the corpus callosum in children ages 8 to 18 years old with nonverbal learning disability (NLD; n = 19), high-functioning autism (HFA; n = 23), predominantly inattentive ADHD (ADHD:PI; n = 23), and combined type ADHD (ADHD:C; n = 25), as well as those demonstrating typical development (n = 57). Midsagittal area of the corpus callosum and five midsagittal anterior-to-posterior corpus callosum segments were examined using magnetic resonance imaging. Controlling for midsagittal brain area and age, no group differences were found for total corpus callosum area. This finding indicates that higher functioning children on the autistic spectrum do not have smaller corpus callosi as has been found in previous research with heterogeneous samples. Following segmentation of the corpus callosum, the NLD group was observed to have significantly smaller splenia compared to all other groups. Smaller splenia in the NLD group was associated with lower WASI PIQ scores but not WASI VIQ scores. Children with HFA were observed to have larger midbody areas than children with NLD and neurotypically developing children. Children with HFA and NLD demonstrated behavioral symptoms of inattention and hyperactivity similar to the ADHD groups indicating that corpus callosum differences seen in the NLD and HFA groups are not related to these behaviors.     

Memory for words and drawings in children with hemiplegic cerebral palsy

A list-learning paradigm was used to study learning and memory of verbal and figurative material in children with right versus left-sided hemiplegic cerebral palsy. Thirty-one children with right (n=18), or left (n=13) congenital hemiplegia were compared with normal controls (n=19). All children had normal intelligence (IQ>80), and were attending standard schools. The inclusion criteria for the two hemiplegic groups were; no epilepsy, no hearing or visual impairments, and a mild to moderate hemiparesis. The aim of this study was to explore material-specific (words and drawings) differences in the acquisition, recall and serial position effects in children with an early unilateral brain lesion. The left-hemisphere impaired (i.e. right hemiplegia) group showed impaired acquisition for drawings, as compared with the normal controls. There was also a material-specific difference in the serial position effect for all three groups. Learning of words followed the primacy principle, whereas the learning of drawings followed the recency principle. There were no group-differences in delayed-recall (i.e. long-term memory) for either words or drawings. The results are discussed in terms of acquisition and retention of verbal and figurative materials in relation to lesion side and size.     

Visuo-spatial working memory span: a sensitive measure of cognitive deficits in children with ADHD.

Working memory (WM) has been hypothesised to be impaired in attention-deficit/hyperactivity disorder (ADHD). However, there are few studies reported on tests measuring visuo-spatial WM (VSWM) in ADHD. Some of these studies used paradigms including episodic memory, others only used low memory loads. In the present study we used a VSWM test that has not been used previously in ADHD research. The sensitivity of the VSWM test and a choice reaction time (CRT) test was evaluated in a pilot study by comparing them to two commonly used tests in ADHD-research; the Continuous Performance Test (CPT) and a Go/no-go test, in children with and without ADHD. The groups differed significantly in performance on the VSWM test (P < .01) and CRT (P < .05) but not on the CPT (P > .1) or on the Go/no-go test (P > .1). The results from the VSWM and CRT tests were replicated in a larger sample of participants (80 boys; 27 boys with ADHD and 53 controls, mean age 11.4 years). The difference between the groups was significant for both the VSWM test (P < .01) and the CRT test (P < .01). The effect size (ES) of the VSWM test was 1.34. There was a significant age-by-group interaction on the VSWM test, with larger group differences for the older children (P < .01). Our results show that the VSWM test is a sensitive measure of cognitive deficits in ADHD and it supports the hypothesis that deficits in VSWM is a major component of ADHD.     

Direct and Indirect Measures of Social Perception,Behavior, and Emotional Functioning in Children with Asperger’s Disorder,Nonverbal Learning Disability,or ADHD

Understanding social interactions is crucial for development of social competence. The present study was one of the first to utilize direct and indirect measures of social perception to explore possible differences among children with nonverbal learning disability (NLD), Asperger’s Syndrome (AS), Attention Deficit Hyperactivity Disorder-Combined (ADHD-C), Attention Deficit Hyperactivity Disorder-Predominately Inattentive (ADHD-PI), and controls (N = 342). Multiple informants provided ratings of the child’s behavioral and social functioning. Results indicated that the NLD and AS groups experienced the most difficulty understanding emotional and nonverbal cues on the direct measure. In addition, children with AS or NLD showed significant signs of sadness and social withdrawal compared to the other groups. Attentional skills, while related to social perception, did not predict social perception difficulties to the same degree as number of AS symptoms.     

Evidence for a double dissociation between spatial-simultaneous and spatial-sequential working memory in visuospatial (nonverbal) learning disabled children

The paper describes the performance of three children with specific visuospatial working memory (VSWM) impairments (Study 1) and three children with visuospatial (nonverbal) learning disabilities (Study 2) assessed with a battery of working memory (WM) tests and with a number of school achievement tasks. Overall, performance on WM tests provides evidence of a double dissociation between spatial-simultaneous processes, underpinning the memorization item positioning in a spatial configuration, and spatial-sequential processes, which allow memorization of the presentation order. In both groups of children of the two studies, a selective impairment either on spatial-sequential or on spatial-simultaneous working memory tasks was observed. These data support the existence of -simultaneous and -sequential modality-dependent processes in visuospatial working memory and confirm the importance of distinguishing between different subtypes of visuospatial (nonverbal) learning-disabled children.     

Asperger syndrome: How does it relate to non‐verbal learning disability?

The syndrome of non‐verbal learning disabilities (NLD) is associated with prominent non‐verbal deficits such as reduced perceptual and spatial abilities, against a background of relatively intact verbal abilities. Asperger syndrome is one of the several developmental disorders for which Byron Rourke has claimed that almost all the signs and symptoms of NLD are present. This study investigated the claim utilizing a battery of neuropsychological tests that were found to be sensitive to NLD in the original learning disordered populations used to describe the syndrome. Children aged between 8 and 14 were recruited to form two groups: (1) children with Asperger syndrome (N=14) and (2) normal healthy schoolchildren (N=20). By contrast to the main principle outlined in the NLD model, children with Asperger syndrome did not display a relative difficulty with spatial‐ or problem‐solving tasks; indeed, they displayed significantly higher performance on some non‐verbal tasks in comparison with verbal tasks. It was only in relation to their high levels of psychosocial and interpersonal difficulties, which are also predicted on the basis of their psychiatric diagnosis, that the children with Asperger syndrome were clearly consistent with the NLD model in this study. These results raise questions about the relevance of the syndrome of NLD for children with Asperger syndrome.     

Spatial and emotional aspects of language inferencing in nonverbal learning disabilities.

Although subtle linguistic deficits have been postulated for children identified with nonverbal learning disabilities (NLD), there is little empirical evidence to support this contention. Two experimental language inferencing measures that have been demonstrated to be problematic for individuals with right hemisphere brain damage (RHBD) and one norm-referenced inferencing task were examined in three groups of children aged 9-13: (1) children with NLD (n = 14), (2) children with verbal impairments (VI) (n = 14), and (3) children without learning disabilities who served as controls (n = 19). The NLD and VI groups did not differ from one another on any of the three measures, indicating a generalized language inferencing deficit in the NLD group. Relative to the control group, however, the NLD group experienced specific difficulties with spatial and emotional inferencing. The implications for right hemisphere involvement in the NLD profile are examined in relation to the effects of working memory on inferential abilities.     

The influence of two years of school music training in secondary school on visual and auditory memory

The present study tested the effect of an extended music curriculum (EMC) for two years in secondary school, consisting of musical instrument, auditory perception, and music theory training, on children's visual and auditory memory. We tested 10-year-old children who had just started EMC and children without EMC (T0) in visual and auditory memory and retested the same children two years later (T1) to observe the effects of school music training. Confounding variables, like intelligence, socioeconomic status, extracurricular schooling, motivation to avoid work, and musical aptitude were controlled. Prior to the beginning of the music training no differences in the control variables and the memory variables between children with and without EMC were revealed. Children with EMC improved significantly from T0 to T1 in visual as well as in auditory memory. Such an improvement was not found for children without EMC. We conclude that extended school music training enhances children's visual and auditory memory.     

Evidence for different components in children's visuospatial working memory

There are a large number of studies demonstrating that visuospatial working memory (VSWM) involves different subcomponents, but there is no agreement on the identity of these dimensions. The present study attempts to combine different theoretical accounts by measuring VSWM. A battery composed of 13 tests was used to assess working memory and, in particular, the hypothesized mechanisms involved in the tasks, that is, active processing and passive recall of visual versus sequential‐spatial versus simultaneous‐spatial versus verbal tasks. The battery consisted of a number of tests already used in previous studies and new tests developed to examine specific components of working memory. We analysed the psychometric characteristics of the tests, the correlations amongst measured variables and estimated the measured variables with structural equation modelling in children attending third and fourth grades. Results revealed that the best model was composed of a specific verbal factor, three visuospatial passive factors (sequential‐spatial, simultaneous‐spatial, and visual) and one visuospatial active factor.     

Ambiguous figure perception and theory of mind understanding in children with autistic spectrum disorders

Researchers in early social‐cognition have found that the ability to reverse an ambiguous figure is correlated with success on theory of mind tasks (e.g. Gopnik & Rosati, 2001 ). The present experiment examined children with autistic spectrum disorders (ASD) without mental delay to see whether a similar relationship existed. Ropar, Mitchell, and Ackroyd (2003) demonstrated that children with ASD with mental delay were impaired on theory of mind tasks, but were as likely as mentally delayed controls to generate both interpretations of an ambiguous figure when informed of its ambiguity. The present study replicated this finding on children with ASD without mental delay. However, overall perception of ambiguous figures was different. These children were less likely to spontaneously generate both interpretations of the figure, and more likely to perseverate on a single interpretation than the comparison children. Like Ropar et al., we found no correlation between theory of mind and informed reversals, but spontaneous reversals were correlated with performance on an advanced theory of mind task. These data suggest that reversals of ambiguous figures are linked to higher‐level representational abilities, which might also be involved in social functioning, and impaired in children with ASD.     

Listening comprehension and working memory are impaired in attention-deficit hyperactivity disorder irrespective of language impairment

This study investigated listening comprehension and working memory abilities in children with attention-deficit hyperactivity disorder (ADHD), presenting with and without language impairments (LI). A 4-group design classified a community sample (n = 77) of boys aged 9–12 into ADHD, ADHD + LI, LI, and Normal groups. Children completed tests of basic language and cognitive skills, verbal and spatial working memory, and passage-level listening comprehension. Multivariate analyses and post hoc comparisons indicated that ADHD children who did not have co-occurring LI comprehended factual information from spoken passages as well as normal children, but were poorer at comprehending inferences and monitoring comprehension of instructions. ADHD children did not differ from normal children in verbal span, but showed significantly poorer verbal working memory, spatial span, and spatial working memory. The ADHD + LI and LI groups were most impaired in listening comprehension and working memory performance, but did not differ from each other. Listening comprehension skills were significantly correlated with both verbal and spatial working memory, and parent–teacher ratings of inattention and hyperactivity/impulsivity. Findings that children with ADHD but no LI showed subtle higher-level listening comprehension deficits have implications for both current diagnostic practices and conceptualizations of ADHD.     

Difficulties in the control of irrelevant visuospatial information in children with visuospatial learning disabilities

This research tested the hypothesis that children's difficulties in visuospatial working memory (VSWM) may mirror difficulties found with verbal working memory tasks in other categories of children. Two experiments compared the number of correct responses and errors in groups of visuospatial learning disabled children (VSLD) and Controls who were engaged in an active task testing visuospatial working memory. Children were presented with sequences of positions on a 4x4 matrix and were subsequently asked to remember only the last position of each series. In the first Experiment, VSLD children showed greater difficulty in both recalling the last positions and avoiding the irrelevant non-final positions compared with Controls. In the second experiment children of different age groups (second-graders and fifth-graders) were also required to stress, by tapping on the table, the irrelevant positions whenever the experimenter pointed to a coloured cell. Results showed that the number of errors was greater in the VSLD children, and the pattern of errors differed with their grade. In particular, the increased activation of stressed locations produced an increase of correct responses, and a decrease of intrusion errors, except in the case of VSLD second-graders, who made a higher number of intrusions for stressed than for unstressed locations. Results confirm that children with VSLD show a specific deficit in active VSWM, and in particular, in the ability to avoid intrusion errors. In general, the control of irrelevant information appears critical for a successful use of VSWM.     

A test battery to assess intrasensory and intersensory development of young children.

The purpose of the study was to develop a battery of tests for use in evaluation of intra- and intersensory development of young children. A battery of 15 tests (4 visual, 4 auditory, 4 tactile-kinesthetic, and 3 intersensory) was administered to 109 normally developing 6- and 8-year-old and 32 slowly developing or learning disabled children. Interdependence of test items within each intrasensory and the intersensory category was determined; intercorrelations ranged from .00 to .78. Reliability estimates were also determined. Face validity was claimed for each item. The effects of age or developmental level on test performance were established. Based upon the interdependence of the tests, reliability estimates, and the capacity of the tests to discriminate among groups classified according to age or developmental level, a battery of 10 intra- and intersensory tests was proposed. The battery has 3 tests of visual perception-visual memory, dynamic depth perception, and size discrimination; 3 tests of auditory perception-auditory discrimination, auditory memory of related syllables, and auditory sequential memory of numbers; 2 tests of tactile-kinesthetic perception-tactile integration and movement awareness; and 2 tests of intersensory integration-auditory-tactile intergration and auditory-visual integration.     

Deficits in verbal long-term memory and learning in children with poor phonological short-term memory skills

Possible links between phonological short-term memory and both longer term memory and learning in 8-year-old children were investigated in this study. Performance on a range of tests of long-term memory and learning was compared for a group of 16 children with poor phonological short-term memory skills and a comparison group of children of the same age with matched nonverbal reasoning abilities but memory scores in the average range. The low-phonological-memory group were impaired on longer term memory and learning tasks that taxed memory for arbitrary verbal material such as names and nonwords. However, the two groups performed at comparable levels on tasks requiring the retention of visuo-spatial information and of meaningful material and at carrying out prospective memory tasks in which the children were asked to carry out actions at a future point in time. The results are consistent with the view that poor short-term memory function impairs the longer term retention and ease of learning of novel verbal material.