Cognitive correlates of mathematical achievement in children with cerebral palsy and typically developing children

Background . Remarkably few studies have investigated the nature and origin of learning difficulties in children with cerebral palsy (CP). Aims . To investigate math achievement in terms of word‐problem solving ability in children with CP and controls. Because of the potential importance of reading for word‐problem solving, we investigated reading as well. Sample . Children with CP attending either special (n= 41) or mainstream schools (n= 16) and a control group of typically developing children in mainstream schools (n= 16). Method . Group differences in third grade math and reading, controlled for IQ, were tested with analyses of co‐variance (ANCOVAs). Hierarchical regression was used to investigate cognitive correlates of third grade math and reading. Predictors included verbal and non‐verbal IQ measured in first grade, components of working memory (WM) and executive function (EF) measured in second grade, and arithmetic fact fluency and reading measured in third grade. Results . Children with CP in special schools performed significantly worse than their peers on word‐problem solving and reading. There was a trend towards worse performance in children with CP in mainstream schools compared to typically developing children. Conclusions . Impairments of non‐verbal IQ and WM updating predicted future difficulties in both word‐problem solving and reading. Impairments of visuospatial sketchpad and inhibition predicted future word‐problem, but not reading difficulty. Conversely, deficits of phonological loop predicted reading but not word‐problem difficulty. Concurrent arithmetic fact fluency and reading ability were both important for word‐problem solving ability. These results could potentially help to predict which children are likely to develop specific learning difficulties, facilitating early intervention.     

A comparison of working memory skills and learning in children with developmental coordination disorder and moderate learning difficulties

The present study compared 6–11 years old with developmental coordination disorder (DCD) and those with moderate learning difficulties (MLD) on measures of memory (verbal short‐term and working memory, visuo‐spatial short‐term and working memory), literacy and numeracy, and IQ. The findings indicate that children with DCD appear to be impaired in all four areas of memory function; in particular they performed at significantly lower levels than children with MLD in measures of verbal short‐term memory, visuo‐spatial short‐term and working memory. In contrast, performance of children with MLD in the memory measures was within age‐expected levels, with deficits observed only in verbal working memory tasks. There were also differential links between memory and attainment between the two groups, and these were significant even after statistically accounting for the contribution of IQ. Reasons for why working memory contributes to learning in these two developmental groups are discussed. Copyright © 2006 John Wiley & Sons, Ltd.     

Face scanning distinguishes social from communication impairments in autism

How closely related are the social and communicative impairments in Autism Spectrum Disorder (ASD)? Recent findings in typically developing children suggest that both types of impairment are highly heritable but have only moderate behavioural and genetic overlap. So far, their respective roles in social perception are poorly understood. Here we show that when looking at other people’s faces, children with ASD who are better at socio‐emotional behaviours than non‐verbal communication look more at the eyes, while those with the opposite profile look more at the mouth (Study 1). For the mouth area, a similar pattern was observed for inverted faces, suggesting that information from this area is perceived on a featural basis. In Study 2, we found that when shown a person performing manual actions, ‘eye‐lookers’ from Study 1 tended to look most at the face of the actor, while ‘mouth‐lookers’ from Study 1 tended to look at the action itself (hand/objects). This result was found in both ASD and typical development. In Study 3, the main finding in Study 1 was replicated in a new sample. Taken together, we interpret these results as supporting the view that the neural systems underlying socio‐emotional versus non‐verbal communication skills are separable, a finding that has important theoretical and clinical implications. The results also suggest that a similar differentiation of looking behaviour may operate in normal development.     

Young children with autism show atypical brain responses to fearful versus neutral facial expressions of emotion

Evidence suggests that autism is associated with impaired emotion perception, but it is unknown how early such impairments are evident. Furthermore, most studies that have assessed emotion perception in children with autism have required verbal responses, making results difficult to interpret. This study utilized high-density event-related potentials (ERPs) to investigate whether 3-4-year-old children with autism spectrum disorder (ASD) show differential brain activity to fear versus neutral facial expressions. It has been shown that normal infants as young as 7 months of age show differential brain responses to faces expressing different emotions. ERPs were recorded while children passively viewed photos of an unfamiliar woman posing a neutral and a prototypic fear expression. The sample consisted of 29 3-4-year-old children with ASD and 22 chronological age-matched children with typical development. Typically developing children exhibited a larger early negative component (N300) to the fear than to the neutral face. In contrast, children with ASD did not show the difference in amplitude of this early ERP component to the fear versus neutral face. For a later component, typically developing children exhibited a larger negative slow wave (NSW) to the fear than to the neutral face, whereas children with autism did not show a differential NSW to the two stimuli. In children with ASD, faster speed of early processing (i. e. N300 latency) of the fear face was associated with better performance on tasks assessing social attention (social orienting, joint attention and attention to distress). These data suggest that children with ASD, as young as 3 years of age, show a disordered pattern of neural responses to emotional stimuli.     

Why is visual search superior in autism spectrum disorder?

This study investigated the possibility that enhanced memory for rejected distractor locations underlies the superior visual search skills exhibited by individuals with autism spectrum disorder (ASD). We compared the performance of 21 children with ASD and 21 age‐ and IQ‐matched typically developing (TD) children in a standard static search task and a dynamic search task, in which targets and distractors randomly changed locations every 500 ms, precluding the use of memory in search. Children with ASD exhibited overall faster reaction time (RT) relative to TD children, and showed no disruption in search efficiency in the dynamic condition, discounting the possibility that memory for rejected distractors augments their visual search abilities. Analyses of RT x set size functions showed no group differences in slopes but lower intercepts for the ASD group in both static and dynamic search, suggesting that the ASD advantage derived from non‐search processes, such as an enhanced ability to discriminate between targets and distractors at the locus of attention. Eye‐movement analyses revealed that the ASD and TD groups were similar in the number and spatial distribution of fixations across the search array, but that fixation duration was significantly shorter among children with ASD. Lower intercepts in static search were related to increased symptom severity in children with ASD. In summary, ASD search superiority did not derive from differences in the manner in which individuals with ASD deployed their attention while searching, but from anomalously enhanced perception of stimulus features, which was in turn positively associated with autism symptom severity.     

Individual and developmental differences in eyewitness recall and suggestibility in children with intellectual disabilities

This study examined two key issues: (1) whether there were developmental improvements in eyewitness memory performance for children with intellectual disabilities (ID); and (2) whether standardised measures of cognitive ability and suggestibility would relate to eyewitness recall and suggestibility. Children with ID and age‐matched controls (ages 8/9 and 12 years) watched a video of a crime and were asked a range of open‐ended and specific questions about the event in a subsequent interview. Free recall increased between the two age levels for children with and without ID, but at a faster rate for those without ID. For other question types, differences in performance between children with and without ID were far more marked than age differences. Standardised measures of interrogative suggestibility (Gudjonsson Suggestibility Scale, GSS), verbal IQ, non‐verbal IQ, mental age and speed of information processing were related to eyewitness performance. In particular, higher eyewitness recall scores (free recall, non‐leading specific questions) were related to higher scores on the standardised GSS free recall measure; and higher eyewitness suggestibility scores were related to higher scores on the standardised GSS suggestibility measures. Mental age was a better predictor of performance on a range of eyewitness memory question types than verbal or non‐verbal IQ; and speed of information processing showed some relationships with eyewitness performance. Copyright © 2006 John Wiley & Sons, Ltd.     

Attenuation of change blindness in children with autism spectrum disorders

Change blindness refers to the difficulty most people find in detecting a difference between two pictures when these are presented successively, with a brief interruption between. Attention at the site of the change is required for detection. A number of studies have investigated change blindness in adults and children with autism spectrum disorders (ASD). Some have produced evidence that people with ASD find changes to social stimuli harder to detect and changes to non‐social stimuli easier to detect, relative to comparison participants. However, other studies have produced entirely contradictory findings. There is a need for consistency in methodology to aid understanding of change blindness and attentional processes in ASD. Here, we replicate a change blindness study previously carried out with typically developing (TD) children and adults and with adults with ASD. Results reveal attenuated change blindness for non‐social stimuli in children with ASD relative to TD norms. Our results are interpreted, alongside others' findings, as potentially indicative of a complex relationship between different influences on attention over time.     

Selective and sustained attention in children with spina bifida myelomeningocele

This study examined memory functioning in children and adolescents with 22q11.2 Deletion Syndrome (DS; velocardiofacial syndrome). An overall verbal better than nonverbal memory pattern was evident on the Test of Memory and Learning (TOMAL), with children with 22q11.2 DS performing significantly below their siblings and children with low average IQ but similar to children with autism on facial memory. Children with 22q11 DS also performed significantly below their siblings on tests of verbal working memory. Children with autism performed significantly poorer than the siblings of children with 22q11.2 DS only on their recall of stories. Delayed recall was significantly poorer in children with 22q11.2 DS and children with autism, compared to sibling controls. Although there were no significant group differences on tests of multiple trial verbal or visual learning, a relative weakness was noted with multiple trial visual learning in children with 22q11.2 DS and their siblings, suggesting that an alternative or interactive factor other than the deletion may account for the relatively better verbal compared to nonverbal memory abilities. Deficits in facial memory in children with both 22q11.2 DS and autism suggest disruptions in ventral temporal pathways such as between fusiform gyrus and parahippocampal/hippocampal regions whereas deficits in verbal working memory in children with 22q11.2 DS implicates dorsolateral prefrontal regions, both intimating aberrant white matter pathways.     

Performance on the dimensional change card sort and backward digit span by young children with autism without intellectual disability

The early development of executive function (EF) and its relation to autism symptom expression is of considerable theoretical interest, particularly in children without general cognitive delay. Executive function was tested in 23 children with autism spectrum disorders (ASD) without intellectual disability and 20 age- and IQ-matched typically developing children. Even though performance was equivalent between the two groups on tests of general intelligence, flexibility in card sorting was lower for children with ASD. Verbal working memory during the backward digit span did not differ between groups. Among children with ASD, poorer performance on card sorting distinguished a subgroup with worse social-communication functioning above and beyond IQ. Controlling for IQ social and repetitive symptoms of ASD did not differ based on card sorting ability.     

Musical rhythm discrimination explains individual differences in grammar skills in children

This study considered a relation between rhythm perception skills and individual differences in phonological awareness and grammar abilities, which are two language skills crucial for academic achievement. Twenty‐five typically developing 6‐year‐old children were given standardized assessments of rhythm perception, phonological awareness, morpho‐syntactic competence, and non‐verbal cognitive ability. Rhythm perception accounted for 48% of the variance in morpho‐syntactic competence after controlling for non‐verbal IQ, socioeconomic status, and prior musical activities. Children with higher phonological awareness scores were better able to discriminate complex rhythms than children with lower scores, but not after controlling for IQ. This study is the first to show a relation between rhythm perception skills and morpho‐syntactic production in children with typical language development. These findings extend the literature showing substantial overlap of neurocognitive resources for processing music and language. A video abstract of this article can be viewed at: http://youtu.be/_lO692qHDNg     

Memory and learning in children with 22q11.2 deletion syndrome: evidence for ventral and dorsal stream disruption?

This study examined memory functioning in children and adolescents with 22q11.2 Deletion Syndrome (DS; velocardiofacial syndrome). An overall verbal better than nonverbal memory pattern was evident on the Test of Memory and Learning (TOMAL), with children with 22q11.2 DS performing significantly below their siblings and children with low average IQ but similar to children with autism on facial memory. Children with 22q11 DS also performed significantly below their siblings on tests of verbal working memory. Children with autism performed significantly poorer than the siblings of children with 22q11.2 DS only on their recall of stories. Delayed recall was significantly poorer in children with 22q11.2 DS and children with autism, compared to sibling controls. Although there were no significant group differences on tests of multiple trial verbal or visual learning, a relative weakness was noted with multiple trial visual learning in children with 22q11.2 DS and their siblings, suggesting that an alternative or interactive factor other than the deletion may account for the relatively better verbal compared to nonverbal memory abilities. Deficits in facial memory in children with both 22q11.2 DS and autism suggest disruptions in ventral temporal pathways such as between fusiform gyrus and parahippocampal/hippocampal regions whereas deficits in verbal working memory in children with 22q11.2 DS implicates dorsolateral prefrontal regions, both intimating aberrant white matter pathways.     

The development of route learning in Down syndrome,Williams syndrome and typical development: investigations with virtual environments

The ability to navigate new environments has a significant impact on the daily life and independence of people with learning difficulties. The aims of this study were to investigate the development of route learning in Down syndrome (N = 50), Williams syndrome (N = 19), and typically developing children between 5 and 11 years old (N = 108); to investigate use of landmarks; and to relate cognitive functions to route‐learning ability in these groups. Overall, measures of attention and long‐term memory were strongly associated with route learning, even once non‐verbal ability was controlled for. All of the groups, including 5‐ to 6‐year‐old TD children, demonstrated the ability to make use of all landmark types to aid route learning; those near junctions, those further from junctions, and also distant landmarks (e.g. church spire, radio mast). Individuals with WS performed better than a matched subset of TD children on more difficult routes; we suggest that this is supported by relatively strong visual feature recognition in the disorder. Participants with DS who had relatively high levels of non‐verbal ability performed at a similar level to TD participants.     

Sensitivity to differences between enjoyment and non‐enjoyment smiles in children with autism spectrum disorder

The sensitivity of male children (5–15 years) with and without autism spectrum disorder (ASD) to the affective state of others was tested using an emotion recognition task. Only children without ASD could reliably differentiate between enjoyment and non‐enjoyment smiles. Results are considered in terms of the social impairments of children with ASD.     

Executive functions in children with Autism Spectrum Disorders

Executive dysfunction is a characteristic impairment of individuals with Autism Spectrum Disorders (ASD). However whether such deficits are related to autism per se, or to associated intellectual disability is unclear. This paper examines executive functions in a group of children with ASD (N = 54, all IQ⩾70) in relation to a typically developing control group individually matched on the basis of age, gender, IQ and vocabulary. Significant impairments in the inhibition of prepotent responses (Stroop, Junior Hayling Test) and planning (Tower of London) were reported for children with ASD, with preserved performance for mental flexibility (Wisconsin Card Sorting Task) and generativity (Verbal Fluency). Atypical age-related patterns of performance were reported on tasks tapping response inhibition and self-monitoring for children with ASD compared to controls. The disparity between these and previous research findings are discussed. A multidimensional notion of executive functions is proposed, with difficulties in planning, the inhibition of prepotent responses and self-monitoring reflecting characteristic features of ASD that are independent of IQ and verbal ability, and relatively stable across the childhood years.     

Executive functions in children with Autism Spectrum Disorders

Executive dysfunction is a characteristic impairment of individuals with Autism Spectrum Disorders (ASD). However whether such deficits are related to autism per se, or to associated intellectual disability is unclear. This paper examines executive functions in a group of children with ASD (N = 54, all IQ?70) in relation to a typically developing control group individually matched on the basis of age, gender, IQ and vocabulary. Significant impairments in the inhibition of prepotent responses (Stroop, Junior Hayling Test) and planning (Tower of London) were reported for children with ASD, with preserved performance for mental flexibility (Wisconsin Card Sorting Task) and generativity (Verbal Fluency). Atypical age-related patterns of performance were reported on tasks tapping response inhibition and self-monitoring for children with ASD compared to controls. The disparity between these and previous research findings are discussed. A multidimensional notion of executive functions is proposed, with difficulties in planning, the inhibition of prepotent responses and self-monitoring reflecting characteristic features of ASD that are independent of IQ and verbal ability, and relatively stable across the childhood years.     

Toddlers with Elevated Autism Symptoms Show Slowed Habituation to Faces

We explored social information processing and its relation to social and communicative symptoms in toddlers with Autism Spectrum Disorder (ASD) and their siblings. Toddlers with more severe symptoms of autism showed slower habituation to faces than comparison groups; slower face learning correlated with poorer social skills and lower verbal ability. Unaffected toddlers who were siblings of children with ASD also showed slower habituation to faces compared with toddlers without siblings with ASD. We conclude that slower rates of face learning may be an endophenotype of ASD and is associated with more severe symptoms among affected individuals.     

An investigation of first‐order false belief understanding of children with congenital profound visual impairment

This study assessed theory of mind understanding in children with congenital profound visual impairment (CPVI): children who have had no access to visual information throughout development. Participants were 18 children with CPVI and no other impairments, aged between 5 and 11 years, and 18 children with normal vision, matched individually on chronological age, verbal IQ and verbal mental age. Three first‐order false belief tasks were presented twice each; the three tasks varied in the extent of deception and involvement of the child. Six of the children with CPVI failed one or more of the false belief tasks; all sighted children passed all of the tasks. The manipulations of deception and involvement did not influence the performance of the children with CPVI. Participant characteristics of the children with CPVI were examined in relation to their performance on the false belief tasks: chronological age and type of school attended were not found to be related to performance; verbal IQ and verbal mental age were found to differ in children with good and poor performance on the false belief tasks. The results are consistent with either a general pattern of delay in theory of mind development for children with CPVI, or with a subset of children who have longer‐term difficulties in this area.     

Changing abilities in recognition of unfamiliar face photographs through childhood and adolescence: Performance on a test of non‐verbal immediate memory (Warrington RMF) from 6 to 16 years

A commonly used test of non‐verbal memory, which measures recognition for unfamiliar face pictures, was developed by Warrington (1984) , the Recognition Memory for Faces (RMF) test. The task has been widely used in adults in relation to neurological impairment of face recognition. We examined the relationship of RMF scores to age in 500 young people aged between 6 and 16 years. A linear relationship obtained between 6 and 10 years, followed by a ‘plateau’ between the ages of 10 and 13, followed by further improvement. Abilities on the test correlated with both verbal and non‐verbal intelligence, but the nonlinear function relating age and RMF survived partialling for intelligence in the younger age groups. The improvement of the adolescents compared with older children also survived partialling for IQ. We found no significant influence of gender or reported pubertal status (which was not obtained for all participants) on RMF once age was taken into account. Performance on other face‐processing tasks (emotion classification and accuracy in line of sight detection) correlated significantly, if moderately, with RMF scores. Despite its age and imperfections, RMF test may nevertheless be a useful indicator of ‘face expertise’ in a developmental context.     

Adaptive training leads to sustained enhancement of poor working memory in children

Working memory plays a crucial role in supporting learning, with poor progress in reading and mathematics characterizing children with low memory skills. This study investigated whether these problems can be overcome by a training program designed to boost working memory. Children with low working memory skills were assessed on measures of working memory, IQ and academic attainment before and after training on either adaptive or non‐adaptive versions of the program. Adaptive training that taxed working memory to its limits was associated with substantial and sustained gains in working memory, with age‐appropriate levels achieved by the majority of children. Mathematical ability also improved significantly 6 months following adaptive training. These findings indicate that common impairments in working memory and associated learning difficulties may be overcome with this behavioral treatment.