The Relationship Between Theory of Mind and Executive Function in a Sample of Children from Mainland China

To explore the relationship between theory of mind (ToM) and executive function (EF) in a sample of individuals from mainland China, 20 children with autism spectrum disorders (ASD), 26 children with Attention Deficit Hyperactivity Disorder (ADHD), and 30 normal control subjects were compared on two batteries of ToM tasks and EF tasks. Children with ASD had a significant theory of mind impairment relative to the other controls, while non-verbal IQ removed group differences in executive function. ToM was significantly correlated with inhibitory control. Performance on inhibitory control tasks, however, did not affect performance on ToM tasks.     

Event-based prospective memory in children with autism spectrum disorder: The role of executive function

The present study investigated event-based prospective memory (PM) and its cognitive correlates in children with autism spectrum disorder (ASD) compared to age- and ability-matched typically developing (TD) peers. Participants included 25 children with ASD, 25 age-matched TD peers, and 28 ability-matched TD peers. Participants completed one PM task, and several executive functioning tasks assessing working memory (Block Recall Task), inhibitory control (Stroop Task), and cognitive flexibility (Dimensional Change Card Sorting Task). Results indicated that children with ASD had significantly lower scores on the PM task than children in the TD groups. Additionally, PM performance of children with ASD was significantly predicted by their nonverbal IQ, whereas PM performance of TD children was significantly predicted by their inhibitory control. These results provide evidence for the PM deficit in children with ASD and the effect of cognitive functioning, rather than a specific aspect of executive function, on the development of PM.     

Neural correlates of executive function in autistic spectrum disorders.

BACKGROUND: Some clinical characteristics of high-functioning individuals with autistic spectrum disorder (ASD) such as repetitive stereotyped behaviors, perseveration, and obsessionality have been related to executive function (EF) deficits, more specifically to deficits in inhibitory control and set shifting and mediating frontostriatal neural pathways. However, to date, no functional imaging study on ASD has investigated inhibition and cognitive flexibility and no one has related EF brain activation to brain structure. METHODS: We compared brain activation (using functional magnetic resonance imaging) in 10 normal intelligence adults with ASD and 12 healthy control subjects during three different EF tasks: 1) motor-inhibition (GO/NO-GO); 2) cognitive interference-inhibition (spatial STROOP); and 3) set shifting (SWITCH). Using voxel-based morphometry, we investigated if cortical areas which were functionally different in people with ASD were also anatomically abnormal. RESULTS: Compared with control subjects, ASD individuals showed significantly increased brain activation in 1) left inferior and orbital frontal gyrus (motor-inhibition); 2) left insula (interference-inhibition); and 3) parietal lobes (set shifting). Moreover, in individuals with ASD, increased frontal gray matter density and increased functional activation shared the same anatomical location. CONCLUSIONS: Our findings suggest an association between successful completion of EF tasks and increased brain activation in people with ASD, which partially may be explained by differences in brain anatomy.     

Executive functions in savant artists with autism

Although executive functions have been widely studied in individuals with autism spectrum disorders (ASD), there have been no direct empirical studies of executive abilities in savants with ASD. This study assessed three facets of executive ability (fluency, perseveration and monitoring) in savant artists with ASD, compared to non-talented adults with ASD or mild/moderate learning difficulties (MLD). Executive functions were assessed in and out of the savants’ domain of expertise: on design fluency and card sort tasks, respectively. The design fluency task suggested a sparing of executive abilities in the savant artists, relative to the non-talented ASD group; an effect not observed on the card sort task. The idea that islets of ability involve functions that are protected from more general cognitive deficits in ASD is explored.     

Étude des profils cognitifs chez les apparentés de personnes avec autisme : hypothèse d’un manque de flexibilité cognitive ?

This study investigated whether first-degree relatives of individuals with autism spectrum disorders (ASD) demonstrate a specific profile of performance on the three cognitive domains studied in the disorders: executive function, central coherence and theory of mind. Parents and siblings of the children with ASD showed poorer performances on all tests, than control, (p > 0.02); furthermore, lack of cognitive flexibility emerged as a potential marker in ASD families, suggesting that this aspect should be further study, as playing a potential role in cognitive theories of autism.     

Brief Report: Further Evidence for a Link Between Inner Speech Limitations and Executive Function in High-Functioning Children with Autism Spectrum Disorders

This study investigated the involvement of inner speech limitations in the executive dysfunction associated with autism spectrum disorders (ASDs). Seventeen children with ASD and 18 controls, statistically-matched in age and IQ, performed a computer-based card sorting test (CST) to assess cognitive flexibility under four conditions: baseline, with articulatory suppression, with a concurrent mouthing task, and while verbalizing their strategies aloud. Articulatory suppression adversely affected CST performance for the control group but not the ASD group. The results additionally showed that overtly verbalizing strategies did not benefit the ASD children as it did the typically developing children. The findings thus provide further evidence that ASD children do not use inner speech to the same extent, or with the same effectiveness, as typically developing children when performing executive tasks.     

Brief Report: Impaired Flexible Item Selection Task (FIST) in School-Age Children with Autism Spectrum Disorders

Cognitive flexibility has been measured with inductive reasoning or explicit rule tasks in individuals with autism spectrum disorders (ASD). The Flexible Item Selection Task (FIST) differs from previous cognitive flexibility tasks in ASD research by giving children an abstract, ambiguous rule to switch. The ASD group (N = 22; Mean age = 8.28 years, SD = 1.52) achieved a lower shift percentage than the typically developing verbal mental-age control group (N = 22; Mean age = 6.26 years, SD = 0.82). There was a significant positive correlation between verbal mental age and shift percentage for children with ASD. Group differences on the FIST converge and extend prior evidence documenting an impaired ability to adapt rapidly to changes in task demands for individuals with ASD.     

Noradrenergic moderation of working memory impairments in adults with autism spectrum disorder

In addition to having difficulties with social communications, individuals with an autism spectrum disorder (ASD) often also experience impairment in higher-order, executive skills. The present study examined the effects of pharmacological modulation of the norepinephrine system on the severity of such impairments. A sample of 14 high-functioning adults with ASD and a demographically-matched comparison group of 13 typically developing individuals participated. An AX continuous performance test (AX-CPT) was used to evaluate working memory and inhibitory control. AX-CPT performance was assessed following administration of a single dose of propranolol (a beta adrenergic antagonist) and following placebo (sugar pill) administration. Individuals with ASD performed more poorly than non-ASD individuals in the working memory condition (BX trials). Importantly, administration of propranolol attenuated this impairment, with the ASD group performing significantly better in the propranolol condition than the placebo condition. Working memory performance of the non-ASD group was unaffected by propranolol/placebo administration. No group or medication effects were observed for the inhibition condition (AY trials). The present findings suggest that norepinephrine may play a role in some, but not necessarily all, cognitive impairments associated with ASD. Additional research is needed to fully understand whether this role is primarily causal or compensatory in nature.     

Spatial Cognition in Autism Spectrum Disorders: Superior,Impaired, or Just Intact?

The profile of spatial ability is of interest across autism spectrum disorders (ASD) because of reported spatial strengths in ASD and due to the recent association of Asperger’s syndrome with Nonverbal Learning Disability. Spatial functions were examined in relation to two cognitive theories in autism: the central coherence and executive function (EF) theories. Performance on spatial tasks, EFs, and global/local processing was compared in children with ASD and controls. While the ASD group had faster reaction times on the Embedded Figures task, spatial performance was intact, but not superior, on other tasks. There was no evidence for impairments in EF or in processing global/local information, therefore contradicting these two theories. The implications of these results for these two theories are discussed.     

Executive and Visuo-motor Function in Adolescents and Adults with Autism Spectrum Disorder

This study broadly examines executive (EF) and visuo-motor function in 30 adolescent and adult individuals with high-functioning autism spectrum disorder (ASD) in comparison to 28 controls matched for age, gender, and IQ. ASD individuals showed impaired spatial working memory, whereas planning, cognitive flexibility, and inhibition were spared. Pure movement execution during visuo-motor information processing also was intact. In contrast, execution time of reading, naming, and of visuo-motor information processing tasks including a choice component was increased in the ASD group. Results of this study are in line with previous studies reporting only minimal EF difficulties in older individuals with ASD when assessed by computerized tasks. The finding of impaired visuo-motor information processing should be accounted for in further neuropsychological studies in ASD.     

An event-related potential and behavioral study of impaired inhibitory control in children with autism spectrum disorder

Autism spectrum disorders (ASD) are characterized by a deficit of dorsal visual stream processing as well as the impairment of inhibitory control capability. However, the cognitive processing mechanisms of executive dysfunction have not been addressed. In the present study, the endogenous Posner paradigm task was administered to 15 children with ASD and 16 typically developing (TD) children to simultaneously investigate and compare the behavioral performance and event-related potentials (ERPs) measures. Children with ASD showed slower reaction time in the incongruent condition but did not significantly differ in the overall conditions and in response accuracy as compared to TD children. The ASD group also exhibited significant impairment on measures of inhibitory control. In terms of ERPs regarding early and late inhibition, there were no significant differences found with regard to N2 latency, N2 amplitude, and P3 amplitude in children with ASD relative to TD children, but the ASD group manifested prolonged latency on the P3 component to target stimuli, especially in the incongruent condition, which is indicative of slow and inefficient stimulus classification speed as compared to TD children.     

Co-segregation of Social Cognition, Executive Function and Local Processing Style in Children with ASD, their Siblings and Normal Controls

Cognitive research proposes that social cognition (SC), executive functions (EF) and local processing style (weak CC) may be fruitful areas for research into the familial-genetic underpinnings of Autism Spectrum Disorders (ASD). The performance of 140 children with ASD, 172 siblings and 127 controls on tasks measuring SC (face recognition, affective prosody, and facial emotion recognition), EF (inhibition, cognitive flexibility, and verbal working memory) and local processing style was assessed. Compelling evidence was found for the interrelatedness of SC and EF, but not local processing style, within individuals and within families, suggesting that these domains tend to co-segregate in ASD. Using the underlying shared variance of these constructs in genetic research may increase the power for detecting susceptibility genes for ASD.     

Caudate nucleus volume and cognitive performance: Are they related in childhood psychopathology?

BACKGROUND: Impaired neuropsychological test performance, especially on tests of executive function and attention, is often seen in children diagnosed with autism spectrum disorders (ASD). Structures involved in fronto-striatal circuitry, such as the caudate nucleus, may support these cognitive abilities. However, few studies have examined caudate volumes specifically in children with ASD, or correlated caudate volumes to cognitive ability. METHODS: Neuropsychological test scores and caudate volumes of children with ASD were compared to those of children with bipolar disorder (BD) and of typically developing (TD) children. The relationship between test performance and caudate volumes was analyzed. RESULTS: The ASD group displayed larger right and left caudate volumes, and modest executive deficits, compared to TD controls. While caudate volume inversely predicted performance on the Wisconsin Card Sorting Test in all participants, it differentially predicted performance on measures of attention across the ASD, BD and TD groups. CONCLUSIONS: Larger caudate volumes were related to impaired problem solving. On a test of attention, larger left caudate volumes predicted increased impulsivity and more omission errors in the ASD group as compared to the TD group, however smaller volume predicted poorer discriminant responding as compared to the BD group.     

Brief Report: Episodic Foresight in Autism Spectrum Disorder

Episodic foresight (EpF) or, the ability to imagine the future and use such imagination to guide our actions, is an important aspect of cognition that has not yet been explored in children with autism spectrum disorder (ASD). This is despite its proposed links with theory of mind (ToM) and executive function (EF), two areas found to be impaired in ASD. Twenty-five children with ASD (M = 5 years, 10 months; 22 male) and 25 mental-age-matched typically developing children (M = 4 years, 10 months; 22 male) completed a series of EpF, ToM, and EF tasks. Significant group differences were detected on several EpF tasks suggesting that children with ASD show impairments in thinking about their future selves.     

Executive processes in Asperger syndrome: patterns of performance in a multiple case series

Mixed evidence exists for executive dysfunction in autism spectrum disorders (ASD). This may be because of the nature of the tasks used, the heterogeneity of participants, and difficulties with recruiting appropriate control groups. A comprehensive battery of ‘executive’ tests was administered to 22 individuals with Asperger syndrome and 22 well-matched controls. Performance was analysed both between groups and on an individual basis to identify outliers in both the ASD and control groups. There were no differences between the groups on all ‘classical’ tests of executive function. However, differences were found on newer tests of executive function. Specifically, deficits in planning, abstract problem solving and especially multitasking. On the tests that discriminated the groups, all of the ASD individuals except one were identified as significantly impaired (i.e. below the 5th percentile of the control mean) on at least one executive measure. This study provides evidence for significant executive dysfunction in Asperger syndrome. Greatest dysfunction appeared in response initiation and intentionality at the highest level—the ability to engage and disengage actions in the service of overarching goals. These deficits are best observed through using more recent, ecologically valid tests of executive dysfunction. Moreover, performance on these measures correlated with autistic symptomatology.     

Abnormalities in the anterior cingulate cortex associated with attentional and inhibitory control deficits: A neurophysiological study on children with autism spectrum disorders

Previous studies showed that the anterior cingulate cortex (ACC) is activated when individuals engage in attention and inhibitory control tasks. The present study examined whether ACC activity is associated with behavioral performance of the two tasks. Twenty normal and 20 children with autism spectrum disorders (ASDs) were subjected to neuropsychological assessments on attention and inhibitory control, as well as electroencephalography recording. Children with ASD performed significantly worse than normal children on attention tasks as shown in their poorer performance on the Digit Span test, the greater number of Omission Errors on both the Continuous Performance Test II and the Go/No-Go tasks. They also performed significantly worse than normal children on inhibitory control tasks as shown by the greater number of False Alarms on the Object Recognition and Hong Kong List Learning Test. Their ACC activities, as indicated by relative theta power, were found to be significantly lower than those of normal controls during performance of the Go/No-Go task. Depressed ACC activities were further found to be significantly associated with poorer performance in attention and inhibition. Clinical implications on the use of theta activities in the ACC as an indicator to monitor intervention progress in children with ASD were discussed.     

Advantages of the multiple case series approach to the study of cognitive deficits in autism spectrum disorder

In the neuropsychological case series approach, tasks are administered that tap different cognitive domains, and differences within rather than across individuals are the basis for theorising; each individual is effectively their own control. This approach is a mainstay of cognitive neuropsychology, and is particularly suited to the study of populations with heterogeneous deficits. However it has very rarely been applied to the study of cognitive differences in autism spectrum disorder (ASD). Here, we investigate whether this approach can yield information beyond that given by the typical group study method, when applied to an ASD population. Twenty-one high-functioning adult ASD participants and 22 IQ, age, and gender-matched control participants were administered a large battery of neuropsychological tests that would represent a typical neuropsychological assessment for neurological patients in the United Kingdom. The data were analysed using both group and single-case study methods. The group analysis revealed a limited number of deficits, principally on tests with a large executive function component, with no impairment in more routine abilities such as basic attending, language and perception. Single-case study analysis proved more fruitful revealing evidence of considerable variation in abilities both between and within ASD participants. Both sub-normal and supra-normal performance were observed, with the most defining feature of the ASD group being this variability. We conclude that the use of group-level analysis alone in the study of cognitive deficits in ASD risks missing cognitive characteristics that may be vitally important both theoretically and clinically, and even may be misleading because of averaging artifact.     

Evaluation of Planning Dysfunction in Attention Deficit Hyperactivity Disorder and Autistic Spectrum Disorders Using the Zoo Map Task

Attention-Deficit-Hyperactivity-Disorders (ADHD) and Autistic-Spectrum-Disorders (ASD) share overlapping clinical and cognitive features that may confuse the diagnosis. Evaluation of executive problems and planning dysfunction may aid the clinical diagnostic process and help disentangle the neurobiological process underlying these conditions. This study evaluates the planning function problems in 80 male children and adolescents diagnosed with ADHD and 23 male children and adolescents with ASD using the Zoo Map Task; both groups were comparable in terms of age and IQ. The relationship between planning function and other executive functions is also assessed. In comparison to the ADHD groups, ASD children presented more errors in the open-ended tasks; these planning function problems seem to be mediated by processing speed and motor coordination, however it does not seem to be mediated by other executive function problems, including attention, working memory or response inhibition. In the time for planning, an interaction between the specific subgroups and working memory components was observed. ADHD and ASD present with different patterns of planning function, even when other components of executive function are taken into account; clinical and educational implications are discussed.     

Inhibitory mechanisms in Down syndrome: Is there a specific or general deficit?

The cognitive profile of individuals with Down syndrome (DS) is known to be characterized by an impaired executive functioning, but inhibition-related processes have not been extensively examined in this setting. The aim of the present study was to investigate whether individuals with DS have any specific or general deficit in inhibitory processes. Tasks measuring prepotent response inhibition (the animal Stroop test), proactive interference (proactive interference task and intrusion errors), and response to distracters (directed forgetting task) were administered together with a working memory test to 19 individuals with DS and 19 typically developing (TD) children matched for mental age. Confirming previous findings, our results showed that the DS group performed less well in a verbal working memory task than the TD children. Analyzing our findings for the three inhibitory tasks yielded a picture of the DS children having a generalized difficulty in suppressing information that is irrelevant, or no longer relevant, to the goals of the task. These results suggest that DS is related not to specific, but rather to generalized inhibitory difficulties.     

Inhibitory mechanisms in Down syndrome: Is there a specific or general deficit?

The cognitive profile of individuals with Down syndrome (DS) is known to be characterized by an impaired executive functioning, but inhibition-related processes have not been extensively examined in this setting. The aim of the present study was to investigate whether individuals with DS have any specific or general deficit in inhibitory processes. Tasks measuring prepotent response inhibition (the animal Stroop test), proactive interference (proactive interference task and intrusion errors), and response to distracters (directed forgetting task) were administered together with a working memory test to 19 individuals with DS and 19 typically developing (TD) children matched for mental age. Confirming previous findings, our results showed that the DS group performed less well in a verbal working memory task than the TD children. Analyzing our findings for the three inhibitory tasks yielded a picture of the DS children having a generalized difficulty in suppressing information that is irrelevant, or no longer relevant, to the goals of the task. These results suggest that DS is related not to specific, but rather to generalized inhibitory difficulties.