The Wisconsin Card Sorting Task (WCST) is the only cognitive flexibility task that has consistently shown deficits in individuals with an autism spectrum disorder (ASD). As this is the only task characterized by limited explicit task instructions and a high degree of disengagement required to perform the switch, we hypothesized that cognitive…

This paper examines the neurobiology of fluid cognitive functions of the prefrontal cortex and considers learning disability as a specific example of a group of developmental disorders characterized by fluid skills impairment in the presence of crystallized intelligence in the normal range. Research indicating fluid cognitive impairments in…

Dysexecutive syndrome has been consistently reported in children and adolescents with autism spectrum disorders (ASD). Particularly, impairments have been documented in working memory, inhibition, and mental flexibility. However, the relationship between executive impairments and intellectual functioning is far from clear in this population. This…

Background: Executive functions (EF) impairments have long been observed in children and youths with autism spectrum disorders (ASD). Until very recently, little attention has been paid to examine EF profiles of adults with ASD. Given the importance of EF to cope with the demands of daily life and participate in society (e.g. maintaining an…

This study used data from six neuropsychological measures of executive function (EF) and general intellectual functioning (GIF) administered to 303 regular users of heroin and/or cocaine as indicators in a latent profile analysis (LPA). Results indicated the presence of three profiles: impaired GIF and EF profile (30.8%), intact GIF and EF profile…

More than 20?years ago, Minshew and colleagues proposed the Complex Information Processing model of autism in which the impairment is characterized as a generalized deficit involving multiple modalities and cognitive domains that depend on distributed cortical systems responsible for higher order abilities. Subsequent behavioral work revealed a…

We conducted a meta-analysis of 31 studies, spanning 30 years, utilizing the WCST in participants with autism. We calculated Cohen's d effect sizes for four measures of performance: sets completed, perseveration, failure-to-maintain-set, and non-perseverative errors. The average weighted effect size ranged from 0.30 to 0.74 for each measure, all…

Autism spectrum disorder (ASD) is characterised by profound difficulties in empathic processing and executive control. Whilst the links between these processes have been frequently investigated in populations with autism, few studies have examined them at the subclinical level. In addition, the contribution of alexithymia, a trait characterised by…

Reading disability (RD) and math disability (MD) frequently co-occur, but the etiology of this comorbidity is not well understood. Groups with RD only (N = 241), MD only (N = 183), and RD + MD (N = 188) and a control group with neither disorder (N = 411) completed a battery of measures of internalizing and externalizing psychopathology, social and…

This study reports on the relationship between motor stereotypies and impairments in executive functions (EF) in children with Autistic Disorder (AD) and in children with Developmental Language Disorders (DLD). We hypothesized that low EF performance would predict higher frequency and longer durations of stereotypies in the AD group only.…

The ability to adapt behavior in a changing environment is necessary for humans to achieve their goals and can be measured in the lab with tests of rule-based switching. Disease models, such as cocaine addiction, have revealed that alterations in dopamine interfere with adaptive set switching, culminating in perseveration. We explore perseverative…

Semantic short-term memory (STM) patients have a reduced ability to retain semantic information over brief delays but perform well on other semantic tasks; this pattern suggests damage to a dedicated buffer for semantic information. Alternatively, these difficulties may arise from mild disruption to domain-general semantic processes that have…

Adolescents with dyslexia exhibit well-established impairments in executive abilities. The Wisconsin card sorting test (WCST) is an executive test that yields surprisingly inconsistent results with this population. The current study aimed to shed light on the contradictory findings in the literature regarding the performance levels by individuals…

Recent fMRI and TMS studies on idiom comprehension have shown that the prefrontal cortex is involved in idiom processing. Since schizophrenic patients exhibit prefrontal "structural" changes and dysexecutive "behavioural" deficits, we hypothesised an impairment in idiom comprehension, correlating with performance on executive…

Recently researchers have begun to explore the extent to which children's cognitive development is influenced by experiences in the family environment. Assessing mother-child dyads exposed to intimate partner violence (IPV), a population at risk for emotional and neurocognitive problems, we examined relationships between maternal emotional…