Objectives: The aim of our study is to assess which EF measures provide good endophenotype candidates for ASD.
Methods: We developed a battery of tasks measuring each EF domain as purely as possible, containing at least two tasks per domain. This battery was administered from children with ASD (n=62), their unaffected siblings (n=38) and parents (n=91), and typically developing (TD) children (n=63) and adults (n=61).
Results: Preliminary analyses comparing 48 ASD and 48 TD children matched for age, IQ and gender, show that ASD children have problems with cognitive flexibility, inhibition and working memory. Their difficulties with cognitive flexibility were expressed as more errors on switch compared to repeat trials in one flexibility task (p < 0.01) and a higher reaction time on switch compared to repeat trials on another task measuring flexibility (p = 0.04). The group differences in inhibition and working memory depended on the task. On one inhibition task ASD children made more inhibition errors (Go/No-Go task, p = 0.03), while on another inhibition task (flanker task) no significant group differences were found. Concerning their working memory capacities, we only observed group differences on the most difficult working memory task (p = 0.02), but not on the other task. So far, no group differences in planning and generativity were found, but not all generativity tasks have yet been analyzed.
Conclusions: We have found evidence that problems with cognitive flexibility, inhibition and working memory are potentially useful ASD endophenotypes, since they co-occur with the disorder. However, we still need to evaluate whether these features are also expressed at a higher rate in their siblings and parents than in the general population. In addition, cluster analyses will be applied to evaluate whether more homogeneous ASD subgroups can be delineated based on their EF performance. At the time of the conference the results of these additional analyses will also be available.
See more of: Cognition and Behavior
See more of: Symptoms, Diagnosis & Phenotype