Executive Function Across Syndromes Associated with Intellectual Disabilities: A Developmental Perspective

Executive function (EF) is a general construct used to represent brain functions related to the conscious control of thought and action. This chapter reviews literature that supports the notion of a componential view of EF, as some disorders were associated with developmentally appropriate performance on some areas of EF, but not others. For example, individuals with Down syndrome were as able as developmentally matched peers in areas related to working memory and inhibition, but were clearly impaired in their abilities to switch flexibly between mental sets. This sparing of certain areas (in relation to developmental level) is inconsistent with the notion of a unitary view, which would imply that difficulty in one area of EF would mean difficulty in all areas of EF. Although the findings reviewed here still leave open the question of whether some combination of unitary and componential views is correct, the chapter provides evidence to suggest that a purely unitary view is unlikely.