Relation between nighttime sleep duration and executive functioning in a nonclinical sample of preschool children.

Sleep is a support for cognitive development in childhood. Most of the studies in the field have focused on school-age children and sleep problems, but less research focuses on the relation between the normative course of sleep and executive functions in preschoolers. Thus, the aim of the present study was to analyze the association between nighttime sleep duration and executive functioning in a 158 non-clinical sample of Spanish participants (M  = 56.35 months, SD = 11.24; ages 38-78 months; 48.1% girls). Sleep habits were measured by parents' self-reports; Shape School task was applied to assess inhibition and cognitive flexibility; Word Span task was used to assess working memory; and Vocabulary subtest from the Wechsler Preschool and Primary Scale of Intelligence-III was used to assess verbal ability. The findings revealed that the relation between sleep and executive functioning was only significant in the cases of inhibition and working memory. Further, age and verbal ability were related and were predictors of inhibition, working memory, and cognitive flexibility. We consider it necessary to continue researching in this area given the importance of forming a correct sleep habit during the preschool age and its impact on health, cognition, and well-being in childhood. In short, our results represent the first approach to the subject under study, which should be completed with objective sleep measures.