Sleep and Executive Functioning Among High-IQ School-Aged Children with Autism

Background: Among typically developing children sleep has been related to executive function (e.g., Karpinski et al., 2008; Beebe et al., 2004) and sleep disorders are more common among children with autism spectrum disorders (ASD) (Humphreys et al., 2013). To our knowledge, there have been no published investigations of sleep and executive control in children with ASD.

Objectives: To test whether young, high-IQ children with ASD differ from typically developing comparison children in parent reported sleep duration and sleep problems, and to test whether sleep is related to executive function among children with ASD.  

Methods: Data collection is ongoing. To date, 34 6- to 11-year-olds with ASD and 36 age-matched controls participated. All children had cognitive ability in the average or above average range. Parent report of sleep was measured via the Child’s Sleep Habits Questionnaire (CSHQ; Owens et al., 2000) for 40 children. Sleep duration was collected from an additional 30 children who completed the executive function battery. The executive function battery included the Backward Digit Span and Stroop tasks, and parent report via the Behavioral Rating Inventory of Executive Function (BRIEF). 

Results: Preliminary results suggest children with ASD had greater sleep-related anxiety, t(38) = 2.52, p < .001, night waking, t(38) = 1.33, p = .01, parasomnias, t(38) = 2.48, p = .02, sleep-disordered breathing, t(38) = 1.25, p < .01 and daytime sleepiness, t(38) = 3.42, p = .02. Scores on sleep duration, bedtime resistance, and sleep onset delay did not differ. Among the group with ASD, children who slept less had more parent-reported difficulty regulating their behavior, r(34)= -.38, p = .03. Children with higher levels of bedtime resistance had more executive dysfunction, r(16)= .53, p = .03, and difficulties with behavioral regulation, r(16)= .63, p < .01. Children with ASD who had reduced sleep duration had more executive difficulties, r(16)= -.77, p < .001, behavioral dysregulation, r(16)= -.71, p < .01, and difficulty with metacognition, r(16)= -.62, p = .01. Children with reduced sleep onset delays had better working memory ability on the backward digit span, r(15)= -.54, p < .04. During the Stroop task, children who had more night waking had reduced accuracy, r(11)= -.71, p = .01 and slower response times, r(11)= .68, p = .02, during the conflict condition. 

Conclusions: Consistent with previous findings, compared to typically developing children, young school-aged children with ASD and IQ in the average range or above had higher levels of parent-reported sleep-related anxiety, night waking, parasomnias, sleep disordered breathing, and daytime sleepiness. Within the group with ASD, sleep duration and resistance to falling asleep related to parent report of behavioral regulation and executive dysfunction. Performance on working memory and inhibition tasks also corresponded with sleep. The ability to fall asleep quickly corresponded with better working memory, whereas the ability to remain asleep through the night corresponded with better accuracy and efficiency inhibiting conflicting information. These preliminary results suggest that more investigation is needed to understand how sleep disruptions are related to poor executive function in children with ASD.