Sleep Restriction in Children and Executive Function Performance
Abstract
Experimental sleep restriction yields data that shows how sleep loss causes declining daytime function in cognition and behaviour, yet few experimental studies have been conducted with preschool children between the ages of 3 and 5 years of age. During the preschool period children achieve important milestones in cognitive development while a significant minority also experience behavioural sleep problems regularly. There is no empirically-based consensus on the impact of reduced sleep in preschool children. To address this gap, parents of preschool children were recruited in a participatory design study to provide input in designing an accessible home-based experimental sleep study with conditions of sleep restriction and sleep fragmentation. Child participants in the experimental study wore actigraphs for 10 days to record their sleep during 7 days of baseline measurement, followed by 3 days of experimental measurement. Children were randomly assigned to a control condition, a 40-minute or 20-minute sleep restriction condition, or to a sleep fragmentation condition where they were kept awake for 20 minutes after first falling asleep. Daytime cognitive outcomes were assessed after the third experimental night using an assessment battery of developmentally-appropriate executive function measures of working memory, response inhibition, and delay of gratification. Contrary to expectation, less sleep relative to baseline was not associated with measured executive function performance decrements among children without pre-existing sleep problems. Experimentally imposing greater sleep restriction before assessment may be necessary to measure changes in executive functioning measures for this age group.