The Goodnight Screen Media Study

The goal of the study is to test the effect of tablet use before bed on the sleep, circadian phase, and executive functioning (EF) of 4-year-olds using a 3-group randomized controlled trial in which children are assigned to receive one of 2 experimental conditions (Group A:1 hour of tablet use in the hour before bed; Group B:1 hour of tablet use 2 hours before bed) or a control condition (no evening screen media use). It is hypothesized that in comparison to no tablet use, daily exposure to tablet use before bed will be associated with a delay in children's circadian phase (e.g., occurring later in the evening/night), a longer sleep latency (i.e., later sleep onset), and shorter sleep duration. It is anticipated that tablet use in the hour before bed will have a greater impact on children's circadian phase and sleep than tablet use 2 hours before bed, or no tablet use before bed. We will explore whether changes in circadian phase and sleep result in poorer performance on measures of EF (i.e., inhibitory control and working memory).