Longitudinal associations of subjectively-measured physical activity and screen time with cognitive development in young children

To examine the longitudinal associations of subjectively-measured physical activity (PA) and screen time with multiple domains of cognitive development in a sample of young children. Participants were 96 children (baseline age: 3.69 ± 0.78 years) and their parents from Edmonton, Canada in the Physical Activity and Cognition in Early Childhood (PACE) study. Different types of PA (organized, non-organized) and screen time (television viewing, video games) were measured using a parental questionnaire at baseline and at 6- and 12-month follow-ups. Total proxy-reported PA, total screen time, and meeting/not meeting the screen time recommendations (2–4 years: ≤1 h/d; 5 years: ≤2 h/d) of the Canadian 24-Hour Movement Guidelines were also calculated. Working memory (Nebraska Barnyard task) and inhibitory control (Fish-Shark Go/No-Go task) were assessed at the three time points. Intellectual ability, including language development, inductive reasoning, and perceptual speed, were assessed using the Woodcock-Johnson III test battery at 6- and 12-month follow-ups. Multilevel growth modeling was conducted. Organized PA (B = 1.26; 95%CI: 0.19,2.33), non-organized PA (B = 0.89, 95%CI: 0.08, 1.71), and total proxy-reported PA (B = 1.03, 95%CI: 0.41,1.66) were positively associated with intellectual ability. In particular, positive associations in regard to language development and inductive reasoning were observed. As for screen time, most associations were not significant, except for positive associations of meeting the screen recommendation with intellectual ability (B = 3.19; 95%CI: 0.002,6.38) and language development (B = 4.32; 95%CI: 0.34,8.30). For young children, promoting PA participation in organized and non-organized activities, as well as meeting the screen time recommendations, appears important for cognitive development.