Early Screen Time Shapes Children’s Brains and Behavior

Children who spent more time on screens before age two later showed changes in brain development that were linked to slower decision-making and higher anxiety in adolescence in a longitudinal study led by researchers from A*STAR Singapore using data from the GUSTO cohort. The research followed the same group of children for over ten years, with brain imaging at several stages, and mapped a possible pathway linking early screen exposure to mental health outcomes in the teenage years. The work focuses infancy as it is a period of rapid, highly sensitive brain development, during which screen use is mainly determined by parental and caregiver awareness and parenting practices.

The team tracked 168 children and conducted brain scans at ages 4.5, 6, and 7.5 to observe how brain networks changed over time instead of relying on a single scan. Children with higher screen exposure in infancy showed accelerated maturation of brain networks involved in visual processing and cognitive control, which the researchers suggest may reflect the intense sensory input from screens. Screen use measured at ages three and four did not show similar effects, underscoring the particular importance of the first two years of life.

According to Huang Pei, first author of the paper published in eBioMedicine, "Accelerated maturation happens when certain brain networks develop too fast, often in response to adversity or other stimuli. During normal development, brain networks gradually become more specialized over time. However, in children with high screen exposure, the networks controlling vision and cognition specialized faster, before they had developed the efficient connections needed for complex thinking. This can limit flexibility and resilience, leaving the child less able to adapt later in life."

This premature specialization appeared to reduce flexibility and resilience and was associated with slower decision-making at age 8.5 on a cognitive task. Children who took longer to make decisions then reported more anxiety symptoms at age 13, suggesting that infant screen use can have long-lasting effects on both brain function and behavior.