Screentime & the Developing Brain

Earlier this month, a study published by Harvard University’s Center for the Developing Child concluded that letting infants watch tablet, phone, and TV screens might have negative effects on their academic achievement and emotional well-being down the road.

This long-term study evaluated nearly 500 children using an EEG at 1, 1-1/2, and 9 years of age. Their collected data demonstrated that extended screen time in infancy was associated with poorer executive functioning skills almost a decade later. Executive functioning skills refer to the brain’s proficiency with time management, organization, self-monitoring, adaptable thinking, and working memory. We use these skills every day academically, socially, and professionally.

The American Academy of Pediatrics discourages all screen exposure for babies under 18 months of age. That said, not all screen time is equal. Video-chatting with grandparents is a more interactive and valuable experience than passively watching animated videos. Digital educational content for infants and toddlers does exist, but for the most part that is just not how kids that age learn. The social back-and-forth is more identifiable in real life than through a screen and is particularly more impactful for younger brains. Additionally, the brightly-colored and rapidly-moving images on a screen are more activating than calming, and tend to elicit agitation in younger kids. That agitated state can be difficult to resolve when the screen is removed.

Similar results have been previously reported by the National Institutes of Health in their 2018 Adolescent Brain and Cognitive Development (ABCD) study which likewise assessed outcomes in 9 and 10 year-olds based on reported screen time at younger ages. For children who endorsed two hours of screen time daily as youngsters, their test scores for language and critical thinking problems were, on the whole, lower. For children who reported more than seven hours of screen time daily, MRI brain scans demonstrated evidence of thinning cortical tissue.

Both studies’ results suggest that increased screen time in infancy contributes to inferior development of executive functioning skills in childhood. However, more research is needed to define exactly which pathways are affected and what threshold of exposure is damaging. With more investigation, we will one day be able to better delineate the exact association between early exposure to screens and cognitive performance later on. For now, though, opting for face-to-face human interaction over digital substitutes when possible seems to have the best predictive outcome for growing brains, both cognitively and emotionally.


From UH Pediatrician and PSI Medical Expert – Dr. Carly Wilbur.

Click here for more great insights from Dr. Wilbur.

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