Children exposed to high levels of screen time before age two showed changes in brain development that were linked to slower decision-making and increased anxiety by their teenage years, according to new study released by the Agency for Science, Technology and Research in Singapore.
Prepared in collaboration with the National University of Singapore (NUS) Yong Loo Lin School of Medicine, the study focuses on infancy, a period when brain development is most rapid and especially sensitive to environmental influences.
The amount and type of screen exposure in infancy are largely determined by parental and caregiver awareness and parenting practices, highlighting a critical window for early guidance and intervention, showed the study, published in eBioMedicine on Tuesday.
It said the researchers followed 168 children before age two and conducted brain scans at three time points (ages 4.5, 6, and 7.5), which allowed them to track how brain networks developed over time rather than relying on a single snapshot.
Children with higher infant screen time showed an accelerated maturation of brain networks responsible for visual processing and cognitive control.
The researchers suggest this may result from the intense sensory stimulation that screens provide. Notably, screen time measured at ages three and four did not show the same effects, underscoring why infancy is a particularly sensitive period.
The study showed that 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.
It said this premature specialization came at a cost: children with these altered brain networks took longer to make decisions during a cognitive task at age 8.5, suggesting reduced cognitive efficiency or flexibility.
Those with slower decision-making, in turn, reported higher anxiety symptoms at age 13. These findings suggest that screen exposure in infancy may have effects that extend well beyond early childhood, shaping brain development and behavior years later.
In a related study, the same team found that infant screen time is also associated with alterations in brain networks that govern emotional regulation — but that parent-child reading could counteract some of these brain changes.
Researchers found that their results give a biological explanation for why limiting screen time in the first two years is crucial.
“But it also highlights the importance of parental engagement, showing that parent-child activities, like reading together, can make a real difference,” said Asst Prof Tan Ai Peng, Clinician-Scientist at NUS, and the study's senior author.
The study concluded that children exposed to high levels of screen time before age two are exposed to endure adolescent mental health, particularly on cognitive performance and anxiety levels.
