Too much screen time too soon? A*STAR study links infant screen exposure to brain changes and teen anxiety

SINGAPORE — 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 research by Asst Prof Tan Ai Peng and her team from A*STAR Institute for Human Development and Potential (A*STAR IHDP) and National University of Singapore (NUS) Yong Loo Lin School of Medicine, using data from the Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort.

Published in eBioMedicine, the study tracked the same children over more than a decade, with brain imaging at multiple time points, to map a possible biological pathway from infant screen exposure to adolescent mental health. This is the first paper on screen time to incorporate measures spanning over ten years, highlighting the long-lasting consequences of screen time in infancy.

Importantly, the study focuses on infancy, a period when brain development is most rapid and especially sensitive to environmental influences. Furthermore, 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.

Infant screen exposure: why the first two years matter

The researchers followed 168 children from the GUSTO cohort and conducted brain scans at three time points (ages 4.5, 6, and 7.5). This 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.

"Accelerated maturation happens when certain brain networks develop too fast, often in response to adversity or other stimuli," explains Dr Huang Pei, the study's first author. "During normal development, brain networks gradually become more specialised over time. However, in children with high screen exposure, the networks controlling vision and cognition specialised 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 specialisation 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 behaviour years later.

How parent-child reading counteracts screen time impact

In a related study published in Psychological Medicine in 2024, 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.

Among children whose parents read to them frequently at age three, the link between infant screen time and altered brain development was significantly weakened. The researchers suggest that shared reading may provide the kind of enriched, interactive experience that passive screen consumption lacks, including back-and-forth engagement, language exposure, and emotional connection.

"This research gives us 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, Principal Investigator at A*STAR IHDP, Clinician-Scientist at NUS, and the study's senior author. The study was conducted in collaboration with researchers from the National University Hospital of Singapore, KK Women's and Children's Hospital, and McGill University. The findings provide an evidence base to guide early childhood policies and parenting practices, contributing to Singapore's efforts to maximise human potential from the earliest stages of life.

Study citations:

Huang P, Chan SY, Zhou K, et al. Neurobehavioural Links from Infant Screen Time to Anxiety. eBioMedicine (2025). DOI: https://doi.org/10.1016/j.ebiom.2025.106093

Huang P, Chan SY, Ngoh ZM, et al. Screen time, brain network development and socio-emotional competence in childhood: moderation of associations by parent-child reading. Psychological Medicine (2024). https://doi.org/10.1017/S0033291724000084