Summary: New research that followed children for more than a decade links high exposure to screens before the age of two with accelerated brain maturation, slower decision-making and greater anxiety in adolescence. Babies who spent more time in front of a screen showed premature specialization in brain networks involved in visual processing and cognitive control, which then reduced flexibility during thinking tasks.
These developmental changes were associated with slower reaction times at age eight and greater anxiety at age thirteen. The findings highlight childhood as an exceptionally sensitive period for brain development, a period when screens can shape neural pathways in ways that only emerge years later.
Key facts:
Sensitive period: Screen exposure before age two, but not at age three or four, predicted long-term brain changes. Altered brain networks: Babies with lots of screen time showed accelerated but inefficient maturation in networks for vision and cognitive control. Aftereffects: These brain differences predicted slower decision-making at age eight and higher anxiety symptoms at age thirteen.
Source: ASTAR
Children exposed to high levels of screen time before the age of two showed changes in brain development that were linked to slower decision-making and increased anxiety in adolescence, according to new research by Associate Professor Tan Ai Peng and her team from the A*STAR Institute for Human Development and Potential (A*STAR IHDP) and the Yong Loo Lin School of Medicine at the National University of Singapore (NUS), using data from the Growing Up in Singapore cohort. Towards healthy Outcomes (GUSTO).
Published in eBioMedicine, the study followed the same children for more than a decade, with brain imaging at multiple time points, to map a possible biological pathway from childhood screen exposure to adolescent mental health. This is the first paper on screen time to incorporate measures spanning more than ten years, highlighting the lasting consequences of screen time in childhood.
Importantly, the study focuses on childhood, a period in which brain development is most rapid and especially sensitive to environmental influences. Furthermore, the amount and type of screen exposure in childhood is largely determined by parents’ and caregivers’ awareness and parenting practices, highlighting a critical window for early guidance and intervention.
Children’s exposure to screens: why the first two years are important
The researchers followed 168 children from the GUSTO cohort and performed brain scans at three time points (4.5, 6 and 7.5 years). This allowed them to track how brain networks developed over time rather than relying on a single snapshot.
Children with more screen time showed accelerated maturation of the brain networks responsible for visual processing and cognitive control. Researchers suggest this may be due to the intense sensory stimulation that screens provide. In particular, screen time measured at ages three and four did not show the same effects, underscoring why childhood is a particularly sensitive period.
“Accelerated maturation occurs when certain brain networks develop too quickly, often in response to adversity or other stimuli,” explains Dr. Huang Pei, first author of the study.
“During normal development, brain networks gradually become more specialized over time. However, in children with high screen exposure, networks that control vision and cognition became specialized more quickly, before they had developed the efficient connections necessary for complex thinking. This can limit flexibility and resilience, leaving the child less able to adapt later in life.”
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 greater anxiety symptoms at age 13.
These findings suggest that exposure to screens in infancy may have effects that extend far beyond early childhood, shaping brain development and behavior years later.
How parent-child reading counteracts the impact of screen time
In a related study published in Psychology Medicine in 2024, the same team found that screen time in babies is also associated with alterations in the 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 babies’ screen time and altered brain development weakened significantly. Researchers suggest that shared reading can provide the type of enriched interactive experience that passive screen consumption lacks, including sharing, language exposure, and emotional connection.
“This research gives us a biological explanation for why it is crucial to limit screen time in the first two years. But it also highlights the importance of parental involvement, showing that parent-child activities, such as reading together, can make a real difference,” said A*STAR IHDP Principal Investigator Assistant Professor Tan Ai Peng, NUS clinical scientist and lead author of the study.
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 empirical basis to guide early childhood policies and parenting practices, contributing to Singapore’s efforts to maximize human potential from the earliest stages of life.
Funds:
ECL received a grant from MOH-001784-00: Promoting Early Relational Health with PlayReadVIP to Prevent Socioeconomic Disparities in Child Development (unrelated to the manuscript) and works in an unpaid role KidSTART Ltd (charity status), International Community School. The rest of the authors declare that they have no conflicts of interest.
Key questions answered:
A: It accelerates the specialization of visual and cognitive control networks before optimal connections have been formed, reducing subsequent cognitive flexibility.
A: No. Only screen exposure in the first two years predicted altered brain network development and later mental health outcomes.
A: Yes. Frequent shared reading at age three weakened brain network alterations related to early screen exposure, suggesting a protective effect.
Editorial notes:
This article was edited by a Neuroscience News editor. Magazine article reviewed in its entirety. Additional context added by our staff.
About this research news on neurodevelopment and mental health
Author: Owen Sia
Source: ASTAR
Contact: Owen Sia – ASTAR
Image: Image is credited to Neuroscience News.
Original research: Open access.
“Neurobehavioral links between childhood screen time and anxiety” by Huang Pei et al. EBioMedicine
Abstract
Neurobehavioral links between childhood screen time and anxiety
Background
Screen time in infants is linked to many negative outcomes, including anxiety, but the underlying neural pathways and correlates remain understudied. Our objective was to evaluate the directional association between infants’ screen time, development of brain network topology, decision-making behavior, and anxiety symptoms in adolescence.
Methods
Using data from the Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort study, we examined the effects of total daily screen time for infants on developmental outcomes using structural equation modeling. Specifically, we analyzed the developmental slopes of network integration for the seven major brain cortical networks between the ages of 4.5, 6.0, and 7.5 years, decision-making behavior assessed using the Cambridge Gambling Task (CGT), and anxiety symptoms assessed using the Multidimensional Anxiety Scale for Children, 2nd Edition (MASC).
This study included 168 children from the GUSTO cohort with data on childhood screen time (ages 1 to 2 years), diffusion MRI (ages 4.5 to 7.5 years), data on decision-making performance (CGT at age 8.5 years), and anxiety symptoms (MASC at age 13 years). Brain network integration was derived from diffusion MRI and developmental slopes for each participant were modeled using latent growth models. Structural equation modeling assessed pathways linking early screen time to adolescent anxiety, mediated by brain network development and decision making.
Recommendations
Greater childhood screen time was associated with a steeper decline in visual-cognitive control network integration between 4.5 and 7.5 years (β = −1.03 (−1.61, −0.46)), which mediated greater CGT deliberation time at 8.5 years. Deliberation time, in turn, was associated with greater anxiety symptoms at age 13. A full serial mediation pathway was significant, linking childhood screen time to later anxiety through accelerated brain network maturation and decision-making behavior (β = 0.033 (0.002, 0.160)).
Interpretation
Increased childhood screen time is associated with accelerated topological maturation of visual and cognitive control networks, leading to prolonged decision latency and increased adolescent anxiety. Impaired sensory processing may underlie this new neurodevelopmental pathway, highlighting a potential target for early intervention.
Funds
This research was supported by the National Research Foundation of Singapore, the National Medical Research Council (NMRC) of the Singapore Ministry of Health, Singapore, the Institute for Human Development and Potential, Agency for Science, Technology and Research, Singapore, the Hope for Depression Research Foundation, USA, the JPB Foundation Toxic Stress Network, USA, and the Jacobs Foundation, Switzerland.
