Screen use is ubiquitous in modern society, with children exposed to digital devices from a very young age. Despite warnings from organizations such as the World Health Organization, the US Surgeon General, and Singapore’s Ministry of Health, many children frequently exceed the recommended limits for early screen exposure This trend increases concerns, as the first 2 years of life are important for brain development, characterized by significant increases in brain volume and the reorganization of networks that are essential for later cognitive, decision-making, and emotional functions.
Earlier studies have linked childhood screen time to variations in brain structure and negative cognitive or emotional effects. Still, these studies have used cross-sectional designs focusing on specific brain regions. A longitudinal network-based approach is required to understand better the impact of early screen exposure on future mental health, since complex behaviors like decision making and anxiety include interactions in many brain networks.
This study aimed to explore a neurodevelopmental link between infant screen time and anxiety symptoms in adolescence. It assessed whether infant screen exposure predicts variations in brain network topology and whether these changes are linked to decision-making behavior in mild childhood. The researchers hypothesized that elevated infant screen time correlates with altered brain network maturation, influencing decision-making and contributing to anxiety later.
Participants were drawn from the Growing Up in Singapore Towards Healthy Outcomes (GUSTO) longitudinal birth cohort. The sample included 168 children born at ≥34 weeks’ gestation with no major birth complications. Infant screen time was assessed at ages 1 and 2 years using parental questionnaires, and the average of these assessments was used as the primary exposure variable.
Brain development was measured using diffusion MRI at ages 4.5, 6.0, and 7.5 years. Structural connectivity matrices were created by using network integration measures in 7 major cortical networks. The developmental trajectories of network integration were characterized by intercepts and slopes estimated using latent growth models. Decision-making behaviour was assessed at age 8.5 years by using the Cambridge Gambling Task, which yields 6 standard outcome measures. Anxiety symptoms were measured at age 13 years by using the Multidimensional Anxiety Scale for Children (MASC). Structural equation modelling (SEM) and mediation analyses were conducted to assess the pathways linking infant screen time, brain network development, decision-making, and anxiety, while controlling for latent socioeconomic environmental factors.
Higher infant screen time was significantly associated with the developmental slope of the integration of the visual-cognitive control network. Greater screen exposure in infancy predicted a steeper reduction in integration between these networks from ages 4.5 to 7.5 years, consistent with accelerated network maturation. No other network integration trajectories were associated with infant screen time, and screen time measured later in early childhood (ages 3 to 4 years) showed no significant associations.
Mediation analyses showed that the slope of the visual-cognitive control network integration fully mediated the association between infant screen time and one specific aspect of deliberation time of decision making. Higher infant screen time was linked to a steeper decline in visual-cognitive control network integration, which in turn was linked with longer deliberation time on the gambling task. Among all decision-making measures, only deliberation time was significantly correlated with anxiety symptoms at age 13. A serial mediation model showed a significant indirect pathway from infant screen time to adolescent anxiety by altered brain network development and increased deliberation time, while direct effects were not significant.
This study provides longitudinal evidence that infant screen exposure is associated with altered anxiety symptoms. The findings suggest that excessive screen time may interfere with the maturation of brain networks involved in visual processing and cognitive control. This accelerated specification could negatively impact higher-order cognitive functions, manifesting as longer deliberation times linked with increased anxiety in adolescence. The findings indicate sensory processing as a potential mechanism connecting early screen use, decision making, and anxiety. The study emphasizes the need to limit screen exposure during infancy and identifies early childhood as a critical period for brain development and mental health.
References: Huang P, Tan Ai Peng, et al. Neurobehavioural links from infant screen time to anxiety. eBioMedicine. doi:10.1016/j.ebiom.2025.106093
