Understanding the Groundbreaking GUSTO Findings on Infant Screen Time

The latest research from Singapore's Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort has uncovered a compelling link between excessive screen exposure in infancy and long-term alterations in brain connectivity. Published in eBioMedicine on December 29, 2025, the study reveals how high screen time before age two accelerates the maturation of specific brain networks, potentially leading to slower decision-making and heightened anxiety during adolescence.

This longitudinal investigation, drawing on data from 168 children tracked over more than a decade, highlights the critical developmental window of the first two years. During this period, the brain undergoes rapid synaptogenesis and pruning, forming foundational neural pathways essential for sensory processing, cognition, and emotional regulation. Excessive visual stimulation from screens appears to disrupt this delicate balance, prioritizing visual pathways at the expense of broader integrative functions.

🧠 The GUSTO Cohort: Singapore's Premier Birth Study Platform

Established in 2009, the GUSTO study represents a collaborative effort among top Singapore institutions, including the National University of Singapore's (NUS) Yong Loo Lin School of Medicine, National University Health System (NUHS), and A*STAR's Singapore Institute for Clinical Sciences (SICS). This prospective birth cohort follows over 1,200 mother-child pairs, collecting multifaceted data on prenatal, environmental, and genetic factors influencing health outcomes.

For this particular analysis, researchers selected 168 participants (54% boys) born at term (gestational age ≥34 weeks, birth weight ≥2000g) to minimize confounds. Data collection spanned infant screen time via parental questionnaires at ages 1 and 2 years (average 2.17 hours per day, exceeding World Health Organization recommendations of zero hours), diffusion magnetic resonance imaging (dMRI) at ages 4.5, 6, and 7.5 years, Cambridge Gambling Task (CGT) at 8.5 years, and Multidimensional Anxiety Scale for Children (MASC) at 13 years.

Methodology: Mapping Brain Networks with Advanced Imaging

The study's rigor stems from its use of diffusion MRI, a non-invasive technique that tracks water molecule diffusion along white matter tracts to reconstruct structural connectivity. Researchers parcellated the cortex into 114 regions using the Yeo atlas, then applied the Louvain algorithm for community detection, yielding seven major networks: visual, somatomotor, dorsal attention, salience, limbic, default mode, and cognitive control.

Network integration was quantified as the probability that regions from different networks cluster together, reflecting communication efficiency. Longitudinal slopes were modeled via latent growth curves in structural equation modeling (SEM), adjusting for socioeconomic covariates like maternal education and household income. Mediation analyses with 10,000 bootstraps tested pathways from screen time to anxiety via brain trajectories and CGT performance.

• Screen time assessment: Weighted average of weekday/weekend self-reports.
• Brain scans: Probabilistic tractography (FSL BEDPOSTX/PROBTRACKX).
• Decision-making: CGT measures deliberation time (key outcome), risk adjustment, etc.
• Anxiety: MASC total score (mean 56.12, SD 26.57).

Key Discovery: Accelerated Maturation of Visual-Cognitive Networks

Higher infant screen time correlated with a steeper decline in visual-cognitive control network integration (β = -1.03, 95% CI -1.61 to -0.46), indicating premature specialization. Typically, integration decreases gradually as networks mature, but screens induce hyper-acceleration, possibly from repetitive visual overstimulation suppressing diverse sensory inputs needed for flexible topology.

This 'front-loading' of visual processing may reduce adaptability, as real-world environments demand multimodal integration. No similar effects were seen for other networks or later screen time (ages 3-4), underscoring infancy's vulnerability.

From Brain Changes to Behavioral Impacts: Slower Decision-Making

The altered network trajectory mediated longer deliberation times on the CGT (β = 0.20, 95% CI 0.01-0.91), where children took more time per bet despite unchanged quality or risk-taking. This hesitation reflects cognitive overload in integrating visual cues with executive control, a precursor to anxiety.

Deliberation time positively correlated with MASC scores (r=0.20, p=0.006), completing a serial pathway: screen time → brain slope → CGT → anxiety (β=0.033, 95% CI 0.002-0.160). These findings align with sensory processing sensitivity theories, where early overstimulation heightens threat perception later.

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Singapore's Screen Time Landscape and Policy Response

In tech-savvy Singapore, a recent Ministry of Health (MOH) survey revealed over 50% of 2-6-year-olds exceed the 1-hour daily limit on weekdays, rising to 81% weekends. MOH guidelines (updated 2025) advocate zero screens under 18 months, ≤1 hour for 2-6 years, prioritizing co-viewing and educational content.

Post-COVID surges amplified usage, with GUSTO data showing 75% of 2-year-olds exceeding norms. This context amplifies the study's urgency for public health campaigns.

Expert Insights from NUS and A*STAR Researchers

Lead investigator Assistant Professor Tan Ai Peng, clinician-scientist at NUHS and principal scientist at A*STAR's Institute for Human Development and Potential (IHDP), stresses: "The first few years are when the brain learns real-world experiences... excessive visual stimulation limits flexibility." First author Dr. Huang Pei adds that early screens reduce resilience, advocating responsible use.

NUS affiliations, including Prof. Yap-Seng Chong, underscore the university's role in translational neuroscience. This collaboration exemplifies Singapore's higher education ecosystem driving impactful child health research.

Global Context and Comparative Statistics

WHO guidelines mirror MOH: no screens <2 years, ≤1 hour 2-5 years. Yet, global averages hover at 1-2 hours for infants, with 2026 reports showing toddlers averaging 2 hours daily. Related studies (e.g., ABCD cohort US) link screens to cortical thinning in attention areas, echoing GUSTO's connectivity shifts.

• Singapore infants: 2.17h/day (GUSTO).
• Global toddlers: ~2h/day (2026 surveys).
• Exceedance: 91% in some Asian regions.

Practical Solutions: Mitigating Risks Through Parental Strategies

Parent-child reading from age 3 buffers effects, per GUSTO extensions. Co-viewing fosters interaction, reducing passive exposure.

• Establish tech-free zones (meals, bedtime).
• Prioritize physical play, outdoor activities.
• Model low screen use; opt for high-quality content.
• Gradual reduction with empathy, per experts.

Singapore programs like HealthHub offer tips, aligning with ECDA preschool limits.

NUS and A*STAR's Pivotal Role in Pediatric Neuroscience

NUS's involvement spans Yong Loo Lin School, Alice Lee Centre for Nursing, and Electrical Engineering, fostering interdisciplinary breakthroughs. A*STAR IHDP provides neuroimaging expertise, positioning Singapore universities as leaders in Asian child development research. Opportunities abound for research assistant jobs in this domain.

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Future Outlook: Implications for Research and Policy

Upcoming GUSTO waves may explore interventions like sensory training. Policymakers could integrate findings into national strategies, enhancing mental health resilience. For academics eyeing Singapore's vibrant scene, explore Singapore university jobs or academic CV tips.

This study not only advances neurobehavioural science but reinforces NUS's commitment to evidence-based child health.

Actionable Insights for Families and Educators

Prioritize real-world stimuli: reading, play, interaction. Monitor via apps if needed, but emphasize quality time. For higher ed professionals, this underscores demand for developmental psychology roles—check university jobs.