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From Cartoons to Anxiety: How Early Screen Time Harms Children’s Brains

I remember having to beg my parents for a  DVD player when I was a child. Tired of tracking down cartoons on TV programming, I wanted my own on-demand entertainment. With my parents being apprehensive at first, we entered a long, arduous negotiation over time limits, school work, and chores. When I finally got the player, I felt like a new world had opened up to me; like no technology would ever top that tiny pixelated screen and its stack of Disney-princess cartoons. 


Now, screens no longer feel like a novelty. Quite the opposite, screens have come to comprise the very fabric of our daily lives: they’re what we wake up to in the morning and what we go to bed with at night. A recent report commissioned by the UK government found that on a typical day, 98% of two-year-olds spend an average of two hours watching TV, videos, or other digital content. An Ofcom report claims that by the age of five, a fifth of UK kids have their own devices. Over a third use social media. 


"on a typical day, 98% of two-year-olds spend an average of two hours watching TV, videos, or other digital content"

Meanwhile, experts agree that the amount of time children spend in front of screens should be tightly regulated. Science shows that excessive screen time at an early age is linked to a slew of problems, from issues with language learning to trouble with emotional regulation. Yet, most scientific evidence we have is not enough to definitively show causation, and the mechanism of damage remains unknown. 


A recent study by a team from the National University of Singapore aimed to help bridge this gap, and explore how early exposure to screens may lead to anxiety in adolescence. The team proposed a mechanism where early exposure to screens initiated changes in brain network development, which then affected the kids’ higher cognitive function — primarily their decision-making capabilities — and that, in turn, caused the manifestation of anxiety symptoms by the age of 13. 


The experiment 


The scientists recruited 168 pregnant women in their first trimester. They then followed the mothers and their children through the pregnancy and the first thirteen years of the kids’ lives. The goal was to track the children’s brain development process, while also noting how much time they were spending on screens. 


During the first two years of the children’s lives, the mothers were asked to complete questionnaires noting how much time, on average, their infants spent in front of a screen. Then, brain development data was collected with imaging: the children underwent MRI scans at 4.5, 6, and 7.5 years of age. Together, these scans created a comprehensive picture of the networks’ functional structure and their evolution over time. 


At 8.5 years old, the children’s decision-making ability was tested using the Cambridge Gambling Task. The test measured a number of metrics defining the higher cognitive processes involved in decision-making. 


Finally, at 13, the teenagers underwent anxiety screening with the Multidimensional Anxiety Scale for Children, where everyone in the cohort filled out a 50-point scaled questionnaire and received a score based on their answers. 


The scientists then used a statistical technique called structural equation modelling (SEM) to see if screen time-related deviations at each step were significantly linked to differing outcomes. SEM allows to test complex hypothesized relationships that involve multiple steps while also using the intermediary points as mediators. In this case, the relationship of interest was the interdependency between screen time and anxiety, mediated by brain network connectivity and decision-making capability.


How we go from brain development to decision-making to anxiety 


The first two years of an infant’s life are crucial for their brain development. When a child is born, its brain weighs about a quarter of what it will grow into in adulthood. By the age of two, the brain grows to 75% of its final size. During this time, the brain shows extraordinary plasticity, with intense synaptogenesis — the process of forming new connections between neurons — happening in all areas of the brain. These connections then group into brain networks responsible for carrying out a specific function, like processing auditory information or recognizing a familiar face. 


Decision-making is a higher order cognitive function, requiring that multiple brain regions come together, process different types of incoming information, and then make a decision based on the provided input. For information to be processed properly, each network has to function exactly the way it is meant to. Otherwise, errors occur. 


"(...) the relationship of interest was the interdependency between screen time and anxiety, mediated by brain network connectivity and decision-making capability."

The Cambridge Gambling Task (CGT) evaluates those decision-making patterns. During the test, ten boxes are presented to a child. Some of them are red, others are blue (the ratio changes with every trial). The child has to try to guess whether a yellow token had been hidden in a blue or a red box, waging a number of points on their bet, with the goal of gaining as many points as possible. Using the CGT, scientists look at metrics important in decision-making: how often the child is right, how long they take to make the decision, how likely they are to bet, and how they adjust those bets based on how many boxes of each color are present. Essentially, the task assesses both the quality of a decision and the child’s ability to make that decision in the first place. 


In anxiety, the brain struggles to process incoming information correctly. It gets the same sensory input as standard baseline but overshoots in estimating an appropriate level of response, and, in doing so, triggers a heightened reaction. 


Both anxiety and decision-making employ similar networks to process information, with neuroimaging studies showing activity of overlapping structures in both. In fact, changes in decision-making patterns have been linked to anxiety in children and adolescents. But, where previous studies have had to rely on interpersonal comparisons at a single point in time to estimate that relationship, this study allows us to track the same child as they develop those patterns of behavior over time. 


The results of the study


First, the scientists tested the relationship between screen time and network development, and discovered that increased screen time significantly affected the integration of the visual-cognitive network, leading to its accelerated maturation. 


Then, they looked at the link between decision-making capabilities and screen time. CGT outcomes were used as proxies for decision-making, each metric of the task tested independently to see which facet of the process was important. Only deliberation time — the time a child spent making their decision — was significantly affected by early childhood screen time. The effect was fully mediated by individual  brain network connectivity. 


"early-childhood screen time could cause issues in sensory processing by affecting network development"

Finally, the team examined the relationship between CGT outcomes and anxiety, using the teens’ scores on the Anxiety Scale.  Of all CGT outcomes, deliberation time was the only one significantly associated with anxiety scores. 


Together, the model tested the relationship between screen time and anxiety, using deliberation time and the visual-cognitive control network integration as mediators. The results showed that the relationship was meaningful only when the mediators were in place - without them, the association lost its significance. So, each part of the mechanism was integral to constructing the overall picture. 


The team believe there are two potential explanations for their results: firstly, as shown in the experiment, early-childhood screen time could cause issues in sensory processing by affecting network development. Alternatively, the problem could lie in the replacement of real human interaction with time spent in front of a screen. Parent-child quality time is crucial for proper infant development, so when that gets substituted for a talking screen, the child’s brain can suffer. While we will not know the mechanisms until more experiments are conducted, this study highlights the urgency of the problem, while also proposing one of the possible explanations. 



References


Fish, L., Bernardi, M., van de Grint-Stoop, J., et al. (2026). Children of the 2020s: home learning environment and screen time at age 2. Research brief. Department of Education. https://assets.publishing.service.gov.uk/media/695fc42241ddb40d13f76527/COT2020s_-_home_learning_environment_and_screen_time_at_age_2_-_research_brief.pdf


Huang, P., Chan, S. Y., Zhou, K. X., et al. (2026). Neurobehavioural links from infant screen time to anxiety. EBioMedicine, 123, 106093. https://doi.org/10.1016/j.ebiom.2025.106093


IntellectusConsulting. Structural Equation Modeling. Retrieved on Feb. 20, 2026 from https://www.statisticssolutions.com/free-resources/directory-of-statistical-analyses/structural-equation-modeling/


Muppalla, S. K., Vuppalapati, S., Reddy Pulliahgaru, A., et al. (2023). Effects of excessive screen time on child development: An updated review and strategies for management. Cureus, 15(6), e40608. https://doi.org/10.7759/cureus.40608


Northwestern Medicine. (2020). The science of anxiety (infographic).  https://www.nm.org/healthbeat/healthy-tips/emotional-health/the-science-of-anxiety



Tierney, A. L., & Nelson, C. A., 3rd. (2009). Brain Development and the Role of Experience in the Early Years. Zero to three, 30(2), 9–13.


World Health Organization. (2019). Guidelines on physical activity, sedentary behavior and sleep for children under 5 years of age. https://iris.who.int/server/api/core/bitstreams/60a1cbaa-2bef-4251-9557-e52ce22112b3/content



This article was written by Dasha Sokol and edited by Julia Dabrowska, with graphics produced by Suzana Sultan. If you enjoyed this article, be the first to be notified about new posts by signing up to become a WiNUK member (top right of this page)! Interested in writing for WiNUK yourself? Contact us through the blog page and the editors will be in touch.

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