Scientists warn about the dangers of introducing children to smartphones too early

Children who spent a lot of time in front of screens during the first two years of life are more likely to experience increased anxiety and make decisions more slowly than their peers by adolescence. These are the conclusions reached by scientists from the A*STAR Institute for Human Development and Potential and the National University of Singapore Medical School, after analyzing data from the long-term GUSTO study. The work is published in the journal EBioMedicine.

The study covered data from 168 children whose development was observed for more than ten years. Participants underwent brain MRIs at ages 4.5, 6, and 7.5 years, which allowed researchers to track changes in the structure and functioning of neural networks over time. This approach for the first time made it possible to link screen time in infancy with biological changes in the brain and mental state in adolescence.

Analysis showed that children with high levels of screen time before the age of two experienced accelerated maturation of neural networks responsible for visual information processing and cognitive control. According to the authors, this is due to the intense sensory stimulation that screens provide. At the same time, a similar connection for screen time at the age of three to four years was not found, which indicates the special vulnerability of the early development period.

"Accelerated maturation occurs when certain brain networks develop too quickly, often in response to strong external stimuli. Normally, specialization happens gradually, but with high screen exposure, the networks responsible for vision and thinking form earlier than the effective connections necessary for flexible thinking have time to develop," explained first author Huang Pei.

Such premature specialization had long-term consequences. At the age of 8.5 years, children with altered neural networks were slower in completing decision-making tasks, and by the age of 13, they more often reported symptoms of anxiety. According to researchers, this points to a possible chain of effects - from screen exposure in infancy to behavioral characteristics in adolescence.

At the same time, scientists found a factor that could mitigate the negative impact of screens. An accompanying study showed that parents regularly reading to children reduces the severity of brain changes associated with early screen time. Shared reading, according to the authors, provides an interactive and emotionally rich experience that passive content consumption lacks.

"Our work provides a biological explanation for why it's so important to limit screen time in the first two years of life. At the same time, it shows that active parental involvement - for example, shared reading - can significantly change the trajectory of development," noted study leader Tan Ai Peng.