Children with high screen time more anxious, slower decision-makers: study

The study tracked 168 children over more than a decade, examining the effects of screen exposure before age two. Parents reported the amount of screen time their children had in infancy, while MRI scans of the children’s brains were taken at various ages to track developmental changes. The children also completed cognitive tests at 8.5 years old to assess decision-making and an anxiety questionnaire at age 13.

Researchers found that children with higher screen exposure showed accelerated maturation of brain networks involved in cognitive control and visual processing. The study suggested that this acceleration is associated with slower decision-making and increased anxiety in adolescence.

"Accelerated maturation happens when certain brain networks develop too fast, often in response to adversity or other stimuli," explained the study’s lead author, Dr. Huang Pei. "During normal development, brain networks gradually become more specialised over time. However, in children with high screen exposure, the networks controlling vision and cognition specialised faster, before they had developed the efficient connections needed for complex thinking. This can limit flexibility and resilience, leaving the child less able to adapt later in life."

The study reported that observed infants averaged more than one to two hours of daily screen time. The World Health Organization recommends no sedentary screen time for one-year-olds and limits two-year-olds to no more than one hour per day.

"The levels of infant screen use observed in our study cohort are concerning, both in their magnitude and in their clear divergence from WHO recommendations," the researchers noted.

Additionally, data for the study were collected between 2010 and 2014, before the COVID-19 pandemic, when screen time for children had likely increased.

"Our data … precede recent evidence of further increases globally, particularly during the COVID-19 pandemic," the researchers said. "The already elevated levels of screen exposure we observed a decade ago are likely even higher today, making the developmental implications of our findings especially urgent."

According to a report by The Register, the research team also published a related study last year examining infant screen time and socio-emotional development, which concluded that children with higher screen exposure showed weaker emotion management skills.