March 2019 –By the time a child is 17 years old, he or she will have been exposed to an average of 60,000 hours of media. In December 2018, the National Institutes of Health began a study to examine the impact of screen time using smartphones, tablets, and video games on 11,000 children ages 9 and 10. The study will follow them for 10 years to determine the long-term effect of media exposure.
The first round of MRIs conducted on subjects in this study found significant changes in the brains of kids who had more than seven hours of screen time daily. For example, researchers found a premature thinning of the outer cortex of the brain in these children, which may indicate earlier brain maturation. This early in the study, the impact of such changes is uncertain.