The study, conducted by researchers at Cincinnati Children's Hospital Medical Center, found that young children who spent more than the doctor-recommended amount of time engaging with screens had lower "white matter integrity."
White matter, which is associated with cognitive function and language skill, "can be roughly thought of as the brain's internal communications network," according to an article published in MIT Technology Review.
The study involved 47 healthy children — 27 girls and 20 boys — between 3 and 5 years old, and their parents. Researchers completed both standard cognitive exams and special MRI scans, which look at the white matter in the brain. Parents involved in the study were asked to fill out a screening questionnaire, which was compared to the scans.
“While relatively small for a behavioral study, this is actually a fairly large MRI study, especially involving young children, [and] the first to explore associations between screen time and brain structure,” Dr. John Hutton, lead author of the study, said in an interview with Technology Review.
Hutton said the study raises a lot of questions about how much screen time is safe for young children to consume. Right now, the American Academy of Pediatrics recommends the following:
- Children younger than 18 months only use screens when it's used for video chatting.
- Children ages 2-5 years old only consume one hour of screen time per day of "high-quality programs."
- Families should designate "screen-free" activities.
- Parents should consume media with their children so they are able to provide context for what they are seeing.
"While we can't yet determine whether screen time causes these structural changes or implies long-term neurodevelopmental risks, these findings warrant further study to understand what they mean and how to set appropriate limits on technology use," Hutton said.
In addition to the lower white matter integrity, researchers found that kids with higher “ScreenQ” scores — calculated based on the AAP screen time recommendations — had lower expressive language, lessened ability to quickly name objects and overall literacy skills.
Hutton said he and his team will continue to research the link between screen time and brain development.