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Is all that screen time hurting your child’s brain? New research raises troubling questions

A child uses a tablet. Adobe Stock

A new study raises questions about whether screen time is affecting the structure of children’s brains, but it’s just the latest in a series of studies that may make parents wish they could crowbar that pesky smartphone and other devices out of their children’s hands.

In the new study, National Institutes of Health researchers, looking at brain scans of 4,500 study participants who were 9 and 10 years old, found differences in the brains of children who used smartphones, tablets, and video games more than seven hours a day, “60 Minutes” reported Sunday.

The preliminary results from the Adolescent Brain Cognitive Development Study showed a pattern of thinning of the brain’s cortex.


Researcher Gaya Dowling, who heads the study, told the CBS News program that it wasn’t clear whether it was being caused by the screen time. Dowling also said it could take years to determine whether it ultimately would cause problems. But the results were worrisome because thinning of the cortex is typically associated with aging.

Dr. Dimitri Christakis, a University of Washington professor and director of the Center for Child Health, Behavior, and Development at the Seattle Children’s Research Institute, said the new findings could end up changing experts’ advice for parents regarding screen time.

“I think those results will clearly impact the current recommendations,” he said.

Christakis was the lead author of one of two 2016 papers — one about younger children and one about older children — in which the American Association of Pediatrics reviewed the existing research on screen time and set out guidelines for screen time.

The papers noted that, among other things, studies have raised questions about social media use and its possible connection to obesity; sleep problems; cognitive, language, and social/emotional developmental delays; Internet addiction; academic problems; risky behaviors; and depression and unhappiness. The papers also noted the problems of cyberbullying, sexting, and privacy violations.

Here is a sampling of some of the key recommendations issued by the AAP:

■  For children younger than 18 months old, parents should avoid exposure to screen media other than video-chatting. For children 18 to 24 months of age, parents who want to introduce digital media should choose high-quality programming and watch it with their children to help them understand what they’re seeing.


■  For children 2 to 5 years old, parents should limit screen use to one hour per day of high-quality programs. Parents should view media with children to help them understand what they are seeing and apply it to the world around them.

■  For children 6 years old and above, parents should place consistent limits on the time spent using media, and the types of media, and make sure media does not take the place of adequate sleep, physical activity, and other behaviors essential to health.

■  Parents should designate media-free times together, such as dinner or driving, as well as media-free locations at home, such as bedrooms.

■  Parents should have ongoing communication with their children about online citizenship and safety, including treating others with respect online and offline.

Christakis has said society is unwittingly in the midst of a massive experiment, exposing children to unprecedented time on screens.

“We don’t know what the effects of all this are yet,” he said in a telephone interview.

“Your brain is undergoing dramatic developmental changes in the first three to five years of life,” said Christakis, whose paper focused on the younger group. “It’s doing so in direct response to external stimulation. The type and frequency of stimulation that young children experience has profound implications for the architecture of the brain.”


He noted that brain development doesn’t stop at age 5; it continues until people are about 25.

It’s important for parents to establish screen time guidelines early in their child’s life to lay a foundation for later, he said, drawing an analogy to healthy eating, saying parents wouldn’t wait until a child was 15 to have their first conversation with the child about a healthy diet.

The AAP suggests that people adopt a family media use plan. The idea, Christakis said, is that people put some “thoughtful effort into setting limits and healthy use” of media.

Christakis acknowledged that ever-changing technology has its benefits and can’t be eliminated but said its effects on children need to be scrutinized.

“We know [screen time] is having effects. That much we can be certain of. We’re not sure if it’s good or bad. The truth is: It’s almost certainly mixed,” he said.

The question about exposing children to technology, he said, is: “How do we extract the good . . . and minimize the bad?”