New Study Shows Screen Time Can Slow Brain Development In Young Kids

The study used MRIs to show that kids who went over recommended screen time limits had slower brain development

We still have a lot of questions about how new technology — and, in particular, an abundance of screens in our lives — affects kids as they grow and develop. We’ve been warned for years that kids need limits on screen time, but why? Well, a new study might hold the answers.

The study was conducted at Cincinnati Children’s Hospital and recently published in the journal JAMA Pediatrics. Researchers used MRI scans to examine the brains of kids aged 3-5, and, based on how much screen time those kids were engaging in on the regular, found some preliminary conclusions that may show more screen time correlates with slower brain development.

Here’s how they made that connection: Researchers first gave kids a test designed by the American Academy of Pediatrics to rate their access to screen time. That test includes, “how much access a child has to a screen (allowed at meals, car, in line at store?), the frequency of exposure (age started, number of hours, at bedtime?), content (chooses own? watches fighting or songs or education?) and “dialogic” interaction (does the child watch alone or does a parent interact and discuss the content as well?).”

The kids were also given a cognitive skills test.

Then, researchers used MRI technology to closely examine the kids’ brains, specifically the parts scientists call “white matter,” which acts like phone cables, forming connections between different parts of the brain, and between the brain and the rest of the nervous system. The scientists found that kids who used screens more than the recommended one hour per day had disorganized and undeveloped white matter in their brains. Those were also the kids who scored lower on the skills test they were given before the MRIs were done.

Scientists say this finding is cause for alarm, because white matter is the part of the brain that’s linked to things like language skills, reading, comprehension, and problem-solving.

“These are tracks that we know are involved with language and literacy,” said Dr. John Hutton, the study’s lead author. “And these were the ones relatively underdeveloped in these kids with more screen time.”

Plus, kids’ brains develop very rapidly before they reach 5 years old, and that lays the groundwork for an entire lifetime of healthy brain development and function.

“That’s when brains are very plastic and soaking up everything, forming these strong connections that last for life,” Hutton said.

Still, the world we live in now is one where screens are everywhere. It’s also important to note that these findings are pretty preliminary. Other studies have shown that kids who have the strongest language and cognitive skills are the ones who are regularly engaged in talk and play with adults, so maybe the problem isn’t screen time, but using screens to replace necessary interactions with others.