Many adults can remember the days when their screen time was limited to Saturday morning cartoons, as well as their class’s weekly visit to the computer lab to play Oregon Trail. It was a quick half-hour of fatigued oxen, snakebites, and surprise bouts of dysentery.
Over the past few decades, screen time has expanded from an occasional treat to a full-day affair. People of all ages stare at screens for work, school, and entertainment. Within the last two decades, scientists have increasingly studied the impact of screen time on the brain.
But what happens when a person steps away from their screen? Researchers are discovering what happens neurologically when a person goes on a digital detox.
Read More: Understanding What People Do on Their Devices Is Key to Digital Well-Being
Scanning the Impact of Screens
To learn more about how a person’s brain benefits from reduced screen time, scientists have been studying how phones, tablets, and TVs affect a person’s cognitive functioning. Technologies like functional magnetic resonance imaging (fMRI) are helping researchers identify differences in people who spend a lot of time or a little time in front of screens.
In a 2018 study in Acta Paediatrica, scientists used fMRI to study functional connectivity in 19 kids aged 8 to 12. Prior to the study, the parents completed questionnaires on how much screen time their children had each day, as well as time spent independently reading.
When the kids were in the fMRI, they were in a resting state, not actively looking at screens or books. The researchers were interested in the level of connectivity in the parts of the brain associated with language and literacy. They found that older kids who spent more time in front of their screens had lower connectivity in these regions than kids who read more.
Similarly, a 2023 study in Child Neuropsychology collected resting-state fMRI data from kids aged 8 to 12 to learn about screen time and its impact on the regions of the brain related to attention and cognitive control. The study found that the more screen time a kid had, the less connectivity they had in these neural networks.
Researchers are also turning to diffusion tensor imaging (DTI), a type of MRI that is able to visualize white matter. In a 2020 study in JAMA Pediatrics, researchers used DTI to examine the white brain matter in the regions supporting language and pre-literacy in preschool-age children. The study found that children who had more than one hour of screen time per day had lower myelination in white matter tracts – meaning they had slower neural signaling.
Adults aren’t immune to the impact of screen time, either. For young adults ages 18 to 25, studies have found higher levels of screen time associated with addiction, lower self-esteem, mental health issues, and slower learning.
A Digital Detox for the Brain
Researchers have been able to measure what happens to a child or young adult’s brain when they step away from their screens and into the fMRI machine. But what is happening in the brain when a person is deep into their phone? And how is that different than when they are reading a book?
In a 2025 study in Developmental Science, a team of researchers set out to measure brain functioning in study participants while they engaged in either a screen-related or book-based activity.
“That is why our study is so exciting, because it’s the first study to actually compare how children’s brains are functioning during screen time compared to shared book reading,” says Meredith Pecukonis, the study’s lead author and a postdoctoral research fellow at the Massachusetts General Hospital Lurie Center for Autism in Lexington, Massachusetts.
The team recruited 28 kids ages 3 to 6, and then had them prepare to wear the functional near-infrared spectroscopy (fNIRS) cap. As many parents can attest, during winter, getting a small child to wear a hat can be impossible. Thus, getting a child to wear a cap attached to probes and wires requires some finessing. Pecukonis’ team gave the children practice caps that had lights and rainbow strings. The kids put the cap on themselves, their parents, and stuffed animals.
“Once we were able to determine that the child was comfortable wearing the practice cap, we would move on to putting on the real cap,” Pecukonis says.
With the real cap in place, children listened to a story being read by a member of the research team while they followed along in a book with matching words and pictures. For the screen time condition, the little participants listened to an audio recording of a story while looking at words and pictures on a screen.
Both conditions involved a story being read, accompanied by pictures and words. One might think, same diff, but the study found the brain activation was distinct. During the book reading, the right temporal parietal junction was activated, but this did not happen during the screen time condition.
“Given that we saw that this region of the brain was active during shared book reading, but not during screen time, suggests that children were more engaged in these social cognitive processes during shared book reading,” Pecukonis says. “This region of the brain is also involved in attention more generally, and so it could be that children were just more attentive during shared book reading.”
Digital Diets
For parents worried about the impact of screen time on their child’s development, Pecukonis recommends following the guidelines set by the American Academy of Pediatrics: No screen time for children ages two and younger, and no more than one hour a day for kids ages three to five.
But Pecukonis also acknowledges that life can get in the way, and a bit of Baby Shark can give parents a moment to fold a basket of laundry or cook dinner. When possible, she recommends co-viewing with the child. Keep an ear out, ask questions about the show, and the emotional states of the characters. Talk about the program after it’s over and apply it to real life.
“[...] Co-viewing should be used to promote learning and social interaction whenever possible,” she says.
Read More: Guilt Over Kids’ Screen Time Is Common − But it can Have a Silver Lining
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
Developmental Science. Do Children's Brains Function Differently During Book Reading and Screen Time? A fNIRS Study
American Academy of Pediatrics. Media and Young Minds
Emilie Lucchesi has written for some of the country's largest newspapers, including The New York Times, Chicago Tribune and Los Angeles Times. She holds a bachelor's degree in journalism from the University of Missouri and an MA from DePaul University. She also holds a Ph.D. in communication from the University of Illinois-Chicago with an emphasis on media framing, message construction and stigma communication. Emilie has authored three nonfiction books. Her third, A Light in the Dark: Surviving More Than Ted Bundy, releases October 3, 2023, from Chicago Review Press and is co-authored with survivor Kathy Kleiner Rubin.
