An entire generation of kids is growing up with smartphones, tablets, and other internet-enabled electronic devices.
This has many parents worried. But it’s also giving scientists a chance to answer the question: What effect does screen time have on kids’ developing brains?
Researchers from the National Institutes of Health recently offered a glimpse of the answer, based on preliminary data from the Adolescent Brain Cognitive Development (ABCD) study.
This study is following more than 11,000 9- and 10-year-olds at 21 sites throughout the United States. The results were presented in December by study director Gaya Dowling, PhD, on CBS’ “60 Minutes.”
The two big takeaways from the initial data are:
The brain scans showed that kids with lots of screen time had a premature thinning of the cortex. This outermost layer of the brain processes different types of information from the senses.
“That’s typically thought to be a maturational process,” Dowling said in the CBS interview. “So what we would expect to see later is happening a little bit earlier.”
Is screen time to blame for these brain and learning differences?
Dr. Ellen Selkie, an adolescent medicine physician at the University of Michigan C.S. Mott Children’s Hospital, told Healthline that “the only conclusion we can draw right now is that two things are happening at the same time. But it’s hard to tell whether one caused the other.”
For example, excessive screen time may lower children’s academic performance. But it could also be that children who have difficulty with certain mental tasks may be more drawn to screens for some reason.
The same is true of the differences seen in some children’s brain scans — did screen time cause those changes, or are children with cortical thinning more drawn to screens?
Selkie wasn’t involved in the study.
Dowling told “60 Minutes” that while some questions about the impact of screen time will be answered over the next few years, the long-term effects won’t be known for many years — possibly with more of an answer.
“We’ll be able to see not only how much time are they spending, how they perceive it impacting them, but also what are some of the outcomes,” said Dowling in the CBS interview. “And that will get at the question of whether there’s addiction or not.”
Earlier research focused on television and console videos games, because that’s what was around at the time. But since the iPhone was introduced in 2007, the screen time landscape has changed drastically.
Many newer studies now include Facebook, Instagram, Snapchat, and other uses of electronic devices.
This includes research mentioned in the “60 Minutes” segment. In one study, Dr. Kara Bagot at the University of California at San Diego and her colleagues scanned teenagers’ brains while they checked their Instagram feed.
They found that when teenagers viewed their Instagram feed, the reward system of their brain activated. Bagot and others believe that electronic devices can stimulate the release of dopamine, a brain chemical involved in cravings and desire.
Another recent study found that teens who use electronic media at night are more at risk for sleep disturbances and symptoms of depression.
Cutting back on screen time may relieve some of these symptoms. Researchers at the University of Pennsylvania found that college students who limited their screen time to less than 30 minutes a day were less lonely and depressed, even after just three weeks.
This research and the ABCD study add to our growing understanding of how screen time affects children, although Selkie cautions against thinking that “electronic devices are melting everyone’s brains.”
“It’s clear that there is an interplay between media and child development,” she said, “but I don’t think it’s realistic to take away all electronic devices.”
For parents concerned about their child’s screen time, the American Academy of Pediatrics updated their media guidelines a couple years ago based on recent research. Their suggestions include:
Researchers from the National Institutes of Health recently offered preliminary data from the Adolescent Brain Cognitive Development (ABCD) study.
They had two early takeaways from the data: