A recent study published on 26th September in Lancet, ‘Child and Adolescent Health,’ expresses concerns over the heavy use of smartphones, tablets and television on growing minds.

However, the study, which captures only a single snapshot in time, reflects that it’s still not known whether too much screen time can actually harm brain development, experts caution.

It states, that in the US, 2 out of 3 kids spend more that 2 hours a day looking at screens. Those children perform worse on memory, language and thinking tests than kids who spend less time in front of a device according to the study of over 4,500 8- to 11-year-olds.

Researchers used data gleaned from child and parent surveys on daily screen time, exercise and sleep, collected as part of a larger effort called the Adolescent Brain Cognitive Development Study.

Cognitive abilities were also tested in that bigger study. As a benchmark for the new study, the researchers used expert guidelines set in 2016 that recommend no more than 2 hours of recreational screen time a day, an hour of exercise and between nine and 11 hours of night time sleep.

Co-author, Jeremy Walsh an exercise physiologist said, “Overall, the results are concerning.” At the time of the study Walsh was at the Children’s Hospital of Eastern Ontario Research Institute in Ottawa, Canada.

Only 5 percent of the children met all three guidelines on screen time, exercise and sleep, the survey revealed.

Twenty-nine percent of the children didn’t meet any of the guidelines, meaning that “they’re getting less than nine hours of sleep, they’re on their screens for longer than two hours and they’re not being physically active,” Walsh says. “This raises a flag.”

The children in the study spent 3.6 hours a day, on average using screens. This was for videos, video games and other fun.  Those children who spent less than 2 hours, on average, using screens, scored about 4% higher on a battery of thinking related tests that those who didn’t meet any of the screen, exercise or sleep guidelines, the researchers found.

What the experts say.

“Without consideration of what kids are actually doing with their screens, we’re seeing that the two-hour mark actually seems to be a good recommendation for benefiting cognition,” says Walsh, who is now at the University of British Columbia in Okanagan.

Children who met the recommendations for both screen time and sleep tested better as well. When analysed on their own, sleep and physical activity didn’t seem to influence test results.

The study can’t say whether screen time — or the resulting absence of other activity — lowered thinking skills in children.

Michael Rich, a paediatrician at Boston Children’s Hospital said: –

“You don’t know which is the chicken and which is the egg here, It could be that smarter kids are less likely to spend lots of time on screens.”

Looking for clear-cut blame is a bit of a “red herring,” Rich says. Simple cause-and-effect relationships often don’t exist in human behaviour and development. Instead of blanket pronouncements, “we need to tailor what we learn from science to individual children.”

Eduardo Esteban Bustamante, a kinesiologist at the University of Illinois, Chicago, says By looking at behaviours in combination, the results offer a comprehensive look at children’s health, one that’s sorely needed.

“We don’t know a lot yet about how these behaviours interact with one another to influence kids’ cognitive development,” he says.

The Adolescent Brain Cognitive Development Study is scheduled to continue collecting similar data from these families until 2028. “I’m really excited to see where this line of research goes,” Bustamante says.