Kids who watched TV or played video games for more than two hours a day were more likely to have attention problems in the classroom, the study found. (Associated Press)

Playing video games may make it harder for some children to pay attention in school, a new study suggests.

Watching too much TV has been linked to attention problems in children, but few studies have looked for a similar effect for video games.

In Monday's issue of the journal Pediatrics, U.S. researchers report that children who exceeded the two hours per day of screen time recommended by the American Academy of Pediatrics were 1.5 to two times more likely to be considered above average in attention problems by their teachers compared to children who met the guideline.

The researchers followed 1,323 children in Grades 3 to 5 and 210 college students. For the children, parents helped log TV and gaming time over a year. The college students filled in reports on their TV and video game exposure and attention problems.

Teachers rated the children on school performance, aggressive behaviour and attention problems using a five-point rating scale.

"In just one year, we would see attention problems in the classroom getting worse related to how much time kids are in front of television and video games," said study co-author Douglas Gentile, an associate professor of psychology at Iowa State in Aimes, Iowa.

While the researchers did take into account earlier attention problems and gender, none of the participants were formally diagnosed with attention-deficit hyperactivity disorder, or ADHD.

Statistically, the effects would be considered small to moderate in size. But public health concerns are often based on relatively small effects, particularly with issues that affect many people, like watching TV and video gaming, said the study's lead author, Edward Swing, a psychology doctoral candidate at Iowa State.

Screen-time limits proposed

"These studies demonstrate that the risk could be reduced if parents followed the recommendation of the AAP to limit children’s exposure to television and video games to no more than two hours per day," Gentile and his colleagues concluded.

"Furthermore, there are theoretical reasons to believe that slower-paced educational, nonviolent content is less likely to cause attention problems, but more studies on this issue are especially needed."

The study cannot determine if using electronic media itself causes reduced attention, since other factors may also contribute that were not considered in the study, the researchers acknowledged in calling for longer-term studies.

For example, some children may stay up late gaming, which leads to attention problems from lack of sleep, or the screen time may mean children fail to get enough exercise, said Judith Wiener, a professor of school and clinical child psychology at the Ontario Institute for Studies in Education in Toronto.

A study earlier this year by the Kaiser Family Foundation found kids aged eight to 18 devote an average of seven hours and 38 minutes per day to entertainment media, or more than 53 hours a week multitasking with media.

The study was partly funded by Medica Foundation, Healthy and Active America Foundation, Fairview Health Services, and Cargill, Inc.

With files from The Canadian Press