A new study by three psychologists at Iowa State University suggests children’s short attention spans can be blamed on a combination of television watching and video games.

Previous research has pointed to TV viewing as a contributing factor in young people’s inability to concentrate. This is the first study to factor in video games.

Doug Gentile, an associate professor of psychology at ISU, says it’s unclear why excessive time in front of video screens ruins a kid’s ability to focus, but he has a theory. “If you spend a lot of time watching screen media, (the images) do a lot of things to help your attention. They flicker, which makes us look at them. They change in sound effect and sound level, which make us look. Therefore, you don’t need to try to pay attention to them. This is why we find television so relaxing,” Gentile says.

He suggests parents restrict their children to no more than two hours a day viewing a screen. “I think many parents, when the teacher says their kid is having problems maintaining attention, they feel at a loss, they don’t know what to do and often they think the only thing they have open to them is perhaps medicating their child,” Gentile says. “This study actually offers some hope for parents that here’s something they can do before they take that step.”

The ISU researchers studied more than 1,300 grade-schoolers in Iowa and Minnesota over 13 months. Their results appear in the August issue of the journal “Pediatrics,” now available on-line.