June 10, 2005 -- Watching violent television programs or video games may affect children's minds even if they don't have a history of aggressive behavior, a new study shows.
Researchers found nonaggressive children who had been exposed to high levels of media violence had similar patterns of activity in an area of the brain linked to self-control and attention as aggressive children who had been diagnosed with disruptive behavior disorder.
"This observation is the first demonstration of differences in brain function being associated with media violence exposure," says researcher Vincent Mathews, MD, of the Indiana University School of Medicine, in a news release.
Although this study shows a link between violent media exposure and brain function differences, researchers say more study is needed before they know if the violent media exposure caused these differences.
Violence May Change the Brain
In the study, researchers measured activity in the frontal cortex (the front part) of the brain in two groups of 14 boys and five girls while they performed a task requiring concentration. Less activity in the frontal cortex has been associated with problems with self-control and attention.
One group of children was considered aggressive and had been diagnosed with disruptive behavior disorder and the other had no history of behavior problems.
About half of the children in each group had been exposed to high levels of media violence, as defined as a higher than average amount of time spent each week watching television programs or playing video games depicting human injury.
As expected, the results showed that all of the aggressive children had reduced activity in their frontal cortex while completing the task, regardless of their levels of media violence exposure.
But researchers found that nonaggressive children who had high levels of media violence exposure also displayed a similar pattern of low activity in the frontal cortex. Children in this group who weren't exposed to high levels of media violence had more frontal cortex activity.
"We found high rates of exposure to violent television and video games in teens, but we are just beginning to explore the possible implications of this exposure for brain and behavioral development," says researcher Kronenberger, PhD, of Indiana University, in the release. "There are myriad articles showing that exposure to violent TV, especially, causes individuals to be more aggressive. We are studying the neurological and self-control processes that underlie the aggressive behavior."