At the annual meeting of the Radiological Society of North America this week, doctors whose specialties include the interpretation of X-rays and MRIs (magnetic resonance imaging) presented data suggesting that teenagers who play violent video games exhibit increased activity in "emotional" areas of the brain. They also display a decrease of activity in "self-control" areas of the brain typical of the primal "fight or flight" response.

　　Dr. Vincent Mathews, a professor of radiology at Indiana University School of Medicine, told Reuters that his study used data collected from MRIs of the brain immediately after subject teens had played either violent or nonviolent games. Mathews and his team monitored the teens, aged 13 to 17, after the gameplay, observing them complete various assigned tasks. The study required the teens to complete tasks requiring concentration and processing of emotional stimuli while their brain activity was scanned.

　　"What we showed is there is an increase in emotional arousal. The fight or flight response is activated after playing a violent video game," Mathews said.

　　The games used in the study were Medal of Honor: Frontline and Need for Speed Underground--the former being the game the doctor said exposed the teens to scenes of violence. Frontline is rated T for Teen, while Underground is rated E for Everyone (though its sequel is rated T for Teen).

　　"Our study suggests that playing a certain type of violent video game may have different short-term effects on brain function than playing a nonviolent, but exciting, game," Mathews told the Reuters news service.

　　The study recorded changes in brain activity in 44 teens. Mathews said he hopes to continue researching the impact of games on the emotional well-being of children.