Whether its through news reports or organizations such as Mothers Against Violent Video Games, video games have long been blamed for real-life violence. Opponents of this theory usually say that a violent person was violent before video games or that it's up to the gamers to know the difference between reality and a game, but new research suggests that violent video games and violent television foster a culture that conditions people to make them more violent.

Researchers found that playing first-person shooters reduced a person's ability to inhibit impulsive behavior, including aggressive impulses; something they say is dependent on good executive control. Two types of cognitive control processes factor into how a person is able to inhibit impulsive behavior: proactive and reactive. Proactive control (the good kind) comes as a result of learning and memorizing for use later on as a "kind of task preparation," whereas reactive control relies on impulsive decisions.

"We believe that any game that requires the same type of rapid responding as in most first-person shooters may produce similar effects on proactive executive control, regardless of violent content," Craig Anderson, director of the Center for the Study of Violence at Iowa State University, said in a statement. "However, this is quite speculative."

The researchers had a group of participants, none of whom played video games often, play either the fast-paced, first person shooter Unreal Tournament, the slow-paced low-intensity Sims 2, or nothing, for 10 sessions over the course of 11 weeks. At the beginning and end of the study, each participant tested for proactive cognitive control and visual attention.

They found significant decreases in proactive cognitive control among those who played the first-person shooter when compared to those who played The Sims or nothing at all. Still, their visual attention skills improved.

For another study, the researchers looked at the TV and video game habits of another 422 people to see how their screen time correlated with attention-related problems and possible aggression. They found that those who tend to watch more aggressive TV tend to be more aggressive and hostile.

They also found that total media exposure and violent media exposure both contributed to attention problems. Their analysis found that the link between impulsive aggression and attention problems was stronger than that between premeditated aggression and attention problems.

So much of today's media is fast-paced. It trains the brain to respond quickly to changes on screen, Anderson says. "What such fast-paced media fail to train is inhibiting the almost automatic first response. This is the essence of ADD, ADHD, and measures of impulsivity. That's why attention problems are more strongly related to impulsive aggression than to premeditated aggression."

The results, which have yet to be published, will be presented at the American Psychological Association annual meeting.