Apparently, video games are more than simple cathartic narrative and fantasy role playing anymore. New research by scientists from the University of Missouri claims to answer whether aggression is linked to playing video games. According to the study, video game players have a diminished brain response to violence the more violent video games they play, which creates an increase in aggression.

The study involved 70 adult participants who were randomly assigned to play either a violent video game or nonviolent video game for about a half hour. Once they were done, the researchers measured brain activity while the participants looked at a series of violent and nonviolent photos. After that the participants were set loose at a task that allowed them to blast opponents with controllable noise; the volume measured their aggression.

Scientists found that the popular culprits of high levels of aggression were games such as Call of Duty, Killzone and GTA. The people that played these games blasted the highest level of noise in the final stage of the study. In addition to the noise blasting, those that played the most violent video games had a reduced brain reaction to the violent photos they saw, confirming desensitization to violence.

The study also found individuals who had no change in brain activity when participating in the study. These unaffected participants were already highly exposed to violent video games and seemed to have met their threshold of desensitization to violence. One researcher did admit that these anomalies with no brain change may represent additional measures to consider.

In a University of Missouri press release, associate professor of psychology at the school, Bruce Bartholow, said, “More than any other media, these video games encourage active participation in violence. From a psychological perspective, video games are excellent teaching tools because they award players for engaging in certain types of behavior. Unfortunately, in many popular video games, the behavior is violence.”