CHICAGO (CBS) — Research presented at the Chicago meeting of the Radiological Society of North America has found a first-ever physiologic link between playing violent video games and changes in behavior.

As WBBM Newsradio’s Mike Krauser reports, Indiana University radiology professor Dr. Vincent Mathews showed changes in brain scan images among 18- to 29-year-old men who played first-person shooter games rated “M” or “mature” for about 10 hours a week.

LISTEN: WBBM Newsradio’s Mike Krauser reports

“What we think is that our results may be an explanation for these behavioral studies that showed increased aggressive behavior following a violent video game, so this actually is a physiologic explanation,” Mathews said.

For the study, 22 healthy young men with low past exposure to violent video games were assigned to two groups.

One group of 11 was asked to play a violent video game for about 10 hours at home for the first week of study, then quit playing for the following week. The other group, which was used as the control sample, did not play the game at all.

During the study, the men went for exams in which they completed an “emotional interference task,” in which they pressed buttons according to the color of words that were displayed. Words suggesting violent actions were interspersed with neutral action words.

The test showed the group that played the game for a week showed changes in brain function during the emotional interference task, as well as during a separate counting task, after one week of violent game play.

The researchers declined to name the game used in the study, only saying it was a popular war game.

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