Wellllll there is a difference between a game that simulates infantry combat and a game that encourages you to pick up hookers in game, then beat the shit out of them to rob them. Don't get me wrong, it was fun to do it once but that was some seriously messed up shit.
While I don't necessarily believe they cause permanent brain changes, when you look at the plethora of racing/driving games, especially the ones where cops are chasing you like the GTA series, and the HUGE amount of police video of high speed chases over the last decade, you gotta wonder if there's a connection to at least some of the real life chases.