Oh, give it a rest... This is not a game specific thing. It happens with anything that is done for a long perioud of time. Like the mariners who when they first got back on land, would sway as if they were still on board their sailing ships....
Look as they try to demostrate that you shooting a load of people in games, leaves you predetermined to shooting loads of people after the game has finished. They forget that just because you have a violent mechanic lingering in your brain, does not mean you have the intent to it....
If this does happen, as described in the study, it must be only to certain players, as after nearly 30 years of, sometimes excesive bouts of gaming, I have never experienced this.