I think anyone who does only one thing all day is going to neglect certain areas of their brain. I love playing computer games, but I also love coaching my son in baseball, listening to live music, reading, playing with the dogs, doing car repair, having sex with my wife, etc. We all need to make our experience well-rounded. I don't think Doom caused the Columbine murders, or even contributed to it. Sick, maladjusted losers who had no alternative, in their twisted tiny minds, but to use violence to get notoriety.