Video games have taken a lot of heat lately, blamed by some for triggering violence and fostering sedentariness. Now the results of a new study suggest that all those hours spent playing Grand Theft Auto3, Halo and other action-packed games might have some positive effects. Researchers writing today in the journal Nature report that the activity boosts attention-related visual skills.

Through a series of experiments, C. Shawn Green and Daphne Bavelier of the University of Rochester determined that habitual video-game players were better able than nonplayers to focus on visually complex situations, to keep track of multiple items at once and to process fast-changing information. To rule out the possibility that their results simply reflected a tendency for gamers to be people with inherently superior visual skills, the team subjected nongamers to action-video-game training, in which they played Medal of Honor for an hour a day, 10 days in a row. Meanwhile a control group was trained on Tetris, which, unlike Medal of Honor, requires focusing on only a single object at a time. After that short training period, the Medal of Honor group exhibited improved visual skills.

"By forcing players to simultaneously juggle a number of varied tasks (detect new enemies, track existing enemies and avoid getting hurt, among others), action-video-game playing pushes the limits of three rather different aspects of visual attention," the authors conclude. "Although video-game playing may seem rather mindless," they add, "it is capable of radically altering visual attention processing."