The largest study yet [nih.gov] into the effects of playing video games on children is out, and it suggests that youngsters who play games have better cognitive performance, and do not suffer from depression or aggression as some smaller, older studies indicated.
The researchers found that the children who reported playing video games for three or more hours per day were faster and more accurate on both cognitive tasks than those who never played. They also observed that the differences in cognitive function observed between the two groups was accompanied by differences in brain activity. Functional MRI brain imaging analyses found that children who played video games for three or more hours per day showed higher brain activity in regions of the brain associated with attention and memory than did those who never played. At the same time, those children who played at least three hours of videogames per day showed more brain activity in frontal brain regions that are associated with more cognitively demanding tasks and less brain activity in brain regions related to vision.
The researchers think these patterns may stem from practicing tasks related to impulse control and memory while playing videogames, which can be cognitively demanding, and that these changes may lead to improved performance on related tasks. Furthermore, the comparatively low activity in visual areas among children who reported playing video games may reflect that this area of the brain may become more efficient at visual processing as a result of repeated practice through video games.