Many parents’ knee-jerk reaction to video games is that they are inherently bad for children. It is assumed that not only is it better to engage in more creative activities, but that video games might harm the developing brain. For example, it is thought that screen technologies cause abnormally high arousal, which, in turn, activates the brain’s addiction and reward systems, leading to craving more screen time, and possibly increasing the risk of other addictions. However, there is surprisingly little compelling empirical evidence to support this or other concerns. This does not mean the concerns about video games are misplaced; it simply reflect the absence of reliable studies on this issue.
By contrast, a number of studies suggest that video games might be beneficial in certain situations. For example, action video games significantly improve reading ability of dyslexic children. Relatively short periods of video gaming are sufficient to cause significant improvements in some cognitive functions of healthy, young adult (reference). Even action video games—that are considered mindless—may improve a number of cognitive tasks, improve visual attention and the ability to switch rapidly between tasks (reported here).
There is a positive association between lifetime amount of playing certain video games and structural changes in the brain. Such physical changes in the brain—possibly associated with improvements in spatial navigation, memory formation, and fine motor skills, can even occur in adults that played video games for only a couple of months (see here). Thus, video games, including action games, may foster positive changes in the brains of children and adults, as reviewed here.
These findings have sparked an entire industry aimed at identifying those video games that can lead to positive cognitive outcomes. One example is SPARX, a game designed for children with depressive disorders, based on the principles of cognitive behavioral therapy. Preliminary evidence suggest that it is effective.
See also Brain Candy, an article in The New Yorker.