After years of focusing on the bad - and there are still legitimate concerns, for instance, about the psychological effects of certain violent games - scientists are increasingly examining the potential benefits of video games. Their studies are revealing that a wide variety of games can boost mental function, improving everything from vision to memory. Still unclear is whether these gains are long-lasting and can be applied to non-game tasks. But video games, it seems, might actually be good for the brain.

The very structure of video games makes them ideal tools for brain training.

If we analyze any video game we'll realize they are hard, because people don’t like to play easy games, and games have figured out a way to encourage players to persist at solving challenging problems.

The games aren’t just hard - they’re adaptively hard. They tend to challenge people right at the edge of their abilities; as players get better and score more points, they move up to more demanding levels of play. This adaptive challenge is “stunningly powerful’’ for learning.

Most games involve a huge number of mental tasks, and playing can boost any one of them. Fast-paced, action-packed video games have been shown, in separate studies, to boost visual acuity, spatial perception, and the ability to pick out objects in a scene. Complex, strategy-based games can improve other cognitive skills, including working memory and reasoning.

Richard Haier,a pediatric neurologist and professor emeritus at the School of Medicine at the University of California at Irvine, has shown in a pair of studies that the classic game Tetris, in which players have to rotate and direct rapidly falling blocks, alters the brain. In a paper published last month, Haier and his colleagues showed that after three months of Tetris practice, teenage girls not only played the game better, their brains became more efficient.

These findings fit with scientists’ increasing understanding of how malleable the human brain truly is. Researchers now know that learning and practicing a challenging task can actually change the brain.