Source: Intelligence and How to Get It: Why Schools and Cultures Count (2009). p. 49.
We have every reason to believe that these sorts of visual exercises actually improve fluid-intelligence skills and the executive functions that underlie them, including working memory and control of attention. Researchers have shown, for example, that video-game players can attend to more things at once than can nonplayers. Video-game players can also ignore irrelevant stimuli more effectively than nonplayers and can see objects in a broader visual field than nonplayers. To make sure that what they have observed of computer-game players is not just a self-selection effect (with the fluid IQ hotshots being the ones most likely to play computer games in the first place), the researchers had non- players learn a game—Medal of Honor [emboldening mine]—that they thought would teach the attention-control skills of their video-game players, and had other nonplayers play a computer game that the researchers did not believe would be capable of teaching attention control, namely, Tetris. Subjects played the computer games for an hour a day for ten days. At the end of the period, Medal of Honor players did better on the attention-control tasks than did Tetris players.
Exclude Medal of Honor that's already cited overhead.