Daphne Bavelier and her team at the University of Rochester have been doing research looking at the effect of video gaming on something called visual attention. This is not the same as what we normally call “attention” which is really something we control and do on purpose. Visual attention is the brains ability to focus on an object or event withing the visual field. It seems that gamers can “see” something new in their visual field more quickly than non-gamers. It also appears that they can also pay simultaneous attention to more objects (gamers = 5, non-gamers = 3). Gamers I talked to said that they could easily keep track of more complex visual environments now than they could back when they started.
Now if we add the idea of cognitive exhaustion; that brains become more efficient in their use of energy (glucose) as it gets better at doing something, then it stands to reason that as gamers get better at “seeing” more objects or events in on the screen, that they do so more effortlessly, leaving more cognitive resources to other cerebral processes like motor reflex.