In controlled scientific experiments, video games have actually been proven to significantly improve selective attention and reflexes (100 ms faster to respond, on average; which is quite substantial). Playing a video game is a perfect way to train yourself to adapt to sudden movements with precision reflex. First-person view shooters are particularly effective in this regard. If you can turn up the game speed to 200%, do it. If you can add a ridiculous amount of computer opponents, do it. If you can pick the smallest level, do it. The more intense and rapid the game is, the faster you will train your reflex to be. The conditioned reflex (moving the mouse) doesn’t necessarily apply outside of using the computer; however shortening the time between perception and response is where the real benefits are reaped. If you aren’t a gamer, try searching for reflex games online – there are loads of them out there.