Here's an odd study to consider: using a 9 volt battery can make your skills at gaming better - as long as you can stand some small level voltage running through your head. According to an odd DARPA-funded study, running low-level electricity through the scalp might help the mind focus on tasks such as video games. The research used low-level electricity in concert with a military training game to test the theory. Researchers found that test subjects playing a military training game had improved performance when they were affected by transcranial direct-current stimulation (tCDS).
Sponges connected to the temples of subjects generated an electrical current were attached to their temples. Then the test subjects played DARWARS Ambush!, a simulation game designed to help train soldiers for serving in Iraq. The simulation lets players scan for dangers on a landscape, such as improvised explosive devices or enemy gunmen.
Neuroscientists at the University of New Mexico conducted the tests. They subjected participants to 2 milliamps of electricity through the scalps of half the group and 1/20 that amount through the other half. The group that received two milliamps showed twice as much improvement after a short amount of time compared to other the group.
Obviously you do not want to try this sort of thing at home unless you are a complete moron..
Source: The Escapist