Four adult epilepsy patients who had had a grid of electrodes implanted on the surfaces of their brains (for the purpose of accurately localizing their seizure focus) learned to move a computer cursor on screen with their mental processes alone and, with only hours of practice, play a simple computer game with their minds. As boing boing, which pointed me to this item, suggested, I wonder how long it will be before the Pentagon starts implanting these grids into their clientele.