Now, a St. Louis-area teenage boy and a computer game have gone hands-off, thanks to a unique experiment conducted by a team of neurosurgeons, neurologists, and engineers at Washington University in St. Louis.The boy, a 14-year-old who suffers from epilepsy, is the first teenager to play a two-dimensional video game, Space Invaders, using only the signals from his brain to make movements.Getting subjects to move objects using only their brains has implications toward someday building biomedical devices that can control artificial limbs, for instance, enabling the disabled to move a prosthetic arm or leg by thinking about it.A number of gamers...