By Emily Mullin
NATHAN COPELAND CONSIDERS himself a cyborg. The 36-year-old has lived with a brain-computer interface for more than seven years and three months. As of today—August 17—that’s the longest anyone has had an implant like this. Four electrode arrays, each the size of a pencil eraser, translate his neural impulses into commands that allow him to control external devices: a computer, video games, and a robotic arm he can move with just his thoughts.