I can trace my search for consciousness in nonresponsive patients to the moment in 1997 when I met Kate, a young teacher from Cambridge, England, who had lapsed into a coma after a flulike illness. Within a few weeks Kate's doctors had declared her to be vegetative—meaning that although she had sleep-wake cycles, she lacked conscious awareness. Her eyes would open and close, and she would appear to look fleetingly around the hospital room, but she showed no signs of inner life and no responses to prompting by her family or doctors.