The research is still early, but it seems to be working for at least one 25-year-old patient, who showed "remarkable" improvement after the treatment. Before doctors used sonic stimulation to rouse the neurons in the patient's thalamus -- a structure in the brain that relays sensor signals and helps regulate alertness -- he showed little concious response and had trouble understanding speech. Within days of treatment, however, the patient was fully awake, responsive to conversation and actively communicating with nods and gestures.

"The changes were remarkable," says Martin Monti, UCLA associate professor of psychology and neurosurgery. "It's almost as if we were jump-starting the neurons back into function." If the treatment works in future trials, it could lead to a low-cost device to help patients recover from the effects of being in a coma.