According to an American study, a man who technically met all the internationally agreed criteria for being in a vegetative state responded to direct commands with his brain. The researchers conclusion is, that this man is not in a true vegetative state and probably is as conscious as we are. The researchers used EEG to record electrical activity in the brain. The subjects were asked to imagine at least four separate actions – either clenching their right fist or wiggling their toes. In three of the people in persistent vegetative state, brain regions known to be associated with those tasks lit up with activity, despite physical unresponsiveness. This suggested to the researchers that the subjects were carrying out a complex set of cognitive functions including hearing the command, understanding language, sustaining attention and tapping into working memory.
Morten Overgaard, cognitive neuroscientist at Aalborg University, says that determining whether the patients are actually responding consciously or whether they are unconsciously reacting to suggestions from the command is difficult to know without further study and that we need signs that are very strong and not just an indication of consciousness.
Read the article: EEG finds consciousness in people in vegetative state in NewScientist10 November 2011