Doctors at Cambridge University's Medical Research Council's cognition and brain siences unit made startling doscovery when they managed to communicate with a man who was in a coma for seven years, The Guardian reported.
The doctors devised a technique to enable the 29-year old comatose patient to answer simple questions as a yes or no, through the use of a hi-tech scanner, monitoring his brain activity.
To answer yes, he was told to think of playing tennis, a motor activity. To answer no, he was told to think of wandering from room to room in his home, visualising everything he would expect to see there, creating activity in the part of the brain that controls spatial awareness.
The patient amazed the doctors by answeringa a series of questions about his family correctly. While this breakthrough is a cause for celebration it is also bound to reignite the debate on euthanising patients in such vegetative states.
Dr Adrian Owen, assistant director of the program said, "We were astonished when we saw the results of the scans and that he was able to correctly answer the questions that were asked by simply changing his thoughts. For the first time in five years it provided the patient with a way of communicating his thoughts to the outside world."
The study tracked 23 patients classified as in a vegetative state and found that four were able to generate thoughts of tennis or their homes and create mind patterns that could be read by an fMRI (functional magnetic resonance imaging) scanner although only one was asked specific questions.
Owen said that 40% of cases people ina vegetativestate were later found to be able to communicate in some way.
He said he believed that the patients who responded in the study were probably "perfectly consciously aware", although he knew others would disagree."To be able to do what we have asked, you have to be able to understand instructions and have to have a functioning memory to remember what tennis is and you have to have your attention intact. I can't think of what cognitive functions they haven't got and still be able to do this," he said.
"These findings have implications in the context of any clinical encounter where we currently rely on behavioural assessment alone to identify consciousness," said Dr Nicholas D Schiff, associate professor of neurology and neuroscience at Weill Cornell medical college, New York.
Schiff said that the next question was to figure out what mechanism accounted for the dissociation of behaviour and integrative brain functions.