My nephew, Declan Smithies, is Assistant Professor in Philosophy at Ohio State University and currently in Australia as Postdoctoral Fellow in the Research School at ANU. He works mainly in epistemology and the philosophy of mind and today sent me a link to the interesting site of Adrian Owen who is engaged in detecting awareness in the "vegetative state".
Owen asked a patient to imagine playing tennis or moving through her house, and then monitored the resulting brain activity in relevant parts of the cortex dealing with motor routines or spatial navigation. The patient concerned was so "locked in" that she could not even move her eyelids to communicate. the startling result was that her brain activity was indistinguishable from that of healthy volunteers. One future possibility may be to to investigate techniques for using brain imagining as a means for communication with such patients.
Declan is interested in the philosophical implications of this research and he rightly guessed that I would be interested in it too. My concern is particularly with the political and legislative treatment of PVS patients. Since the Bland judgement it has been acceptable in England to starve and dehydrate PVS patients to death in their "best interests". Remember too, that Tony Bland was not dying and was not in pain.
Declan also passed on news of the film The Diving Bell and the Butterfly which explores the experience of Jean Dominique Bauby who suffered "locked in syndrome" and could only blink his left eyelid. He wrote the book on which the film is based, one letter at a time by having a person recite the alphabet so that he could blink at the correct letter. To improve efficiency, the alphabet was ordered according to the frequency with which the letters occur in the French language.