The Guardian is reporting today that a certain sleeping pill has resulted in dramatic (but temporary) improvements in patients that have been in persistent vegetative states for years. For at least a few hours, they could talk with their families and watch tv after being given the drug.
This just shows is how little we know about comas and vegetative states. How a sleeping pill resulted in awakening these patients is beyond my medical knowledge, but clearly our knowledge is lacking, at best. I've often thought that people in these states may be having profound experiences that the rest of us in our supposedly preferable "conscious" state do not have access to. Maybe its something like an extremely deep meditation. I suspect that its a state that we can't even imagine (like explaining colour to a person who has never had sight) because it is too far from our experience.