Last week, Cambridge and Belgian researchers reported that they could observe almost identical brain activity in healthy volunteers as a patient purportedly in the persistent vegetative state following emergence from a coma (the patient was originally in a car crash in July 2005). The implications of this functional MRI work are that some (but by no means all) PVS patients may have consciousness to some degree despite their outwardly appearing inanimate.
It is incredibly tragic to imagine that there might be PVS patients who do have some consciousness but cannot move or communicate with the outside world. Functional MRI may in the long-term lead to a way to communicate with such patients.
That said, there is a long way to go before fMRI or any other technique can provide us with a full understanding of the persistent vegetative state and some researchers are cautious of extrapolating the Cambridge findings too far. Indeed, if you read my report about the research in the latest issue of SpectroscopyNOW.com, you can see quite clearly that the fMRI scan of the control volunteer and the patient are superficially similar – activity is in the same region, after all – but the level of activity appears to be markedly less prominent in the patient. This could have important implications for what is meant by such a patient having consciousness as we know it.
Much more research is now needed to help us redefine the PVS. This is perhaps a matter of some urgency given the current definition of PVS states that these patients cannot experience pain and suffering as these are attributes of consciousness.