If you read the print version of the NZ Herald today you would have seen featured on the front page a miraculous case of a man [Rom Houben] recovering from a persistent vegetative state and communicating with the world through a touch screen with the help of a carer. The topic of persistent vegetative state (PVS) is an interesting one and has received increasing attention in recent years. It would seem that this man was incorrectly diagnosed after an accident as being in a PVS while at the time of the accident it is more likely that he was in a minimally conscious state (MCS). A fine distinction sometimes and an excellent summary of the differences between the two diagnoses and the difficultly of accurately deciding between them can be found at the Science Based Medicine site.
Essentially a PVS is defined as the patient exhibiting no signs of consciousness, as with everything, whether you find something is dependent on how hard you look, simply opening a couple of drawers and glancing in the cupboard may not turn it up. In determining a case of PVS a more thorough search will reveal fewer legitimate cases as you may find extremely subtle signs of intermittent consciousness that will then flip the designation to a MCS. This process is also dependent on the sensitivity of the equipment used to perform the examination, the sophisticated scanning technology we have today simply did not exist 20 years ago. This equipment is the equivalent of rummaging around in the back of the couch and looking behind the fridge.
That this man was unfortunately diagnosed incorrectly is not in dispute, we have made significant advances in brain imaging technology that allows us to determine activity quite well. The issue here is the man’s ability to communicate so coherently and poetically. After so long without mental stimulation it seems bordering on the fantastic that this could be the case. When watching the video of the touch screen being used to bring this man’s thoughts to the world it seems very close to a practice known as Facilitated Communication, (this is actually confirmed in the TimesOnline article) this consists of a facilitator supporting the arm or hand of a subject ostensibly to allow them to then choose letters and words themselves which otherwise they would not have the strength or the focus to do.
The difficulty here is that this technique is very susceptible to the unconscious influence of the facilitator. In this way it can seem as though it is the patient communicating when in reality it is the thoughts of the facilitator that we are hearing. It is difficult to say for sure in this case, the video is ambiguous as to how much control the patient has over his movements so it is possible that we are indeed being exposed the inner world of a man with a very unique perspective but from the evidence shown it is equally plausible that the facilitator is the true originator of these words.
I would be interested in if any simple tests to determine the true origin of this material have been carried out, some of the suggestions I have seen elsewhere include swapping the facilitator for someone who does not speak the patient’s language, asking the patient questions that presumably only he would know, or asking the facilitator to leave the room while the patient is shown an object or told specific information and then seeing if this can be reliably produced after the facilitator returns. Any of these would help determine whether this man is truely communicating.
The print version of the Herald is mostly credulous in it’s coverage of this story but it appears that enough scepticism has filtered through the journalistic world that the online version has incorporated some of it. Better late than never.
[EDIT: The incomparable Dr Novella of the SGU and SBM has posted his take on this news item, as I hoped he would. Get the thoughts of a neurologist. Also had to add a link to this video from Dr.N’s site that shows the patient typing with his eyes closed, simply not possible. Added Patient’s name]