To much international fanfare, news emerged this week that Steven Laureys, a coma researcher at the University of Liège in Belgium appears to have demonstrated that a man believed for 23 years to be in a vegetative state was in fact minimally conscious, presumably for the entire period. Laureys discovered Rom Houben was conscious when his brain was scanned using fMRI imaging, which revealed that it was “functioning almost normally”.
Earlier this year, Laureys, together with other researchers, conducted a study in which he re-diagnosed 44 patients thought to be in a vegetative state and found that 18, or 41 per cent were “minimally conscious”, a liminal zone between consciousness and unconsciousness, in which pain can be felt, some emotion can be experienced, a certain measure of communication is possible and recovery to full consciousness is more likely. By contrast, In a vegetative state (VS), reflexes are intact and the patient can breathe unaided, but there is no awareness.
Although the extent to which these 41% are conscious will surely vary, these results appear significant, as they suggest that many people currently presumed to be in a coma, may, like Houben, have residual or even full consciousness.
Houben’s work and this anecdotal rescue’s savvy public airing are interesting not only because of the deeply personal issues involved in thinking about loved ones at the brink of engagement with the world, but also because they touch on a deep-seated problem fundamental to neuroethics and the philosophy of mind: namely, the causes or correlates of consciousness, full stop. Where to draw the physiological threshold of consciousness continues to be a hotly debated issue because it involves the tense interplay of phenomenological subjectivity and intersubjective scientific practice. The problem is essentially that phenomenological consciousness, which is generally presumed to be only subjectively accessible, needs to be inferred from intersubjectively accessible markers (e.g. communication, fMRI data), which are gathered more or less rigorously, but are nevertheless not strictly isomorphic to what is commonly taken to be phenomenological consciousness.
An example of this problem tending towards the less rigorous end of evidence for consciousness was illustrated by controversy surrounding Houben’s means of communication, called “facilitated communication”, in which Houban communicates himself with assistance from an aide who helps guide his finger to the letters on a touchscreen. Some of the news footage of Houben appears to show him and his therapist typing on his computer screen with his eyes closed. Art Caplan has likened this method to a Ouija board, and famous skeptic James Randi has also expressed skepticism, although he maintains that the more rigorously collected fMRI data suggests his diagnosis as minimally conscious is correct.
– CJ Murdoch