Doing Your Mind

Research, comments and musings about active minds.

Coma, Consciousness and Sensorimotor Scepticism

The BBC have an article and video about Rom Houben, a Belgian man who was misdiagnosed as being in a coma for 23 years, but for that entire time claims to have been normally conscious.

Aaron Sloman has made the point on the PHILOS-L mailing list that this case challenges any sensorimotor theory of consciousness, or any theory with strong embodiment claims. All such cases of being “locked in” are significant reminders that whatever cognition and consciousness are, they are not simply movement-related.

Can enactivists defend the approach successfully against such cases?

At present I don’t think there is a wholly defensible position for enactivists on this issue, and I think it raises important questions about the relationship between cognition and embodiment. At best, at the moment, we must refer to the skills, habits and motivations that Mr. Houben had developed over the course of his life up to the time of his accident. Such concepts are not utterly described by particular bodily movements but by actions appropriate to a given context – oftentimes they involve gross motor movement but often they don’t.

Our account of skills, habits and motivations is at best lacking, though, and precisely their relationship with the body needs a lot more explication – how are skills inscribed in the body? Can they be “triggered” without contextualisation within motivated, deliberate action? How are they used in cases like Mr. Houben where no movement is possible?

In particular, I would be fascinated to know how Mr. Houben would describe his consciousness during the period when he was thought comatose, and what kinds of things he was able to learn during that time. Has he managed to develop any new skills or practised old ones to a high level through mental practice?

For the enactive approach it is not movement per se that matters for cognition and consciousness, but rather the integration of something into the value system of the agent. In the case of Mr. Houben, that value system was only partially disrupted – the “deep embodiment” of metabolism was not affected (he survived, after all), and his relationships with other human beings were clearly supported, giving him feedback, however continuously frustrating, on his (failing) attempts to communicate through the plethora of social skills he had developed prior to being injured.

While enactivism doesn’t have really satisfying responses to the challenge of such cases, I don’t think that there is quite sufficient cause to jump to the other extreme – that input and output don’t matter, and that cognition occurs as abstract computation of some kind. It is a signal of work to be done, more than work to be abandoned.


Wired have posted some potential criticisms of the means of communication between Mr. Houben and his interviewers as evidenced in the recent press surrounding him. While this doesn’t take away from the kind of challenge well documented in locked-in cases, it may well add some important detail to the kinds of things that an enactive approach would need to explain

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