Saturday, April 24, 2010

Noë on Locked in Syndrome?

Consciousness is not something the brain achieves on its own.  Consciousness requires the joint operation of brain, body, and world.  (Noë, 2009, p. 10).
Noë notes that there are individuals who suffer from locked in syndrome.  (Noë, 2009, p. 17f).  They appear to be totally unconscious displaying no actions or behaviors commonly taken to be indicative of consciousness, but they are nonetheless conscious.  How is this possible on Noë’s view?  If consciousness requires the joint operation of brain, body, and world, then how can there be inactive individuals who are nonetheless conscious?

A. Noë, Out of Our Heads: Why you are not Your Brain, and Other Lessons from the Biology of Consciousness. (New York, NY: Hill and Wang, 2009).


  1. Sensory deprivation is probably something related to this problem: it seems that people who spend too much time sensorily deprived end up building hallucinations.

    It seems to speak for the need of the senses in order to have any meaningful mental activity. What happens with locked-in syndrome? Do patients live with such hallucinations?

  2. Thanks for this thought provoking comment. I think there are many issues here.

    For me, it would be helpful to articulate in more detail what is meant by "meaningful mental activity". To me, at least, hallucinations might be meaningful if they are like dreams where, say, you think you are flying. A dream or hallucination of flying seems to me, in some sense, having a meaningful form of mental activity. Such dreams might be contrasted with just a chaos of flashing lights, or something.

    There is also unpacking the notion of "needing the senses". Is this need causal or constitutive, or what?

    Then, there is the empirical question of whether individuals with locked-in syndrome are sensorily deprived. They do, after all, hear sounds, one might think. Moreover, light will stimulate their retinas even though their eyelids are shut. I think that eyelids screen out only about 90% of incoming light.

    I'll try to look into this, but references are welcome.


  3. Ok. So, here is an ERP study of a case of total locked-in syndrome (LIS). It suggests that this patient can recognize names.

    So, it seems that we should not assume that total LIS is like a state of sensory deprivation (unlike, perhaps, what Noë's strong enactivism presupposes).

    Nevertheless, the relationship between sensory deprivation and cognition remains intriguing.

  4. Thanks for answering, and pardon me for being so allusive and so slow to answer.

    By meaningful, I'm using the kantian/hegelian definition: in order to be meaningful, something needs to point to empirical content. In the case of hallucinations, there is indeed empirical content. For instance, when subjects see flies, their experience of flies fills this perception. What I am worried about is more the loss of meaning in this particular example, because the usually thight link between representations of reality and reality itself is being broken.

    The worry is mainly in the diagnostic, which is very theory-ladden: the hallucinations must come from the need of the organism to have this feedback from the world, and that lacking it goes wild in a way or another. Therefore, if the mind was left more time in isolation, it would go even worse, and have less meaningful hallucinations.

    There's an assumption that the smarter parts of the brain works only (or almost only) with some kinds of supervised algorithms, that require feedback and interaction (e.g. Harnad 2005). It does not dispell everything, but apparently it's not as strong an assumption as one could think (cf. Clark & Lappin 2010:, or the works of Jenny Saffran, who see unsupervised algorithms at different levels in language learning).

    In other words, I seriously doubt my assumptions about sensory deprivation now.

    As for references, what I know of it mostly comes from a conference from Hugo Mercier and conversations with fellow grad students. Mercier mentioned two studies made in McGill, one during the cold war in link with interrogation techniques, led by Donald Hebb; he also mentioned that researchers from McGill had recently redone Hebb's shady study with similar results, but I could not find it. There seems to be quite a litterature around it, though, although the UQÀM proxy doesn't grant access to most of it.

  5. Regarding sensory deprivation and cognition, one does have to be cognitizant of the difference between synchronic and diachronic claims. One might formulate these roughly as follows:

    S: To think now, one now needs sensory stimulation.

    D: To maintain a functioning cognitive system, one needs "regular" sensory stimulation.

    D is probably not that controversial, but there are times when at least some fans of the role of sensorimotor stimulation in cognitive science favor S.