User talk:Axel Cleeremans/Proposed/Computational Correlates of Consciousness

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    Review of Cleeremans

    The article is clear, succinct, illuminating, and in general very well composed. The notion of seeking bridging principles between ‘hardcore’ neuroscience and ‘pure’ phenomenology is attractive. I have a few general comments to make here – specific comments are placed directly within the article.

    • It is assumed that the bridging principles are to be construed in terms of computational processes. However, not all theories discussed would describe themselves as computational, nor would their proponents necessarily accept that the brain is fundamentally an information-processing system (e.g., Tononi, Edelman). Does the author think it is conceivable for bridging principles to be non-computational? I do not suggest that this needs to be discussed at length, but some short discussion would be welcome. One point of reference might be Seth’s recent discussion of ‘explanatory correlates’ which seems to develop the same intuition but without making explicit computational/information-processing assumptions (see ref. below).

    • ‘Computational’ or no, Figure 1 is very useful. Perhaps it could be updated from the 2000 version to include new theories. For example, where would the ‘virtual reality’ models of Hesslow, Revonsuo (and to some extent Metzinger) fit? What about the author’s own ‘radical plasticity’ theory? Other theories might include Sloman and Chrisley’s ‘virtual functional machine’ perspective and O’Regan & Noe’s sensorimotor theory. Finally both Crick & Koch and Edelman & Tononi have updated their ideas since 2000, with Tononi now proposing a different (though) related theory to the dynamic core hypothesis.

    • I’m not completely convinced that non-specialized process theories are really independent of location. To take the dynamic core example again, Edelman & Tononi do emphasize the importance of the thalamocortical system. Tononi, admittedly, goes further by claiming that any system having high ‘phi’ would be conscious, and so the author’s claim is certainly justified here.

    • In the section on ‘stability’ perhaps some discussion could be given of the notion of ‘metastability’, following Bressler, Kelso, Varela, and the like. This idea captures the notion that conscious states are only transiently stable, and shade naturally into successive conscious states.

    • In the summary, the parting shot mentions the distinction between access consciousness and phenomenal consciousness. It may help the reader to unpack this distinction a bit more extensively and perhaps earlier. Also, I don’t think its true that all the theories mentioned deal only with access consciousness. Crick & Koch (synchrony), Lamme (local recurrence) and Tononi/Edelman deal explicitly with phenomenal consciousness.

    • Seth, A.K. (2009). Explanatory correlates of consciousness: Theoretical and Computational Challenges. Cognitive Computation.

    Review of Computational Correlates of Consciousness by Axel Cleeremans

    This is a very clear, well-written paper that provides a very good introduction to this issue. I recommend publication and I have only a few comments, mostly some minor suggestions, that the author might want to consider for improving the quality of the manuscript.

    1) The treatment of Tononi’s theory could have been a bit extended, as it constitutes a nice attempt to provide a purely computational index of subjective experience. Maybe a few more sentences on the computational principle characterizing phi would help the reader appreciate how computational measures of complexity can be directly related to consciousness.

    2) Surprisingly, the radical plasticity hypothesis offered by the author was not even listed in the draft. That is a shame, as this theory offer a very nice example of a recent theory relating philosophical accounts (Rosenthal’s “Higher-Order Thought” theory) and connectionist models.

    3) Not everyone would agree with the following sentence “Of course, any putative computational principle that differentiates between information processing with and without consciousness will necessarily be implemented by specific neural mechanisms occurring in the brain”. The necessity assumption is a bit strong and as far as I know the functionalism vs. physicalism controversy has not yet been resolved.

    4) The fact that Crick and Koch appear for both Specialized and Non-specialized process theories (while only with the former type of theories in the figure) might be a bit confusing for the reader.

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