The merely verbal problem of consciousness

The whole point of my article [1xTwo neural correlates of consciousness. Block, N. Trends Cogn. Sci. 2005; 9: 46–52Abstract | Full Text | Full Text PDF | PubMed | Scopus (248)See all References][1] is to give empirical evidence against the objection that Baars and Laureys raise [2xSee all References][2]. After sketching the evidence for two phenomenal NCCs, I introduce their position as the ‘doubter’, saying ‘The doubter may say that without access, there can be no true phenomenal contents but only proto-contents that become contents when globally broadcast’ (p. 48). The rest of the article is an argument against that position. For example, I appeal to work [3xTwo distinct modes of sensory processing observed in monkey primary visual cortex (V1). Super, H. et al. Nat. Neurosci. 2001; 4: 304–310Crossref | PubMed | Scopus (278)See all References][3] in which a neural marker of phenomenal consciousness (‘contextual modulation’, which is a marker of recurrent processing, itself a marker of phenomenal consciousness) is disconnected from access. A monkey is trained to saccade to a target, but if the target is low enough in salience or the number of catch trials is high enough, the marker of phenomenal consciousness is equally likely to be present whether the monkey accesses (saccades to) the target or not. Baars and Laureys appeal to cases in which activations of sensory cortices are not sufficient for access consciousness. Such cases are irrelevant because they do not conflict with my argument, which was that recurrent activation of sensory cortices (e.g. MT/V5) is sufficient (given certain other background conditions) for phenomenal consciousness. For example, if I am right about the occurrence of the phenomenal NCC without the access NCC, then if some patients who are now classified as vegetative have recurrent processing in sensory cortices, they would have to be re-evaluated.The evidence I cited suggests that there are neural correlates of the phenomenal contents [4xThe refutation of idealism. Moore, G.E. Mind N.S. 1903; xii: 433–453CrossrefSee all References][4] of sensory states (the ‘redness of red’ as opposed to the ‘blueness of blue’). There is no reason to think that those phenomenal contents must be any different depending on whether they are accessed (or even accessible) or not. And if they are phenomenal, then they can be said to be conscious in one of the many senses of that term. Kanwisher [5xSee all References][5], citing Baars, refers to a ‘common intuition about perceptual awareness (e.g. Baars, 1988), if you perceive something, then you can report on it through any output system’. But what this ‘common intuition’ comes to is a remark about how we commonly use terms like ‘consciousness’, ‘awareness’ and ‘phenomenal’, namely to refer to what I call access consciousness. Although there is indeed a strong strand in these vague terms that points to access consciousness, there is also a strong strand in our use of these terms that points to phenomenal consciousness. But, and this is a much more important point, why should a scientist (except maybe a linguist) care so much about how we use terms like ‘consciousness’, ‘awareness’ and ‘phenomenal’? The substantive empirical point is that we have evidence that the content of experience can exist in the back of the head without the access to it that is based in the front of the head.