Consciousness and the Brainstem
This entry was posted on 1/6/2007 8:23 AM and is filed under Neuroscience,Consciousness.
I am under the impression that philosophers who talk about consciousness by and large focus on state consciousness and neglect creature consciousness, perhaps because they think that creature consciousness reduces to (is analyzable in terms of) state consciousness, or at any rate state consciousness is the ontologically more fundamental notion. Is this correct?
To explain a bit further: state consciousness is what makes a difference between a conscious belief (or desire, percept, etc.) and an unconscious one; creature consciousness is what makes a difference between someone who is normally awake or in REM sleep and someone who is in a coma or in non-REM sleep. It is tempting to suggest that someone is creature-conscious if and only if she has at least one state that is state-conscious. Thus, one might think, creature consciousness is analyzed in terms of state consciousness. Is this what most philosophers think?
At any rate, even if one thinks that creature consciousness does not entirely reduce to state consciousness, one might still think that creature consciousness is not important for the ontology of phenomenal consciousness. Perhaps it's just an auxiliary functional notion, which does not make a difference to the holy grail of phenomenal consciousness.
If this were a correct picture of what most philosophers think, it would explain why philosophers seem to pay so little attention to the role of the brainstem in consciousness. It is well known that the brainstem modulates the global state of the brain so as to determine whether the organism is awake, asleep, more or less alert, etc. This seems extremely relevant to creature consciousness, but not directly relevant to state consciousness (under the prevailing picture tentatively sketched above).
Well, is it even true that philosophers who talk about consciousness pay little attention to the brainstem and its role for consciousness? If so, is my diagnosis correct?
If I'm on the right track, we should consider the possibility that this approach is missing something important. That is, suppose that creature consciousness were ontologically more fundamental than state consciousness. Then, it would be a mistake to develop theories of state consciousness without saying anything about creature consciousness. Rather, a correct approach to consciousness should begin with an account of creature consciousness. It might be that progress on the question of what makes a state state-conscious can be made only by building on an independent account of creature consciousness.
By the way, these reflections are partially motivated by a target article forthcomign in BBS, in which the Bjorn Merker, a neuroscientist, argues that the brainstem can sustain phenomenal consciousness even in the complete absence of the cerebral cortex! Needless to say, this goes way beyond the orthodoxy about the brainstem.