Sunday, October 22, 2006

Consciousness Is Back

So says John Searle in the New York Review of Books in a review of a new book by Nicholas Humphrey. I'm not so sure that consciousness - meant as a topic of discussion in philosophy - ever went away.

It is true that the study of mind has been taken over by neurobiologists, neuropsychologists, and artificial nitelligence programmers over the past two decades. Philosophers of mind often think of themselves as doing this kind of work, rather than more traditional studies of consciousness, which Searle notes raises again the old, shopworn mind-body dualism.

This problem, the traditional problem of the relation of conscious experiences to the physical brain, of "mind" to body, is precisely Nicholas Humphrey's target of investigation in Seeing Red: A Study in Consciousness. I think he would agree with my definition of consciousness and with my claim that it is irreducibly subjective. But he takes exception to my claim that one of its important functions is conscious perception and he strongly disagrees with my claim that a central problem is to try to get an account of how brain processes cause conscious experiences. He, on the contrary, thinks that all perception is unconscious, and that instead of trying to find a causal explanation for consciousness we should try to find an equation: i.e., if we are going to solve the problem of the relation of the mind to the body, we have to show that conscious mental experience is identical with the content of the physical brain.

It is important to see the differences between these two approaches. On the standard account, neurobiologists are seeking the "neuronal correlate of consciousness" (NCC). The idea is that if we could first identify the NCC—the events in the brain that occur when we have subjective experiences—we could then test to see if the correlation is causal, and finally we would like to develop a theory showing how the neuronal correlates cause the conscious experiences. This research is currently widely pursued and is making some progress. Humphrey's entire approach differs from mainstream philosophy and neuroscience. He dismisses the search for the NCC on the grounds that it "privileges neuronal events over all the other ways we might wish to describe what is going on in the brain." For him any explanation has to be of the form mind = brain, m = b [Searle, rather, takes a causal account, rather than this kind of equation assumption]...

...Mind and brain appear to be in different dimensions, because mind has qualitative subjectivity and brain does not. If you try to say, for example, that the experience of red is identical with neuron firings, the terms of the equation seem to be in different dimensions, because the conscious experience of red has the qualitative sub-jectivity that I described earlier, while neuron firings do not. It is a first-person phenomenon, whereas neuron firings are objective, third-person phenomena that would theoretically look the same to any observer, if they could be observed.

That's the classic problem, the one even Descartes may have thought he had resolved by locating the nexus between physical, objective brain and nonphysical, subjective consciousness in the pineal gland. This was always, perhaps even for Descartes, a pretty silly explanation.

But there has been quite a bit of work done on consciousness and Searle's own assumption that there is some kind of "return" to studies of consciousness requires overlooking quite a bit of research and philosophical work. Searle, in fact, operates here on his own variation of the assumption that m=b.

Owen Flanagan, among others, has long worked on consciousness as a function of body where the brain plays a significant but not exclusive role in first-person consciousness. Rather, consciousness is a set of evolutionary processes that require phenomenological, neural, psychological analyses. Yes, the mind is basically the brain, but where the brain is taken as an evolutionary nervous system of mutation, genetic drift, natural selection, migration.

The ego, the conscious self of subjective experience, is therefore emergent in the context of environment. Wiping away the full context and panoply of processes involved in understanding consciousness in order to reduce it to 'm=b' or 'b causes m' seems to miss real possibilities of understanding and explanation, and it may very well be the fetishiziation of explaining mind-body via artificial intelligence programs that has served to set aside context and complex processes. Apparently, some neuropsychologists are even returning to William James' 100+ year-old notion that the body, more generally speaking, is the source of consciousness given that there is evidence that the body - and not simply the brain - "knows" before the mind does.


MT said...

Maybe the study of consciousness never disappeared but has been the whole time in a Chinese room that speaks more than one dialect?

I'd vote NCC if I thought Searle's representation of others' arguments in defense of his own deserved my trust, but I don't. I'll agree that he does make m=b sound dumb in that excerpt. That said, I could believe that it didn't exclude an understanding of consciousness as a moving target within the brain though. In fact, if that's it's assumption, it becomes easier for me to imagine an m=b type point that adds to Searle's NCC and doesn't conflict with it. Perhaps if we could see the moving target that is consciousness, then in cross-section it would be something like the visualizations that my Windows Media Player churns out to music-- superimposed on a CT or MRI cross-section of the brain. Those whorls and spirals bear some mathematical relationship to whatever music I'm playing, I suppose. Perhaps that's like the equation we're supposed to search for. And so maybe the point of it is to steer the discussion of consciousness away from a traditional neuroanatomical view of brains having discrete regions that do different mental tasks and don't move around, which maybe predisposes us to expect the NCC will be a clump of neurons here, here and here doing this, this and this. Maybe the young turk sees Searle as over-emphasizing the chip, and neglecting that engineers have equations for how the concatenation of all its subcircuits will behave before they ever build the chip. "Be more of an engineer," he might be advising. I suppose that wouldn't be inconsistent with Searle's seeming contention that there's no philosophical breakthrough there.

helmut said...

Consciousness is the new black, just like black is the new black.

This all sounds reasonable to me, MT. But even if it's inaccurate to say that consciousness can be physically located in the packaged, segmented sense, the problem doesn't seem overcome by consciousness as a "moving target." That's another way of describing consciousness as a physical occurrence.

I have no doubt that there is some correlation between processes of the brain and mental states. That's not the issue. There's simply a lot lost in either m=b or m causes b. We can see neuronal sparking. We can't "see" consciousness, unless we a priori equate those physical processes with not only consciousness but the self-awareness of consciousness. Of course, maybe what's lost is simply philosophical perplexity. But I still have the sense that that extra ingredient of consciousness of significantly, rather than trivially, perplexing for discerning the relations between the physical brain and mental states or consciousness.

MT said...

I know my own consciousness is subjective, but I don't believe philosophy has proved that yours is. It seems like Descartes' proved to himself that he had subjectivity, but what do I know? Maybe the mistake is to accept that consciousness can be substantially represented in the abstract, as for many purposed we conventionally accept a blueprint as a full representation of the Empire State building. But you can't have a wedding reception at a blueprint, so I might regard buildings as posing just as profound a puzzle as consciousness. If I identified with buildings like I identify with people, I probably would. Similarly we don't fault scientists for being unable to turn back time. We credit a high-energy physicist with creating a muon and capturing its exact behavior in equations, even though she can't go back and create literally "the same" muon doing the same loop-de-loop again. Their understanding of muons is none the weaker because of this inability. "Vantage" and "perspective" in fact are as elusive as "consciousness." We just assume that all that matters to a vantage is vision, and that all our eyes and visual processing systems work the same. Neither is true. Just as a computer game maker could capture everything about the light and topography of a perspective, a neuroscientist someday may be able to represent the state and relationship of all the neurons in Hank Aaron's brain when he hit his record-setting home run; and thanks to cryogenics and future hardware, she might be able to tweak Hank Aaron's brain in a vat to thinks it's Hank Aaron and having the that very experience (for the first time naturally). In so doing I'd say she demonstrated an understanding of "what it was to be Hank Aaron." If at the same time she knew in detail what aspects of Hank Aaron's brain activity corresponded to his subjective experience, I'd credit her with solving the problem of Hank Aaron's consciousness for the historic period in question. Should I note that she is not herself Hank Aaron and never even played baseball, and therefore credit her with neither? In a romantic mood, sure I will. In a novel I might do well to do so. But I think for philosophy the temptation is a trap.