Saturday, April 22, 2006

1.2 A Spectrum of answers

Here Koch goes over several different approaches and explanations regarding the consciousness problem.

Some of them are:

Consciousness is illusory
Here he is talking about the theories proposed by Dan Dennett. In page 6 Koch says: "(Dennett) argues that consciousness as most people conceive of it is an elaborate illusion". And then "Given the centrality of subjective feelings to everyday life, it would require extraordinary factual evidence before concluding that qualia and feelings are illusory".
It is important to point out the "as most people conceive of it" in Dennett's proposal. He is not saying that subjective feelings don't exist. He is saying that they do exist, only that they are dispositions rather than magical 'quales'. It seems to me that Koch's own way of seeing qualia (that we will analyze in subsequent chapters) is much much closer to Dennett's point of view than he acknowledges.

Consciousness requires behavior
This is a very interesting proposal. O'Regan and Noe propose that: "The behaving organism embedded in a particular environment is what generates feelings".
Koch doesn't like this account, and I don't really like it either in the way O'Regan a Noe propose it. But it is clear that there is something to this way of seeing the problem. They point out that neuronal activity doesn't have a tag that says "I am visual" or "I am auditory" and that there aren't a priory reasons to feel activity coming from the eyes as visual and not some other way. So, sure enough, there must be a developmental interplay between sensory, motor and reward related activity to generate what we call today a visual perception.
This is indeed interesting and mind-opening, but their account of phenomenal experience didn't sound convincing. Koch points out that while dreaming we have phenomenal states that don't relate directly with the external world. In this article they directly address this point, in fact not answering it at all! Here is the section where they describe this:

"It is often claimed that dreaming, or other types of mental imagery, provide a counterexample to our denial that the brain must represent what is seen. Since dreams and mental images are apparently pictorial in nature, this seems to show that we are, after all, capable of creating an internal iconic image. Penfield's classic observations (e.g. Penfield & Jasper [1954]) of visual memories being created by stimulation of visual cortex might also be thought to indicate that there are internal pictorial representations.
It is easy to be misled by these arguments, which for some reason are peculiarly compelling. But it is important to appreciate that they are misleading. Whether dreams, hallucination, or normal vision are at stake, these arguments are another instance of the error of thinking that when we see things as picture-like (be it when we look at reality or when we have a dream), this must be because there is some kind of internal picture. But this is as misguided as the supposition that to see red, there must be red neurons in the brain. The supposed fact that things appear pictorial to us in no way requires there to be pictures in the head. Therefore the fact that we dream, hallucinate and imagine does not provide evidence in favor of the view that brain contains pictures of the detailed environment
A corollary of this confusion about dreams and mental imagery is the idea, expressed by a number of authors (e.g. Zeki [1993], Kosslyn [1994], Farah [1989]) that feedback from higher brain areas into the retinotopic cortical map of area V1 would be a good way of creating mental imagery. This argument is somewhat misleading. It could be taken to be based on the implicit assumption that mental imagery occurs because of activation in V1: the topographic, metric layout of V1 would make it a good candidate for the cortical areas that possess what Zeki [1993] has called an "experiential" quality -- i.e. the capacity to generate experience. But again, the metric quality of V1 cannot in any way be the cause for the metric quality of our experience. It is as though in order to generate letters on one's screen, the computer had to have little letters floating around in its electronics somewhere.
There may also be a second confusion at work in the argument from dreaming that we are considering. We have already noted that from the fact that dreams are pictorial, it does not follow that, when we dream, there are pictures in the head. But do we really have reason to believe that dreams are pictorial? People certainly do say that they are. But does this give us reason to believe it is so? Just as we have observed that the idea that seeing is pictorial reflects a kind of naïve phenomenology of vision, it may very well be that the claim that dreaming is pictorial is similarly ill-founded phenomenologically. Certainly it is not the case that when we dream, it is as if we were looking at pictures. A hallmark of dream-like experiences is the unstable and seemingly random character of dreamt detail. For example, the writing on the card is different every time you look at it in the dream[16]. This suggests that without the world to serve as its own external model, the visual system lacks the resources to hold an experienced world steady."

Ok, but where in this explanation do they address the fact that the dreamer is indeed having a visual experience, and that this experience is not directly related to anything in the real world? Is there anything, apart from neuronal activity, required for this particular experience(call it visual or not)? Ok, so you need a real world to mold the brain in a way that visual experiences are possible, but that doesn't mean that at this very moment my visual experience is generated by the brain AND the external world. They seem to be mixing up the development of sensation with the mechanisms of sensation.
Maybe I am missing something in the explanation, but at the very least they don't make it clear.


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