Q_Goest said:
Hi Pythagorean. My apologies in advance for the length.
Good evening Q_Goest, no worries about the length. I welcome your comments.
Note that in the following, I’ll be using a fundamental assumption that both you and Dennett appear to agree on, that being computationalism. That is, that the interactions of neurons is what produces the emergent properties of conscious experience.
I'm reluctant to label myself that specifically yet. I don't completely understand computationalism yet. There are definitely aspects of computation I agree with (especially what you mentioned above). But the definition you gave above is only one defining aspect of computationalism. Alone it seems to be a narrow view of physicalism.
I say narrow because it's not necessarily neurons doing all the work. Neuroscience is more recently beginning to recognize the role glial cells play (says my neurobiology instructor; I always thought they were merely a support system myself) though it's new enough not to be in our textbook.
We do know that we can represent a neuron with an equivalent circuit. But I don't have any reason to think that this is the only important aspect of what's going on (though, we must admit that it plays a significant role).
What I can say about computationalism is that the brain seems to be very well capable of it. But does that mean it's limited to it? I don't think so. At least, not in the traditional input/output sense.
I mention this because I think it’s important to understand the basic assumptions that go into an argument such as Dennett provides because different assumptions often lead to different conclusions, and the conclusions Dennett comes to seem to indicate there’s a fundamental flaw in our notions of what conscious experience is.
We agree on this. As Dennett said in one of his presentations "Everybody thinks they're an expert on consciousness". Everyone has their definition.
Kristof Koch agrees. One of the way he is confronting that problem is by proposing several different kinds of consciousness that exist simultaneously in a single brain.
Specifically, he means there are certain assumptions we make about our own experiences that do not coincide with a logical analysis of those experiences. Those assumptions he outlines as follows:
Just an FYI. I can only comment on the ones you comment on as I haven't heard of Quinning Qualia and I'm not completely sure of the way those terms are going to be applied to consciousness or your interpretation of it until you open discussion about it. Obviously, "intrinsic" alone doesn't tell me much, since I've used that term in a number of different ways in my undergrad degree, but since you've extrapolated here:
Intrinsic in the sense that the correlation is intrinsic to nature. Every time that particular computation is performed, the experience will follow, and be supervenient on that physical substrate that is performing the computation. So when we flipped the plug 180 degrees, then if we believe the computation is intrinsic, then we believe that with this reversed input, the experience will also be flipped.
If you read my links, you might understand why I view this is a harmful (in terms of productive discussion) oversimplification. It assumes a reversible connection... I don't know what this correlates to neurally, or if it's even a valid correlation of anything in the neural sense.
Now let’s go back to the thought experiment. This:
INPUT --- COMPUTATION --- OUTPUT
Produces the same output for any given input as this:
INPUT -x- COMPUTATION -x- OUTPUT
Similarly, we must also assume that every person has a slightly different computation going on inside their brain. So let’s say person 1 has this:
INPUT --- COMPUTATION(1) --- OUTPUT
And person 2 has this:
INPUT --- COMPUTATION(2) --- OUTPUT
Where COMPUTATION(1) is not equal to COMPUTATION(2). We can safely assume this because of multiple realizability. None of our brains are identical, but if we want to believe that qualia are intrinsic, then we must accept that my red is the same experience as your red. Now how many different people are possible? There are roughly 7 billion people on the Earth today and I’m guessing billions more who have already passed away. I don’t know how many different people there could possibly be, but I’m guessing it is many orders of magnitude larger than 7 billion, resulting in there being hundreds of billions or perhaps millions of billions of computations that produce the same intrinsic experience of a given color. And if we believe that a small, evolutionary step backwards or forwards does not change the experience, then we have to assume that there are also an array of different brains such as Cro-Magnon, Neanderthal and perhaps Orangutan brains must also experience the same intrinsic qualia that we homo sapiens experience. We could continue to extend this to other animals, so the number of different brains that potentially produce the same experience of the color red for example, must begin to approach an insanely huge number. If qualia are intrinsic, then we have to accept that the number of different computations that will produce the same experience is huge. I won’t say infinite, because I can’t be sure of that.
I think we can be sure that it's infinite, since we're capable of recursive operations. However, this doesn't concern me since it's not the individual signals themselves that matter, it's the classification of signals.
"You never cross the same river twice.".
In the same way, you never listen to the same set of audio signals twice. You may play a song twice in a row, and recognize it as the same song, but because of the inherent non-linearity of the real world, you'll never receive the signal in the exact same way.
But this is fine! We have an excellent classification and generalization system in terms of computation. It also leads to problems, of course (stereotyping and prejudicing, faulty assumptions when comparing things that are have similarities... such as the gravitational and electromagnetic fields for example).
I have some suggestive evidence that colors are, in fact, intrinsic. The obvious example is black and white. If you do not agree, I will extrapolate, but I assume most philosopher who speak of qualia and color have an argument in their pocket for this since they never bring up black vs. white and the point seems to be self-evident to me. By not explaining it, I hope to prove it's self-evidence as well.
Here's my suggestive evidence:
Babies prefer the colors black, white, and red. They are drawn to them because of the contrast (in an anecdote way, I can confirm this as a father of two months now) between them. This is important to me. If everything was all one color, would we see color? I don't think we would even have a word for it. There would be no evolutionary purpose for sure. Perhaps the significance then, is in the comparison of one color to another.
Humans also tend to associated common emotional terms with colors:
red - anger and sex... intensity
black -depression
yellow - happiness (I've actually heard annoying here too
(more in the link)
http://en.wikipedia.org/wiki/Color_symbolism_and_psychology
Also, evolutionarily, the significance of color in nature allows animals to be afraid of poisonous things. It even allows animals that aren't poisonous to pretend they're poisonous (cuttle fish are one example).
The taste of sweetness signifies that something is good for you (remember this is evolutionarily... our taste buds haven't evolved to our modern day where sugar is mass produced enough to be bad for you. Sugar was much more rare in our evolutionary history)
To make matters worse, each brain is also plastic, rewiring itself as time proceeds. Yet even with this rewiring, if qualia are intrinsic, then the these new computations that are taking place as time goes on, must also produce the same experience inside the same, rewired brain. This includes rewiring of inputs and outputs.
Of course, this is fine in the sense of a neural network learning, classifying, and generalizing to create a world model based on its inputs.
I wouldn't say that they must produce the same experience, I would say the same class of experience. Also, are you sure that the plasticity occurs in the part of the brain where experience is concerned? Or is the plasticity a response to the experience? I.e., we remember to avoid negative experiences and do so by classifying and predicting them in future experiences. The way we react to the experience itself may change, (and so we have a new after-experience). For instance, we may feel disappointment that we managed to have the same crappy experience a second time.
But you can't conveniently choose where plasticity occurs for the purpose of your argument, especially when neuroscientists themselves don't know where consciousness "is" in the brain yet. Plasticity may not affect the base experience of a sensation, only the emotional reactions to that base experience. But even if it does, all that remains necessary for me is that the experience is of the same class.
As an aside, plasticity is reduced in a lot of the brain for adults. Strangely enough, our olfactory system is one of the regions of the brain where plasticity remains in adults. Of course we used to believe that all plasticity stopped in the adult brain, which we now know is not true. However, it's not near as plastic as the youth so I just want to make sure no one has gotten that impression.
It's late here now and I'm tired, so I should probably respond to the rest of your post at a later time, unless I've changed the direction of our debate in which case you'll want to reply to what I've already said so far.
Cheers,
Pythagorean