From newshub.ccs.yorku.ca!ists!helios.physics.utoronto.ca!news-server.csri.toronto.edu!rpi!sarah!cook!psinntp!psinntp!scylla!daryl Mon Mar  9 18:36:04 EST 1992
Article 4341 of comp.ai.philosophy:
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>From: daryl@oracorp.com (Daryl McCullough)
Subject: Re: Definition of understanding
Message-ID: <1992Mar7.154451.20145@oracorp.com>
Organization: ORA Corporation
Date: Sat, 7 Mar 1992 15:44:51 GMT

orourke@unix1.cs.umass.edu (Joseph O'Rourke) writes:

> 2. It seems conceivable that qualia are dependent upon the
> neurotransmitters passed in synapses.  Maybe our feeling of redness is
> just how it feels to have certain chemicals released from neurons in
> certain brain areas.  I know little of neurobiology, but suppose for
> the moment that this were true.

> 	Then it could be that the functionality of a single neuron is
> indeed computable, and silicon-substitutable.  But as more and more
> neuron interconnections are replaced, less and less of the
> neurotransmitters are around to be experienced as qualia.  Then the
> person would indeed experience a fading of qualia.

Joe, Chalmer's argument is not that qualia can't fade; for instance,
presumably in the last few seconds before a person dies, the qualia
gradually fade out. What seems to be impossible is that qualia could
fade away with *no* change in the brain's functioning. If qualia were
due to neurotransmitters, and you started running out of the stuff,
then wouldn't you start noticing that things aren't as bright red as
they used to be? If someone asked you "Do your qualia seem as intense
as in the past?", you would say "yes".

Thus, your example may be an example of fading qualia, but it is not
clear why it would be fading qualia with no change to behavior.

Daryl McCullough
ORA Corp.
Ithaca, NY





