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Article 4675 of comp.ai.philosophy:
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>From: forbis@milton.u.washington.edu (Gary Forbis)
Subject: Re: aliens eat fading qualia
Message-ID: <1992Mar23.205033.9268@u.washington.edu>
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Organization: University of Washington, Seattle
References: <1992Mar23.145207.7892@oracorp.com>
Date: Mon, 23 Mar 1992 20:50:33 GMT
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In article <1992Mar23.145207.7892@oracorp.com> daryl@oracorp.com (Daryl McCullough) writes:
>And your argument about brain-eating aliens has not helped to make (b)
>any more plausible. *How* can qualia fade and make no functional
>difference? Introspection would tell you that if your qualia became
>less intense, then you would notice it; it would affect your thoughts
>(and very likely your behavior, as well).

I've been thinking about this fading qualia thing and want to give some 
experiential data for people to consider.

We can all relate to the obvious examples of change in qualia.  We notice
the closing of our eyes and the injection of novocaine.  We see objects
move through our field of vision.  We feel the prick of sharp things and
spell odors that waft our way.  The grosser changes in qualia cannot be
denied and these changes have a behavioral effect.

I have a bad eye.  When I look though it and ignore the very blury spot
I still notice some differences in sensation.  The bad eye generally has
a darkness to it but contrast in enhanced on larger areas.  The junction
between surfaces makes the lighter surface appear even lighter than with
my good eye.

It seems clear to me that if peripherial replacements are to be functionally
equivalent they must cause the same qualia.  Doesn't this mean there are
ways to convince oneself (provided the technology exists) that a replacement
for some neurons do not affect qualia?  One needn't commit oneself to a
total replacement all at once and if a change in qualia exists one would
notice it.

--gary forbis@u.washington.edu


