From: epfaith@sunkist.berkeley.edu (Edward Paul Faith)
Newsgroups: comp.ai.philosophy
Subject: Re: Consciousness
Date: 7 Sep 92 03:08:14 GMT
Organization: U.C. Berkeley Math. Department.
NNTP-Posting-Host: sunkist.berkeley.edu

Subjective experience and its physical support.

Here I want to question whether subjective experience actually
occurs in the brain.

Take a specific everyday subjective experience, and ask whether it occurs in
the brain.  How would we determine such a thing?  I think we could
do it by asking, "what physical events must necessarily take place in
order for the subjective experience to occur."  Via a thought 
experiment, we could imagine that the brain exists 
isolated in a vat, and it receives input from a computer.  
But the complexity of the computer input can
vary greatly.  An experience that simply involves passively observing
scenery only requires a simple sort of input.  But an experience that
involves grabbing hold of objects in the environment and feeling them and
manipulating them etc. requires much more complex input, input so
complex that in the real world, Dennett seems to say, the computer
would actually need to be hooked up to reality to provide the full
richness that is needed to create the experience.

Therefore, an experience that involves manipulation of the
environment requires the environment itself, or rather that part of the
environment which is involved.

The same thing holds true for elements of the brain.  Certain parts of
the brain are involved in subjective experience more than others.
The removal of certain parts results in greatly reduced ability to
experience (loss of sight, or even death).  Meanwhile, the removal
of other parts has very little effect on subjective experience as
reported by the subject.  I conjecture that the important parts form a
system, all parts of which are in constant contact with each other.  I
further conjecture that the parts of the brain which do not much
affect subjective experience do not interact much with that system.

So on the one hand, we have parts of the outside world which play
greater or lesser role in the subjective experience (and which are
therefore more and less indispensable), and on the other hand, we
have parts of the brain which play a greater or lesser role in the
subjective experience.  And I conjecture finally, that those parts of
the outside world which are most indispensable to a given
experience form a causally linked system with those parts of the
brain which are most indispensable to that experience.

The result is that an experience does not require simply the brain to
exist, but rather requires a combination of the brain plus part of the
outside world in order to exist.

I think this puts into serious doubt the notion that a specific
subjective experience occurs entirely in the brain.  Recall that I
attacked the question in a certain way, by asking what physical
events were necessary in order for a specific experience to occur.
When we extend our hand and manipulate real objects, we also
extend the physical support for our experiences.  When we retract
our hand, or when we slice out a small portion of our brain, we
reduce the physical support.

I would be very grateful for comments.
Xref: sparky comp.ai.philosophy:6016 sci.bio:3142 soc.men:16165 soc.women:16346