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Article 2140 of comp.ai.philosophy:
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>From: weemba@libra.wistar.upenn.edu (Matthew P Wiener)
Newsgroups: comp.ai.philosophy
Subject: X-cell-ent minds are not the issue
Message-ID: <60317@netnews.upenn.edu>
Date: 15 Dec 91 20:02:29 GMT
References: <1991Dec14.110633.28844@oracorp.com>
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Reply-To: weemba@libra.wistar.upenn.edu (Matthew P Wiener)
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In-reply-to: daryl@oracorp.com

In article <1991Dec14.110633.28844@oracorp.com>, daryl@oracorp writes:
>> In article <310@tdatirv.UUCP>, sarima@tdatirv (Stanley Friesen) writes:
>> >We may not have every detail nailed down, but every month brings us closer,
>> >and so far those working in neurology have found no significant barriers or
>> >discrepencies other then the sheer overwhelming *complexity* of a mammalian
>> >brain.

>> No significant barriers other than the "sheer overwhelming *complexity*"?

>You are completely missing Stanley's point. He is not saying that the
>problem of mind has been solved, or that we are even close to solving
>it. Only that he thinks that the fundamental principles are known.

He can think that.  Some days I'll agree with him.

>This is no more ridiculous than the assertion that, in spite of the
>enormous complexity of weather systems which makes long-term
>prediction impossible, there is no reason to think that there is some
>unknown fifth force involved.

I don't quite think this is a fair analogy.  The point is: do we know
enough to conclude that when we eventually tie together all that is
right for neuropsychological explanation, we will get a result that
is Turing computable?

To explain what I mean, let me invent the X-cell theory of mind.  We
postulate that evolution actually started us vertebrates with three
immune systems: B-cells, T-cells, and the previously unknown X-cells.
All three systems have primitive intelligence and consciousness: they
do pattern recognition, they generate response, they learn, they have
memory, and they distinguish self from nonself.  The primordial B and
T systems were what we have today, more or less.  But the X system was
redundant, and eventually found a new role: pattern recognition on the
bioelectric fields of primitive vertebrate neural networks.  These
networks evolved in sync with the X-cell system, which grew ever more
complicated.  Our brains today are the I/O unit for the X-cell CPU.
The sophistication of our neural wiring is caused by the need to
produce a cellular sized encoding of the macroscopic world.

What do I think of this theory?  Good enough for science fiction aliens.
Good enough for temporary philosophical suspension of disbelief.  That's
about it.  I have no idea how trivial it is to shoot down with the known
evidence.  Note that the X-cell-ent theory of mind is not invalidated by
brain lesion studies--such lesions turn off access to the X-cells.  The
X-cell-ent theory is not invalidated by the predetermined neural growth
experiments--the X-cells interact deep in the brain, not at the other
end of the nerves.  Obviously, experiments with artifical blood could
destroy the X-cell-ent theory.  But I'm not calling for any.

To summarize: I'm definitely willing to agree that there is no fifth
force, and that there is no third immune system, and the like.  I still
see no reason to accept a "conclusion" that mind is digital computation.
There is no real evidence for a physical Church thesis, and this is why
I'm objecting.  Especially in light of "sheer overwhelming *complexity*".

>> >So, until the neurologists find a problem with the model of mind as the
>> >emergent product of neural data processing, I will apply KISS and assume
>> >that this model is correct, or at least a useful aproximation.

>> **WHAT** MODEL OF MIND AS THE EMERGENT PRODUCT OF NEURAL DATA PROCESSING?

>The word "model" was mistaken, I think. I believe that he means that
>the *approach* of viewing mind as a computational phenomenon.

You're right, I'm probably overreacting here.  Most of us on USENET use
computer metaphors instinctively.  I used I/O and CPU and wiring above
--deliberately and half-paradoxically--to emphasize that as metaphors
they do indeed convey the essential chunk of what I'm trying to say.

Meanwhile, my point is that Occam's razor is useless for selecting
between approaches or pretheories.

>> Until one theory dominates and clearly explains giant chunks of how mind
>> works, there's no strength to appealing to any philosophical principles.
>> Experiment, not enthusiasm, not expectation, will decide.

>I don't see how the issue under discussion will be resolved by
>experiment.

Build a digital mind.  Or build a quantum mind.

>	     The question being discussed is whether computation is
>sufficient to produce understanding. Experiments can certainly test
>various theories of how the *brain* works, but without an
>*independent* objective test for understanding (as opposed to
>*seeming* to understand), I don't see how the question of the sufficiency
>of computation is susceptible to experiment.

If the digital school makes a digital mind that explains so much that
is still so mysterious--sleep, schizophrenia, hypnotic trances, self
deception; if the digital school takes this digital mind and starts
making working predictions--predicted cures for schizophrenia, aging
memory loss, and so on; if the digital school wins over all other
attempts to deal with real live minds, then I'd say they have passed
the experimental test.

This has happened before.  The psychoanalytic approach to depression
is pretty much dead--the pharmaceutical approach (valium) is a clear
winner.

I would expect the same for quantum minds.  Or X-cell-ent minds.

>> And how does computation show any special *psychologically* relevant
>> effect?

>One thing that is so frustrating about this whole discussion is that
>what seems painfully obvious to one person seems dubious or patently
>false to another. Anyway, it is obvious to *me* that computation is
>psychologically relevant, in the sense that much of what is
>psychologically interesting (again, to *me*) about human beings can be
>found in exchanges such as those found in News, which are computations
>in the broad sense (whether they are in the narrow sense, as well, is the
>subject of this discussion; and this *newsgroup*.)

I am aware of the field of computational psychology, if that's what you
mean.  I do not think its practitioners are cretins, or anything even
close to that.  I'm all in favor of more funding all around.  I just
have my own mental bets on a different horse, and may the best horse
win.  But I'm not impressed by starting gate claims--I want to see the
finish line.

(Yeah, I know, my extending metaphor is like beating a dead horse.  I
couldn't help myself.)

>> Your "in order to challenge" is incomplete, by the way.  I can also
>> challenge the computational mind paradigm from the other side: forty
>> years of coming up short is a dismal record for any research claim.

>Perhaps some subjects are difficult, and take more than forty years to
>show results.

Indeed.  But it's more than enough to question the alleged obviousness
of the claim.
-- 
-Matthew P Wiener (weemba@libra.wistar.upenn.edu)


