From newshub.ccs.yorku.ca!ists!helios.physics.utoronto.ca!news-server.csri.toronto.edu!rpi!think.com!ames!nsisrv!mimsy!harwood Wed Dec 18 16:02:18 EST 1991
Article 2203 of comp.ai.philosophy:
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>From: harwood@umiacs.umd.edu (David Harwood)
Newsgroups: comp.ai.philosophy
Subject: Re: Scaled up slug brains
Message-ID: <45083@mimsy.umd.edu>
Date: 17 Dec 91 19:10:23 GMT
References: <12723@pitt.UUCP> <40705@dime.cs.umass.edu> <12743@pitt.UUCP>
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In article <12743@pitt.UUCP> geb@cs.pitt.edu (Gordon Banks) writes:

>>We have abilities which are not present at all in worms: as mentioned
>>before, language seems to represent a radical step.
>
>Certainly, but when you look at our brain and an ape brain, the
>circuitry is very similar.  Our brain has additional cortex and
>thus additional circuits, but that seems to be the extent of the
>difference.  There are no radical new types of cells or new neurotransmitters,
>or other geegaws.  It would seem to me that Occam's razor would say
>that it is most likely that the language abilities are in the new
>neural circuitry, especially since the regions of the brain responsible
>for the production and understanding of language are pretty well defined
>through what happens when they are injured.
\\\\\\\\\\\\
	Ahem - there is plenty of evidence that language-processing
activates very large parts of the left hemisphere - 80% or more  of a
normally lateralized brain - not some small localized parts. In fact it 
was discovered that pyramidal motor neurons are activated in simple 
word recognition. Moreover, lesser parts of the other hemisphere are
activated. 
	I think you are misrepresenting the situation - No scientist
thinks that if you separated these well-known localized parts from the
rest of the brain, they could produce or understand anything normally.
(How could they without memory and perceptual/motor associations?)
	Even if there are only a few "types" of neurons and neuro-
transmitters, it is not at all true that neurons are largely "generic" 
cells, and it is not at all true that neuro-scientists definitely
understand what, largely, are the physically relevant characteristics of 
even small neuron assemblies for "information processing" - natural
organisms, unlike, man-made machines are not built according to abstract
designs, abstracting function from form; they evolve (not smoothly) as
forms with different information and survival capacities and rates.
	Computer simulations of biological intelligence assume there is
a simple, useful abstraction of function from form, but I think this
is doubtful in the case of the brain because of its extreme complexity
combined with extreme physical sensitivity.



