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Article 5465 of comp.ai.philosophy:
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>From: erwin@trwacs.fp.trw.com (Harry Erwin)
Newsgroups: comp.ai.philosophy
Subject: Re: brains and information processing
Message-ID: <572@trwacs.fp.trw.com>
Date: 7 May 92 16:41:48 GMT
References: <1992May1.180642.15402@msc.cornell.edu> <1992May2.170158.5837@organpipe.uug.arizona.edu> <1992May5.201703.17963@psych.toronto.edu> <1992May6.205923.14479@organpipe.uug.arizona.edu>
Organization: TRW Systems Division, Fairfax VA
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bill@NSMA.AriZonA.EdU (Bill Skaggs) writes:

>In article <1992May5.201703.17963@psych.toronto.edu> 
>christo@psych.toronto.edu (Christopher Green) writes:
>>...
>>Nothing like a little whole-hearted question-begging to get things off on the 
>>right foot, eh? Brains are no more *essentially* information processing
>>devices than weather systems are. If you define them as such from the outset,
>>it is little wonder you end up with the conclusion you had assumed. 
>>Nice try. :-)

>  All right.  I am willing to be enlightened.  Brains must have a
>function or they would not exist.  How would you describe that
>function?

>	-- Bill

I assume you are asking this question in the context of biology.
Biological objects need not have a function to exist, they must 
1. evolve, and
2. once they evolve, they must be stable against mutations.
This question should have been phrased: "What is the selective advantage
of a brain?" It turns out that the selective advantage is in
implementation of a stimulus-response loop. The brain characteristics
needed in most ecological niches are surprisingly minimal: the genetic
encoding of the basic response loop, and the ability to calibrate the
response to the specific environment of the individual. That's why most
species are more constrained by limited behavioral plasticity than by
phenotypic adaptation--the cost of being able to enter a wide range of
niches is that the species has to be able to behave appropriately in all,
which implies a larger genome unless some sort of genetic innovation has
emerged that allows more flexible learning. 

Cheers,
-- 
Harry Erwin
Internet: erwin@trwacs.fp.trw.com


