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Article 6062 of comp.ai.philosophy:
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>From: cam@castle.ed.ac.uk (Chris Malcolm)
Newsgroups: comp.ai.philosophy
Subject: Re: Grounding: Real vs. Virtual (formerly "on meaning")
Keywords: symbol, analog, Turing Test, robotics
Message-ID: <22237@castle.ed.ac.uk>
Date: 3 Jun 92 17:00:58 GMT
References: <1992May25.202001.7388@psych.toronto.edu> <21988@castle.ed.ac.uk> <613@trwacs.fp.trw.com>
Organization: Edinburgh University
Lines: 25

In article <613@trwacs.fp.trw.com> erwin@trwacs.fp.trw.com (Harry Erwin) writes:

>Evidence from extant groups on brain size
>suggests that normal human behavior can be sustained by a brain size half
>that seen in the average adult male.

Sustained, maybe, acquired, no. The average adult human does very
little learning past the late teens. In fact the rate of brain loss
with age in the adult correlates well with use, in the sense that
those who use it least suffer the most loss.

>All this suggests that the large
>brain evolved in some isolated group not under evolutionary pressure and
>now survives due to some capability other than simple brain size.

Only if you make the assumption that the "normal behaviour" you cite
above happens to correspond with the behaviour employed by the
isolated group in question. The fact that not only did we grow large
brains, but also developed subcutaneous fat and lost body hair,
suggests a rather different environment from that of today's
hunter-gatherers.
-- 
Chris Malcolm    cam@uk.ac.ed.aifh          +44 (0)31 650 3085
Department of Artificial Intelligence,    Edinburgh University
5 Forrest Hill, Edinburgh, EH1 2QL, UK                DoD #205


