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Article 2256 of comp.ai.philosophy:
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>From: weemba@libra.wistar.upenn.edu (Matthew P Wiener)
Newsgroups: comp.ai.philosophy
Subject: Linear -> Non-linear theory bifurcation
Keywords: PPC=pumped phonon condensate
Message-ID: <60668@netnews.upenn.edu>
Date: 18 Dec 91 20:37:16 GMT
Article-I.D.: netnews.60668
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Reply-To: weemba@libra.wistar.upenn.edu (Matthew P Wiener)
Organization: The Wistar Institute of Anatomy and Biology
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I thought I'd spell out more directly how extrapolation from the example
of olfactory cortex neural net models could easily break.  According to
Walter J Freeman MASS ACTION IN THE NERVOUS SYSTEM (1975), there is a
linear relation between certain internal (membrane-membrane) and certain
external (averaged evoked) potentials _in the olfactory bulb_.  He's
stated repeatedly in his papers that this simple relationship was a
motivating factor in choosing olfaction.  The chaos models were based
on measurements of these external potentials, while the actual biological
neural network is driven by the internal potentials.  Linearity makes it
easy to relate the measurements to the network dynamics.  Too easy.

We'll call a cognitive theory "internal" if it asserts that cognition
depends on the dynamic internal arrangement of neural wiring.  And we'll
call a cognitive theory "external" if it asserts that cognition depends
on other cortical phenomena.  So DNN models are internal, while PPC
(pumped phonon condensate--I assume in the future I can stick to the
acronym) models are external.

In the case of olfaction, there is no way to distinguish internal from
external.  Biological neural network activity would drive a PPC based
on the dipole oscillations inherent in the network.  The PPC might not
be following the BNN literally, but it would be a simple transform.

Once we leave the simplicity of olfaction, the two kinds of theories
diverge.  If cognition is in fact internal, then DNNs have a bright
and meaningful future.  But if cognition is in fact external, then
DNNs work only in the case of simple relationships between internal
and external.

Is there such a bifurcation in mental capabilities?  I think so.  I
look at the evolutionary path from slug brains to Dan Quayle to homo
sapiens, and quite simply, I do not see scale up.  I see something
fundamentally new and different.  To me, this is rough experimental
evidence against internal theories of cognition.
-- 
-Matthew P Wiener (weemba@libra.wistar.upenn.edu)


