Newsgroups: comp.ai.alife,comp.ai.philosophy
From: ohgs@chatham.demon.co.uk (Oliver Sparrow)
Path: cantaloupe.srv.cs.cmu.edu!das-news2.harvard.edu!news2.near.net!howland.reston.ans.net!pipex!peernews.demon.co.uk!chatham.demon.co.uk!ohgs
Subject: Re: Cognitive Function, Reduction, and Quantum Mechanics
References: <3la5qr$86@oahu.cs.ucla.edu> <mws.17.00335B80@pond.com> <D6ML5u.7GL@gpu.utcc.utoronto.ca> <mws.24.00498740@pond.com> <D6u59r.L7n@gpu.utcc.utoronto.ca> <3mdchv$i8e@wanda.pond.com>
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Date: Wed, 12 Apr 1995 08:10:16 +0000
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I agree with Fred Mitchell. We know a lot about how neurons work and a 
remarkable amount about the dynamic behaviour of the functioning brain. One 
can, for example, track centres of activation to a voxel (3D pixel) of a few 
millimetres cube in millisecond time across the entire structure with some 
emerging techniques lifted from 3D seismic. We know - from lesions, from other 
evidence - a great deal about areas of specialisation, data storage and the 
like. 

This being said, why do people feel so strongly attracted to views about
cortical functioning that make vague references to quantum mechanics? There 
is neither evidence for quantum-related phenomena - such as, for example, 
succeptibility to magnetic fields - nor key roles to be played in the models 
that we have of cognition that quantum mechanics can play.

We note the conditions in which quantum mechanics becomes a pervasive 
influence in explaining what is observed: in isolated or very cold structures 
in which individual particles or associations of particles are, as it were, 
defining their role in respect of other particles. We look in vain for such 
systems in the brain: neurons are huge when compared to quantum-coherent 
systems, are thermally agitated in ways which would swamp a QM signal and 
act in massively parallel ways. A single synapse may use hundreds of vesicles 
containing billions of neurotransmitter molecules to transmit a signal to 
hundreds of thousands of receptor molecules. Signal transmission involves the 
flows of tens of billions of cations across membranes. A "signal" is not, 
however, a single pulse by a train of pulses, each spike of which involves 
the same degree of complexity. Neurons respond to such trains in ways which 
reflect their local short and long term environment: inhibitory or excitatory 
signals from other neurons, their endogenous state of excitement or otherwise, 
the local hormonal environment; and so forth. Not much room in this for the 
decisive QM event.

This being common currency for anyone interested in the subject, why do people 
persist in mystifying what should be the object of clarification? Because, I 
suggest, their needs are not *for* clarification. People who are deeply 
uncertain grope for certainty; and they tend to do this amongst (or in 
reaction to) prevailing symbols of success and potency. The rejectionist 
terror movements of the Seventies focused upon aeroplanes because these were 
the daily emblem of an intrusive outside world that challenged their dearest 
truths. Science, to many, is a similar validating of challenging source of 
potency: "science says that..". An aspect of science which says that, in 
particular, "here be mysteries" is, naturally, doubly attractive. To link a 
mysterious area with something of deep concern - who am I? What do I count 
for in the scheme of things? - is, therefore, attractive: for thereby, I 
contain mysteries, I transcend. This collage of borrowed bits ad bobs does 
not add up to anything useful - in the sense of permitting soemthing to be 
done which could not previously be considered - and is more in line with the 
teenagers habit of plastering his (*usually* his) bedroom wall with similar 
icons of power and escape.
 
The above spleen vented in irritation at the dingbat cross posting which are 
clogging my (and others') mailboxes.

_________________________________________________

  Oliver Sparrow
  ohgs@chatham.demon.co.uk
