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From: esrmm@warwick.ac.uk (Denis Anthony)
Newsgroups: comp.ai.neural-nets
Subject: Re: Postulates on the number of neurons
Message-ID: <1990Dec11.152350.16930@warwick.ac.uk>
Date: 11 Dec 90 15:23:50 GMT
References: <1990Dec11.040646.20760@noose.ecn.purdue.edu>
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In article <1990Dec11.040646.20760@noose.ecn.purdue.edu> muttiah@welsh.ecn.purdue.edu (Ranjan S Muttiah) writes:
>
>
>What do researches think about why there are so many _individual_ neurons
>in the human brain (something like 10^19) ?  Is there some critical number
>needed for "intelligent behaviour" ?
>
>[It's much like asking why there are so many epithelial cells, white blood
>cells and the like but I can think of a few reasons for these ...in the
>case of neurons I have difficulties].

The speed of processing of the nervous system (milliseconds) and the amount
of computation required for (e.g.) vision in real time, and the number of
simultanious computation systems (vision, sound, proprioception, cognition etc.)
require a large number of parallel processes. (all pretty obvious).

Clearly there is a minimum number, but whether it must be of order 10^19 or not
I do not know. There is some redundancy in that fairly large portions of the
cerebrum may be lost before gross brain damage is manifest (though other parts of the
brain are less robust).

Perhaps some-one from the neuro-sciences can help out on this one.

Denis