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From: schiebel@cs.wvu.wvnet.edu (Darrell Schiebel)
Newsgroups: comp.ai,sci.bio,sci.psychology,alt.cyberpunk
Subject: Re: The Bandwidth of the Brain
Message-ID: <1146@h.cs.wvu.wvnet.edu>
Date: 18 Dec 90 18:13:31 GMT
References: <37034@cup.portal.com>
Followup-To: comp.ai
Organization: WVU Statistics and Computer Science
Lines: 37

In article <37034@cup.portal.com>, mmm@cup.portal.com (Mark Robert Thorson) writes:

	<...interesting behaviorial studies deleted...>

> I think the reason people believe the brain has enormous computational bandwidth
> is that people see bundles of nerve fibers, and assume they are like wires
> in a computer or a communications network.  They falsely assume that each fiber
> is an independent channel, and that the total channel capacity is the product
> of multiplying the capacity of an individual fiber by the number of fibers.
> This is clearly not true -- you can't have all the fibers in your spinal cord
> jumping simultaneously.  Likewise, when I view a bit-mapped graphics display
> with my retinas, I cannot simultaneously perceive all the dots on the screen
> and I certainly can't remember or interpret them if they are changing 15 times
> a second.  Presented with a single frame of random dots, I might be able to
> memorize some small 10 x 10 grid subset of the image if given enough time
> to memorize them (like an hour).

Although you might not be able to memorize (or "preceive") all of the pixels on
a screen, I would bet most people could RECOGNIZE a huge variety of images
displayed on the screen, including images President Bush's face each with
different expression in different lighting with combinations of hats, sun
glasses, etc.  My point is that this is the sort of task that humans excel
at, and it involves processing huge amounts of information quickly, and
most likely involves the interactions of many neurons which are not 
"processing" the "same" information, i.e. interactions in the lateral 
geniculate nucleus (LGN), striate cortex, prestriate cortex, and the 
inferior temporal lobe.

As for the communication studies, perhaps the lack of bandwidth is not due
to inefficiencies in the processing mechanisms, but rather inefficencies in
the communication medium.


						Darrell Schiebel
						Computer Science
						West Virginia University
						(schiebel@a.cs.wvu.wvnet.edu)