Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!uunet!tdatirv!sarima
From: sarima@tdatirv.UUCP (Stanley Friesen)
Newsgroups: comp.ai.philosophy
Subject: Re: CoOntinuous vs discrete
Message-ID: <188@tdatirv.UUCP>
Date: 7 Apr 91 17:16:01 GMT
References: <91082.223501DOCTORJ@SLACVM.SLAC.STANFORD.EDU>
Reply-To: sarima@tdatirv.UUCP (Stanley Friesen)
Organization: Teradata Corp., Irvine
Lines: 29

In article an article DOCTORJ@SLACVM.SLAC.STANFORD.EDU (Jon J Thaler) writes:
<One thing that has always bothered me about the comparison between
<computers and brains is that (most) computers are finite state machines,
<while it is not obvious to me that brains are.

In my biologist persona, I rather tend to disagree.  The brain appears to
me to be quite discrete.  It is simply not *binary*.  Why you ask?
Let me preset a few simple facts about neurotransmission.
1.  Firing of a neuron is an all or none response.  There is no such thing
    as weak or strong signals.

2.  A neuron may only fire up to a certain maximum rate, due to a refractory
    period after each firing.

Thus the behavior of a neuron is in fact directly mappable onto a discrete
system.  As near as I can make out from my reading on the subject a single
neuron encodes its data in *unary* rather than binary.

<  It is well known that
<mathematical modelling of continuous systems on disctrete lattices
<will miss some classes of solutions entirely, so I have trouble following
<the arguments based on analogies between computers and brains.  Can someone
<out there shed some light on this for me?

As near as I can tell all relevent properties of neurons can be adequately
modeled by discrete mathematics.
-- 
---------------
uunet!tdatirv!sarima				(Stanley Friesen)