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From: kovsky@netcom.com (Bob Kovsky)
Subject: Re: Chaos and Computation
Message-ID: <kovskyD8vyA2.B8F@netcom.com>
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References: <dougD8FM8y.GI6@netcom.com> <D8MqGE.6on@intruder.daytonoh.attgis.com> <3pj7gc$5u5@remus.reed.edu>
Date: Sat, 20 May 1995 16:39:38 GMT
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In article <3pj7gc$5u5@remus.reed.edu>, jfaludi <tcarpent@reed.edu> wrote:
>In article <D8MqGE.6on@intruder.daytonoh.attgis.com>
>David E. Weldon, Ph.D. <David.E.Weldon@DaytonOH.ATTGIS.COM> writes:
>
>> There is a facinating relation between "alpha" wave frequency (10 Hz) and
>> serveral perceptual phenomena that suggest that our brains sample the
>> environment every 100 msec. and process the sample during that period.  The
>> brain, in short, freezes the world every 100 msec., taking in frames of
>> information, along with additional data on motion in the visual field.  
>
>
>Pardon me, but this seems fishy.. could you post/email your sources?
>
>...You see, if we sampled data at a rate of 100msec, that would only be
>a sampling frequency of 10KHz.  Considering that we can hear sounds up
>to 22KHz, and that you need to have your sampling frequency be at least
>twice the frequency of whatever you want to accurately sample, this
>would seem to say we must intake information at at least 44KHz.  

	Aural frequency analysis takes place in the inner ear, not in the 
brain.  There is, in other words, a nerve fiber (using an approximation 
for simplicity) into the brain that signals amplitude of 20 kHz.

	Anyway, with a sample rate of 100 msec., the maximum frequency
detected is considerably below 10 kHz.  (If these figures were precise,
your sample of a 10 kHz. sine wave would be a constant.) There is a simple
equation for the maximum detectable frequency for a given sample rate, 
the name and terms of which I have forgotten.  No doubt it will appear in 
this thread soon.

-- 

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    Bob Kovsky          |  A Natural Science of Freedom 
    kovsky@netcom.com   |  Materials available by anonymous ftp
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