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From: mmm@cup.portal.com (Mark Robert Thorson)
Newsgroups: comp.ai,sci.bio,sci.psychology,alt.cyberpunk
Subject: Re: The Bandwidth of the Brain
Message-ID: <38006@cup.portal.com>
Date: 14 Jan 91 04:18:23 GMT
References: <37034@cup.portal.com>
Organization: The Portal System (TM)
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[I was asked to post this for uunet.uu.net!crossck!dougm (Doug Merritt)
who cannot post from his site.]

It is a well known result of Information Theory that such "pre-understanding"
is *not* part of the bandwidth of transmitted information, although it
is completely essential for practical purposes. With no such context,
information is transmitted at a certain bandwidth, but cannot be interpreted.
Interpretation is not part of Information Theory, but bandwidth is, and is
defined quite precisely.  Imprecisely, it amounts to the log of the number of
different messages that *could* have been transmitted.
 
Of course, it is simple to point out that the number of interpretations
that can be consistently (repeatably) and deterministically derived from
any given message is exactly the same as the number of possible messages.
 
So this "pre-understanding" business has nothing to do with bandwidth.
 
It may, on the other hand, reflect a lot about the number of states
in the black box's internal automata, which could potentially be
far more complex than the bandwidth of information transmitted
to and from the black box.
 
This additional complexity will show up in the distribution
of different messages (i.e. complexity of prediction over time).
If no such complexity of prediction occurs, then, and only then,
can you say that the internal automata is either internally non-complex,
or redundently complex. Kolmogorov complexity is the appropriate
measure.
 
Most of the discussion I've seen has concentrated on bandwidth arguments,
but neglected prediction complexity; *both* are essential for
speculations about the brain.
 
I think that is pretty much the last word on the subject from an
abstract point of view.

[Well, I really blew it big time by not distinguishing between communication
bandwidth and internal thought bandwidth.  Obviously the preunderstandings
are not communication, but these preunderstandings get activated while
interpreting communication, hence they should be counted under mental
bandwidth.  What units should be used?  I think it can be thoughts
per second.  I don't think anyone ever really has more than one thought
at a time, though it might seem like that when two thoughts are separated
by only a fraction of a second.  Bomb, reactor, Enola Gay ... these are
all one thought each.       --mmm]