Newsgroups: bit.listserv.csg-l
Date:         Wed, 23 Dec 1992 18:02:10 EST
From:         mmt@BEN.DCIEM.DND.CA
Subject: Re: PCT Fanatics

[Martin Taylor 921223 17:40]
(Rick Marken 921223.1300)

Nobody is in the office here either.  Aren't we all a bit crazy?

Rick, would you accept a small revision--

> How could
>geniuses like Freud (psychodynamic theory),  G.A. Miller (information
> theory),Skinner (reinforcement theory), Green and Swets (signal detection
> theory), Estes (stimulus sampling theory),  Rummelhart (parallel distributed
> processing theory), Chomsky (transformational grammar theory),  Guilford
>(trait theory), Tolman (sign-stimulus theory) etc etc ALL BE WRONG?
>...
>
>The answer is that ALL of these theories were based on a completely
>incorrect view of behavior. They are ALL based on the idea that outputs
>(neuroses, responses, operants, decisions, behavior, speech, intelligence,
>movements) are caused by events in the environment or the brain.

Not all of these examples are theories of behaviour, and so I might
suggest adding to your first paragraph " ... ALL BE WRONG as applied
to behaviour."

I think specifically of information theory, signal detection theory,
and PDP, all of which exist quite independently of whether there is
a living organism in the neighbourhood.  And the first two are mathematical
statements which have universal applicability, even within PCT, if
they are used appropriately.  The problem with them is not that they
are wrong in themselves, but that they are often wrongly applied and
misunderstood.

As for PDP, it is interesting that the simplest form of the connections
within the perceptual side of a control hierarchy is exactly a
multilayer perceptron, so that from PDP you can find an existence
proof--anything a multilayer perceptron can discriminate is potentially
controllable.  And that means any configuration is controllable in a
three-level hierarchy (maybe it is four, but I think three).
So even if PDP is used poorly under normal circumstances (and I have
long thought it is, before I heard of PCT), nevertheless you can point
to it to show that simple structures simply connected CAN control
perceptions of arbitrary complexity.

The flip side of that is that if the PDP people ever, with any kind of
node, demonstrate the possibility of making any kind of classification
or recognition, you can immediately say that this is demonstrably a
controllable kind of percept.  So PDP provides an ever-rising lower
bound on the known possibilities of PCT.  PDP isn't a theory of
behaviour, although people have used its possibilities that way (as
you say, wrongly).  But it does what it does, and you can use it without
fear and trembling.
>
> I guess
>Martin is preparing a thesis on the value of information theory
>for understanding control . I?m waiting with great interest to see
>what  have missed by ignoring iformation theory. I have read
>several rather unconvincing attempts to show that  some versions
>of behaviorism are equivalent to control models of behavior. If
>anyone else out there has a non-PCT theory that  they think provides
>a real great explanation of some aspect of behavior then I?d sure
>like to hear about it.

I hope you aren't putting me in with people offering a non-PCT theory.
I thought that what I had shown was thay information theory provided
a demonstration of the necessity of PCT, but apparently I wasn't
convincing.  When I subsequently showed my posting around here, the
reaction was that it made intuitive sense.  So I have hopes that a
more careful discussion will make intuitive sense to more people.

People don't necessarily bring in ideas that have proved useful elsewhere
just because they have a great fondness for the ideas and don't understand
that PCT stands isolated.  There IS the possibility that PCT hasn't
reached the limits of its potential.

Martin
PS. You may be amused to know that I have observed in myself much the
reaction you often express when reading or listening to psychologists
talking in areas I used to think important.  "What stupidities are they
thinking of...Don't they know it's all control?"
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