[From Rick Marken (980204.0930)]
Bruce Nevin (980203.2049 PST)--
What's the distinction between controlled input and controlled
perception?
The input is the environmental correlate of the controlled
perception.
Tim Carey (980204.1810)
Is what you're saying this: when we see someone repsond to a
stimulus in a psychophysical experiment, all we are seeing are
actions opposing disturbances?...
Basically, yes. What I am saying is simply that a psychophysical
experiment is the same as any other conventional psychology
experiment; a stimulus (disturbance) variable is manipulated and
a response (output) variable is measured. If the subject of the
experiment is a control system then any observed relationship
between stimulus and response reflects characteristics of the
environment, not the subject. I think I give a reasonably clear
description (and demonstration) of what is going on in such
experiments (psychophysical experiments and all other conventional
experiments) in my "Behavioral Illusion" demo at
http://home.earthlink.net/~rmarken/demos.html
Once one understands the _principle_ illustrated by this demo --
and sees why it works (I describe the same demo, using rubber
bands instead of computer programs, in the "Dancer..." paper) --
one will see why, _in principle_ the results of psychophysical
experiments tell us very little about the subject in the
experiment but a great deal about the subject's environment.
This discussion has led me to a (possibly false) realization
about why some people are able to grasp the revolutionary
significance of PCT while others are not. Of course, much of it
has to do with protecting existing beliefs from the disturbance
of PCT. But I think some of it has to do with a difference in the
way people look at what we call "demos".
When I programmed my first tracking demo and saw that there was
no correlation between cursor movements (stimulus) and handle
movements (response) I realized that, if this held up (and it did,
as shown in my "S-R vs control" demo), then the foundations of
experimental psychology were shattered. I knew that this simple
tracking task illustrated a _general principle_ and that the
principle held whether the controlled input was a cursor in a
tracking task of a drug in an addiction situation; if inputs
don't cause the outputs that keep the inputs under control,
this is true for all the inputs and outputs that are involved in
control.
I feel the same way about the "Behavioral illusion" demo. This
demo illustrates the behavioral illusion in a simple situation
where we know what variable the subject is controlling (shape or
angle) and we know (well, I, the programmer, knows) the feedback
function relating output to input. But I see the demo as illustrating
a general principle -- one that applies to all experiments where
a stimulus is manipulated and a response is measured with no
awareness that both may have an influence on some controlled
perceptual variable -- the principle that we call "the behavioral
illusion".
I look at the PCT demos as illustrations of important general
principles in simple situations where these principles can be
seen clearly. I see the PCT demos of control phenomena as
analogous to Galileo's "demos" of physical phenomena. When I
hear people say "sure, the behavioral illusion occurs in that
simple demo but not in real, psychophysical experiments" I realize
that these people see these demos differently than I do. It's like
hearing someone say to Galileo "sure, balls accelerate downward in
your demo but that doesn't mean that really interesting objects,
like people, bridges, etc.accelerate downward; they're not balls
and they're not rolling on planes".
So there's really nothing I can say in reply to Bruce Abbott
(980204.0505 EST), who apparently sees the PCT demos differently
than I do. Bruce says:
So you see, Rick, when I perform psychophysical studies I am
learning a good seal about the characteristics of the organism,
contrary your assertion that I am only learning about the
characteristics of the environment. This is no "behavioral
illusion."
Maybe all I can do is paraphrase my hero: "And yet, it is an
illusion"
Best
Ricardo Galilei
···
--
Richard S. Marken Phone or Fax: 310 474-0313
Life Learning Associates e-mail: rmarken@earthlink.net
http://home.earthlink.net/~rmarken