[From Jeff Vancouver 980330.1330 EST]
[From Rick Marken (980330.0940)]
Rick, thanks for getting back to me so soon. One of the advantages of the
internet is that we can interaction to obtain more clarity. I have a
couple of questions regarding your comments.
You have a great opportunity to discuss the "control of perception"
aspect of PCT in your discussion of the "fundamental differences"
between PCT and the TOTE model. The analog vs digital and serial
vs parallel distinctions you draw between PCT and TOTE (p. 13) are
real, but not fundamental. What is fundamental is the difference
between PCT and TOTE regarding what behavior _is_. The TOTE model
views behavior as an S-R process; the TOTE model suggests how Ss
lead to Rs (by comparison of current S to "goal" S). The PCT model
views behavior as a control process; the PCT model explains how
this control is achieved via closed loop control of perceptual
representations of environmental variables.
First, on the issue of discussing "control of perception" it seems the
issue of closed loop is central. I have been asked to expand that part of
the chapter as it was a source of much disagreement between me and another
member of the expert panel. When I get that reworked I might post it for
comments.
Regarding TOTE, your comment prompted me to reread part of the "Plans..."
book as the S-R description does not correspond with my understanding of
their position. Specifically, in the beginning of chapter 4 they describe
Lewin's position on intention. They say:
"And we agree that the associationistic doctrine described above can never
provide an adequate explanation." (p. 60)
They are agreeing with Lewin and this seems to be decidedly not S-R. But I
seems to remember you saying something about S-R as more broad (but of
equal loathe) than associationism. If this is true, can you explain your
position?
Where I think the TOTE model faulters is where they part company with Lewin
(which I had missed before). They note that Lewin talks about humans
creating quasi-need states. Instead, they suggest that humans create
plans. Plans are presciptions of behavior, quasi-need states are much more
like subgoals (lower-level reference conditions). Hence, their departure
from Lewin also parted them from PCT (not that Lewin's ideas were nearly a
well-conceived as PCT).
I talk more about this behavior (plans) issue when I talk about action
control. It is the distinction that I use to separate action control from
PCT.
Once you have explained "control of perception" you can then
explain how to go about studying it. You can talk about how the
goal of research on control of perception is to determine the
perceptual variables that people are controlling. I'd Give a brief
description of the how to test for controlled perceptions and
(perhaps) explain why the results of conventional research provide
little more than hints about the perceptions any person _might_
be controlling.
I will cite your article here instead of me going over it again. For one
reason, I am sure to get it wrong.
I also caught what I consider some small errors in your discussion
of PCT.
On p 10 you say that the source of the top-most reference signal
in PCT remains a mystery. In fact, there is no mystery; the HPCT
model says that the top-most references are not the outputs of
still higher level systems. There is no mystery about the model.
The mystery concerns how the organisms actually work.
You are saying what those reference signals are not, not what they are (or
where they come from). This still seems a mystery to me. I also recall a
thread on the topic. It seems Bill P. noted the possibilities and
acknowledged the lack of knowing which it was (or when it was which). What
am I missing?
On p. 10 you say that Powers began his work seeking to replace
behaviorism and the reflec arc. This is very misleading. Powers
began his working seeking to understand behavior. He noticed
that organisms produce consistent results in highly variable
circumstances; that is, he noticed that organisms _control_ the
results of their actions and he saw that a control model could
explain this phenomenon. He also realized that control systems
control their perceptions, not their outputs, and that this must
be true of organisms too. Finally, he saw that control of
perception _looks like_ S-R or caused output and that, therefore,
conventional psychology was built on an illusion (I think this is
when Bill must have realized that PCT had something like a snowball's
chance in hell of being accepted (or understood) by the scientific
establishment).
This seems reasonable. What say you Bill P.? The perception you are
attempting to control is your understanding of behavior.
On the other hand, was not part of that that no current conceptualization
allowed him to perceive that he had an understanding? I am taking my
perspective from Bill's early writings. But this is hardly a key point.
It was more a literary device for transitioning.
On p. 12 you say "Powers was trying to highlight the central role
of the comparison of a perception [with] a goal and the effect of
that comparison on subsequent perceptions". This is not true at
all. Powers was (and is) trying to highlight the fact that in
a closed loop control system, what is central is that a perceptual
_variable_ is kept matching a fixed or varying reference signal.
The idea that comparisons have an effect on _subsequent_ perceptions
is exactly the kind of sequential view of control system operation
that Powers was trying to expose as _incorrect_. A control system
is always acting, as necessary, to keep a perceptual variable
matching the reference signal, protected from disturbance.
Yeah, this is me "not getting it." I still do not understand how lag is
ignored such that no time passes between the effect of the disturbance and
behavior on the perception, the error, and behavior. (By the way, have you
ever looked at the difference between RMS calculated simutaneously, and RMS
calculated by using the target position and the cursor position from a
couple of milliseconds later?)
Anyway, I think I am partially addressing this with the parallel v. series
distinction. The "always acting, as necessary" aspect. Is that not
relevant at all?
Again though, given that I am trying to represent Powers, I will rewrite
this and post it. That way I might get confirmation on what he was(is)
trying to say.
Becuase you have been invited to write this chapter, you have an
excellent opportunity to explain PCT to a potentially large audience.
I hope you take it.
I am guessing your Psychological Methods paper will see a larger audience.
Sincerely,
Jeff
