Fred's Limited Grasp of PCT

I'll confess right away to a limited understanding of PCT but, what the
heck, expanding it is what this list is here for, right?

The little diagram below captures the essence of my meager grasp of PCT.

I'm the big box directly below. Part of me is the little box with the
question mark inside the big box. The question mark signifies that I'm not
sure what all goes on inside me or just how I deal with reference conditions
and perceived conditions.

I have or hold reference conditions (RC). I also perceive conditions about
me (PC). Presumably, some kind of comparator function derives error signals
that lead to action on my part. My actions affect the external conditions;
however, all I really know about this is by way of what I perceive. Hence,
I'm stuck with having to compare perceived conditions because I can't really
know the external conditions.

In the meantime, other factors and actors are affecting the external
conditions as well, leading on occasion to what I view as "disturbances" in
my perceived conditions. My aims, purposes, goals, what have you, are
essentially a matter of keeping my perceived conditions (PC) aligned with my
reference conditions (RC). My behavior (i.e., actions) are the means
whereby I do that.

    ><-----------------------------|
___|______________________ |

  > > > >
  > ____ | |
PC--->| | | |
       > > > >
RC--->| ? |--> Action ---> Conditions <----- Other Factors & Actors
       >____| |
__________________________|

Okay, dyed-in-the-wool PCTers, do I have it right so far? If not, please
correct...

Regards,

Fred Nickols
Senior Consultant
The Distance Consulting Company
nickols@worldnet.att.net

[From Rick Marken (970929.0815)]

Fred Nickols (970928) --

    ><-----------------------------|
___|______________________ |
> > > > >
> > ____ | |
> PC--->| | | |
> > > > >
> RC--->| ? |--> Action ---> Conditions <---Other Factors & Actors
> >____| |
>__________________________|

Okay, dyed-in-the-wool PCTers, do I have it right so far?

Yes! But I would add some things for purposes of clarification.
The box with the question mark is a "comparator". Basically
it _continuously_ subtracts PC (perception) from RC (reference).
The difference is the error signal which drives action. So
the arrow coming out of the little box should be labelled "error".
The error doesn't cause action directly. The little error signal
has to be amplified to produce the big actions (arm movements and
what not) that influence external conditions. So I would add
another box before the "Action" statement labelled "output
function"; this box represents factors (like the properties of
the muscle response of neural (error) signals) that turn a little
error signal into a big output (like a force).

I would also add a box between the (controlled environmental)
"Conditions" and the perceptual signal (PC). This box is the
"perceptual function"; it is _very_ important to include this box
in the diagram because it makes clear that it is some _aspect_ of
the external "conditions" that is percepived and controlled.

It might also be useful to point out that the way to visualize
the dynamic (over time) behavior of this system is as follows:
PC is kept nearly equal to RC over time. If RC varies (the intention
changes) the PC (the perception) will change right along with it
with almost no lag. If RC is constant (constant intention) then
PC will remain nearly constant. PC will vary a bit if the "Other
Factors and Actors" have effects on controlled "Conditions" that
vary over time. But the observed amount of variation (over time) in
PC will be _much_ smaller than it would be if the system were not
continuously varying it's own effects on controlled "Conditions"
(its Actions) so that those Conditions, as perceived (PC) keep
tracking the constant or varying value of the reference, RC.

Best

Rick

ยทยทยท

--
Richard S. Marken Phone or Fax: 310 474-0313
Life Learning Associates e-mail: rmarken@earthlink.net
http://home.earthlink.net/~rmarken