Newsgroups: bit.listserv.csg-l
Date:         Mon, 14 Dec 1992 17:53:00 CST
From:         TJ0WAH1@NIU.BITNET
Subject:      input functions vs. disturbances

[from Wayne Hershberger 921214]

Grandpa Powers:  Congratulations.

      Bill Powers (921212) There are others who would argue on
      your side [Wayne]...that any separation of the organism from
      its environment is a conceptual mistake. It's all just one
      big system, so there's no point in trying to take it apart
      into components in order to understand it.

This is NOT my point; rather, I am saying that when taking
something apart that works, one wants to keep track of all the
working parts and to not mistake a limited set of parts for a
complete set.  However, I am also suggesting that in taking
functional wholes apart one wants to divide them into whole
functional parts.

      Bill Powers (ibid) I for one have never found that
      contemplating the WHOLE THING leads to anything but
      bafflement...We could just as well say that the actions of
      the Little Man consist of altering...output, not
      perception...because when you start with the motor output
      forces and keep adding all the things directly related to
      and dependent on them, you end up back with the output
      forces after one trip around the loop. Making all the
      substitutions to eliminate intermediate terms, you end up
      with output = f(output). Or perception = f(perception), or
      error = f(error). It all depends on where you start.
            In our modeling efforts, we have found it definitely
      useful to distinguish the organism from its environment.

Perhaps, but it seems to me far more useful (indeed, essential) to
identify the two inputs to the canonical loop: the reference input
and the disturbances (considered collectively).  These two inputs
to the loop (neither is an input to the organism) mark the
functional joints at which the loop is best carved.  There is no
better example of this argument than your own 1978 _Psychological_
_Review_ article where you identify p* and d, using the
organism/environment distinction, effectively, for pedagogical
purposes.

The reference signal and disturbance provide the basis for saying
that control systems control their inputs rather than their
outputs.  That is, at the point in the canonical loop where the
loop is intersected by the reference signal (i.e., at the
comparator), it is the loop's input to this intersection (the
variable in the loop downstream of the final disturbance) not the
loop's output from this intersection which corresponds to the
reference value.  THIS IS TRUE WHETHER OR NOT THERE ARE ANY
EFFECTORS OR RECEPTORS (I.E., ORGANISM/ENVIRONMENT INTERFACE) IN
THE LOOP.  So, whether or not organisms can control environmental
variables appears to be another question, altogether.  It depends
upon where the organism/environment interface is located relative
to the last disturbance in the loop.

In your HPCT you have labeled each loop's input to a comparator p
(for perception), and hypothesized that higher order perceptions
are "subjective EVs" realized by complex input functions--no
problem.  But the question of whether or not organisms also
control objective EVs depends upon the location of the last
disturbance in the loop, not merely upon the complexity of the
input functions.  There appear to be two different matters at
issue here.  What do you think?


When I said that conceptual EVs (involving imagination) and
perceptual EVs are lawfully related I was agreeing with your
earlier post when you said:

      Bill Powers (921210) the behavior of the environment is
      lawfully and reliably related to the perceptual signal, as
      long as the form of the input function remains the same.

I read your expression "the environment" as referring to a
disciplined conceptual model comprising objective EVs (i.e., EVs
of physics).  I am using the expression perceptual EVs to include
all levels of perception including conceptual levels--as you do.
The lawfulness that concerns me is not the regularity between
lower level and higher level perceptions, but between EVs
described objectively (by scientific models) and EVs described
subjectively.

Because the lawfulness of these related realizations may mean
nothing more and nothing less than the reality of the laws of
their relation, the expression "Boss Reality" seems far to
redolent of agency and substance to serve as an appropriate label.
Boss Reality sounds like something with a mind of its own.  It
puzzles me why you use the expression while seeming to reject its
connotations--why not coin phrase?


Warm regards, Wayne


Wayne A. Hershberger             Work: (815) 753-7097
Professor of Psychology
Department of Psychology         Home: (815) 758-3747
Northern Illinois University
DeKalb IL 60115                  Bitnet: tj0wah1@niu
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