[from Mary Powers (971205)]
First I'll put my CSG secretary hat on for Fred Nickols (and maybe some
others? 
) and do what that stupid treasurer forgot. Dues can be sent to:
The Control Systems Group
73 Ridge Place
Durango CO 81301-8136
                * * *
Bruce Abbott (971205.1040 EST):
"Although all these changes are happening concurrently, this does not mean
that there is no temporal ordering...causes precede effects, because
physical interactions take time."
"For me the most important thing is ... that the effect is the result of the
cause -- an influence in a particular direction. The crucial aspect of this
is that effects do not precede their causes".
I think I'm trying to say that temporal ordering is what an external
observer sees when he perceives cause and effect. The subject sees it this
way too if his attention also is engaged at the appropriate level in the
hierarchy. However, the subject to which the cause (disturbance) is
happening perceives nothing that would lead to an effect until a perception
that deviates from a reference signal reaches the comparator where that
reference signal is present. All along that comparator has been receiving
both perceptions and reference signals. The output of that comparator is
"no error, no error, no error, ERROR. In the control system involved, the
disturbing perception does not precede the reference signal. And the
reference signal is just as important as the perception for the effect to
occur. If there is no disturbance to the perception, the cause does not
have an effect (as Rupert said). If the reference signal were not present
at a particular value, there would also be no effect.
To say (as you did somewhere) that the cause is "mediated" by the organism
which then produces the effect is to use the black box model of what goes on
in the brain that psychologists quite legitimately used when not much was
known about what goes on in there. PCT, however, IS a model of what goes on
in there. As Bill has often said, this is A model, not necessarily THE
model, but it works. And, as far as I know, it is the only model currently
proposed that does work in a plausible way (as opposed, say, to a computed
output model). Unfortunately, the way it works contradicts a lot of
expectations psychologists have had about how it would work. And one
feature that seems hard to grasp is that external causes are only part of
the picture - a disturbance to a reference state. The reference signal is
also an independent variable. And because the reference signal is there,
and the comparator, the process involved is not mediation, but control, and
what is controlled by control systems is perception, not behavior.
It is the reference signal, jointly with the cause, that determines the
direction of the effect. The "response" to the "cause" is not just some
random flailing around (except in very young or simple organisms or
extremely stressed and reorganizing ones). When you say "the effect is the
result of the cause - an influence in a particular direction", just what
direction do you have in mind? In my mind the direction is entirely up to
the organism being disturbed, and that direction is some action that will
reduce the error - the error produced partly by the perception, and partly
by the reference signal. The cause has a part in the organism's experience
of error, but not in the organism's desire to reduce and not increase it.
Consider two people on horseback, who have agreed to participate in this
little demo. Assume they have their horses walking along. Now they are told
"turn right". One rider gives a little pull on the right rein, and the
horse turns right. The other rider picks up the left rein and lays it
across the left side of her horse's neck, and that horse also turns right.
Each person heard the order, and had the same discrepancy between desired
and intended perceptions (I'm going straight and I want to turn right). They
each reduced the error a different way. Each horse was provided with a
different disturbance yet both horses turned the same way.
Now all these combinations of causes and effects can be described, but the
real question is "can they be explained?" You say "the crucial aspect of
this is that effects do not precede their causes". What's so crucial?
"Causes precede effects" is an observation. It is not an explanation. The
two horses turned the same way because in both cases the perceived input
(the pressure of the bit in the mouth, the pressure of the rein on the neck)
was different from the reference state, and since neither had any particular
reference level for which way they were going, they corrected the error by
turning. Do you really attribute the direction in which they turned to the
cause? To my mind, the cause simply presents a situation. Whether or not
it is perceived as a disturbance, and what is done about it, is up to the
organism.
The explanation that has grown out of the observation that causes precede
effects is "Causes make effects happen". This seems to work ok in the
physical world - "gee, if we use it in psychology too we'll be scientists
just like physicists!" I, for one, prefer to go with the idea that
organisms are control systems.
Mary P.