From Tom Bourbon [940714.1750]
[Paul George 940714 11:00]
From Tom Bourbon [940713.1538]
But what you call "chaff" is the entire social and scientific establishment
called "radical behaviorism." The quality of Skinner's "understanding" is
not something I dismiss as readily as you. He touted that understanding as
_the_ very science of behavior, not as a personal understanding.That is what I call 'fluffing the ware's' (legal & economic phrase). People,
particularly scientists, scholars, and methodologists control for recognition
or status (I hope I phrase that correctly). This often leads to advertising for
product differentiation and declairing that one has the one true solution. I
concurr with your conclusions about the effect of radical behaviorism.
It looks as though we ar approaching something of an agreement on Skinner,
at least in terms of how he did his fluffing. That's good. 
Instead, he developed a technology, which he called a science, in which he
treated all behavior as though it were a result of environmental stimulation.Just for clarification, the distinction between technology and science is...??
I was using Skinner's term. For some audiences, he said behaviorism was
only a technology, not a science; for others, he claimed behaviorism was
_the_ science of behavior (TB: "the only" was understood). I assume that
when he said it was a technology, he was trying to evade challenges to the
quality of behaviorism as science -- "You don't think behaviorism measures up
as science and those are the reasons you give? Not to worry! Behaviorism
is only a technology -- a set of handy tools for controlling behavior."
Notice the neat dance to the side? What a nifty way to stay out of
arguments, one of those mythical feats for which Skinner was noted during
his life. Of course, the fact that there was more to behavior than
radical behaviorists allowed to meet their eyes was ignored and
behaviorists-as-THE-behavioral-scientists could go on about their "Science"
undisturbed. Come to think of it, Skinner was being a damned effective
control system, wasn't he?
There is a bit of a point of view problem. Clearly the environmental stimuli
(though that is a loaded term, I prefer 'influence' or 'event') affects
behavior because stimuli is what can be perceived.
Agreed, up to a point. In the right conditions, it is possible to see a
contingent temporal sequence of stimulus followed by response. (See Rick's
paper on the blind men and the elephant for a PCT analysis of that
S-R interpretation -- oh, by the way Paul, Rick and the rest of us know the
story was around long before Rick used that as his title; that's why he
picked the title.) But the fact that I can see that sequence does not mean
I have seen what the observed system "is doing:" controlling specific
perceptions. Once I see _that_ fact, then an infinite array of specific
stimulus-response contingencies can be predicted with great precision and
they can be explained and modeled as though the system acts to eliminate the
effects of disturbances that affect variables related to its (the system's)
controlled perceptions.
When I have a continious or
rapidly cycling system (i.e. environment+organism) with what I deem cause and
what I deem effect is largely an artifact of at what point I arbitrarily start
to follow the chain of interaction.
I guess that could occur, were you observing a truly discrete
system-environment interaction sequence. Can you identify some intractions
in which that is really what occurs? Those aren't the kinds of things you
see when control syatems interact with their environments, but there _are_
circumstances when that can _appear to be_ the case. Again, see Rick's
paper, and "Models and their worlds," by Bill Powers and me, and my paper on
"Mimicry and repetition." Easy for me to say that : all thre papers are in
our ghetto journal, _Closed Loop_. Mary Powers can supply copies, at cost.
It is a classic chicken and egg situation.
Not in a closed loop.
As I said earlier, I think PCTrs look at the situation from the organisim's
point of view while others look at from a theoretical external observer's point
of view. However, as Hiesenburg pointed out, the observer and observed affect
one another wherther they want to or not. PCT thus gives a clearer view of what
is going on as it recognizes interacting control systems.
Heisenberg wasn't talking about the behavior of organisms, so I'm not
certain we can assume that his comments will automatically apply to our
work, but that caveat aside, I agree.
I never thought of a control system as something that functions because
the number of its parts is at least one greater than some threshold number
of parts.I believe it has beed demonstrated that there is behavior whose complexity is a
step function of the number of components. It is certianly the case that
certain concepts or theories cannot be understood until one has aquired a
certain minimal set of facts (or other theories) - the pieces just won't fit
together.
But PCT is about an empirical, nontheoretical phenomenon -- control, and
about the minimal organization of a system that can achieve control. It is
not about how many _pieces_ there must be, but about the specific functions
that must occur, whether they occur in a person, or a pigeon, or a bacterium,
or a chemical reaction. A control system -- a person or a rat for example
-- can loose many identifiable parts and still function as a control system.
What matters is not the absolute numnber of parts, but the specific
organization of the ones that remain.
Incidentally, in Wales, Pedro Mendes gave an exciting presentation on his
work in which he applies the PCT model to biochemical reactions. There is
no nervous system involved there, or in the modeling of bacteria by Bill P.
and Rick. What is important is that the requisite functions occur. Their
occurrence is of course dependent upon enough "pieces" being present,
whatever the substance of the pieces might be, but the number of pieces
alone has nothing to do with what happens when they are connected and put
in motion. It is the specific organization of the system that matters.
The organization represented in the PCT model seems to have wide
applicability as a model for control -- we are willing to start suggesting
that it will apply to control by all living things.
I can't control a process (a.k.a control a perceptual pattern) until
I have the right set of perceptions and actions to control it. I can't track
the cursor or target unless I can recognise azmuth and elevation. Azmuth and
range won't cut it. I also can't perform the tracking task unless I have a
stick and the ability to move it in 2 directions.
And having said all of those true things (ignoring for now the possibility
that we might need to explore the meaning of "recognise azimuth and X"),
you (generic you) have said exactly nothing about how it comes to pass that
a person can use a control stick to keep a cursor aligned with a target.
That explanation requires a model for the organization of the person, not
for the number of parts in the person.
Perhaps you should give me your definition of 'gestalt'.
Ah, it ws _you_ who introduced the term into the discussion. I've called
_your_ hand. Show your cards!
In hierarchical PCT models, there are no distributed nodes, each with its
controlled variable(s). We seem to be talking about different kinds of
systems.Say what??? Then how would you describe a HPCS?? Must all of a control network
occupy the same locus? Sight and motor control are the same parts of the brain
and use the same variables? A HPCS can't involve more than one individual? I
think we may be using different meanings for 'distributed'.
See my post earlier today -- was it to Bill Leach? I was speaking of what I
saw (perhaps incorrectly) as an appeal by you to the kind of "distributed
system" that is in Albus's papers. The PCT model, whether in the
single-loop or hierarchical version, is not like the "models" in the Albus
papers. You still have not told us whet your own model would look like, if
not like Albus's.
Me
Nope, while action and input may be linial, control is usually continuous or
at least periodic.But you didn't describe it that way. You described a lineal process that
includes the production of pre-programmed outputs, selected to match
present-time inputs.Unfortunately language is linial.
Yes, it is. But you also included a diagram, and it was clearly a diagram
of a lineal system for input-process-output.
Inputs arrive relatively constantly,
evaluation occurrs relatively constantly, and a given 'action programs' run
concurantly, though usually for a period of time.
But living control systems don't work "relatively" constantly; they work
constantly -- continuously. And the world works constantly, not
intermittently.
When I decide to throw a
punch or execute a block, I do not have to concentrate on the micro movements.
Yes. Isn't it amazing?! That's the nature of perceptual control -- the
actions that produce your behavior -- yuur controlled perceptions -- seem to
"just happen" as though by magic.
That task is spawned into to what is probably an autonomus control loop or 'sub
process'.
Oops! I won't even start to reply to this until after you have a chance to
read some things about PCT. If you still want to say this after you have
done the reading, then we can go at it in earnest. 
It is a predefined pattern of actions that may be activated at need.
Ouch! In spite of what I said a sentence earlier, I can't hold back from
saying that this is completely outsidce the understanding of behavior in
PCT. I believe we have developed somepretty convincing arguments that
nothing like this happens in control behavior. Nothing.
I am not constantly prepared to punch or block at all times. I have a little
trouble with the idea of a multitude of control loops monitoring at all times
every existing controlled variable waiting for an positive error signal to
occur.
Read about it. I think you will enjoy it. And I think yuo will find that
the characterization you just gave is not an accurate one of the hierarchical
PCT model. (That is not meant as a criticism or put down, but as an
acknowledgement that you still have not read the literature or hung around
the net long enough to know what we say about such things.)
A cascade system seems much simpler and more efficient, but I am
contaminated by my experience as an engineer.
That's OK. We'll forgive you for the bad company you fell in with, earlier
in your life.
I guess the empirical question is whether all action in an organism is the
result of a continiously active control loop, or whether some are cyclical or
activated on demand (i.e. triggered by a discontinuous event).
The question, the $64,000,000 question (I'veraised th anyee ten fold, Rick)
is is there a "controlled variable." The next question is, "If there is a
controlled variable, what kind of system could control it?" The answer will
always be, "A control system could control it." And many other kinds of
systems -- including all lineal systems -- could not.
Note that if the
period of a cycle is sufficiently rapid relative to the rate of change of
inputs and outputs it appears continious. This is why we are able to use
digital computers for control.
Fine, especialyfor people who want to make a living using digital computers
for achieving control. But that does not necessarily have anything to do
with how living systems achieve control -- in fact, itprobably has _nothing_
to do with how living systems control.
Tracking a cursor, as you eloquently explained below, certainly is a
situation where continuous negative feedback loop applies. You are in fact
continiously controlling something. It is not clear in my mind how or why the
concept of triggering a learned action pattern that goes away when the task is
completed is inappropriate.
Read "Models and their worlds," by Bill P and me. If after that you still
think a triggered action pattern can explain tracking, I'll be pretty
disappointed with our writing skills. (I'll stop short of saying, "I'll
eat my control handles.")
Perhaps an extension of the 'little man' problem to
two little men playing the computer game 'pong' would be enlightening.
The problem is probably my lack of understanding of HPCT.
I don't have exactly that program, but I do have a lot of programs with two
people, two hands, two models, and a model and a person, all interacting
in about five or six identifiable kinds of interactions. And I'm still
overcoming my profound ignorance about the amazing phenomenon of control.
I think these two replies (to Bill and me) are the clearest indications yet
that you are talking about a different kind of system from us. A system,
incidentally, that is very similar to the ones described by Albus -- you
must think of him as more than just someone to use as raw meat to cast
before the PCT modelers. ;-)) You seem to envision a "system" as a kind of
"meta-assemblage" of independent systems, each of which accomplishes an
assigned task, then passes off the result to the next system(s) in the chain
(or net) which uses the received result as fodder for its own processes, and
so on.Sorry for the confusion,
No apology needed. I'm just trying to understand your point of view -- and
you certainly are up against it, trying to understand ours.
Time to shut down and vanish for a protracted weekend, marrying off the
"baby" in the family. If this post is filled with typos, I apologize -- it
was done on the fly.
I can't imagine how I'll even read all of the mail I know will come in by
Monday!
Once more around the loop
Keep chomping on that bandwidth!
Later,
Tom