PCT vs cognitivism

[From Rick Marken (920814.2200)]

Well, thanks to penni for giving me something to do this evening
that's more fun than watching "Lifestyles of the Rich and Famous"
(actually, I've never watched it for fear that one of my old high
school buddies would be on).

Ok. That's the header. Now to business.

penni sibun (920814) says:

sorry. i was just at the cognitive science conference with several
hundred psychologists, and they didn't strike me as s-r modelers;

They've got new words for it. Let's just say they are cause-effect
modellers. Actually, lets not even say they are modellers.

one
of the keynote addresses was by turvey, who is a gibsonian (that is,
has an interactionist model of organism/environment)

I won't say a thing.

Well. OK I will refer you to the two papers in chapter 6 of my "Mind
Readings" book. They are dedicated to Turvey and his bunch. I don't
think he's ever read them, though, unless he was a reviewer. I don't
think he would like them.

I must also mention that Turvey has the honor of having published the
longest, most systematic and most incorrect critique of PCT to date.
If you want to see ignorance posturing with pompous authority, check out
the first chapter (pp 1-39) in G. Stelmach (Ed.) Information
processing in motor control and learning. New York: Academic Press
(1979) -- the article is by Fowler and Turvey. A must read for PCTers.

i think it would be a lot more
constructive for me to understand your position if, instead of
distinguishing your view from behaviorism, you distinguished it from
cognitivism. care to give it a shot?

Sure. Though I think we've done it before.

There are many incarnations of cognitivism. But what is common to all
of them (and what is commonly wrong) is that they view behavior as the
end result of mental processing. PCT says that it is perception that is
the result of "mental events" (reference signals). This apparently small
distinction is as big as the distinction between behaviorism (which
sees external events as the cause of behavior) and PCT. There are
several cognitive "models" that illustrate my point. One I particularly
like is a "hierarchical control" model of movement sequence generation
proposed by Rosenbaum. This model assumes that the results of cognitive
plans (the little demons moving around the hierarchy) will be exactly
as expected. There is no notion that these results are also influenced
by external disturbances and that it is, thus, highly unlikely that
repeating the "plan" will repeat the result. What is probably happening
is that the subjects are controlling (among other things) perceptions
of transitions, sequences and configurations and maintaining these
perceptions at intended levels.

There are many other examples of cognitive "models" (I use quotes
because they never really try to make these models work in real
environments; if they did, they would learn a lot, FAST) but they
all have one thing in common -- once all the processing
has occurred, behavior just "pops out" as the end result. Sorry,
but behavior CANNOT happen that way. So, no matter how clever the
processing carried out by these "models", they cannot behave; so they
cannot be correct.

There are some cognitive models that have some closed loop character-
istics; and probably qualify as control system models of the control
of higher level variables. An example is Simon's theorm prover (and
current models that are similar, like the prolog language itself).
These models try to satisfy certain logical conditions (the reference
condition) by trying to satisfy other logical conditions in their
database. These are control models that work in a logical (not a
real) environment (the database). These are interesting models and
they may eventually become useful as models of what Powers calls
"program level" control. I have no beef with these models -- I think
they are very clever. They are just not yet connected in a realistic
way to behavior.

in order to convince me, and other people
(characterized as above) who loosely consider themselves to be
interactionists, or situated activity theorists, or whatever, you need
to step back from the pro-/anti-behaviorism debate.

I'm game.

if you think it's too weird to consider that organism and environment
are fundamentally inseparable, why not consider a slightly different
take on it: action and perception are inseparable; there is no way
you can draw a line and say that on one side is the organism's action
and on the other is the organism's perception. on this view, what
could it mean to locate control in the head of the organism?

In Bill Powers' "Living control systems" page 251-252, precisely
this question is answered, simply and quantitatively. The short
answer is "because the organism amplifies, the environment dampens".
(my quotes, not Bill's).

on the interactionist view, control is neither in the head not in the
environment.

Sounds fine; but it turns out to be wrong -- a common problem when
trying to understand the world with words instead of models.

I would like to learn about interactionism. But I
didn't really learn much from the quotes you provided. Perhaps
you could describe an interactionist model of some very
simple phenomenon. Matter of fact, perhaps you might start by
explaining the nature of the phenomenon that interactionism
explains. Does it explain the phenomenon of control? If so, how?

Best regards

Rick

···

**************************************************************

Richard S. Marken USMail: 10459 Holman Ave
The Aerospace Corporation Los Angeles, CA 90024
E-mail: marken@aero.org
(310) 336-6214 (day)
(310) 474-0313 (evening)

[Martin Taylor 920816 03:00] Almost back from holiday.
(Rick Marken 920814.2200)

The short
answer is "because the organism amplifies, the environment dampens".

Not always true, and certainly not true of that part of the environment
that contains control systems. Not true in sensitive parts of the environment
that don't (e.g. bifurcation points, such as things balanced on table edges).
Sufficiently often true that it is a beguiling temptation to take it as truth.

Look at my mirror diagram of a few weeks ago to see another view, according to
which control is indeed exerciesed in the head but on an environment that
cannot be seen as "outside" except by the controller. (There are better
versions of the mirror diagram in my abstract of my Paris talk, which I have
sent to Bill, and will send if anyone else urgently wants it (50 pages, so
I don't want to send too many).)

(Lots of interesting stuff been going on in the time since the meeting. I don't
suppose I'll comment on much of it (do I hear sighs of relief?), but this just
struck me as worth a note.)

Martin

(penni sibun 920816)

   [marken 920814]

   I must also mention that Turvey has the honor of having published the
   longest, most systematic and most incorrect critique of PCT to
   date.

i'll believe you. i don't think that detracts from the fact that he's
not a behaviorist.

   There are many incarnations of cognitivism. But what is common to all
   of them (and what is commonly wrong) is that they view behavior as the
   end result of mental processing. PCT says that it is perception that is
   the result of "mental events" (reference signals).

i think this charaterization overstates cognitivism. i don't think
cognitivism necessarily sees beh. as the ``end result'' of mental
processing; i think cognitivism sees mental processing as crucial for
behavior.

   This apparently small
   distinction is as big as the distinction between behaviorism (which
   sees external events as the cause of behavior) and PCT.

no, it's not: they both have the word ``mental'' in them, and
behaviorism clearly does not. the emphasis on the ``mental''
distinguishes cognitivism and pct from behaviorism.

   There are some cognitive models that have some closed loop character-
   istics; and probably qualify as control system models of the control
   of higher level variables. An example is Simon's theor[e]m prover (and
   current models that are similar, like the prolog language itself).
   These models try to satisfy certain logical conditions (the reference
   condition) by trying to satisfy other logical conditions in their
   database. These are control models that work in a logical (not a
   real) environment (the database). These are interesting models and
   they may eventually become useful as models of what Powers calls
   "program level" control. I have no beef with these models -- I think
   they are very clever. They are just not yet connected in a realistic
   way to behavior.

you don't find the fact that they are intractable problematic?
interesting (but somewhat off the point).

   >if you think it's too weird to consider that organism and environment
   >are fundamentally inseparable, why not consider a slightly different
   >take on it: action and perception are inseparable; there is no way
   >you can draw a line and say that on one side is the organism's action
   >and on the other is the organism's perception. on this view, what
   >could it mean to locate control in the head of the organism?

   In Bill Powers' "Living control systems" page 251-252, precisely
   this question is answered, simply and quantitatively. The short
   answer is "because the organism amplifies, the environment dampens".
   (my quotes, not Bill's).

this is simply sloganeering; it doesn't address the question in any
obvious way (though i realize it's been addressed in later messages).

   >on the interactionist view, control is neither in the head not in the
   >environment.

   Sounds fine; but it turns out to be wrong -- a common problem when
   trying to understand the world with words instead of models.

do you think you could cut down on the _ad hominem_ rhetoric?

   I would like to learn about interactionism. But I
   didn't really learn much from the quotes you provided.

fair enough. read almost anything by agre. i can give you preston's
address and you can ask for her paper.

   Perhaps
   you could describe an interactionist model of some very
   simple phenomenon.

see below about driving.

   Matter of fact, perhaps you might start by
   explaining the nature of the phenomenon that interactionism
   explains.

behavior. the same phenomenon that cogitivism and behaviorism
explains.

   Does it explain the phenomenon of control? If so, how?

no. it does not seek to explain control. unlike cognitivism and
behaviorism, interactionism is not founded on the premise that the
idea of control is crucial to understanding or explaining behavior.

   [from Avery Andrews (920815)]
    (penni sibun 920814, on marken 920808)

   What I'd say to this is that PCT is not cognitivist, because the *phenomenon*
   of control is only found when an organism (or other `Agent') is put in an
   appropriate environment (e.g. if the road is covered with an oil-slick,
   one ceases to observe control of the direction in which the car is going).
   The phenomenon of control is just what Rick says it is: when you introduce
   disturbances that you would expect to change some aspect of the environment,
   but that aspect doesn't change, because the Agent consistently does things
   that `mysteriously' counteract your attempted disturbances.

on an interactionist view, there's nothing mysterious going on.
(though, frankly, i must confess that i don't really understand
y'all's rhetorical use of ``mysterious''; i don't really know what's
supposed to be mysterious to whom.)

   PCT goes on to say (at least) two further things:

     a) an Agent that is efficacious in the real world must effect control

     b) the only way control can be effected is by means of certain kinds
  of internal arrangments - perceptors, comparators & effectors
  appropriately connected so as to constitute negative feedback loops
  in the context of the actual environment.

i think it's conceivable that pct-type control might be more
interactionist than any of us understands at this point. however,
part b) is squarely cognitivist: it requires an inside-outside line
to be drawn, and puts crucial stuff on the inside of the line.

   [From Bill Powers (920815.0800)]

   Penni Sibun (920814) --

   You say some things, and represent others as saying some things, that fall
   strangely on my ear. For example:

      >for these folks
      >and others in ai, for gibsonian psychologists, for
      >ethnomethodologists, etc., agents and their worlds are *not
      >separable*. how can you have a respond to b's stimulus when a and b
      >are the same thing?

   If they can't separate agents and their worlds, they're trying to use the
   same model for the inanimate environment and for living systems. This is
   simply a mistake: the inanimate world does not run by the same rules as the
   animate one. Of course if you jack yourself up to a high enough level of
   abstraction, everything is the same as everything.

hold on. doesn't everything bottom out in physics? certainly the
current view is that everything is made of the same subatomic building
blocks, in a very fundamental, not abstract, way.

   But then you have
   nothing interesting to say, because all the interesting things we say about
   ourselves and the world are about relationships between independent things.
   If you can't tell things apart, because of having abstracted too far, then
   you can't see any relationships.

ok, i agree that when we say interesting things, we say things about
objects and relationships that we have individuated for the purpose of
talking about them; certainly there are things that we typically
individuate (like organisms) so that we can talk to each other. on
the interactionist view, there is nothing sacrosanct about these
typical individuations. whenever you look very closely at a clearly
drawn line, you begin to see that it gets rather fuzzy. the line
between action and perception is a paradigmatic example of this.

   It's hard for me to see how
   a person who doesn't make this distinction [bet. perception and
   action] can understand what it means to
   say that action controls perception, unless that person means that
   perception IS action, or that perception follows faithfully from action
   (which it doesn't -- that's not the meaning of "control").

all true if you assume control. but as i said, the interactionist
view doesn't assume a model of control.

   But action and perception are completely separable; among our most basic
   and elementary demonstrations of control processes is one that shows an
   almost total LACK of correlation between a person's actions and the
   perception that they control. If you don't understand this fundamental
   separation, then you've missed a basic point about how control works.

   This is such a basic concept that I don't think we can understand each
   other until we reach some sort of agreement on it.

i understand what you're saying, and i do in fact agree that you have
an interesting and efficacious model of control. you can build little
creatures who do cool things with your model. you might even be able
to build little creatures that are better than anyone else's (though i
think the jury's still out on that one).

but i don't think your model is sufficient to account for human
behavior (or the behavior of any creature you didn't build yourself).

   Think of the car and driver. The driver controls a perception of the car's
   position in its lane by the action of applying a turning-moment to the
   steering wheel. Essentially all of the driver's actions are present only to
   oppose the effects of independent disturbances on the car's path. Those
   disturbances are unpredictable and invisible. Nevertheless, the driver's
   actions correlate highly (negatively) with their net vector sum. But the
   driver's actions correlate hardly at all with the visually-detected
   position of the car on the road, which is the controlled perception.

   How does this jibe with saying that action and perception are inseparable?

i'm not going to answer this question head-on at the moment. your
formulation of what's going on is in terms of separate action and
perception; it's difficult to answer that question within your
framework. let me try to get a step closer by formulating the
situation in my own terminology, which is interactionist but is
undoubtably somewhat idiosyncratic (there isn't ``standard''
interactionist terminology).

new england is covered in backroads--they are twisty, hilly, narrow,
and old, and are subject to nearly all possible weather conditions.
the way one drives them is to keep one's left wheels near, or quite
possibly over, the center line (if it is visible). essentially, one
drives down the middle of the road; this is becuase the danger of
running into someone else is much less than sliding ingloriously off
the road (when a highschool friend of mine ran off the road shortly
after getting his licence, all the adults clucked and opined that
obviously he had stayed too close to the edge of the road). the road
changes constantly with the weather; if there's been an inch of snow
already but nothing's been plowed, driving down the road means driving
in the tracks established by previous drivers, even if the tracks are
suboptimally placed, since following the tracks is safer than crossing
them.

in california, the roads are much newer, and since they'r never
plowed, they have little reflecting bumps on the painted road
markings. so driving down the road means being mindful of not
crossing the bumps (which are quite effective at rattling the car).

the roads in the santa cruz mountains are as twisty as and much
steeper than the backroads of new england (but they are better made
and have reflector bumps). there are no speed limits in the
mountains: if you know the road, you drive fast; if you don't, you
drive slow; if you're stupid and drive fast where you don't know the
road, you lose. what is crucial is that you stay on yr side of the
reflectors no matter what. if you cross the line, any sort of
encounter is a disaster. if you stay on your side, the only hazard is
rearending bicyclists.

i280 in san mateo county calls itself the world's most beautiful
freeway. i don't know about that, but it's certain one of the world's
best built, and the traffic's reasonably light. i have the sort of
commute that it's easy to zone out on, there's so little to pay
attention to. i do tend to notice roadsigns, though, and i know, for
instance, that after the woodside exit, the road's going to take a
gradual curve to the left, and i can account for that.

ok, that's my car and driver story. i mean it to illustrate that
there's no such thing as simply ``someone keeping a car on the road.''
there's always a whole lot more stuff involved. i have mentioned at
least the following factors: customs; geography; weather; road
construction; individual experience; various sources of information
about the road (eg, reflector bumps, road signs). i argue, first,
that to model this as a single process of controlling for the
perception of a single variable (or a bunch of them) would be
hopelessly baroque and probably impossible; second, if you did extract
from all this a common thing that we could agree was the essence of
``keeping to the road,'' then you're going to have to tell me where
you're going to put all the rest of the stuff that i've mentioned and
can produce pretty good evidence for.

the short interactionist story is that none of this stuff gets thrown
away, and it's not obviously locatable either Inside or Outside. the
long one will have to wait till my hands recover.

[From Rick Marken (920817.2000)]

I'll try to finish this fast so that I can watch the fascist fandango
in Houston -- featuring my favorite actor (really!).

Actually, all I really want to do is straighten out an unfortunate
misunderstanding (yes, folks, for a change I have better things to
do than post to the net). What I want to straighten out is this:

I said:

  Sounds fine; but it turns out to be wrong -- a common problem when
  trying to understand the world with words instead of models.

and penni said:

do you think you could cut down on the _ad hominem_ rhetoric?

I want to sincerely apologize if this seemed like a personal attack.
I did not mean you (penni) personally. I was thinking of theorists
(and there are loads of them) who come to conclusions about how things
work by "thinking them through" in words, rather than by building
working models. This has been a particular problem when it comes to
understanding the behavior of closed loop systems (witness the TOTE
unit of recent discussion).

I'm glad that you are participating in this conversation; again I
apologize if I offended you.

Believe it or not I don't like ad hominem arguments. I did make fun
of Turvey -- but that is because he took a rather harsh pot-shot
at Powers (in his article) and has never been open to discuss it.
I consider that kind of thing crappy -- so I said some mean things
about him, but even then, I did it with some reluctance.

CSG net is for discussion and solving problems. Some of the
discussions get pretty heated, but I think we have avoided ad
hominum attacks pretty well. The reason, I think, is because our best
arguments are ultimately solved by demonstration -- showing how an idea
works as a working model or experimental demonstration.

Anyway, please accept my apologies for the apparent ad hominum.
I don't agree with your position, but I am trying to understand
it and to present mine as best I can (within the limits of the
medium). Although I think you are wrong, I assume that you are
well intentioned. So enjoy the conversation but remember, I can't
help thinking that I'm right any more than you can help thinking
that you are. We'll both probably be disappointed when we meet
Ms. Truth up there.

Best regards

Rick

···

**************************************************************

Richard S. Marken USMail: 10459 Holman Ave
The Aerospace Corporation Los Angeles, CA 90024
E-mail: marken@aero.org
(310) 336-6214 (day)
(310) 474-0313 (evening)

[From Rick Marken (920817.2000)]

s'cool. thanks for reminding me about the show!

        --penni

[From Rick Marken (920818)]

First some off the wall comments before I try to answer some of penni
sibum's specific comments.

1. The fascist fandango was too scarry for me; I had to turn it off after
Buchanan's speech. What a sweet, caring, tolerant bunch of what, I
suppose, have to be classed as human beings.

2. Did anyone (such as you, Bruce Nevin) invite that editor from Discover
to listen in on CSGnet? I think it would be a nice idea to try to get
something published in that forum.

penni sibun (920816) says:

i don't think
cognitivism necessarily sees beh. as the ``end result'' of mental
processing; i think cognitivism sees mental processing as crucial for
behavior.

  In the cognitive model I used as an example, a behavior -- a sequence of
finger taps -- is thought to be generated by a hierarchical set of commands.
These commands are generated by a mental plan (that presumably exists in
the brain). As this plan unfolds it generates the appropriate finger sequence
(in theory) The movement of each finger produces the sequences of taps which
is the behavior being accounted for by the model. So the behavior (sequence
of taps) is the end result of the mental plan. It works like this:

mental plan >> efferent commands >> finger movement>> taps

This is a lineal causal process which I argue is characteristic of ALL
cognitive models. Note that behavior (in this case, the taps) is at the end
of the line.

The problem with this model is that it neglects some important aspects of the
situation -- namely, disturbances. Disturbances are known to enter the
process right after the efferent commands are generated. Efferent
commands are neural impulses that cause muscles to tense; but the amount of
tension per unit efferent signal varies considerably over time; so the result
of efferent commands is disturbed by variations in the effect of neural
commands on muscles. Environmental disturbances enter the picture after
muscle tensions occur and influence the effect of these tensions on the
results they are intended to produce. For example, changes in the initial
position of the finger will influence whether or not a particular amout of
tension will result in a tap or not.

The existence of disturbances means that there is no way for a system to
reliably produce an intended result via the same means (in this case, the
same efferent commands). This meams that there is no question that
Rosenbaum's sequence production model will not behave as the subjects
do in a real environment (the same environment as the one the subjects work
in).So this type of cognitive model is unquestionably wrong.

The only way that a system can be designed to produce reliable results in a
disturbance prone enviroment is to design the system so that is controls
the perceptual representation of those results; this sort of model is based on
a closed loop organization -- it is a control model. The important
characteristicof such a model is that is varies its output (efferent commands)
in order to keep the perceptual representation of the result at an internally
specified reference level; it controls its perception. Once you understand
this, then you realize that the process of understanding behavior is not a
matter of learning how systems generate complex sequences of outputs. It is
a matter of learning what aspects of their own perceptual experience are
being controlled. Behavior is organized around the control of perception;
indeed, I would say that behavior IS perception in action (a slogan, I
know, but one that makes sense when you watch the behavior of a
control hierarchy, especially from the point of view of the control hierarchy
itself). If you think about it, you will realize that your own behavior, from
moving your fingers to trying to argue the virtues of interactionism, is a
matter of producing the perceptions that you want to produce. In fact, there
is no behavior without perception; I argue that you can't do anything (intent-
ionally) that you cannot perceive (I know that we do a lot without attending;
but how much do you do without perceiving?). I know that there are some cases
where behavior seems to happen without perception; for example, you can
move your leg even though you cannot perceive it because you've slept on it
all night. But I would argue that what you are controlling is perceptual side
effects produced by throwing the leg around basically; you certainly can't
control the degree of bend real well, if you can't perceive it.

The fact that perception is fundemental to PCT means that people who have
always been students of perception (like myself) have a whole new level
of justification for their interest. The study of perception is no longer
just an arcane little sidelight to understanding behavior; it's what behavior
is all about. So it is strange to me to hear you say:

penni sibun (920817)

  >there's just tons of literature on

perception that suggest that perc. is a *lot* of work; in fact it
involves action--perhaps to the degree that p. and a. are inseparable.

(``active vision'' is a current buzzphrase.)

All the literature in the world won't convince me that I'm working hard as I
glance around and perceive different aspects of the world (my neural
networks may be computing some very complex functions of my sensory
inputs, but it feels pretty effortless). There's different levels of bright-
ness, lots of colors and sounds, patterns, objects (here's a computer screen,
there's a bunch of books), relationships (I'm closer to the computer than to
the door), events (the secretary just when to the other office), sequences.
I can even perceive principles and system concepts with little effort (I was
perceiving some pretty ugly ones last night, that's for sure -- though, of
course, they were only ugly relative to my own references; the people at the
convention seemed to think they were perceiving great principles).

While it takes no effort to perceive, it can take substantial effort to con-
trol those perceptions (get them to the level you want). If I want to perceive
that big book over here rather than over there I'm going to have to exert
some energy to change that perception. Controlling principles and system
concpets can require some real heavy duty effort; but perceiving the
principle or system concept seem seffortless to me.

I have to imagine that active vision is controlled visual variables--
and it seems to be from your examples (like squinting to reduce glare).
Maybe these active vision people are, indeed, doing PCT.

Anyway, back to controlling other perceptions.

Regards

Rick

···

**************************************************************

Richard S. Marken USMail: 10459 Holman Ave
The Aerospace Corporation Los Angeles, CA 90024
E-mail: marken@aero.org
(310) 336-6214 (day)
(310) 474-0313 (evening)

[from Gary Cziko 920818.1632]

Rick Marken (920818) asks:

2. Did anyone (such as you, Bruce Nevin) invite that editor from Discover
to listen in on CSGnet? I think it would be a nice idea to try to get
something published in that forum.

Thanks for the reminder. I just sent Carl Zimmer some introductory
propaganda on PCT and CSGnet. We'll see if he bites.--Gary

···

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