Down…Â
···
From: Richard Marken [mailto:rsmarken@gmail.com]
Sent: Monday, June 12, 2017 9:53 PM
To: csgnet@lists.illinois.edu
Subject: Re: William T. Powers is dead - long live William T. Powers
[From Rick Marken (2017.06.12.1250)]
Eetu Pikkarainen (2017-06-12)-
EP: The issue is ONLY that we do NOT control anything in the environment but only our own perceptions - even though the control is realized by affecting the environment.
RM: This is simply not true. See my recent post to Martin. I’ll just repeat my last point: If people controlled only their perceptions then there would be no way for anyone other than the person doing the controlling to know this.
HB : All that people can do, is they can only control their perception. What can they do more ?
Even observer would never know anything about �observed person� if he wouldn’t control perception. And yes. There is no way that other person would know exactly what other person control in the whole hierarchy. For now there is no method to precisley �look� into brain of other people. So if observer can’t see directly into brains of people arround he can’t know anything about what other people think or feel or what their references are. But observers can make better or worse guess on the bases of selfexperinces of �Control of perception� and his other �knowledge� and his actual obervations. So it depends from observer how good he will guess what other people are controlling.
Other persons can do �Control of perception� of �Control of perception� of other people so they can guess what people �Control�. But they can’t see it. The same is with behavior. From behavior we can make worse or better guess what peple are controlling, but it’s again limited to observers life-experiences and his �knowledge�.
RM : For example, we can see that people are controlling for being upright as they walk over irregular terrain (the disturbances).
HB : Wherever people walk they »Control perception« of the terrain and perception of many other variables. It’s no need for the terrain to be »irregular«. »Control of perception« works everywhere.
RM : We infer that they are doing this by controlling (among other things) a perception of the location of their center of gravity)
HB : Among other things ? How perception of the »location of center of gravity« can be controlled ? What is perception of the »location of center of gravity« ?
Is »center of gravity« some external variable that is controlled by »Control of behavior« ?
Who can perceive »center of gravity« ? Or how »center of gravity« is perceived ? Does observer see a »little circle« on the ground bellow the person walking which represent »center of gravity« ?
I think it’s again your behavioristic analyses »variable that is controlled outside«. There is no »controlled variable« in outer environment. You said it for yourself.
RM earler : The controlled variable is not in the outer environment; rather it is a function of physical variables that are in the outer environment; the function is called a perceptual function.
RM earlier : Ignoring the fact that I know that controlled variables are not in the environment,…
HB : So it seems that for a moment we agreed that the only »controlled variable« in control loop is »perceptual signal«. So we have to see how perceptual signal is controlled in organism so that we could understand walking from PCT perspective.
Those other things which you mentinoned are essential for understand how people control perception of the posture and how they determine »center of gravity«. »Center of gravity« can be some theoretical explanation for walking posture, but it’s not what people are controlling. Their wished states are perceptions from many sources. You mentioned one.
If perception of »Center of gravity« is determined it can be determined only by real perceptions in the organism. Nobody can directly perceive »Center of gravity«. It’s abstract term probably from physics.
»Center of gravity« as probbaly »outside variable« which by Ricks’ oppinion can be »seen« in environment. We just don’t know how observer can perceive »center of gravity« through posture of »walking person« ?
I think »center of gravity« is irrelevant for people controlling perceptions of walking. Maybe consequently we can assume there could be such a theoretical thing, but for real control in organism is irrelevant. »Center of gravity« is determined relativelly through many perceptions.
People control relativelly many perceptions which determine posture. (See Henry Yin article). I doubt that people are aware of some »center of gravity« when they walk. But they are aware of many perceptions and relative control of these perceptions as that is how they behave on general. And that is what PCT is explaning. »Control of perception«.
So we need some PCT explanation of walking posture. But in this case we don’t need »controlled variable« in environment but we have to »Control many perceptions« (the only controlled variables) in organisms which relativelly determine the posture in accordance with success in control.
Perception of walking consists of many perceptions that are controlled on different levels of hierarchy. You Rick mentioned one of it (visual perception). There are also perceptions of vestibullar apparatus, perceptions of preasure on the foot, pereptions of antigravitational muscles, etc.
It’s a very complex nerv net for walking »control«, so I will not descibe it here.
For people who walk it seems that the most important are perceptions of state in »vestibullar apparatus« which »cooperate« with perceptions of preasure on the foot, with visual perceptions….etc.Â
I doubt that »vestibullar apparatus« knows what is »center of gravity«. The references for all perceptions that are affected by output is formed in nervous system. They can’t be transffered into outside environment in anyway. There is no »referenced control variable« in environment when walking behavior is analyzed.
The position of vestibullar apparatus« in respect to perception of other sources of perception is probably the main issue here. Nervous system on the bases of these afferents controls relative position of perceptual inputs which are affected by output that are means of affecting all perceptions of the »upright posture«. I’ll not go in details how everything works in nervous system but it is obvious that PCT explanation fits to what is happening during walking. RCT definition is far from it.
Walking (upright) is a typical case that can be solved easily with PCT, but it is impossible to solve it with RCT. Whatever Rick (observer) thinks it’s happening during walk it’s only »effects of output on input«. And this is called »feed-back« in PCT. Just »effects of output on input« no »acting on things in environment«. No »controlled variable« in environment of walking persons. The only »controlled variables« are perceptual signals of various sources (vestibullar apparatus, visual input, pressure on the foot…etc) which determine »»control«.
And for the bonus there is no »protection from disturbances«. Central nervous system is »correcting«, compensating, cancelling, opposing, etc. effects of gravitational disturbances. How can you be Rick protected against »gravitational disturbances« ??? How can any perosn be protected against »gravitational disturbances«.
So all in all from perceptions comming from various sources nervous system control afferents (input) and produce in accordance with references for those perceptions on hierarchical levels »error« signal which is all the time »correcting« perceptual input so that it matches references from all perceptual sources which are very complexly »coordinated« on different levels of hierarchy.
HB : So Eetu was right.
EP: The issue is ONLY that we do NOT control anything in the environment but only our own perceptions…
HB : You Rick directed with your example of walking that PCT is the only sensibile explanation for all human and other LCS behavior. It’s �Control of perception� and behavior are means by which people act on environment so to keep perception near references. Walking case is perfect example of how this function.
Walking case is thus percfect example of �Control of perception�. There is only �feed-back� in environment of walking person. Output is only directly affecting input. No �controlled variables in environment of persons�. It’s exactly as Bills’ diagram LCS III is showing.
So I don’t understand why do you Rick promot �Control of behavior�, �Controlled variable� in environment of the person and �Protection from disturbances�. There are no such things in PCT.
Boris
EP: I think you partly replied on behalf of in your message [From Rick Marken (2017.06.11.1640)] but only partly. You wrote:
RM: “a controlled perception is an inference based on observation of the fact that certain variables in what is perceived by an observer as the subject’s environment are controlled (maintained in reference states, protected from disturbance).â€?
EP: This means that an observer sees something special happen in the environment and from that s/he infers that the subject is controlling some perception.
RM: Right. The “special” thing that is seen in the environment is that a variable is being controlled (maintained in a fixed or variable reference state, protected from disturbance). For example, we can see that people are controlling for being upright as they walk over irregular terrain (the disturbances). We infer that they are doing this by controlling (among other things) a perception of the location of their center of gravity)
EP: As part of that inference the observer can do tests and try to disturb the subject’s controlling.
RM: I would say that the inference is the theory of how this control occurs: PCT. The testing that then occurs involves determining what perceptions that are being controlled that are the basis of this observed control: is it perceived center of gravity, perceived visual orientation with respect to the ground, etc.
EP: What the observer is seeing is not control, but stabilization, see below…
RM: No, if they see a variable being maintained in a fixed or variable reference state, protected from disturbance, then they are seeing control. Stabilization is not control. In stabilization (as in a mass-spring system) there is a stable (“equilibrium”) state of a variable that could be seen as a reference state but the variable is not protected from disturbance when it is in this state.
EP: Question is about the definition of control in PCT.
RM: The definition of control in PCT is completely in terms of observable variables…“Perception” is not part of this definition; perception is a component of the theory that accounts for this objectively observable phenomenon.
EP: Perception may not be a part of the definition, but the reference is.
RM: Yes, the reference state is part of the definition of control. The reference state is an observable state of the variable. The reference signal in the PCT model accounts for the constant or variable reference state of the variable that is observed.
EP: Like perception, also the reference is only inside the subject / organism.
RM: The reference signal is inside the organism; the reference state is outside the system.
EP: So the definition of control (in PCT) cannot be defined completely in terms of observable variables.
RM: Again, this is “plain and simple” untrue not a lie because I"m sure the error is unintentional).
EP: When you see (the fact) that something is (in a certain way and conditions) stabilized in the environment of the subject, you can infer from that to (the fact of) control. It is like all science a hypothetical and fallible inference, but by experience a more reliable inference than many everyday alternatives. That is just the glory of science: you can know something what you have not (immediately) perceived.
RM: I appreciate your enthusiasm for PCT, Etau, but I think, at this point in your PCT learning curve, it would be wise for you to take the advice of our recent American winner of the Nobel Prize for Literature and “know your song well before you start singin’”.
Best
Rick
–
Richard S. Marken
"Perfection is achieved not when you have nothing more to add, but when you
have nothing left to take away.�
–Antoine de Saint-Exupery