[From Rick Marken (2014.12.15.1730)]>
Martin Taylor (2014.12.14.17.25)--
MT: So it has been with Powers and his theory that what is controlled is NEVER something in the environment, but is always a perception of that thing, and THEREFORE it looks as though behaviour controls the thing in the environment
RM: This is the most completely incorrect description of what PCT is about that I have ever read. I will give a more detailed explanation later but this was such a huge disturbance that I just had to react immediately.
RM: And now I will explain why.
RM: It is simply false to say Powers' theory (PCT) says that "what is controlled is NEVER something in the environment". If PCT said that it would be inconsistent with the fact that it seeks to explain. PCT was developed to explain the fact that organisms control various aspects of their environment (the environment in which their nervous system operates, which includes the organism's internal and external environment). For example, people can be seen to be controlling the distance between their car and the car in front of them. This distance is an environmental variable that is under control. Powers theory was developed to explain how organisms produce controlled results like this. According to PCT they do it via negative feedback control of a perceptual representation of the environmental state of affairs -- the distance between cars in this case. So PCT doesn't say that "what is controlled is NEVER something in the environment"; rather PCT explains the observed control of aspects of the environment (such as the controlled distance between cars) as negative feedback control of perceptual representations of the aspect of the environment that is under control.
RM: Another way to see that Martin's statement is false is by looking at any PCT diagram of a control organization. For example, take a look at Figure A.1 in B:CP and you will see that the controlled variable, q.i (also called the controlled quantity; these terms were used interchangeably to refer to the aspect of the environment that was under control) is sitting out in the environment side of the system/environment boundary. So the variable that the system is controlling, q.i, is IN THE ENVIRONMENT.
RM: So why do we say that behavior is the control of perception if what is controlled is an aspect of the environment? One reason is that the aspect of the environment that is controlled is a perception from the point of view of the behaving system. But more importantly, the organism's perceptual function, which transforms environmental input into a perception, defines the aspect of the environment that is under control. This fact is extremely important to understand and is, perhaps, best illustrated by my "What is size" demo at <http://www.mindreadings.com/ControlDemo/Size.html>http://www.mindreadings.com/ControlDemo/Size.html. In this demonstration you can control the size of a rectangle, where size can be a perception of the area, width*height, or perimeter, 2*(width+height), of the rectangle. Both area and perimeter are variable aspects of the environment -- the figure out there on the screen. Which aspect of the environment (figure on the screen) you control (as "size") depends on which perceptual function you "look through" to perceive the size of the figure on the screen. If you look through a perceptual function that calculates a perception proportional to width*height you will control area; if you look through a perceptual function that calculates a perception proportional to 2*(width+height), you will control perimeter.
RM: The fact that area and perimeter are aspects of the environment is demonstrated by the fact that the state of these variables can be continuously measured by the computer (without looking inside the head of the person controlling them) . And the computer, using calculations based on the PCT-based Test for the Controlled Variable (TCV), can determine which (if either) of these two aspects of the environment -- area or perimeter -- were under control. By determining which aspect of the environment is under control in this situation, the computer (using the TCV) is able to perceive what the controller is perceiving. This could not be done -- and a science of perceptual control would be impossible -- if it were true that PCT showed that "what is controlled is NEVER something in the environment". In fact, PCT shows that what is controlled is ALWAYS some aspect of the environment -- it's the controlled variable or controlled quantity -- and, therefore, it is always possible -- at least in principle - for an observer of the control system to determine what perceptual variable -- what aspect of the environment -- a control system is controlling using the TCV.
RM: Since understanding the behavior of living organisms is, according to PCT, largely a matter of understanding what perceptions -- what aspects of the environment - they are controlling, the TCV is an essential component of PCT research. I've tried to demonstrate the use of the TCV to understand the behavior of people (and other animals, like dogs) intercepting moving objects. In this case there were several possible perceptions that a person (or dog) might be controlling as the means of carrying out the behavior of intercepting the object. But in all cases, these perceptual variables were all measurable aspects of the environment; therefore it was possible to test to determine which of these aspects of the environment corresponded to the perceptions that were being controlled by the organisms intercepting the object.
RM: So fortunately for PCT science Bill Powers did not come up with a theory that said that what is controlled is NEVER something in the environment. What he did was come up with is a theory that explains how organisms control aspects of their environment (by negative feedback control of perception) and a method of testing this theory (the TCV) by disturbing different aspects of an organism's environment and seeing which aspects of the environment were protected from these disturbances.
Richard S. Marken, Ph.D.
Author of <http://www.amazon.com/Doing-Research-Purpose-Experimental-Psychology/dp/0944337554/ref=sr_1_1?ie=UTF8&qid=1407342866&sr=8-1&keywords=doing+research+on+purpose>Doing Research on Purpose.
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