[From Rick Marken (2015.11.27.1630)]
David Goldstein (2015.11.26.1314)
DG: My understanding is that the intensity level is about how strong or weak stimulation is at sensory receptors. There are reflexes in the eye and ear which regulate intensity.
Martin Taylor (2015.11.26.14.44)–
MT: That is presumably the concept, but what receptors produce an output that is a function of the intensity of the physical effect at that specific receptor, for which the function is independent of time and of the physical effect on neighbouring receptors? Are there any?
RM: The first approach to identifying the levels of perception that are controlled was described in Part II of Powers, et al General Feedback Theory paper, starting on p. 26 of LCS III. Six levels of perceptual control were identified (but not really named) mainly using reaction time studies. Very clever stuff.
RM: I think the first description of a scheme for classifying the types of perceptions that might be controlled at each level in the proposed control hierarchy is found in B:CP. Bill used several different approaches to coming up with his definition of the types of perception controlled at different levels (orders) of the control hierarchy. The first three orders of perceptual classes – “intensity”, “sensation” and “configuration” type perceptions-- were defined in terms of physiological and experiential data. An example of the physiological data can be seen in this quote: “Any one first-order perceptual signal [sensory produced afferent neural signal - RMl] can vary only along one dimension frequency (see Granit 1955 for extensive discussion of this fact).”(BCP, 2nd ed, p. 94). And an example of the use of experiential data is discussed on BCP, 2nd ed, pp. 95 and 96.
RM: The definitions of the types of perceptions controlled at hierarchy levels 4 through 9 in B:CP are based mainly on behavioral and experiential data. As Bill says at the start of the chapter defining “transition” type perceptions “as help from experiments with the brain diminishes…the emphasis will turn more toward an analysis of direct experience…”(p 129). It’s the world we experience as objective reality, at least up to the “Higher levels” (levels 6-9) where we "… pass from classes of perception that can be seen as exterior to us [such as configurations of sensations and intensities that we see as objects “out there” --RM] to those which seem to be inside ourselves [such as “principles” like honesty – RM] – from the world of “physical reality” to the world of “subjective reality”.
RM: Powers spends a good part of B:CP defining the different types of perceptions that people might control. Indeed, 1/3 of B:CP is dedicated to describing (and justifying the descriptions of) the perceptions that might be controlled at the different levels of the hierarchy. This was done for two reasons. First, the goal was to show that all behavior – from tensing a muscle to running a business – could, in principle, be explained as control of perception rather than control of output. Tensing a muscle involves control of a perception of muscle tension – an intensity perception-- rather than control of the efferent impulses that cause the muscle to produce the tension; running a business involves control of the perception of the “business” – a “system concept” perception, perhaps – rather than control of the means used to get the business to run properly (and, indeed, the means are themselves lower level controlled perceptions).
RM: The second goal was to provide a set of hypotheses to serve as the basis of research to test this model of behavior. This is particularly true for hypotheses about the perceptions controlled when we see people performing behaviors that seem to involve control of perceptions at the levels above what Powers identified as intensities and sensations. This would be a rather new kind of research, aimed at getting a more precise definition of the perceptions people are controlling when we see them behaving in various ways-- rather than at figuring out the causes of that behavior.
RM: I wrote all this mainly to encourage people like Fred who are teaching PCT to try make the above points about the hierarchical model. You should make a point of presenting it, not as known truth, but to show how control of perception can, in principle, account for everything we call behavior, even complex behaviors, like playing scrabble, that appear to be an output resulting from complex internal calculations. You could also say that the types of perceptions shown in the hierarchy diagram are hypotheses about what perceptions people are actually controlling when they do things like manage a division of a company, say, and research is needed to give us a better idea of exactly what these perceptions are. For now, the hierarchy of perceptions shows that PCT can, in principle, account for all behavior.
RM: And you should really start by explaining that a control of perception model is the right model to explain all behavior (of living systems), from simple to complex, because, as Powers has shown, all behavior IS control; everything we call behavior, from lifting a book to writing one, is a process of producing a pre-selected result (a lifted book, a written book) in a disturbance prone environment. And the only systems that can do this are control systems and they do it by controlling a perception of the intended result relative to an internal specification for the state of that perception. A book gets lifted to a pre-selected height because a perception of some aspect of the book is brought into a match with the internal reference specification for height; the book gets written to a pre-selected finish because a perception of some aspect of what is being written is brought into a match with the internal reference specification for “finished”.
Richard S. Marken