[Eetu Pikkarainen 2017-10-19]
[Martin Taylor 2017.10.18.16.18]
[EP] Some thoughts. A differentiation between simple and complex. The differentiation is relative but there could be some clear or maximal cases. The most simple
control system is on control unit. It is probably very complex neurologically but functionally assumed to be most simple. Easiest for me is to think about a âborderlineâ? controller which is connected to some sense organ and to some output organ (muscle or
gland). This is probably at lowest level of the control hierarchy. We assume the whole control hierarchy consists of these most simple, basic or elementary control units. All units except perhaps the highest ones in the hierarchy get the reference signal from
other units above. The borderline controllers perceive simple perceptions. The world as the environment of the organism is supposed to be an infinitely complex whole (containing also this organism itself). One simple perception is a narrow sample of the infinite
possible effects by which the world could affect the organism and its sense organs. Because we humans have similar sense organs and live in quite similar conditions the these simple perceptions feel very similar and realistic and basic (foundational). For
them and building on them we have developed more and more fine instruments to test and refine these perceptions. So we have a tendency to believe that these perceptions are analogs of the aspects of the external world. The (only) proof to this belief is that
our perceptions seem to be analogs of the perceptions of others and of the measurements by instruments. Any way it is natural and reasonable to think so because we have no better alternatives.
[EP] So the simple perceptions are analogs of the aspects of the reality and these aspects are CEVs (note: not complex but simple here) of our perceptions. From
this it still doesnât follow that we control those aspects when we control our perceptions. This depends on our concept of control. I think control means: comparing a value to a predefined reference value and bringing it near to that reference and keeping
it there. Control units have reference values for perceptions but they cannot not have them for CEVs. They affect CEVs so that their perception becomes near the reference and stays there. As a consequence the value of CEV becomes somewhere and stays there.
I would call that stabilized value CET (corresponding environmental target value). Presumably the CET is some kind of an analog of the reference. I understand the great temptation to say that now CEV is controlled and perhaps there is no great danger to say
so if we remember that what we perceive happening is a not ârealâ? control but a consequence of it (an intended effect).
[EP] A more complex control system is a hierarchical whole consisting of many borderline units and one or (probably much) more units higher in the hierarchy. This
system is controlling the perception of the highest unit and this perception is a complex, a structured whole of the perceptions of the many lower units. So it is a whole of the bunch of the before mentioned simple perceptions. However, complex perceptions
are not just sums of their parts but the whole is structured. The basic perceptions have different relations between them and they can form part wholes which again have different relations between them. This possibility of complex structure makes it unreasonable
to try to reduce all perceptions to basic perceptions or some simple structures of them. Do complex perceptions have complex CEVs? Do complex CEVs exist in the reality? Perhaps the answer to the first is cautious yes and to the second that some do but not
necessarily all. For us controllers perhaps the much more important question is are these perceptions controllable by ourselves or collectively. If they are, then it is again reasonable to believe that they exist.
[EP] Complex control is complex to two directions: then organization of the participant control units is complex and also the feedback chain is complex. The latter
one is in principle empirically researchable. Has anyone tried to make an empirical or theoretical (thought experimental) description of how someone controls e.g. such complex perception like democracy? Or perhaps something more simple. I think it could interestingly
combine phenomenological research to study of action / behavior.
(I know Kent and Martin have been writing and are writing something but any others?)
Please, regard all my statements as questions,
no matter how they are formulated.
[MT] As long-term readers of CSGnet will know, I held a long-standing opinion that what Boris says here was true, and have argued with
Rick about it.
But for several reasons over the last year or two I have modified that opinion in favour of a more nuanced view. I don’t know if Rick will agree with my view, but at least
I am less likely to complain if he says that an environmental variable is controlled. Let me review, in no particular order, some of the reasons.
[MT] (1) Collective control. When many people control related perceptions of related CEVs (“Complex Environmental Variable”, Bruce), they may all be controlling their perceptions, but the environmental that is most closely stabilized may not be the CEV that
is perceived by any of them. In Kent’s original demonstration of collective control at CSG-93, two controllers controlled perceptions of the same CEV and wound up in conflict but to an outside observer of the CEV they were apparently controlling that CEV to
a reference value actually held by neither.
[MT] When there are more than two, the more the merrier, the actual CEVs might be quite different in each individual, but it nevertheless looks as though a CEV perceived by none of them is strongly (high gain) controlled to a reference value held by none
of them. The same may be true within a brain. Bill approximated the firings of many neurons, each of which would have its own individual collection of synaptic collections, and called the sum of the firings averaged over some time interval a “neural current”.
The value of that neural current, in one particular part of a control loop, is a “perceptual variable” or a “perception” in PCT. But nowhere in the brain is that perception actually represented. It is distributed over tens, hundreds, or thousands of neurons,
and is stochastically represented over time.
[MT] (1a) Related to (1) is the paper and demo by Bill for which Rick [From Rick Marken (2017.10.17.0840)] provided links. It demonstrates that to control a single environmental variables does not require a dedicated special perception of that environmental
variable. The CEV represented is distributed over the brain even more widely than is suggested in (1).
[MT] (2) Evolutionary necessity. A rock that smashes your skull will kill you. A perception of such a rock will not. A shield raised to ward off the rock will save you, but if you control the position of the shied to where you perceive it will intercept the
rock and you are wrong, you are just as dead, even though you controlled your perception of the position of the shield extremely well. What matters is what happens in the environment. Controlling a perception is useful only if the environmental property to
which it corresponds actually exists and is as stably related to a perceptual reference value as is the perception itself.
[MT] (3) Basic mathematics of the control loop. An environmental property is what it is, whether it is perceived or not. When it is perceived, that perception is delayed, if only slightly, and there is always a resolution limit to the precision with which it
is perceived. That’s why we have microscopes and telescopes. The perception is what it is, but every value of the environmental property corresponds to a range of perceptual values that it might induce, and vice-versa. Nevertheless, on average any specific
value of the environmental property is most likely to correspond with a specific value of the perception, and vice-versa, provided that the time-delay of perception is not long compared with the rater of change of the environmental property. Therefore, when
the perception is controlled in a canonical control loop, so is the CEV that corresponds to that perception.
[MT] (4) “Real reality”. We can never know what is truly “out there”, whatever we perceive. But what is really “out there” that determines our life course. That we can control many perceptions means that we can have an illusion that we are influencing real
reality – think of Bishop Berkeley kicking a rock to prove its existence (or was it the friend who did the kicking?). In that sense, it is only the control of perceptions that matters, if anything does. The correspondence between the CEV and real reality
might be entirely illusory, but so long as it is perceived as acting as it would if it were real, the Evolutionary Necessity argument overrides the “it’s all perception” argument.
[MT] (5) On the Other Hand: When we control a perception, that perception, not the CEV, is what we are acting to vary so as to bring it near a reference value and keep it there. We do so by apparently acting on something in the environment that changes what
our senses tell us. No matter that if we waste resources by controlling perceptions of things that aren’t there we may put our survival in jeopardy, we still can control only our perception, however distributed across the brain its physical/physiological manifestation
[MT] (6) Summing up. Perception is all we have that we can control. The environment is that we really need to control. We can control the environment only to the extend that it behaves as though our perceptions correspond to it reasonably well. So for most
practical purposes other than careful theory or metaphysical philosophy, it doesn’t matter a whit whether we say that perception or the CEV is controlled.
[MT] On nomenclature: I think it unfortunate that Bill used “CV” (“controlled variable”) even casually to refer to an environmental variable. The theory is called Perceptual Control Theory for a good reason. In discussions with Kent and Eetu a similar complaint
was raised about “CEV” (“Complex Environmental Variable”). Any variable in the environment could be one of those, so we agreed among ourselves that “CEV” (Corresponding Environmental Variable) would be better. Corresponding to what? To a perception, controlled
or not. Above, I mentioned the old expansion of the acronym, because it might have been familiar to many long-time readers. But in future I will try to use “Corresponding Environmental Variable” as something in the environment that is perceived.