Opportunities for PCT

In the 150th Anniversary issue of Nature (7 Nov 2019 p31) There is the following passage: Neuroscience, like genetics, has been restricted in the questions it can ask by the data it can gather. Functional Magnetic Resonance remains a blunt tool, showing where things are happening in the brain […] but not what transpires. […].

[…] More data, although extremely valuable as a resource, will not help us without new ideas. These are i short supply. As […] Matthew Cobb at the University of Manchester writes, “no major conceptual innovation has been made in our overall understanding of how the brain works for over half a century”.

It’s no surprise, then, that the hard problem of consciousness is barely articulated, let alone understood. […] the only valid starting point for a theory of human experience. That […] view harks back to how US psychologist William James ignored “the traditional antithesis between reality and appearance”, as Nature put it in 1915. As for claims that neuroscience has banished free will (for example, because decisions can be predicted from brain scans in advance of their conscious manifestation) merely returns us to British Philosopher Gilbert Kyle’s famous “regression of mental homunculi”.

It seems to me that this passage offers several openings for PCT. The “regression of mental homunculi” issue, for example, disappears when one recognizes that the non-conscious control hierarchy necessarily functions before anything emerges into consciousness to seem like an experienced “decision”.

Of course, although PCT is a “major conceptual innovation […] in our understanding of how the brain works”, the innovation did not occur in the last half-century. To the mainstream, however, PCT thinking would even now be a novel major innovation.

I wonder if a focus on some domain in which unsolved problems have been acknowledged might be a reasonable wedge for the propagation of PCT.


There may be clues as to audience and ways forward by following up the reference to Gilbert Ryle (not Kyle—a PDF transcription error?). He is more famously the source of the phrase “the ghost in the machine”.

Ryle likened the work of a philosopher to that of a cartographer. More recent philosophy of mind folks like Dennett carry onward within his phenomenology, including his fundamental errors, e.g. Ryle’s dismissal of purpose as a baseless explanatory principle (or as he says, a myth, like phlogiston). Understanding the domiciles, streets, and furniture of their conceptual village may show us particular points of leverage and disclosure to open their way to recognize PCT.

It is significant that this passage in a retrospective summary article focalizes philosophy of mind. Maybe not all will admit it, but I believe neuroscientists do pay attention to the puzzling and contending of philosophers just as philosophers likewise closely follow and try to interpret the findings of neuroscientists.

Regarding Martin’s quote, I continue to be amazed at the apparent lack of knowledge and awareness of PCT among mainstream psychologists. The most recent example to me is a recent article on “Environmental Neuroscience” by Berman, Stier, & Akcelik in the American Psychologist, 74(9), December 2019, pp. 1039-1052, that includes no reference to Powers or other PCT scholars nor do the references cited that I checked that apparently should have. According to the article, given that “Environmental neuroscience is an emerging field devoted to the study of brain-mediated bidirectional relationships between organisms and their social and physical environments” and that “environmental neuroscience is fundamentally a neuroscience and is interested in phenomena that involve the brain and its interactions with the environment”, I am, once again, stunned by the lack of reference to Powers’ writings and PCT.

I wonder whether part of the problem may be the abstract technical nature of the names “Perceptual Control Theory” and “Method of Levels”. “Cognitive-behavioural therapy” tells you it’s a therapeutic procedure, and that it involves both cognition and behaviour. MoL might in a parallel form be called “internal conflict resolution therapy” or something like that (I grant that a four-word label is hardly catchy, but it means something to an outsider, where as “Method of Levels” only suggests (to me) questions: Levels of what? Method to achieve what? Why should this be of any interest to me? What is it supposed to be a method to do?

“Perceptual Control Theory” does suggest something, but what it suggests may not be what we would like it to suggest. In my direct personal experience, it can turn off even Ph.D. psychological researchers, who image controlling other people by controlling what they can and cannot perceive (in the manner of Nazi control of the public media and the present-day concept of “Fake News” and “Alternative Facts”).

Granted, my direct experience of this was with a lunch-table of four female researchers, who I tried to get interested in PCT. They immediately rejected my attempts with a reaction along the lines of “Why would you want to promote something like that?”. [Aside: Does gender affect the likelihood of this kind of first impression? Why are there so few female contributors to CSGnet or this ne forum?]

The name “PCT” describes to us, the in-group, How Living Things Function, but it does not, unless you are part of our in-group, describe What Living Things Do. Nor does it suggest that PCT is a research domain with any relation to Psychology. The word “Control” sounds like domination, domination not of one’s own properties, but of others. One has to learn a bit about the Theory to realize that domiation is not what it is about at all.

Since control is central to the theory, I suppose it should be in the name somewhere. But where? On the other hand, perhaps it could be replaced by “Stabilization” such as in "Personal Environmental Stabilization Theory, which would unfortunately omit “perception”. But Personal Environmental Stabilization is the reason our ancestors survived for us to be alive now. Perceptual Control was the means, not the objective.

First impressions are important, and names provide a good part of a first impression. I don’t have solutions, but maybe these notions could jog loose some creativity, and produce attractive names for PCT, MoL, and other aspects and implementations of PCT, including my own “Layered Protocol Theory”.

Why couldn’t PCT stand for Personal Control Theory?

Sounds good to me, but what would I know? I guess it needs testing on a few people who should know about PCT but don’t.

I’ll give it a shot

Bruce – I’ve been delving into analytic philosophy recently (initially to track down “ghost in the machine”) and latched onto Ryle’s work. For me, it’s tough stuff, way outside my training. Subsequently, through a few links, came across Julia Tanney’s entries in Stanford’s encyclopedia where she has supplements on perception (https://plato.stanford.edu/entries/ryle/perception.html) and imagination ( https://plato.stanford.edu/entries/ryle/imagination.html). I would welcome a PCT interpretation of these, perhaps starting with perception. It seems to me these Ryle/Tanney interpretations are open loop.
Comments welcomed.


After reading (only once) both linked articles, my first comment is that Ryle/Tanney deal only with conscious perception. The philosophical issue of “experiencing” is separate from PCT. That’s my conclusion. Read the following only for the skeleton of my argument to reach this conclusion.

What did Powers suggest about conscious perceptions on the few occasions when he did talk about them on CSGnet? Without searching the newly provided archives (congratulations and thanks to all concerned with that effort), my main takeaway is that he argued that any conscious perception is likely to be one that could be produced by a perceptual function that exists in the control hierarchy (non-conscious, of course, like everything in the control hierarchy).

Both of the linked papers ignore the possibility of non-conscious, therefore not experienced, perceptions being sometimes available to consciousness. Perhaps they would call reference to the control hierarchy (probably totally unknown to either Ryle or Tanney) “mechanism”, which is explicitly of no interest to them. However, to Powers, consciousness had the job of influencing, and perhaps helping to reorganize, the control hierarchy, changing the actions that would be observed to correct experienced error. Does not the success of MoL support the “reorganizing” part of that idea?

Imagining is a part of all that, is it not? Tanney uses as an example the ability to hear and experience a live performance of a Bach partita without previously knowing “how it goes”, an ability not available to “hearing it in the mind’s ear”. That difference seems to be a real problem to Ryle/Tanney. For PCT, to experience the partita in one’s head requires one to know “how it goes”, because that perception is derived from the (?)sequence level perceptions in the unconscious hierarchy, invoked when “controlling in imagination”.

But to invoke the perceptual control hierarchy is to explain mechanism. and Ryle/Tanney are explicitly not interested in mechanism. I think their many questions can be reduced to two related questions: What is consciousness? and “Why do we have consciousness?” Those questions may be linked to PCT, evolution, and reorganization some day, but for me right now, they are entirely independent of PCT.

Ryle is an ‘ordinary language’ philosopher. The first (Ryle on perception) seems thoroughly kerfluffled with semantic categorizations of words. The second (Ryle on imagination) goes a little farther, declaring that language that is appropriate for talk about perceptions derived from the environment is not licensed for imagined perceptions. He talks of neural signals in the brain, and shows the folly of supposing that replicas or images or representations of the world reside in the brain (and an infinite regress of homunculi or ‘ghosts’ to perceive them).

The error is to place the difficulty between perception and language, when it is between perception (signal) and perception (experience), and language as always stands off to the side.

Drawing your metaphoric sword Bruce and, just like Alexander, sliced right through the Gordian knot of Julia Tanney’s exegesis of Ryle’s views. Nice.

Aw, gosh, thanks. Oh what tangled webs we weave when first we talk of how we perceive.

I think the problem is that people understand “control” as control of action. It can be that some person or organization controls how I or some other person may act (or even think) or then I control myself. I am not a native English speaker but for me the name “perceptual control theory” first sounded like a theory about how to control someone by affecting the perceptions of that someone.

What I think that should be communicated as meaning of the name of PCT is that it is a theory of action (or behavior if you necessarily want) as control of the perceptions of the actor.

One suggestion for a replacement (which is probably not a realistic idea at all) could be APCT = “Action as Perceptual Control Theory”. However, it could be better to use old PCT as an abbreviation but open it with an explanation that it means a theory
which tries to explain the action (or behavior) of a human being or any organism as control of the perceptions of that same person or organism.

I think that your description is technically correct, Eetu. However, I think of PCT as how we control something out there as evidenced by our perceptions. As control systems, we do indeed control our perceptions but doing so is our means of controlling things out there.

I agree Fred. But when you are introducing PCT to outsiders, they certainly already understand action (or behavior) as controlling or affecting something out there. What PCT adds there is the idea that when the subject acts by affecting something out there she is actually controlling her own perceptions.

I think this is in a way quite near to the classic or humanistic idea of free action: we do not act because something forces or controls us but we act because we have a goal and we want something. And thus it is the actor oneself who is controlling - not controlled.

Perhaps it is this kind of idea which we should stress to make a more positive impression of PCT.

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Most people I know are well aware that all they know of the world out there is known to them by way of their perceptions. To tell them that they really control their perception of something instead of the something is likely to elicit a quizzical look followed by “So what?” So, I’ll ask you, Eetu, So what?

my post was mainly a reaction to this Martin’s post:

So how to introduce PCT so that it would not suggest those negative connotations? You say that the formulation I suggested would cause a “So what?”. In my experience it causes rather “Aah, yes, it is possible”. Any way from that you can continue to explain more about PCT.


I don’t try to interest people in PCT to interest them in the theory; I try to interest them in ways that theory can improve their practice of improving human performance, especially in training. Here’s one example:

Years ago, I ran the Navy’s programmed instruction writers training course. I redesigned it based on the notion that if they could properly evaluate programmed instruction materials they could also create them. The redesign proved my notion was correct. They adjusted their “writing behaviors” so as to produce a satisfactory product.

Similarly, many years later, registrants for a certification test were doing a lousy job of filling out the registration form and many had to be returned to the registrants. Clearly, they did not know how to tell if they had done a good job filling out the form. Two factors were in play. One, they didn’t have adequate reference signals for a correctly filled out form and there was a “disturbance” in the form of a code list that was improperly organized. Did PCT help me resolve that problem? Of course it did but the people I work with aren’t interested in PCT for PCT’s sake; instead, they want to know what it can do for them.


That’s the difference!

I perfectly understand and appreciate your position. That is effective and easier for you and for the people you help. I am helplessly too theoretical for that but fortunately theory happens to be my work. I think that if I manage to make
people to understand their action in a new way then they could help themselves and I don’t need to do it. That is just what helps you to help your customers: that you understand their action from the PCT perspective. Of course also your broad experience, creativity
and other personal properties are needed – much of which I am missing. So I just try to get people think differently than they used to do.

Also I believe that if scientists of many fields of research would understand PCT theory and way of thinking our sciences would proceed better that now.

If PCT meant “Purpose Control Theory” it wouldn’t meet these particular confusions. Maybe in introductions that could be given as an alternate spelling-out of the acronym. There’s even a degree of technical correctness to it: for anything above Intensities, a comparator is controlling the purposes (the reference signals) of comparators below it. It is an easily accepted abbreviation that we use all the time: “I’m controlling being in Chicago” vs. “I’m controlling a perception of being in Chicago” as I decide whether to fly or take the train.

Yes, by means of varying its error output, as ramified by neural branching and diversely amplified by multiplying synaptic connections, that higher-level comparator is actually controlling its perceptual input, which is assembled from the perceptual signals that those lower systems are controlling. Each perceptual signal is experienced as an aspect of the environment. When the word “perception” refers to experience rather than signals, it feels obvious that we control our purposes. That’s where attention and intention goes. When “perception” refers to signals, it is necessary to say that we control our perceptual input. Unpacking PCT as “Purpose Control Theory” speaks to the world of experience, from which we can draw people into the world of perceptual signals and other partly demonstrated theoretical entities in the PCT model.