The speed�?curvature power law of movements : a reappraisal

Down ….



[From Rick Marken (2017.10.31.2215)]

On Tue, Oct 31, 2017 at 9:01 AM, Alex Gomez-Marin wrote:

AGM: regardless of your helicopter data and RCT mantras, it would be good if someone from CSGnet took seriously the challenge to PCT that the speed-curvature power law entails.

RM: What challenge? PCT explains it quite nicely as a mathematical property of curved trajectories. This fact explains why it appears as a side effect of intentionally produced curved movement… But apparently no one else on CSGNet sees it that way so your paper has demonstrated to me that no one on CSGNet (no one who posts, anyway) understands PCT. At least, they don’t understand it the way I do. This has convinced me that I must withdraw my Preface to LCS IV because I can’t in good conscience say that the papers in that book will be based on Powers’ theory and, thus, honor his legacy.

HB : Good that you’ll withdraw your Preface. This is the way to preserve Powers theory. With not contributing RCT to any published literature.

AGM: any figure panel of our paper proves rick’s mathematical claims wrong: the PL is not a must and when it takes place it is not trivial and can have different exponents.

RM: There is nothing in your paper that proves that any of the claims made in our paper are wrong. We will explain this all in our own “reappraisal” of your “reappraisal”. But for now I’ll just say that our paper didn’t say that the power law was trivial; it showed that the power law is an illusion in the sense that it looks like it is relevant to understanding how organisms produce movement when it is not.

HB : Maybe I could agree with you about the way »Power Law« was presented till now. It seems that it can’t explain how organisms function. Or even how nervous system function. And how by your oppinion organisms produce movements ??? With independent control units like you described in your artcile about »Power Law«. If I compare the »nothing« explained about how organisms function by your example of »helicopter« and »Power Law« I’d say that »Power Law« include less of »nothing« than your example with helicopter. It’s worse. Helicopter example shows »stimulus . respons«. People move in accordance to movement of helicopter. Where did you see this in reality ? Amd this should be the case of »purposefull behavior«.

RM : Nor did we say that the power law can’t have different exponents; in fact we showed precisely why you do find different exponents for the power law; it’s because you omit a variable from the regression analysis used to determine that exponent.

AGM: now, how can “control of perception” explain that phenomenon? claiming it is an illusion because it does not fit in the dogma is like creationists insisting that dino fossils are bogus.

RM: No, we say it is an illusion because it is demonstrably a side effect of controlling perceptions, as demonstrated by the model of toy helicopter pursuit that we present in the paper (and that you simply dismiss as wrong for no apparent reason other than that it just must be).

HB : As I said above. You demonstrated with helicopter example that »environment is controlling« people movement. You proved simple »stimulus-respons« theory. There is no »purposefull« behavior in your example so that we could answer the question how people decide for their behaviors. In your case people »decide« to move along with helicopter movement probably because they were told to do so. How will you understand from this example how people form purposefull behavior.

And your assunption is that they produce purposefull behavior with two independent control units. Is this how nervous system function ? Is this a joke ?

AGM: so, as adam and myself take this job seriously, and given how many optimal control and nonPCT theories explain the data,

RM: I have not seen any control models that explain the data; the term “controlled variable” is not to be found anywhere in your paper or in any other papers I have read in the area. The models I have seen that “explain” the power law are all output generation models – what Powers called “curve fitting” models – that would fail completely if they had to account for the fact that the observed curved movements being modeled are produced in a disturbance prone environment; the curved movements are themselves controlled variables.

HB : Behavior itself is a »controlled variable« ? How organisms produce »controlled behavior« ?

AGM: I think Bill would really find his edifice crumbling, or at least unable. so, take your best shot at it and really challenge your “revolutionary paradigm changing” theory of behavior.

RM: I think you are right about that. If Bill has been listening in on CSGNet for the last 4+ years he would, indeed, see his revolutionary paradigm crumbling.

HB : You are the one that contributed most of it.

I knew that people would disagree with me as much as they did with Bill

HB : Who said that Bill agreed with you ? He did protect you. But at least once you tryed to aline your and his knowledge and he answered in clear »no«. Your and Bills’ knowledge are not aligned. Anyway you show in every post disalignment with his literature.

RM : ….but I was surprised by the intensity and meannness. But I know there are one or two people out there (not on CSGNet) who not only agree with my understanding of PCT (which I’m pretty, pretty, pretty sure is the same as Bill’s) but are also doing excellent PCT research.

HB : I’d really like to meet these two people who don’t understand PCT ? You don’t understand PCT. And you never will.

RM: It’s too bad; I really thought you really considered PCT a possible explanation of the power law. I guess my trusting nature got the football pulled away from me again. You are obviously very talented at research. It would have been great to have you working on doing research based on an understanding of PCT. But, alas, I guess it’s not to be.

HB : I agree that it would be good for people to use PCT. but not RCT.




On Sun, 29 Oct 2017 at 02:48, Richard Marken wrote:

[From Rick Marken (2017.10.28.1745)

On Sat, Oct 28, 2017 at 3:34 PM, Alex Gomez-Marin wrote:


RM: Finally! Thank you, Alex. I hope the journal gives us an opportunity to respond. But for now I have only one word for you: helicopter movements. Oh, that’s two words But you know how bad I am at math;-)



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

Alex Gomez-Marin

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