Powers' Model of a PCT-Based Research Program

Hi Bruce

RM:…If you could give a nice, clear description of some of the results from Henry’s lab that would be great!

BN: Included thus by reference to the appropriate topic.

RM: I’ve read some of this stuff. My interpretation of it is quite different than theirs. But I didn’t ask to see work on the cerebellum. I wanted to see a nice, clear description of Henry’s work, which is the kind of neurophysiology that is directly relevant to testing the PCT model. How about giving it another try.

BN: I have asked Henry for comment but I have no indication that “the results from Henry’s lab” include specific investigations of the anterior and posterior cerebellum.

RM: Still, from what I understand of Henry’s work it is far more pertinent to PCT research than the stuff on the cerebellum that you posted.

BN: My recollection is that he and Bill called it the configuration of the arm. When I say that we can see it either as configuration or as relationship I mean we as armchair analysts. What level is actually controlled when I take a sip of tea is surely not equivocal, so this purely verbal ambivalence (configuration? relationship?) is a failure to refer to empirical data.

RM: I currently know of no empirical data that will tell you what type of perception is being controlled or even whether their are types of perception. Powers’ model for a PCT based research program – the program I am trying to develop – is all about figuring out how to find out whether controlled perceptions fall into different types and, if so, what those types are and whether they are hierarchically related.

BN: I believe Henry’s data suggests it is the lower of those two levels.

RM: That is my understanding as well. The research in Henry’s lab shows that there is a hierarchical relationship between structures in the nervous system associated with the relationship between the variables involved in control. They named the variables controlled at different levels of the nervous system using the names Powers used to identify what he thought were the different types of perceptions at different levels. These names are nice descriptions of the variables involved in Henry’s studies but we still don’t know whether these names describe actual different types of controlled variables, as predicted by the hierarchical PCT model.

RM: The work in Henry’s lab (as I understand it) shows that the apparent hierarchical relationship between the behavioral variables involved in control is reflected in the hierarchical relationship between the structures in the NS that are involved in control. So it would be great if you could provide a nice, clear description of Henry’s work because I think it is very relevant to Powers’ vision of a PCT-based research program. The neurophysiological research you posted about the cerebellum provides much to coarse a picture of the operation of this component of the nervous system to be of much use use in terms for evaluating models of hierarchical control.

Best

Rick