# Try Perceptual Control Theory

**URL:** <http://discourse.iapct.org/t/try-perceptual-control-theory/11785>\
**Category:** CSG1993\
**Created:** [October 7, 1993, 7:00pm UTC](http://discourse.iapct.org/t/try-perceptual-control-theory/11785 "1993-10-07T19:00:15Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![\_Martin\_Taylor](http://discourse.iapct.org/letter_avatar_proxy/v4/letter/_/a9adbd/32.png) [@\_Martin\_Taylor](http://discourse.iapct.org/u/_Martin_Taylor)\
**Post date:** [October 7, 1993, 7:00pm UTC](http://discourse.iapct.org/t/try-perceptual-control-theory/11785/1 "1993-10-07T19:00:15Z")

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[Martin Taylor 941007 14:50]  
(Rick Marken 931007.0830)

> > If you have been talking about  
> > "donkey" and you want to say "flunky" it is highly likely that you will  
> > move the "u" away from the sound of the "o" in "donkey", as compared to  
> > the way you would have said it in the context of a discussion on servants.
> 
> Yes. And there's this exciting new theory called Percetual Control  
> Theory (PCT) that explains how this mysterious movement occurs;

I seem to have heard of this theory somewhere. Could you provide a reference?

Seriously, your following description sounds really like Bill's  
"dormitive principles," since it says nothing about how the shifts  
required to maintain contrast come to be the way they are. For example:

> According to PCT, the appropriate action (just the right  
> amount and direction of movement of "u") occurs because "u" movement  
> is part of a closed negative feedback loop. Variations in "u" movement  
> influence the perceived word result, which is also affected by all the  
> "context" you mention -- in PCT this context is called "disturbance".

Sure, but just where IS the closure of the feedback loop before the  
word is spoken. Remember, it is spoken once and then is gone. The  
next occasion for the "same" word is in a different context. I'm  
saying that the closure is in imagination. If there is error in the  
imagined percept of the category of the spoken word, the appropriate  
changes in output are done in the normal way. The eventual output to  
the real world cannot be controlled on the basis of error in the  
perception of the effect of the word on the listener, though that can  
affect the likelihood of reorganization in the word-perception control  
loop.

> The mobile category boundaries (in PCT) are changing reference specifications  
> for categorical perceptions; they change (dependent on context) as a means  
> of controlling other (higher level) perceptions. For example, what you are  
> willing to categorize as "a car" (when you want to buy "a car") changes with  
> your budget;

Yes, that's right. But I think it is quite a different effect from what  
we have been discussing.

> PCT does conflict with a great deal of conventional wisdom concerning the  
> nature of behavior and how behavior works. An understanding of PCT does  
> force the abandonment of some old, familiar ways of looking at behavior.  
> But, I think that the benefits of seeing behavior from the PCT perspective  
> far outweight the costs of abandoning the old ways.

Right on, baby! I may use that paragraph sometime. Once I get that  
reference so I can find out what this notion called PCT might be!

Martin