Thursday, 5 January 2012

Perceptual Control Theory and Method of Levels - New Approaches to Psychotherapy

In the last two blogs we discussed the possible role for a Transdiagnostic approach to psychotherapy, emphasising the importance in recognising underlying processes across psychological disorders. We have also looked at the role of metacognition (awareness of our thinking processes) both as a theory and a therapeutic approach. A third approach which ties in with these theories is a therapy formulated by Tim Carey called Method of Levels (MOL). Based on the principles of Powers' Perceptual Control Theory (PCT), it incorporates metacognition and suggests a possible mechanism underlying the transdiagnostic approach - inflexible control. 

What is PCT?

Powers' Perceptual Control Theory has one central idea; that we seek to control our perceptions not our behaviours. That is, the primary intent of our actions and behaviour is an attempt to respond to, influence and ultimately control our perceived environment in such a way that our perceptions are in line with our internal goals (or in CBT terms, 'schemas'). Powers defines control as '...achievement and maintenance of a preselected perceptual state in the controlling system, through actions on the environment that also cancel the effects of disturbances'. Simply, the model is as follows:

Perception --> Compared to Reference (goal) --> Behaviour --> Perception

Consider the following example as part of the model: 

Perception - "I have upset my friend" --> Compared to a reference (our goals - "I don't want to upset people, it is wrong") --> Behaviour (seeks to change perception "I am sorry I didn't mean to upset you" --> Perception (the person accepts apology) - hence the new perception is in line with the reference.

An important feature of this model is that it represents a negative feedback loop in which our behaviour feeds back to influence our perceptions. This process is analogous to that of homeostasis in the body and in fact most examples of control you can think of, for example in engineering.

Hierarchy of Goals, Inflexible Control and Conflict 

Before we apply this to psychological disorders, we must understand that the 'comparison' part of the model consists of our internal goals, "I want to be independent", "I want to be good", "I want to be successful" and so on. These goals are arranged in both a hierarchy and in parallel such that some are lower level goals "I want to pass my exams" and others are high level goals "I want to have a good job and support my family". Carey explains that psychological problems arise as a result of conflict between two goals, such that '...correcting the error in one system increases the error in another hence its corrective efforts.' Warren Mansell provides an excellent example, explaining it is as if a room is controlled by two thermostats, one set 20 degrees, the other at 30, thus conflict occurs as whatever temperature is achieved will not be satisfactory for both. A further example applied to human behaviour courtesy of Powers, is a man who wishes to appear strong in front of his friends, yet is dependent on their feedback.

Put simply this can be thought of as analogous to cognitive dissonance. Problems occur when our goals conflict. The emphasis however, is that the problem arises from our inflexible attempts to control these conflicts which, in turn, leads to further conflicts and a vicious cycle. These inflexible approaches at control fail because they target the conflicting goals directly, the obvious problem is that controlling perception for one will produce a negative perception for the other. It is this concept of inflexible control which links in with Mansell's transdiagnostic approach, by providing a possible factor which collectively accounts for the various transdiagnostic processes he identifies. 

MOL as a PCT-based Therapy

The solution, Carey explains, is to focus and draw awareness to higher level goals which will lead to reorganization of the hierarchy such that the lower level goals no longer conflict. It is this shift in metacognitve awareness that MOL aims to achieve.

It's two aims are to use Socratic questioning to help the patient describe their problem and also to help them focus and shift their attention to higher level goals, such that a) they recognise the lower goals are a means to more important higher goals and that b) the new awareness will lead to successful reorganization of the hierarchy. In other words the aim of the session is to encourage the client to explore their hierarchy of goals.

During an MOL session the client chooses to talk about any particular problem they wish to discuss. The therapist questions the client and encourages them to focus on background thoughts, which are cued through hesitations, change in tone of voice or flow of conversation. By pointing out and questioning 'meta-thoughts' (thoughts reflecting on the problem the patient is discussing) of the client, it is hoped that their attention and awareness will be drawn to a higher goal level.

Evidence for MOL

MOL is a new therapy, very much in its infancy, as such trials are limited but nevertheless show potential. A study by Carey and Mullan 2008 showed improvements in patients who attended between 2 and 6 sessions for stress, anxiety and depression with moderate to large effect sizes 0.59 - 0.88. Obviously the next step it larger scales randomised control trials which test MOL against alternative therapies such as CBT. Further research into MOL as a possible transdiagnostic approach for cases where there is comorbidity, no diagnosis, or lack of response to conventional treatment, should also be considered.

Chris Meechan

References and further reading

Powers, W. T. (1973a). Behavior: The control of perception (1st ed.). Chicago: Aldine.

Evaluating the method of levels Timothy A. Carey, Richard J. Mullan  Counselling Psychology Quarterly Vol. 21, Iss. 3, 2008

Carey, T. A. (2008). Perceptual Control Theory and the Method of Levels: Further contributions to a transdiagnostic perspective. International Journal of Cognitive Therapy, 1(3), 237-255

Mansell W. (2005). Control theory and psychopathology: An integrative approach. Psychology and Psychotherapy: Theory, Research and Practice, 78, 141-178. eScholarID:1d26443

PCT website


  1. I read it Chris, it was good. But, what kept me skeptical and wondering is the fact that how can its applications work on patients who have a poor insight into their problems? Also, from the article, it seems that, a lot of work is needed from the patient in understanding the nuances of their own perception, both in understanding the process being employed and also in the results and groundwork the process commands you to do. Pray clarify these doubts!

    -Kartik Angara

  2. Cheers Kartik. Basically, I agree! with regards to poor insight, i think any form of psychotherapy falls down here. CBT tries to improve insight in initial sessions by normalising mental illness and formulating explanations for the patients symptoms. But it is widely accepted that it can provide little use to patients who deny their symptoms or have little or no insight (as far as I know).

    I mentioned in the blog about PCT providing one possible example of an underlying process for all disorders. This certainly doesn't imply nor does it claim it to be so, that it leads to a universal therapy.

    Also I agree re your second point. I dont think MOL involves much direct advice or explanation to the patient with regards to the theory behind it. I'm not sure if it is explicitly explained to the patients to focus on 'higher level' goals. I will look into this more. I think MCT sounds appealing too personally. I don't know if there have been attempts to combine MCT with the PCT theory, they seem pretty compatible.

    I will email Warren Mansell and see if he would mind posting a comment RE your points.