Richard S. Marken

Perceptual Control as a unifying concept in psychology

We show how a control system model of behavior called Perceptual Control Theory (PCT) can provide a unifying framework for research in all traditional areas of psychology—as a basis for building hypotheses, working models, and applications. PCT views behavior, at all levels, as the control of perceptual inputs. This view is virtually the opposite of that of now standard models—exemplified by the General Linear Model—which view behavior as controlled by perceptual inputs. The PCT model calls for a new approach to research that is aimed at discovering the input variables that organisms control, rather than the input variables that control organisms. This new approach, called The Test for the Controlled Variable, can be applied to the study of all aspects of behavior, from motor control to cognitive neuroscience to counseling and clinical psychology.

Testing for controlled variables: a model-based approach to determining the perceptual basis of behavior

Perceptual control theory (PCT) views behavior as being organized around the control of perceptual variables. Thus, from a PCT perspective, understanding behavior is largely a matter of determining the perceptions that organisms control—the perceptions that are the basis of the observed behavior. This task is complicated by the fact that very often the perceptions that seem to be the obvious basis of some behavior are not. This problem is illustrated using a simple pursuit-tracking task in which the goal was to keep a cursor vertically aligned with a target set at various horizontal distances from the cursor. The “obvious” perceptual basis of the behavior in this task is the vertical distance between cursor and target. But a control model suggests that a better description of the perceptual basis of the behavior is the angle between cursor and target. The experiment shows how a control model can be used to do the test for the controlled variable, a control-theory-based approach to distinguishing the actual from the apparent perceptual basis of any behavior.

Understanding the Change Process Involved in Solving Psychological Problems: A Model-based Approach to Understanding How Psychotherapy Works.

UNLABELLED A review of the literature on psychotherapy suggests that improvements in effectiveness, efficiency and accessibility have been hampered by a lack of understanding of how psychotherapy works. Central to gaining such understanding is an accurate description of the change process that occurs when someone solves a psychological problem. We describe the Perceptual Control Theory (PCT) model of human functioning, which can be used to understand the nature of psychological problems and how they are solved. PCT suggests that problems can be broadly grouped into two categories: those that can be solved using existing skills and those that require the generation of new skills. In general, psychological problems belong in the second category. PCT describes a fundamental form of learning in which existing structures and systems are reorganized to create new skills, perspective and insights. Psychotherapy based on PCT is aimed at directing reorganization to the source of the problem. KEY PRACTITIONER MESSAGE Understanding the phenomenon of control is central to understanding how psychotherapy works. Conflict could be considered a general formulation for psychological distress. Therapy will be efficient when the reorganization process is focused at the right level of the clients control hierarchy. Therapy will be effective only when the clients reorganization system-not the therapist-has managed to come up with a solution to the clients problem. What the client says about the nature and reason for their problem is less important than the point of view from which these problems are being discussed.

Taking purpose into account in experimental psychology: testing for controlled variables.

Experimental research in psychology is based on a causal model—the General Linear Model (GLM)—that assumes behavior has causes but not purposes. Powers (1978) used a control theory analysis to show that the results of psychological experiments based on such a model can be misleading if the organisms being studied are purposeful (control) systems. In the same paper, Powers presented evidence that organisms are such systems. Nevertheless, psychologists continue to use methods that ignore purpose because the behavior in most experiments appears to be non-purposeful (a caused result of variations in the independent variable). The experiments described in this paper show how purposeful behavior can appear to be caused by the independent variable when an organisms purposes are ignored. The results show how taking purpose into account using the control theory-based “Test for the Controlled Variable” can provide a productive new methodological direction for experimental research in psychology.

The power law of movement: an example of a behavioral illusion

The curved movements produced by living organisms follow a power law where the velocity of movement is a power function of the degree of curvature through which the movement is made. The exponent of the power function is close to either 1/3 or 2/3 depending on how velocity and curvature are measured. This power law is thought to reflect biological and/or kinematic constraints on how organisms produce movements. The present paper shows that the power law is actually a statistical artifact that results from mistaking a correlational for a causal relationship between variables. The power law implies that curvature influences the velocity of movement. In fact, the power law is a mathematical consequence of the way that these variables are calculated. The appearance that curvature affects the velocity of movement is shown to be an example of a “behavioral illusion” that results from ignoring the purpose of behavior.

The Origins and Future of Control Theory in Psychology

The construct of “control” is virtually ubiquitous in psychology and it links to a comprehensive range of real-world outcomes. Control theory is critically important in this regard because it describes and models the dynamic systems that enable control to occur. Yet, the origins and principles of control theory in psychology are often misunderstood. This leads to a failure to capitalize on its strengths as a unifying, dynamic framework. We address this gap in knowledge by describing the early origins of control theory and its 2 main paths of development within psychology, as a “man−machine system” approach, and as a “grand theory” of psychology. We introduce the grand theory approach to control theory, pioneered by William T. Powers (1926-2013). Powers (1973) proposed that behavior is the control of perception and he introduced a closed-loop, hierarchical architecture to implement this principle. We propose that Powers’ control theory provides a wholly new perspective on psychological science and is, as such, a third grand theory, after the behaviorist and cognitive theories. We describe a range of advances in neuroscience, animal behavior, social processes, and mental health, based on Powers’ theory, to illustrate its potential to transform the nature of psychological research and practice.

Making Inferences about Intention: Perceptual Control Theory as a “Theory of Mind” for Psychologists

Theory of Mind (ToM) assumes that humans and possibly other primates understand behavior in terms of inferences about intentions. While there is evidence that primates make such inferences, little attention has been paid to the question of their validity. In order to answer this question it is necessary to know the true intentions underlying behavior. The present paper shows that Perceptual Control Theory can provide a scientific basis for making such determinations using methods derived from control engineering. These methods—called the “Test for the Controlled Variable” (TCV)—are based on the assumption that intentional behavior is equivalent to the process of control. The TCV provides an objective approach to inferring the intentions underlying behavior in terms of the perceptual variables under control and the goal states of those variables. Thus, Perceptual Control Theory represents an empirical ToM for psychologists—one that can be used to understand behavior in terms of inferences about intention that are based on the results of active experimentation rather than passive observation.

Motor control as the control of perception.

This paper describes a test of Perceptual Control Theory (PCT), which views motor control as part of a process of controlling perceptual inputs rather than motor outputs. Sixteen undergraduate students (M age = 19.9 yr.) were asked to control one of three different perceptual aspects of an animated display—a shape, a motion or a sequence—using the same motor output, a key press. Animation rate was varied while quality of control was measured in terms of the proportion of time that the perception was maintained in the goal state. The results showed that increased animation rate made it hardest to control the more complex perceptions (motion and sequence) even though the same output was used to control all perceptions. This result is consistent with PCT, which predicts that the temporal constraints on control are ultimately a function of the type of perception controlled rather than the type of output used to control it.

Control blindness: Why people can make incorrect inferences about the intentions of others

There is limited evidence regarding the accuracy of inferences about intention. The research described in this article shows how perceptual control theory (PCT) can provide a “ground truth” for these judgments. In a series of 3 studies, participants were asked to identify a person’s intention in a tracking task where the person’s true intention was to control the position of a knot connecting a pair of rubber bands. Most participants failed to correctly infer the person’s intention, instead inferring complex but nonexistent goals (such as “tracing out two kangaroos boxing”) based on the actions taken to keep the knot under control. Therefore, most of our participants experienced what we call “control blindness.” The effect persisted with many participants even when their awareness was successfully directed at the knot whose position was under control. Beyond exploring the control blindness phenomenon in the context of our studies, we discuss its implications for psychological research and public policy.

The power law as behavioral illusion: reappraising the reappraisals

Marken and Shaffer (Exp Brain Res 235:1835–1842, 2017) have argued that the power law of movement, which is generally thought to reflect the mechanisms that produce movement, is actually an example of what Powers (Psychol Rev 85:417–435, 1978) dubbed a behavioral illusion, where an observed relationship between variables is seen as revealing something about the mechanisms that produce a behavior when, in fact, it does not. Zago et al. (Exp Brain Res. https://doi.org/10.1007/s0022-017-5108-z, 2017) and Taylor (Exp Brain Res, https://doi.org/10.1007/s00221-018-5192-8, 2018) have “reappraised” this argument, claiming that it is based on logical, mathematical, statistical and theoretical errors. In the present paper we answer these claims and show that the power law of movement is, indeed, an example of a behavioral illusion. However, we also explain how this apparently negative finding can point the study of movement in a new and more productive direction, with research aimed at understanding movement in terms of its purposes rather than its causes.