text: what is perceptual control theory?   perceptual control theory (pct) is a psychological theory of animal and human behavior originated by william t. powers.  http://en.wikipedia.org/wiki/perceptual_control_theory#history  in contrast with other theories of psychology and behavior, which assume that behavior is a function of perception — that perceptual inputs determine or cause behavior — pct finds that an organism's behavior is a means of controlling its perceptions.  pct differs from engineering control theory in that the reference variable for each negative feedback control loop in a control hierarchy is set from within the system (the organism), rather than by a separate controller.  the control systems group is a non-profit professional organization of individuals involved in research in and applications of perceptual control theory.