text: Perceptual control theory (PCT) is a psychological theory of animal and human behavior originated by William T. Powers.\n\nhttp://en.wikipedia.org/wiki/Perceptual_Control_Theory#History\n\nIn 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.\n\nPCT 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.\n\nThe Control Systems Group is a non-profit professional organization of individuals involved in research in and applications of perceptual control theory.