William T. Powers (August 29, 1926 – May 24, 2013) was a medical physicist and an independent scholar of experimental and theoretical
psychology
Psychology is the scientific study of mind and behavior. Psychology includes the study of conscious and unconscious phenomena, including feelings and thoughts. It is an academic discipline of immense scope, crossing the boundaries between ...
who developed the
perceptual control theory Perceptual control theory (PCT) is a model of behavior based on the properties of negative feedback control loops. A control loop maintains a sensed variable at or near a reference value by means of the effects of its outputs upon that variable, as ...
(PCT) model of behavior as the control of perception. He was the son of the well-known cement scientist and economist
Treval Clifford Powers.
PCT demonstrates that rather than controlling their behavioral outputs, living things control their perceptual inputs, and explains how they vary their behavior as the means of affecting inputs to their sense organs. Living control systems differ from those specified by
Engineering control theory (a thermostat is a simple example), for which the reference value (setpoint) for control is specified outside the system by what is called the
controller
Controller may refer to:
Occupations
* Controller or financial controller, or in government accounting comptroller, a senior accounting position
* Controller, someone who performs agent handling in espionage
* Air traffic controller, a person ...
, whereas in living systems the reference variable for each
feedback control loop in a control hierarchy is generated within the system, usually as a function of error output from a higher-level system or systems.
Powers and his students and colleagues in diverse fields have developed many demonstrations of autonomous negative feedback control with endogenously generated reference values, and computer models or simulations that replicate observed and measured behavior of living systems (human and animal, individuals and groups of individuals) with a very high degree of fidelity (0.95 or better).
Some corresponding control structures have been demonstrated neurophysiologically.
Powers also designed the board game ''Trippples'', originally produced by Benassi Enterprises, later transferred to Aladdin Industries and granted US Patent 3,820,791 in 1974 He published a number of science fiction stories. Through the network of science fiction writers, he was also an early advocate of
Dianetics
Dianetics (from Greek ''dia'', meaning "through", and ''nous'', meaning " mind") is a set of pseudoscientific ideas and practices regarding the metaphysical relationship between the mind and body created by science fiction writer L. Ron Hub ...
, which he abandoned in the early 1950s.
Selected bibliography
* Powers, William T. (1973). ''Behavior: The control of perception.'' Chicago: Aldine de Gruyter. . 2nd ed. (2005) New Canaan: Benchmark Publications. Chinese tr. (2004) Guongdong Higher Learning Education Press, Guangzhou, China. .
* Powers, William T. (1989). ''Living control systems''.
elected papers 1960-1988.New Canaan, CT: Benchmark Publications. .
* Powers, William T. (1992). ''Living control systems II''.
elected papers 1959-1990.New Canaan, CT: Benchmark Publications.
* Powers, William T. (1998). ''Making sense of behavior: The meaning of control.'' New Canaan, CT: Benchmark Publications.
* Powers, William T. (2008). ''Living Control Systems III: The fact of control.''
athematical appendix by Dr. Richard Kennaway. Includes computer programs for the reader to demonstrate and experimentally test the theory.New Canaan, CT: Benchmark Publications. .
Notes
External links
The International Association for Perceptual Control Theory (f.k.a. the Control Systems Group)
{{DEFAULTSORT:Powers, William
1926 births
Systems psychologists
2013 deaths
20th-century American psychologists