An operant conditioning chamber
(sometimes called a "Skinner box" after B. F. Skinner, its inventor) is an experimental apparatus used by psychologists
to study operant conditioning
. The structure forming the shell of a chamber is a three-dimensional box large enough to easily accommodate the organism (rat
, pigeon, monkey, etc) serving as the subject in the research. Conditioning chambers have at least one operandum (or "manipulandum"
) that can automatically detect the occurrence of a behavioral
response or action. Typical operanda for monkeys and rats are "response levers"
; if the subject presses the lever, the opposite end moves and closes a switch that is monitored by a computer or other programming device. Typical operanda for pigeons and other birds
are "response keys"
with a switch that closes if the bird pecks at the key with sufficient force
. The other minimal requirement of a conditioning chamber is that it have a means of delivering a primary reinforcer or unconditioned stimulus like food or water
With such a simple configuration, one operandum and one feeder, it is possible to investigate uncountable psychological phenomena. Modern conditioning chambers typically have many operanda, like many response levers, two or more feeders, and a variety of devices capable of generating stimuli (lights, sounds, chords, figures, drawings, etc.) in the chamber.
Although commonly referred to as operant conditioning chambers
, these apparatuses are also used to study classical conditioning--especially in pigeons (c.f., autoshaping).