operant conditioning chamber
an apparatus used to study free-operant behavior. Generally, it provides a relatively small and austere environment that blocks out extraneous stimuli. Included in the environment are devices that can present stimuli (e.g., reinforcers) and measure free-operant responses. For example, the apparatus for a rat might consist of a 25-cm3 space containing a food tray, which can be filled by an automatic feeder located outside the space, and a small lever that the rat may press to release food from the feeder. Measurement of behavior and presentation of stimuli in the apparatus are usually automatic. The apparatus was initially developed in the 1930s by B. F. Skinner. It later became known colloquially as the Skinner box, although Skinner himself disliked this term.