Skinner box

Skinner box

Etymology: Burrhus F. Skinner, American psychologist, 1904-1990; L, buxus, boxwood

a boxlike laboratory apparatus used in operant conditioning of animals, usually containing a lever or other device that when pressed reinforces by either giving a reward, such as food or an escape outlet, or removing a punishment, such as an electric shock. Also called standard environmental chamber. See also operant conditioning.

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conditioning [kon-dish´un-ing]

1. in physical medicine, improvement of physical health by a program of exercises; called also physical conditioning.

2. in psychology, a form of learning in which a response is elicited by a neutral stimulus which previously had been repeatedly presented in conjunction with the stimulus that originally elicited the response. Called also classical or respondent conditioning.

The concept had its beginnings in experimental techniques for the study of reflexes. The traditional procedure is based on the work of Ivan P. Pavlov, a Russian physiologist. In this technique the experimental subject is a dog that is harnessed in a sound-shielded room. The neutral stimulus is the sound of a metronome or bell which occurs each time the dog is presented with food, and the response is the production of saliva by the dog. Eventually the sound of the bell or metronome produces salivation, even though the stimulus that originally elicited the response (the food) is no longer presented.

In the technique just described, the conditioned stimulus is the sound of the bell or metronome, and the conditioned response is the salivation that occurs when the sound is heard. The food, which was the original stimulus to salivation, is the unconditioned stimulus and the salivation that occurred when food was presented is the unconditioned response.

Reinforcement is said to take place when the conditioned stimulus is appropriately followed by the unconditioned stimulus. If the unconditioned stimulus is withheld during a series of trials, the procedure is called extinction because the frequency of the conditioned response will gradually decrease when the stimulus producing the response is no longer present. The process of extinction eventually results in a return of the preconditioning level of behavior.

aversive conditioning learning in which punishment or other unpleasant stimulation is used to associate negative feelings with an undesirable response.

classical conditioning conditioning (def. 2).

instrumental conditioning (operant conditioning) learning in which a particular response is elicited by a stimulus because that response produces desirable consequences (reward). It differs from classical conditioning in that the reinforcement takes place only after the subject performs a specific act that has been previously designated. If no unconditioned stimulus is used to bring about this act, the desired behavior is known as an operant. Once the behavior occurs with regularity the behavior may be called a conditioned response.

The traditional example of instrumental conditioning uses the Skinner box, named after B. F. Skinner, an American behavioral psychologist. The subject, a rat, is kept in the box and becomes conditioned to press a bar by being rewarded with food pellets each time its early random movements caused it to press against the bar.

The principles and techniques related to instrumental conditioning are used clinically in behavior therapy to help patients eliminate undesirable behavior and substitute for it newly learned behavior that is more appropriate and acceptable.

physical conditioning conditioning (def. 1).

respondent conditioning conditioning (def. 2).

work conditioning a physical exercise program designed to restore specific strength, flexibility, and endurance for return to work following injury, disease, or medically imposed rest; it may be part of a complete work hardening program when other aspects of functional restoration are required.

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Skinner box

an experimental enclosure for testing animal conditioning, in which the subject animal performs (e.g. presses a bar or lever) to obtain a reward. See also instrumental conditioning.