Skinner box

 

Skinner box with 2 respond levers, 2 cue lights, 1 electrified floor, 1 house light and 1 speaker are above the cage

 

An operant conditioning chamber (also known as the Skinner box) is a laboratory apparatus used to study animal behavior. The operant conditioning chamber was created by B. F. Skinner while he was a graduate student at Harvard University (studying for a master’s degree in 1930 and a doctorate in 1931). It may have been inspired by Jerzy Konorski’s studies. It is used to study both operant conditioning and classical conditioning. Skinner created the operant chamber as a variation of the puzzle box originally created by Edward Thorndike.

 

Purpose

An operant conditioning chamber permits experimenters to study behavior conditioning (training) by teaching a subject animal to perform certain actions (like pressing a lever) in response to specific stimuli, such as a light or sound signal. When the subject correctly performs the behavior, the chamber mechanism delivers food or another reward. In some cases, the mechanism delivers a punishment for incorrect or missing responses. For instance, to test how operant conditioning works for certain invertebrates, such as fruit flies, psychologists use a device known as a “heat box”. Essentially this takes up the same form as the Skinner box, but the box is composed of two sides: one side that can undergo temperature change and the other that does not. As soon as the invertebrate crosses over to the side that can undergo a temperature change, the area is heated up. Eventually, the invertebrate will be conditioned to stay on the side that does not undergo a temperature change. This goes to the extent that even when the temperature is turned to its lowest point, the fruit fly will still refrain from approaching that area of the heat box. These types of apparatuses allow experimenters to perform studies in conditioning and training through reward/punishment mechanisms.

 

Structure

The structure forming the shell of a chamber is a box large enough to easily accommodate the animal being used as a subject. (Commonly used model animals include rodents—usually lab rats—pigeons, and primates). It is often sound-proof and light-proof to avoid distracting stimuli.

Operant chambers have at least one operandum (or “manipulandum”), and often two or more, that can automatically detect the occurrence of a behavioral response or action. Typical operanda for primates 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 programmed 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 has a means of delivering a primary reinforcer (a reward, such as food, etc.) or unconditioned stimulus like food (usually pellets) or water. It can also register the delivery of a conditioned reinforcer, such as an LED (see Jackson & Hackenberg 1996 in the Journal of the Experimental Analysis of Behavior for example) signal as a “token”.

Despite such a simple configuration, one operandum and one feeder, it is possible to investigate many psychological phenomena. Modern operant conditioning chambers typically have many operanda, like many response levers, two or more feeders, and a variety of devices capable of generating many stimuli, including lights, sounds, music, figures, and drawings. Some configurations use an LCD panel for the computer generation of a variety of visual stimuli.

Some operant chambers can also have electrified nets or floors so that shocks can be given to the animals; or lights of different colors that give information about when the food is available. Although the use of shock is not unheard of, approval may be needed in countries that regulate experimentation on animals.

 

Research impact

Operant conditioning chambers have become common in a variety of research disciplines including behavioral pharmacology. The results of this experiments inform many disciplines outside of psychology, such as behavioral economics.

An urban legend spread concerning Skinner putting his daughter through an experiment such as this, causing great controversy. His daughter later debunked this.

 

Commercial applications

Slot machines and online games are sometimes cited as examples of human devices that use sophisticated operant schedules of reinforcement to reward repetitive actions.

Social networking services such as Google, Facebook and Twitter have been identified as using the techniques, critics use terms such as Skinnerian Marketing for the way the companies use the ideas to keep users engaged and using the service.

Gamification, the technique of using game design elements in non-game contexts, has also been described as using operant conditioning and other behaviorist techniques to encourage desired user behaviors.

 

Skinner box

 

Students using the Skinner box, at National University of San Marcos in Lima, Perú.

 

Skinner is noted to have said that he did not want to be an eponym. Further, he believed that Clark Hull and his Yale students coined the expression: Skinner stated he did not use the term himself, and went so far as to ask Howard Hunt to use “lever box” instead of “Skinner box” in a published document.