Rescorla–Wagner theory
an influential theory of classical conditioning that posits that conditioning proceeds from pairing to pairing as a fixed proportion of the maximum amount of conditioning that can be achieved with the unconditioned stimulus (US). For example, if food (the US) produces 100 ml of salivation (the unconditioned response [UR]), and after one pairing of a tone with food, the tone elicits a conditioned response (CR) of 40 ml of salivation (i.e., 0.4 of the maximum amount achievable), a second trial will increase the magnitude of the CR by 24 ml (i.e., 0.4 × [100 – 40]), so that the response will be 64 ml. After a third trial, the magnitude will be 78.4 ml—that is, 40 + 24 + (0.4 × [100–64])—and so on until the CR is 100 ml (the maximum achievable). Also called Rescorla–Wagner model. [proposed in 1972 by Robert Rescorla (1940– ) and Allan Wagner
(1934– ), U.S. experimental psychologists]