classical conditioning

A process of behavior modification in which a subject learns to respond in a desired manner such that a neutral stimulus (the conditioned stimulus) is repeatedly presented in association with a stimulus (the unconditioned stimulus) that elicits a natural response (the unconditioned response) until the neutral stimulus alone elicits the same response (now called the conditioned response). For example, in Pavlov's experiments, food is the unconditioned stimulus that produces salivation, a reflex or unconditioned response. The bell is the conditioned stimulus, which eventually produces salivation in the absence of food. This salivation is the conditioned response.