conditioned reflex (redirected from conditioned reaction)

conditioned reflex [kən′dish·ənd ′rē‚fleks]

(psychology)

Response of an organism to a stimulus which was inadequate to elicit the response until paired for one or more times with an adequate stimulus.

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Conditioned reflex

A learned response performed by a trained animal to a signal that was previously associated with an event of consequence for that animal. Conditioned reflex (CR) was first used by the Russian physiologist I. P. Pavlov to denote the criterion measure of a behavioral element of learning, that is, a new association between the signal and the consequential event, referred to as the conditioned stimulus (CS) and unconditioned stimulus (US), respectively. In Pavlov's classic experiment, the conditioned stimulus was a bell and the unconditioned stimulus was sour fluid delivered into the mouth of a dog restrained by harness; the conditioned stimulus was followed by the unconditioned stimulus regardless of the dog's response. After training, the conditioned reflex is manifested when the dog salivates to the sound of the bell.

Ideally, certain conditions must be met to demonstrate the establishment of a conditioned reflex according to Pavlov's classical conditioning method. Before conditioning, the bell conditioned stimulus should attract the dog's attention or elicit the orienting reflex (OR), but it should not elicit salivation, the response to be conditioned. That response should be specifically and reflexively elicited by the sour unconditioned stimulus, thus establishing its unlearned or unconditioned status. After conditioned pairings of the conditioned stimulus and the unconditioned stimulus, salivation is manifested prior to the delivery of the sour unconditioned stimulus. Salivation in response to the auditory conditional stimulus is now a “psychic secretion” or the conditioned reflex.

To this day, Pavlov's methods provide important guidelines for basic research upon brain mechanisms in learning and memory. Scientists all over the world have paired a vast array of stimuli with an enormous repertoire of reflexes to test conditioned reflexes in representative species of almost all phyla, classes, and orders of animals. As a result, classical conditioning is now considered a general biological or psychobiological phenomenon which promotes adaptive functioning in a wide variety of physiological systems in various phylogenetic settings. See Cognition, Memory