Conditioned reflex

The Russian Physiologist Ivan Pavlov first demonstrated ‘theconditioned reflex’ phenomenon. The cerebral cortex controls the conditioned reflexes. It is also called the classical conditioning, in which a stimulus comes to elicit a response similar to the response produced by some other stimulus. In his experiment, Pavlov presented a dog with a sound of a bell (Neutral stimulus) followed by meat (Unconditioned stimulus). This combined stimuli stimulated the dog to salivate (unconditioned response). After many such conditioned pairings the sound alone (Conditioned stimulus) would stimulate the dog to salivate (Conditioned response - CR).The bell sound initially called the neutral stimulus which after a number of trials pairing with the unconditioned stimulus viz., the meat piece, becomes the conditioned stimulus. Similarly the salivation of the dog during the initial trials of pairing (NS + UCS) is called Unconditioned Response (UR). This unconditioned response later on becomes designated into a conditioned response (CR). It will be elicited just by bell sound (CS). The conditioned reflexes are developed in animal’s life in association with previously established reflexes. This is the basis of learning and memory.