The following are the important features of classical conditioning (1) Unconditioned stimulus (UCS):
Unconditioned stimulus means unlearned and natural response produced by a stimulus. For example: On seeing the food, a hungry dog starts salivating which is a natural response. The food is an unconditioned stimulus for dog.
(2) Unconditioned response (UCR): Unconditioned response means any kind of physiological response which is unlearned. In Pavlov's experiment, the response of salivation is unconditioned response. (3) Conditioned stimulus (CS): It is a natural stimulus. It helps in eliciting an unconditioned response when it is presented with unconditioned stimulus.
(4) Conditioned response (CR): This response was not associated with a particular stimulus before. But after learning and practice, when conditioned stimulus is presented, it elicits a conditioned response. For example : In Pavlov's experiment, the sound of the bell causes secretion of saliva in dog.
(5) Reinforcement: Reinforcement refers to the administration of reinforcement by an experimenter. Reinforcer is any stimulus which strengthens the response. In Pavlov experiment food was the reinforcer. (6) Extinction If the conditioned response is not reinforced, i.e. unconditioned stimulus(food) is not presented continuously for several trials along with conditioned stimulus(bell), the conditioned
response(salivation) slows down gradually and ultimately stops. This is called extinction. (7) Stimulus generalization: It means considering other stimulus as the stimulus presented before.
(8) Stimulus discrimination: It means to be able to differentiate between stimuli.