Question about classical conditioning

Unconditioned Stimulus (UCS)
A stimulus that elicits a response without conditioning

Unconditioned Response (UCR)
Automatic response elicited by the unconditioned stimulus

Conditioned Stimulus (CS)
A neutral stimulus that when paired with an unconditioned stimulus (UCS) elicits a similar response
Conditioned Response (CR)
A response that is learned by pairing the originally neutral conditioned stimulus (CS) with the
unconditioned stimulus (UCS)

Acquisition
The acquisition phase is the consistent parings of the CS (bell) and the UCS (food) that produces a CR (salivation).   In the example above, this phase occurs when the dog begins to salivate at the sound of the bell.   Conditioning occurs more rapidly when the food follows the bell by a half a second.

Extinction
The extinction phase is when the conditioned response no longer occurs after repeated pairings without the unconditioned stimulus.  The dog’s response to the bell can be extinguished by repeatedly presenting the bell (CS) without the food (UCS).   The dog has not completely forgotten the association between the bell and the food.   If the experimenter waits a day, the dog may have a spontaneous recovery of the conditioned response and salivate again to the bell.

Generalization
Occurs when there is a small difference in the presented stimulus and the original conditioned stimulus.   If Pavlov’s dog heard a bell of a similar tone, the dog would still salivate.

Discrimination
The opposite of generalization, discrimination happens when a conditioned response does not occur when there is a difference between the presented stimulus and the original conditioned stimulus.   If Pavlov’s dog heard a bell with a different tone and was not awarded the unconditioned stimulus (food), the dog would learn not to salivate to the second tone.

UCS : unconditional (unlearned) stimulis
ex: food has been put infrong of a dog, the food is something desired without learn.

UCR: unconditional response
ex: the dog got hungry when he saw the food, it's naturall he got hungry without getting learned to be hungry for food.

CS: conditional (learned) stimulus
ex. hitting on the door three times, before giving the food to the dog, the dog will realize that hitting on the door three times associated with food.

CR: conditional respond.
ex. everytime the dog hears the knocking on door three times, he gets hungry. as he expect that door knocking represent food.