Classical conditioning involves:
© 1997, Dr. Gordon C. Bruner II
A stimulus which produces an almost certain response in a subject, called unconditioned stimulus and unconditioned response, respectively.
Then, some other stimulus (the conditioned stimulus) is associated with the unconditioned stimulus.
After the two stimuli have been associated several times it may be possible to elicit the same response as earlier (now called the conditioned response) when only the conditioned stimulus is presented.