Russian physiologist Ivan Pavlov was the first to describe classical conditioning. In classical conditioning, also called “respondent conditioning” or “Pavlovian conditioning,” a subject comes to respond to a neutral stimulus as he would to another, non neutral stimulus by learning to associate the two stimuli.
Pavlov’s contribution to learning began with his study of dogs. Not surprisingly, his dogs drooled every time he gave them food. Then he noticed that if he sounded a tone every time he fed them, the dogs soon started to drool at the sound of the tone, even if no food followed it. The dogs had come to associate the tone, a neutral stimulus, with food, a non neutral stimulus.