Pavlov's dog learned to anticipate food whenever he was presented with stimuli associated with food. pavlov knew that his dog associated specific stimuli with food because the was elicited by the stimuli conditioned response

Russian physiologist Ivan Pavlov originated the study of classical conditioning while studying the salivation of dogs and finding that they would begin salivating even when they were not supposed to. Pavlov's classic experiment consisted of his paring of the ticking sound of a metronome with the presentation of food to see if the dogs would eventually salivate to just the sound of the ticking metronome.