Pavlov's experiments with the conditioned and unconditioned responses of dogs to cues involving food are his most famous contribution to psychology. The term "Pavlovian response" refers to his findings.
Pavlov's experiments involving the responses of dogs had a major influence on the development of behavioral psychology. He conducted a number of different experiments of this nature, but his most famous involved conditioning dogs to salivate upon hearing the sound of a bell. In this experiment, Pavlov had linked the bell's sound to the appearance of food in the dog's presence. After conditioning, dogs consistently salivated after only hearing the bell, even with no food present. This lead Pavlov to conclude that the response was an unconscious process but could be conditioned with training.
Though Pavlov may be most widely recognized for the Pavlovian response, he was also equally accomplished in physiology, if not more so. In his early career, Pavlov won university honors for his investigations of the pancreatic nerves as a student, and in 1904 he won the Nobel Prize for his research on the digestive organs of dogs. He brought physiology and psychology together in the late period of his career, which was spent studying the human brain and conditioned reflexes in human patients.