- I·van Pe·tro·vich [ee-vahn pyi-traw-vyich] /iˈvɑn pyɪˈtrɔ vyɪtʃ/, 1849–1936, Russian physiologist: Nobel Prize in medicine 1904.
- Ivan Petrovich (iˈvan pɪˈtrɔvitʃ). 1849–1936, Russian physiologist. His study of conditioned reflexes in dogs influenced behaviourism. He also made important contributions to the study of digestion: Nobel prize for physiology or medicine 1904
- Russian physiologist known for his discovery of the conditioned response. He won a 1904 Nobel Prize for his research on the nature of digestion.
- Russian physiologist who studied the digestive system of dogs, investigating the nervous control of salivation and the role of enzymes. His experiments showed that if a bell is rung whenever food is presented to a dog, the dog will eventually salivate when it hears the bell, even if no food is presented. This demonstration of what is known as a conditioned response prompted later scientific studies of human and animal behavior.