Nobel Prize portrait, 1904
|Born||September 14, 1849 |
|Died||February 27, 1936 |
Leningrad, Soviet Union
|Residence|| Russian Empire |
|Nationality|| Russian |
|Field||Physiologist, psychologist, physician|
|Institution||Military Medical Academy|
|Alma Mater||Saint Petersburg University|
|Known for||Classical conditioning |
|Notable Prizes||Nobel Prize in Physiology or Medicine|
Ivan Petrovich Pavlov (Russian: Иван Петрович Павлов) (September 14, 1849 – February 27, 1936) was a Russian physiologist, psychologist, and physician. He was awarded the Nobel Prize in Physiology or Medicine in 1904 for research pertaining to the digestive system. Pavlov is widely known for first describing the phenomenon now known as classical conditioning in his experiments with dogs.
Ivan Pavlov was born in Ryazan, Russia. He began his higher education as a seminary student, but dropped out and enrolled in the University of St. Petersburg to study the natural sciences. He received his doctorate in 1879.
In the 1890s, Pavlov was investigating the gastric function of dogs by externalizing a salivary gland so he could collect, measure, and analyze the saliva produced in response to food under different conditions. He noticed that the dogs tended to salivate before food was actually delivered to their mouths, and set out to investigate this "psychic secretion", as he called it. He decided that this was more interesting than the chemistry of saliva, and changed the focus of his research, carrying out a long series of experiments in which he manipulated the stimuli occurring before the presentation of food. He thereby established the basic laws for the establishment and extinction of what he called "conditional reflexes" — i.e., reflex responses, like salivation, that only occurred conditionally upon specific previous experiences of the animal. These experiment were carried out in the 1890s and 1900s, and were known to western scientists through translations of individual accounts, but first became fully available in English in a book published in 1927.
Pavlov was a dexterous operator who was compulsive about his working hours and habits. He would sit down to lunch at exactly 12 o'clock, he would go to bed at exactly the same time each evening, would always feed his dogs at exactly the same time each night and he would always leave Leningrad for Estonia on vacation on the same day each year. This behavior changed when his son Victor died in the White Army — after which he suffered from insomnia.
Unlike many pre-revolutionary scientists, Pavlov was highly regarded by the Soviet government, and he was able to continue his researches until he reached a considerable age. Pavlov himself was not favorable towards Marxism, but as a Nobel laureate he was seen as a valuable political asset. After returning from his first visit to the United States in 1923 (the second was in 1929), he publicly denounced Communism, stated that the basis for international Marxism was false, and said that "For the kind of social experiment that you are making, I would not sacrifice a frog's hind legs!" In 1924, when the sons of priests were expelled from the Military Medical Academy in Leningrad (the former Imperial Medical Academy), he resigned his chair of physiology announcing, "I also am the son of a priest, and if you expel the others I will go too!"  After the murder of Sergei Kirov in 1934, Pavlov wrote several letters to Molotov criticizing the mass persecutions which followed and asking for the reconsideration of cases pertaining to several people he knew personally.
In later life he was particularly interested in trying to use conditioning to establish an experimental model of the induction of neuroses. He died in Leningrad. His laboratory in Saint Petersburg has been carefully preserved.
Conscious until his very last moment, Pavlov asked one of his students to sit beside his bed and to record the circumstances of his dying. He wanted to create unique evidence of subjective experiences of this terminal phase of life. The great scientific courage of Pavlov is exhibited by this story: he tried to learn, and to increase knowledge of physiology, even in his deathbed.[citations needed]
Pavlov contributed to many areas of physiology, neurology and psychology. Most of his work involved research in temperament, conditioning and involuntary reflex actions.
Pavlov performed and directed experiements on digestion which earned him the 1904 Nobel Prize in Physiology and Medicine  Experiments included surgically extracting portions of the digestive system from animals, severing nerve bundles to determine the effects, and implanting fistulas between digestive organs and an external pouch to examine the organ's contents. This research served as a base for broad research on the digestive system.
Further work on reflex actions involved involuntary reactions to stress and pain. Pavlov extended the definitions of the four temperament types under study at the time: phlegmatic, choleric, sanguine, and melancholic. Pavlov and his researchers observed and began the study of transmarginal inhibition (TMI), the body's natural response of shutting down when exposed to overwhelming stress or pain. This research showed how all temperament types responded to the stimuli the same way, but different temperaments move through the responses at different times. He commented "that the most basic inherited difference. .. was how soon they reached this shutdown point and that the quick-to-shut-down have a fundamentally different type of nervous system."
Carl Jung continued Pavlov's work on TMI and correlated the observed shutdown types in animals with his own introverted and extroverted temperament types in humans. Introverted persons, he believed, were more sensitive to stimuli and reached a TMI state earlier than their extroverted counterparts. This continuing research branch is gaining the name highly sensitive persons.
William Sargant and others continued the behavioral research in mental conditioning to achieve memory implantation and brainwashing.
Interestingly, Pavlov's term "conditional reflex" ("условный рефлекс") was mistranslated from the Russian as "conditioned reflex", and other scientists reading his work concluded that since such reflexes were conditioned, they must be produced by a process called conditioning. As Pavlov's work became known in the West, particularly through the writings of John B. Watson, the idea of "conditioning" as an automatic form of learning became a key concept in the developing specialism of comparative psychology, and the general approach to psychology that underlay it, behaviorism. The British philosopher Bertrand Russell was an enthusiastic advocate of the importance of Pavlov's work for philosophy of mind.
Pavlov's research on conditional reflexes greatly influenced not only science, but also popular culture. The phrase "Pavlov's dog" is often used to describe someone who merely reacts to a situation rather than uses critical thinking. Pavlovian conditioning was a major theme in Aldous Huxley's dystopian novel, Brave New World, and also to a large degree in Thomas Pynchon's Gravity's Rainbow.
It is popularly believed that Pavlov always signaled the occurrence of food by ringing a bell. However, his writings record the use of a wide variety of stimuli, including whistles, metronomes, tuning forks, and a range of visual stimuli, in addition to ringing a bell.