Ivan Petrovich Pavlov

Ivan Petrovich Pavlov 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 of classical conditioning.

Pavlov contributed to many areas of physiology and neurology. Most of his work involved research in temperament, conditioning and involuntary reflex actions. He performed and directed experiments on digestion which earned him the 1904 Nobel Prize in Physiology or Medicine. The 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.

Transmarginal inhibition (TMI) is the body’s natural response of shutting down when exposed to overwhelming stress or pain. Pavlov enumerated details of TMI on his work of conditioning animals to pain. He found that organisms responded had different levels of tolerance. He commented “that the most basic inherited difference among people was how soon they reached this shutdown point and that the quickto-shut-down have a fundamentally different type of nervous system.” Patients who have reached this shutdown point often become socially dysfunctional or develop one of several personality disorders. Often patients who dissociate during and after the experience, will more easily dissociate or shut down during stressful or painful experiences, and may experience post traumatic stress disorder for the remainder of their lives.

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 use 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.