Conditioned Reflex

Invented by : Ivan Pavlov

Invented in year : 1910

Conditioned Reflex is an acquired response that is under the control of (conditional on the occurrence of) a stimulus. It was developed by Ivan Petrovich Pavlov, a Russian physiologist. Conditioned Reflex is also known as the "Pavlovian theory on higher nervous activity". Pavlov and his disciples were the first researchers to integrate the studies of psychology of learning with experimental analysis of brain function. They showed that conditioned reflexes originate in the cerebral cortex, which is, in Pavlov's words, "the prime distributor and organizer of all activity of the organism". Over a number of years he and his disciples arrived at the basic laws that govern the operation of the cerebral cortex in conditioned learning.

The classic experience of Pavlov is that of the dog, the bell and the salivation to the view of a piece of meat. Whenever we present a piece of meat to the dog, the mere seeing and sniffing it, makes the dog salivate. What is the effect on the animal when we ring a bell? An Orienting Reaction. It simply looks around and turns its head to look for where that sound stimulus comes from. If we repeatedly ring the bell, and immediately after show the meat and give it to the dog, after a certain number of times, simply ringing the bell provokes salivation in the animal, preparing its digestive system to receive the meat. The bell becomes a sign of the meat that will come later. The whole body of the animal reacts as if the meat was already present, with salivation, digestive secretions, digestive motricity etc. An stimulus that has nothing to do with feeding, a mere sound, becomes then capable to induce digestive modifications. This reaction to stimulus is known as Conditioned Reflex.

History

Upon studying the physiology of the gastrointestinal system, Pavlov made one of the greatest scientific discoveries of modern era during 1900's. He conducted series of experiments. These 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. He used the salivary secretion as a quantitative measure of the psychical, or subjective, activity of the animal, in order to emphasize the advantage of objective, physiological measures of mental phenomena and higher nervous activity. He sought analogies between the Conditional Reflex and the Spinal Reflex.

This research served as a base for broad research on the digestive system. Indifferent stimulus, combining with another stimulus capable to elicit an unconditioned reflex, produces an unconditioned answer. After some time the indifferent stimulus is capable, by itself, to provoke an answer that can, then, be considered a conditioned one. Those indifferent stimulus can come from external environment (auditory, luminous, olfactory, tactile and thermal stimuli) as well as from the internal environment (visceras, bones, joints). His experiments earned him the 1904 Nobel Prize in Physiology and Medicine.

Development in the Invention of Conditioned Reflex

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, updating the names to "the strong and impetuous type, the strong equilibrated and quiet type, the strong equilibrated and lively type, and the weak type." 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 by electric shock. This research showed how all temperament types responded to the stimuli the same way, but different temperaments move through the responses at different times.

Beginning about 1930, Pavlov tried to apply his laws to the explanation of human psychoses. He assumed that the excessive inhibition characteristic of a psychotic person was a protective mechanism—shutting out the external world—in that it excluded injurious stimuli that had previously caused extreme excitation. In Russia this idea became the basis for treating psychiatric patients in quiet and non-stimulating external surroundings. During this period Pavlov announced the important principle of the language function in the human as based on long chains of conditioned reflexes involving words. The function of language involves not only words, he held, but an elaboration of generalizations not possible in animals lower than the human.

Carl Jung continued Pavlov's work on TMI and correlated the observed shut-down 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 behavioural research in mental conditioning to achieve memory implantation and brainwashing (any effort aimed at instilling certain attitudes and beliefs in a person).

Role of Conditioned Reflex in the Improvement of Human Life

• The invention laid the basis for the scientific analysis of behaviour.

• This system became physical and psychological method for relaxing the voluntary muscles during labour. Conditioned Reflex was used as means of distraction to decrease women’s perceptions of discomfort during labour contractions. These techniques include deep and shallow breathing and brought comfort to laborious mothers.

• Pavlov ushered the era of scientific study of psychism, by coupling it to Neurophysiology.