Pavlov, Ivan Petrovich 1849-1936
Pavlov was a Nobel Prize-winning physiologist, whose research into the process of the conditioned reflex is considered a landmark discovery in both modern physiology and behavioral psychology. Pavlov was recognized by the Nobel Committee for his work with mammalian digestion; however, later experiments with canine salivation led to his theorization of the learned or conditioned reflex—a physiological response to associated but otherwise unrelated stimuli. Pavlov observed that dogs presented with some additional stimulus that accompanied regular feedings, such as a flash of light, could be made to salivate when only the additional stimulation, and no food, was offered. From these and similar experiments, Pavlov established the physiological basis of certain types of learned behavior. In theory, Pavlov also applied his discovery of the conditioned reflex to human beings. In addition to his study of digestion and higher nervous activity, Pavlov is remembered for his work with the physiology of blood circulation and as an accomplished scientific administrator.
Pavlov was born on 26 September 1849 in Ryazan, Russia. He was educated at Ryazan Ecclesiastical High School and later attended the Ryazan Ecclesiastical Seminary, where he exhibited considerable interest in the natural sciences. In 1870 Pavlov opted to leave the seminary and to continue his studies at St. Petersburg University. There Pavlov began working with the physiologist Elie de Zion and honing his surgical skills. After graduation in 1875, Pavlov entered medical school at the Military Medical Academy in St. Petersburg, and served as a laboratory assistant to Zion, who had recently been named chair of the academy's physiology department. Pavlov later transferred for two years to the Veterinary Institute following Zion's dismissal, and in 1877 traveled to Breslau, Germany (now Wroclaw, Poland) to study digestion under Rudolf Heidenhain. Pavlov was honored with a scholarship for postdoctoral study after earning his medical degree in 1879 and returned to Germany to further his research into circulation and digestion. In 1895 Pavlov was named chairman of physiology at the St. Petersburg Institute for Experimental Medicine and remained in this position for much of his subsequent career. For his continued studies into the process of mammalian digestion he was awarded the Nobel Prize for Medicine or Physiology in 1904. By this time, Pavlov had begun his experiments on conditioned reflexes in laboratory dogs. Following the Bolshevik Revolution in 1917, Pavlov occasionally spoke out against the Soviets, but was nevertheless given preferential treatment by the Communist Party, which hoped to use his experiments with the conditioned reflex for political ends. In 1935 the Soviet government built Pavlov an extensive, state-of-the-art laboratory where he could continue his work. He died of pneumonia shortly thereafter on 27 February 1936 in Leningrad (now St. Petersburg).
Few of Pavlov's works are available in English translation and, in addition, critics discern that most of the writings attributed to him represent to some degree the combined efforts of Pavlov and his many laboratory assistants—though it is clear that Pavlov is the principal intellectual force behind all of the following texts. The Work of the Digestive Glands (1902) contains the culmination of Pavlov's experiments on the alimentary canal of dogs performed in the late 1880s and 1890s. Pavlov and his fellow researchers studied digestion by surgically altering laboratory dogs, principally by modifying canine stomachs to create a "Pavlov pouch," into which gastric juices could be separated for observation and testing. Pavlov's later and more well-known work on the conditioned reflex is available to English-speaking audiences in Lectures on Conditioned Reflexes (1923) and Conditioned Reflexes: An Investigation of the Physiological Activity of the Cerebral Cortex (1960). These texts record the results of Pavlov's further experimentation with dogs. Again using surgical procedures, Pavlov and his team studied the relationship between the higher nervous system and the action of the salivary glands. By associating certain unrelated stimuli—such as the presence of a lab assistant, the ring of a bell, or a flash of light—with the routine feeding of the dogs, Pavlov was able to demonstrate the performance of conditioned reflexes. This he succeeded in doing by stimulating salivation without actually offering food, through the simple recreation of those stimuli (bell, light, assistant's presence) that had been related to feeding. Drawing from these experiments, Pavlov theorized the existence of a physiological component to psychological processes, and differentiated between the mechanisms of innate and conditioned reflexes. Pavlov's collected works, including a significant number of scientific articles and research essays, appear in the five-volume Russian compilation Polnoe sobranie trudov (1940-49).
Critics have observed that Pavlov's discovery of the conditioned reflex has been quite influential in the scientific community, particularly in Russia, where research into Pavlovian physiology has continued, uninterrupted, through the end of the Soviet regime and of the twentieth-century. Since Pavlov's death, however, many reassessments of Pavlovian theory have occurred. Contemporary scientists have uncovered a number of errors within the details of Pavlov's thought. Critics likewise have acknowledged that Pavlov's failure to satisfactorily explain the true mechanism of the conditioned reflex represents a serious limitation. Nevertheless, scholars have continued to see Pavlov as a pioneering figure in the study of physiology and have observed the tremendous influence his work with the conditioned reflex has exerted on the modern field of behavioral psychology.
*Experimental Data Concerning the Accommodating Mechanism of the Blood Vessels (physiology) 1877
Lektsii o rabote glavnykh pishchevaritelnykh (physiology) 1897 [The Work of the Digestive Glands, 1902]
**Lectures on Conditioned Reflexes (physiology) 1923
"The Conditioned Reflex" (physiology) 1934 [published in the book The Great Medical Encyclopedia]
Dvadtsatiletnii opyt ob'ektivnogo izucheniia vysshei nervnoi deiatel' nosti zhivotnykh (physiology) 1938 [Conditioned Reflexes: An Investigation of the Physiological Activity of the Cerebral Cortex, 1960]
Polnoe sobranie trudov. Five vols. (physiology) 1940-49
Psikhopatologiia i psikhiatriia (physiology) 1949 [Psychopathology and Psychiatry, 1960]
Izbrannye trudy (physiology) 1951 [Selected Works, 1955]
**Experimental Psychology, and Other Essays (essays) 1957
*Published in Russian.
**English edition of work originally published in Russian.
SOURCE: "Pavlov's Theory of Conditioning," in the Psychological Review, Vol. 41, No. 2, March, 1934, pp. 199-206.
[In the following essay, Guthrie offers a critique of Pavlov's theory of the conditioned reflex.]
Pavlov's recent article, 'The Reply of a Physiologist to Psychologists,'1 deals with two items printed some time ago in the Psychological Review, one by Lashley on 'Basic neural mechanisms in behavior,' and one by the writer, 'Conditioning as a principle of learning.' The issues raised by Pavlov deserve some further discussion because they are fundamental. My own article would have been justified if its only effect had been to persuade Pavlov to additional writing on the conditioned reflex, since by his laboratory experience he is undoubtedly its most competent exponent. However, on a number of points I remain quite unconvinced after reading his 'Reply.'
The first difference of opinion that he mentions concerns a very general issue. He says,
The psychologist takes conditioning as a principle of learning, and accepting the principle as not subject to further analysis, not requiring ultimate investigation, he endeavors to apply it to everything and to explain all the individual features of learning as one and the same process. . . . The physiologist proceeds in quite the opposite way. At every phase of his investigation he endeavors to analyze the phenomena individually and in connection with facts, determining as much as is possible of the conditions for their existence, not trusting to mere deduction or to a single hypothesis.
This characterization is substantially correct. Pavlov has been reporting many detailed experiments with resulting generalizations as numerous as the varieties of experimental procedure. It was the writer's belief that the time had arrived when an hypothesis could be set up in order to direct experimental work. The hypothesis suggested was an old and familiar one, that the phenomena of learning, when described in terms of altered movement or secretion, may be described in terms of one principle, which was called the principle of conditioning. Its statement was this: Stimuli acting at the time of a response tend on their recurrence to evoke that response. In other words, it was suggested that the outstanding characteristics of learning, which have been expressed in terms of frequency, intensity, irradiation, temporary extinction, conditioned inhibition, forgetting, forward and backward conditioning, and so on, are all derivable from a more general law, the law of simultaneous conditioning or association by contiguity in time. To this end an analysis of these various phenomena was undertaken, an analysis that was, to the writer at least, very plausible.
Pavlov's second objection concerns this analysis in so far as it applies to backward conditioning. According to him the question is: What elementary properties of the brain-mass form the basis of conditioning? Backward conditioning, practice with the conditioned stimulus following the unconditioned, has a double effect, " . . . at first, temporarily, it assists in the formation of the conditioned reflex, and then destroys it,"—becoming eventually an inhibiting stimulus.
Pavlov's explanation of this is that
.. . the cell excited by the conditioned stimulus is inhibited or comes to an inhibited state with repeated concentration on the part of the unconditioned stimulus—and the conditioned stimulus in this way meets in its cell a permanent state of inhibition.
To this there is an objection. An understanding of the phenomenon of backward conditioning can be had only by finding the conditions under which it occurs. No properties of the brain-mass have been observed; no technique for observing states of inhibition in cells has yet been suggested. An explanation in these terms is and will remain unverifiable and entirely useless for prediction. In place of this unverifiable and useless hypothesis the writer had suggested that experimental search might disclose overlapping stimuli whose presence or absence would mark the presence or absence of backward conditioning. This would be to explain backward conditioning in terms of simultaneous conditioning. No act is instantaneous, and in backward conditioning the belated cue may accompany the later part of a sustained mascular contraction. This may be the explanation for the lessening effect of backward conditioning as the interval between cue and original stimulus is increased. In the writer's experiments with backward association2 with human subjects the cue could be practised before or after the original stimulus with like associative strength, and the writer is convinced that backward conditioning occurs only when, and in some measure to the degree that, there are overlapping stimuli.
Concerning remote forward conditioning, or "delayed and 'trace' reflexes," the writer had evidently not made himself clear. Pavlov says,
.. . if we grant with the author that not the bell but the centripetal flow of impulses from the motor act of listening is the true stimulus for the conditioned effect, why does that effect, in the case of delayed reflexes, nevertheless come out, not at once, but after an interval—and (furthermore) in accordance with the length of the interval between the beginning of the stimulus and the beginning of the unconditioned reflex?
For this Pavlov's explanation is two-fold.3
Many cyclic phenomena take place inside the animal's body. . . . The alimentary canal is periodically filled or emptied; and, in fact, changes in practically all the component tissues and organism are capable of influencing the cerebral hemispheres. This continuous cycle of direct and indirect influences upon the nervous activity constitutes the physiological basis for the estimation of the duration of time.
This is his first suggestion. The second is as follows:
Although prolonged for a significant length of time, the conditioned stimulus remains one and the same; but for the central nervous system (and it is especially necessary to think of the cerebral hemispheres) it is distinctly different in different periods of its course. This comes out particularly clearly with olfactory stimuli, which we sense at first very keenly, and then quickly as weaker and weaker, even if they remain objectively constant. Obviously the state of the stimulated cortical cell under the influence of an external stimulus undergoes successive changes and in the case of delayed reflexes only the state of the cell near the time of the addition of the unconditioned reflex acts as a signal for the conditioned stimulus.
The writer had made his suggestion expressly to account for the fact that the delayed reflex was...
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SOURCE: "A Criticism of Pavlov's Concept of Internal Inhibition," in the Psychological Review, Vol. 44, No. 4, July, 1937, pp. 297-312.
[In the following essay, Wenger points out a flaw in Pavlov 's theory of conditioned response concerning the notion of "internal inhibition. "]
The concept of the conditioned response, with or without Pavlovian terminology, has become an important consideration in any contemporary theory of the learning process.12 The major phenomena discovered in the laboratories of Pavlov (18) and Bekhterev (2) have been verified by many other workers. However, Pavlov's interpretations of some of these phenomena have not met with general...
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SOURCE: "Toward A Theory of Conditioning," in the Psychological Review, Vol. 46, No. 5, September, 1939, pp. 425-44.
[In the following essay, Irwin outlines Pavlov's general theory of conditioning, provides a critique, and presents an alternative interpretation of the subject.]
The manner in which the title of this paper is worded—toward a theory—implies a conviction that aside from Pavlov there exists no fully-developed systematic theory of conditioning. There are, however, some experimental data which may be used for the beginnings of a new formulation. A great deal of incidental questioning, if not outright criticism, is current in the literature on the...
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SOURCE: "The Man of Science," in Everybody's Political What's What, Constable and Company Limited, 1944, pp. 200-13.
[In the following excerpt, Shaw considers the absurdity of Pavlov's experiments as they refelct modern scientific practice.]
The department of science with which governments are most concerned is biology, the science of life. It includes physiology and psychology, and is the basis of public health legislation and private medical practice. It has gone far beyond the Churches in its violations of individual liberty and integrity. The Christian Church takes an infant from its mother's arms, sprinkles a few drops of water on it, and dedicates it as a soldier...
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SOURCE: "Stalin and the Uses of Psychology," in World Politics, Vol. VIII, No. 4, July, 1956, pp. 455-83.
[In the following essay, Tucker explores Soviet attempts to use Pavlovian theory in the creation of a policy for the controlled transformation of humanity.]
The influence of ideological conceptions upon the men who make Soviet policy has been frequently and rightly emphasized. Some observers are so deeply impressed by this influence that they tend to regard the Soviet system as a kind of ideocracy. It is undeniable that ideology has been one powerful factor in the shaping of Soviet policies and actions from the time of the October Revolution to the present. But one...
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SOURCE: A review of Experimental Psychology, and Other Essays, in Isis, Vol. 50, No. 162, December, 1959, pp. 514-16.
[In the following review, Hoff investigates the limitations and likely abuses of Pavlovian theory.]
The esteem in which the world of science, and* physiologists in particular, hold Ivan P. Pavlov is equalled only by that exhibited by the public at large. Indeed, he is one of the few physiologists of any age or country whose views have captured the public fancy and entered its everyday thinking; probably Freud alone in this century has had as great an influence. These considerations alone should insure for this volume of the selected works of...
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SOURCE: "Pavlov and Darwin," in Evolution after Darwin, edited by Sol Tax, University of Chicago Press, 1960, pp. 219-38.
[In the following essay, Gantt equates the importance of the scientific discoveries of Pavlov with those of Charles Darwin and surveys Pavlovian and post-Pavlovian research.]
The lives of Pavlov and Darwin overlapped. When Darwin was producing the great work which we now celebrate, Pavlov was a stripling lad of ten years, romping and scuffling with the urchins on the streets of Ryazan in central Russia. They both lived in the great age of the adolescence of science, in the century when science, like a rambunctious youth, felt the cocksureness of the...
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SOURCE: "Pavlov and Freud," in Science & Society, Vol. XXV, No. 2, Spring, 1961, pp. 129-38.
[In the following review of Pavlov and Freud by Harry K. Wells, Bartlett cites Wells's failure to produce a satisfying materialist critique of Freud using Pavlovian theory.]
Wells' Pavlovian Critique of Freud [Sigmund Freud: A Pavlovian Critique, by Harry K. Wells. (Volume II of Pavlov and Freud.) New York: International Publishers, 1960, 252 p.] is based upon a one-sided but commonly-held view of what constitutes philosophic materialism in the field of mental disorder. Thus, it requires an attention out of proportion to its actual merits, for,...
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SOURCE: "Psychology as the Science of Behavior: Ivan Pavlov and John B. Watson," in Pioneers of Psychology, W. W. Norton & Company, 1979, pp. 295-338.
[In the following excerpt, Fancher surveys Pavlov's life, experiments, theories, and influence.]
At the turn of the present century, the Russian physiologist Ivan Petrovitch Pavlov (1849-1936) was on the horns of a dilemma. He had just completed a monumental series of studies on the physiology of digestion that would win him a Nobel Prize, and he was looking for new scientific challenges. Some incidental observations he had made in the course of those studies seemed to point to a new and promising area, but Pavlov...
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SOURCE: "Pavlov's Religious Orientation," in Journal for the Scientific Study of Religion, Vol. 25, Summer, 1986, pp. 320-27.
[In the following essay, Windholz demonstrates that Pavlov, although a professed atheist, advocated the tolerance of religion as part of his theory of higher nervous activity.]
"Religion is the most basic and predictable human instinct" I. P. Pavlov.
In the post World War II era, Soviet anti-religious propaganda supported its position by describing Ivan P. Pavlov as a convinced atheist. As we shall see, in his personal belief, Pavlov was an atheist. But the propagandiste campaign distorted...
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SOURCE: "Pavlov's Physiology Factory," in Isis, Vol. 88, No. 2, June, 1997, pp. 205-46.
[In the following essay, Todes details the work produced in Pavlov's laboratory at the Imperial Institute of Experimental Medicine, analyzing Pavlov's scientific and managerial vision, as well as the forces and relations of production in the lab.]
What is a scientific laboratory? It is a small world, a small corner of reality. And in this small corner man labors with his mind at the task of . . . knowing this reality in order correctly to predict what will happen, .. . to even direct this reality according to his discretion, to command it, if this is within our...
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