The first appearance of the science of higher nervous activity is usually regarded as having taken place with Pavlov’s presentation at the general meeting of the International Medical Congress which was held in Madrid in 1903. The lecture was later published as an article entitled “Experimental psychology and psychopathology in animals” which opened Ivan P. Pavlov’s major book, Twenty years’ experience of objective research of higher nervous activity (behavior) in animals (Pavlov, 1951). The article is usually known as the Madrid speech, and since its publication more than 90 years have passed.
A need arose to estimate the significance of Pavlov’s ideas for psychology. Their great influence on world science during Pavlov’s lifetime is well known. In 1922, Pavlov mentioned with satisfaction that some authoritative scientists in the Soviet Union and abroad followed his research or were close to it (Bekhterov and his colleagues, Kalisher, Thorndike, Yerkes, Watson). Later, the number of authors employing Pavlov’s theory increased immeasurably.
Scientific laboratories emerged in many cities of Europe and in the United States developing various aspects of the theory of higher nervous activity. Many talented Russian scientists, Pavlov’s followers, such as P.K. Anokhin (1975), E. A. Asratyan (1981), L. A. Orbeli (1954), and others became widely known.
Let us try to understand the roots and causes of the gripping force of Pavlov’s theory. Possibly, its strength and influence reflect the fact that it provided a radically new perspective or opened some important objects in the world and thus led to the development of a completely new paradigm in science. For Pavlov the object was the higher level of brain activity coordinated with behavioral and psychological phenomena. In the Madrid speech this is expressed in the very first words, when he informs the audience that he will speak about the history of a physiologist’s conversion to the sphere of phenomena usually treated as psychological ones (Pavlov, 1951, p. 13). Some pages later he explained:
“A new unlimited area of fruitful research has been opened to us. It is the enormous part of physiology of the nervous system — the nervous system that mainly establishes coordination not between the parts of the organism (that was mainly our concern until now), but between the organism and its environment” (Pavlov, 1951, p. 16).
This view, together with specific practical techniques, many experimental facts, and theoretical hypotheses, formed a special science — the science of higher nervous activity that influenced deeply general science, psychology, physiology, and medicine.
The requirements for objectivity and causality are a distinguishing feature of Pavlov’s approach. In this he presents himself as a strict follower of I. M. Sechenov, a scholar whose views were shared by Pavlov. In his Madrid speech Pavlov wrote, “Our new object is subject to a fully objective analysis” (Pavlov, 1951, p.21), and stressed further that “Objective research of a living substance that was originated in the theory of tropisms of elementary living beings can and must be preserved when it comes to the highest appearances of an animal organism, so-called psychological phenomena of highest animals” (Pavlov, 1951, p.22).
In his other publications Pavlov consistently refers to this idea, speaking of the necessity “of purely physiological, purely materialistic, purely spatial explanation” (Pavlov, 1951, p.266). He regards causality as a “supreme principle even in the extreme area of the living nature”, the highest level of brain activity (Pavlov, 1951, p.437).
Pavlov’s determinism was quite consistent: he considered the “psyche” as characteristics that cannot be included as a chain into physiological processes. This position was progressive not only at this time, but preserves its significance nowadays, for there are conceptions which consider the “psyche” as the highest level controlling brain processes.
Pavlov developed a special program for psychological research. One can see a kind of paradox in his view regarding psychological investigations. On the one hand, he demanded purely objective and physiological analyses of psychological phenomena — this explains why he penalized his colleagues for using psychological terminology in explaining experimental data. On the other hand, he did not at all deny the reality of the subjective world. Pavlov repeatedly stressed its significance for a person (“our most important concern is our consciousness, the tortures of our consciousness”; Pavlov, 1951, p.23). Pavlov even supposed that the possibility for human beings to achieve happiness comes through conceiving the inner world.
However, the paradox turns out to be quite superficial. Already in his Madrid speech Pavlov proclaimed the connections between physiological and psychological phenomena, the transfer of objective data to our subjective world. He suggested a criterion for such a transfer, “the similarity or identity of overt appearances” (Pavlov, 1951, p.23). Later Pavlov developed this idea and suggested “a comparison between physiological and psychological data,” putting a “psychological pattern on the physiological canvas,” and also “the fusion of subjective and objective data” (Pavlov, 1951).
These were treated as a sign of Pavlov’s parallelistic approach, because only separate processes can be superimposed one on another. But there is only a verbal misunderstanding: Pavlov never spoke of superimposing a psychological process on the physiological one, but of putting together the descriptions of psychological and physiological data into a complex knowledge. In modern science Pavlovian suggestions still seem to be very timely, and they have much in common with the holistic system-oriented research into psychophysiological objects.
In Pavlov’s laboratory some examples of such complex approaches may be found. Several forms of brain activity were described in coordination with psychological phenomena:
- Temporary connection as a basis for psychological associations;
- The classical conditioned reflex as a characteristic form of a behavioral response of an animal to a signal;
- The instrumental conditioned reflex as an elementary volitional act;
- Generalization as a mechanism by which objects are internalized in consciousness;
- Differentiation as a mechanism of subjective discrimination of impression;
- Dynamic stereotypes as a basis of habits and emotions;
- Properties of the nervous system and their combinations as the basis of individual behavior; and
- The second signal system as a mechanism of verbal and intellectual actions.
These and other phenomena were not equally highly developed in the Pavlovian school. Some of them are grounded by many experimental facts, others are only sketched as general ideas, such as the conceptualization of the second signal system. This means that the theory is open for further development, but does not mean that the experimental data are dubious. On the contrary, the data described by Pavlov are highly authentic and reproducible.
Pavlov’s theory shows its proximity to the substantial problem of psychological science. This is the reason why it was accepted with enthusiasm by many psychologists. In the textbook written in 1929 by K.N. Kornilov (Director of the Psychological Institute in Moscow at the time) Pavlov’s theory was regarded as the most important basis for the development of psychology (Kornilov, 1929).
A very well-known Soviet scientist, P.P. Blonsky (1921), analyzed psychological phenomena from the Pavlovian point of view. Connections between psychology and physiology in the form of the theory of higher nervous activity were stressed by the prominent Russian scientist P.P. Lazarev (1922) .
The application of Pavlovian ideas to psychology was systematically developed by the school of B.M. Teplov (1961) and V.D. Nebylitsyn (1972). The main idea being developed by them was that the fundamental properties of the nervous system are the basic psychophysiological features underlying individual forms of behavior. Many researchers from the Teplov-Nebylitsyn school have included in their own investigations issues related to the physiological essence of nervous system properties, the principle of their organization, the problem of temperament, the integral individuality.
Great importance was attached to research into the psychological appearance of nervous system properties. The bottom-up approach represented by Teplov consisted of moving from physiology of higher nervous activity to psychology. So, nowadays the successors to the Teplov-Nebylitsyn school are engaged into the investigation of many psychological issues from a physiological stand-point, such as memory and abilities (Golubeva, 1980), emotionality (Olshannikva, 1996), cognitive abilities (Izyumova, 1996), professional selection (Gurevich, 1970), the genetic basis of individual differences (Ravich-Shcherbo, 1978), activity and self-regulation (Krupnov, 1996; Leites, 1972), integral individuality (Bazylevich, 1996), capacity for work (Rozhdestvenskaya, 1979), and other issues.
The concept of dynamic temporary connections as developed by E.I. Boiko (1976) is of great significance for psychology. This concept is based on the idea of regular and lawful modifications of temporary connections set up between signals and response activities of the organism. According to Boiko, there is a universal physiological mechanism inherent in the human brain which consists of interactions of previously established connections. Such interactions result in regular changes in the internal structures of the interactive connections which immediately spring up in new functional structures. This is the mechanism of the so-called dynamic temporal connections. From Boiko’s point of view, the flexible, dynamic connections form the physiological act and present a very characteristic peculiarity of humans. Boiko supported his theoretical views experimentally, inventing a special method which allows the investigation of neurodynamics in the course of several mental processes going on in a person (the so-called method of testing stimulus). Boiko’s approach was developed experimentally and theoretically by his students and has been extended to the areas of verbal mechanisms (Ushakova, 1979) and perception (Chuprikova, 1969).
A valuable contribution to Pavlovian psychology was research on the mechanisms underlying perception as developed by E.N. Sokolov (1958). Sokolov conducted a wide range of experiments in which he demonstrated that the process of perception should be regarded as an activity of complex systems of reflexes: adaptive ones, connected with the specific paths of excitation; orienting ones of tonic and phasing types, involving the mechanisms of nonspecific activation; and defensive ones, including activity of both adaptive and defensive systems. It was shown that the mechanism of perception is not restricted to the conduction of afferent impulses to the projective cortical zones. An impulse arouses a complicated reflex process involving many reciprocal reactions.
Pavlov’s concept of temporary connections was substantially developed by M.N. Livanov (1972), who had revealed the processes of temporary and topological organization of periodic brain processes underlying associations. According to Livanov’s data it was possible to estimate the type and tension of mental activity using toposcopic pictures of electrical brain activity (Livanov, 1982). This line of research has been continued by A.N. Lebedev and his coworkers. They have shown that some characteristics of periodical brain processes can serve as parameters of equations used to quantitatively describe the peculiarity of some psychological processes: choice reaction time, the extent of short-term memory, retrieval speed, the speed of visual search, and others. So, one of Pavlov’s ideas — to find quantitative correlations between physiological and psychological phenomena — has been realized by Russian scientists (Lebedev, 1993).
In addition to the research mentioned above, which is generally regarded as the most important, there are many other studies in which Pavlovian theory has been applied to psychological issues.
In parallel with the wide recognition of Pavlov’s contribution and his powerful influence on world science, there is a persistent criticism regarding his theory. One of the serious critical arguments points out that contemporary neurophysiological data on brain activity do not confirm the “mechanistic” ideas of Pavlov. In particular, when recording neuronal activity during a behavioral act of an animal one does not see any movement of excitation from the afferent structures of the brain to the efferent ones. Experimental data show that the cortical and subcortical neurons are acting in a substantially more complicated regime, subject to the organizational rules of the system involved in the behavioral act. As V.B. Shvyrkov wrote, “the physiological mechanisms of stimulus analysis and the mechanisms of action shaping are utilized simultaneously in the course of developing the indivisible system processes for the whole organism” (Shvyrkov, 1978, p.187).
From our point of view, research in which an animal’s neuronal activity is correlated with its behavior presents a valuable aspect of physiological investigation. At the same time, this research is at a relatively early stage of its development. For this very reason, final conclusions regarding the general rules of neuronal mass activity in a behavioral act are a little bit premature.
However, we must admit that contemporary research shows that there were some gaps in Pavlov’s conception of the spatial architecture of the conditioned reflex. But certainly the whole theory cannot be discredited. Pavlov developed his theory when electrophysiology did not yet exist. It would have been a miracle if he had guessed the peculiarities of neuronal activity which are sometimes so surprising even for contemporary experts.
Another point of Pavlovian theory that is subject to criticism is the evaluation of the conditioned reflex as the central phenomenon of higher nervous activity in animals and humans. The question arises: Is it reasonable to assign to this phenomenon universality, to consider it as a basis of all forms of behavioral and psychological phenomena? In spite of the fact that some authors stress the wide character of the conditioned reflex, its multiformity (Asratyan, 1981, p.355), one can understand the disagreement regarding the universality postulate. In this connection it is necessary to remind oneself that Pavlov himself did not consider the conditioned reflex to be a universal phenomenon of higher nervous activity. Specifically, by suggesting the concept of second signal system, which he characterized as an “extraordinary addition,” he introduced a new principle into the activity of the nervous system. Similarly, Pavlov did not regard behavior of animals that is guided by causality as only a reflex phenomenon: an example he mentions is the behavior of a monkey extinguishing a fire by using water.
In general, the question regarding the role of conditioned reflexes in behavior is not a question of taste, but of facts. Having found behavioral phenomena which do not correspond to the reflex characteristics, scientists naturally directed their search towards new ideas and mechanisms.
This is exactly what P.K. Anokhin (1975) did when developing his theory of functional systems aimed at explaining goal-directed behavior. The same idea was inherent in the conceptualization of dynamic temporary connections to explain the mechanisms of human creativity (Boiko, 1976). It is quite natural that the science of higher nervous activity should develop further. Developments must take place in several directions, and one of them is the search for brain mechanisms which naturally, not by force, explain different forms of behavior and “psyche.” Pavlov’s theory, which has developed to cover vast areas, can allow this kind of expansion. The opening up of a new area is the major part of Pavlov’s indisputable historical service to science.