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Lecture notes, cheat sheets
Zoopsychology. Instinct (lecture notes)
Directory / Lecture notes, cheat sheets Table of contents (expand) Topic 2. Instinct 2.1. The concept of instinct. Modern ideas about instinct The history of the study of instinctive behavior dates back several centuries, but a clear, unambiguous and universally accepted definition of instinct has not yet been developed. Since the time of Charles Darwin's work, instinctive behavior has been understood as that part of animal behavior that is species-typical and fixed hereditarily. One of the first attempts to give an accurate interpretation of the concept of "instinct" was the definition of the German zoologist G.E. Ziegler ("Instinct", 1914). He singled out five points on which "instinctive" behavior differs from "rational" behavior. instinctive behavior: ▪ hereditarily fixed; ▪ no additional training is required for its development; ▪ is the same for all individuals of a given species, i.e. species-typical; ▪ optimally matches the organization of the animal, its physiology; ▪ optimally adapted to the natural living conditions of animals of a given species, often even associated with cyclical changes in living conditions. This definition of instinct has its drawbacks, for example, it does not take into account the possible variability of instinctive behavior. The famous Russian physiologist I.P. Pavlov (1849-1936, "Conditioned reflexes: a study of the physiological activity of the cerebral cortex", 1925), one of the founders of the reflex theory, proposed to consider the concepts of reflex and instinct identical. In this case, instinctive behavior corresponds to an unconditioned reflex. This idea significantly narrowed the concept of instinct, but it was very convenient for studying the acquired components of behavior, higher nervous activity. Dutch scientist N. Tinbergen (1907-1988) defined instinct as “a hierarchically organized nervous mechanism which responds to certain proposed and permissive impulses (external and internal) with fully coordinated, vital and species-specific movements.” [6] Tinbergen created a hierarchical theory of instinct, which we will get acquainted with later. Soviet physiologist HELL. Slonim gives the following definition: “Instinct is a set of motor acts and complex forms of behavior characteristic of an animal of a given species, arising in response to stimuli from the external and internal environment of the body and occurring against the background of high excitability of the nerve centers associated with the implementation of these acts. This high excitability is the result of certain changes in the nervous and hormonal systems of the body, the result of changes in metabolism." [7] Slonim drew attention to the fact that instincts can appear and disappear during the life of an organism. For example, the instinctive behavior associated with the sucking reflex in young mammals disappears over time, but instincts related to reproduction and nest-building activity appear. HELL. Slonim points to constancy as the main property of instinctive behavior. In his opinion, insignificant individual differences cannot refute this property, but are only fluctuations in its manifestation. Plasticity of instinctive behavior. This question is one of the key ones in animal psychology. To understand an animal's behavioral responses, it is important to determine whether innate behavior is constant or whether it can be modified. Currently, scientists have come to the conclusion that individual instinctive actions are not inherited; only the framework within which the development of instinctive reactions occurs is genetically fixed. The Russian biologist and psychologist made an invaluable contribution to the development of this problem. V.A. Wagner (1849-1934). In the book "Biological Foundations of Comparative Psychology" (1913-1919), he came to the conclusion that instinctive behavior develops under the influence of external influences of the environment, therefore it cannot be invariable. This is a plastic and labile system that develops under the influence of natural selection. Only species-typical frames are stable, which determine the amplitude of the variability of instinct. Subsequently, other scientists continued to develop questions of the variability of instinctive behavior. So, L.A. Orbeli revealed the dependence of the degree of plasticity of animal behavior on maturity. A.N. Promptov pointed out that individual conditioned reflex components acquired during life make instinctive behavior plastic. As mentioned above, Promptov introduced the concept of "species stereotype of behavior", that is, behavioral features typical of a given species. They are formed by a combination of innate species-typical instinctive reactions and conditioned reflexes acquired on their basis in ontogenesis. These representations of A.N. Promptov were illustrated by the observations of E.V. Lukina for nest-building activities (see topic 1.1, p. 16). Promptov's ideas about the combination of innate and acquired components in the behavior of animals are very important for a correct understanding of the problem of instinctive behavior. However, according to these ideas, the instinctive actions themselves are not subject to variations, their variability is ensured only by acquired components. At present, it is believed that instinctive behavior is subject to changes within the limits of the hereditarily fixed norm of response. These limits are species-typical; outside of them, instinctive behavior under normal conditions cannot change. At the same time, in extreme conditions that go beyond the norm of response, an important role is played by the individual experience of the animal. It allows instinctive behavior to change quite a lot. Moreover, in addition to the highly conserved innate mechanisms, there is a variable component of behavior. A.N. Severtsov in his writings gave an analysis of the variability of the instinctive and acquired components of behavior. Severtsov showed that in mammals, adaptation to changes in the external environment is carried out in two ways: through a change in organization, that is, the structure and functions of the body, and through a change in behavior. Changes in the organization allow only slow changes in the environment to be adjusted, because they require a long period of time. Changes in behavior do not require a restructuring and functioning of the animal's body, therefore, they occur at a fairly high speed. Such changes arise due to acquired, individual forms of behavior and allow the animal to adapt to drastic changes in the environment. In this case, the greatest success will be achieved by animals that can quickly develop plastic skills, whose behavior is flexible, and whose mental abilities are quite high. With this, Severtsov connects the progressive development of the brain of vertebrates that occurs in evolution. According to Severtsov, instinctive behavior is not sufficiently changeable; therefore, its significance in evolution is roughly comparable to changes in the structure of the animal's body. Changes in innate behavior can also allow an animal to adjust to slow environmental changes. However, the role of such changes should by no means be underestimated. According to Severtsov, "instincts are species adaptations, useful for the species to the same extent as certain morphological characters, and just as constant." The ability to learn, according to Severtsov, depends on the hereditary height of mental organization. Actions in this case are not instinctively fixed. And in instinctive behavior, both action and the level of mental organization are hereditarily fixed. In other words, instinctive behavior is an innate program of actions that is realized in the course of the accumulation of individual experience. Thus, the instinctive, innate, behavior of animals is determined by a genetically fixed program of actions, which is realized in the course of acquiring individual experience. Instinctive behavior must be sufficiently unchanging and stereotyped, because it concerns vital functions for the animal. If the instinct depended on the conditions in which the development of each member of the species takes place, individual individuals would not be able to benefit from the experience of the species. The slight plasticity of instinctive behavior is designed only for extreme changes in conditions. The ability to survive in all other changing conditions of existence is provided by the acquired components of behavior, learning processes. These processes make it possible to adapt a fairly rigidly fixed innate program of behavior to specific environmental conditions. With all these changes, the hereditary program itself must remain unchanged in order to ensure the performance of vital functions. 2.2. Instinct as the basis for the formation of animal behavior Any behavioral act is a combination of interrelated components: instinct and learning. They cannot determine the behavior of an animal separately from each other. At every moment, one component prevails, but they do not exist in their pure form. Separation of instinct and learning in behavioral responses is rather conditional, therefore, it is often difficult to implement, although each of these components has its own characteristics. Instinctive behavior can be divided into a number of instinctive actions, or instinctive acts, which, in turn, are made up of instinctive movements (separate postures, sounds, etc.). The instinctive component of behavior determines both the very functioning of the animal's organs and the orientation of this functioning in time and space. Thus, not only how these organs will be used, but also when and in what direction are hereditarily fixed. Learning as a plastic component of behavior cannot change the functioning of organs, but it can affect the orientation of their functions. For example, an animal that does not have flexible fingers cannot be trained to hold a glass. It does not have morphological and functional preconditions for this, it can perform only those actions for which its organs are adapted. However, training (i.e., artificial learning) can make an animal use its limbs at a certain time in a certain way. The main thing is that the very method of using the limbs should be natural for this animal. Consequently, learning can influence the orientation of the animal's functions in time and space, but the functions themselves are determined by instinctive movements. Thus, the life process of the organism is based on instinctive reactions, and the elements of learning are completed on their basis. Congenital reactions provide all vital functions, the metabolic process, as well as such important aspects of an animal's life as reproduction and care for offspring. The development of the mental component of animal behavior is necessary in the process of evolution in order to adapt instinctive reactions to environmental conditions, to ensure the adaptation of the animal to these conditions. Hereditary behavioral responses cannot take into account the entire variety of conditions that each member of the species will encounter. In addition, instinctive behavior includes the basic mechanisms for regulating functioning and its orientation in space and time, and the learning process complements this regulation and orientation. 2.3. Internal and external factors. Structure of instinctive behavior Internal factors of instinctive behavior. For a long time it was believed that learning was determined by external factors, and instinctive behavior - exclusively by internal factors, and the nature of these factors was unknown. A search and clarification of the internal factors of instinctive behavior would make it possible to answer the question of what determines the motivation of behavior. Internal factors undoubtedly influence the instinctive behavior of animals. In the middle of the XX century. the American biologist P. Whit conducted experiments with spiders, during which he studied the weaving of the web when various chemicals entered the animal's body. The desired substance was applied in the form of a drop directly onto the web or injected with a syringe into the victim. Each substance stimulated the spider to weave a web of a certain type, while the very reaction of weaving a web is hereditary in a spider. So, caffeine made spiders weave a shapeless web of randomly tangled threads, while the spider experienced a semblance of neurosis. When pervitin entered the body, the spider became very restless and did not weave the entire web. The hydrochloride caused the spider to become numb, and he did not finish the web. And lysergic acid helped increase the focus on weaving, and the spider wove the web very carefully and evenly, while its quality was superior to natural. The internal environment of the body is constant, various regulatory processes are aimed at maintaining the physico-chemical composition of the environment. It is constantly updated, however, all its parameters are maintained at a certain level due to self-regulation, which ensures the flow of all biochemical reactions. The peculiarity of the internal processes of the animal organism is that they often proceed in the form of rhythms. In the 1930s Soviet zoopsychologist V.M. Borovsky put forward the assumption that it is the deviations of these internal rhythms of the body from the norm that are the primary motivation for behavioral reactions. Under certain conditions, the internal coherence of physiological rhythms is disturbed, and the former balance in the new conditions does not ensure the normal functioning of the organism. An internal impulse arises, aimed at restoring internal balance, i.e., a need appears. Instinctive behavior in this case will be aimed at satisfying this need. The most important sources of internal stimuli for instinctive behavior are hormones and receptors. It is known that sex hormones and pituitary hormones stimulate a number of forms of behavior associated with reproduction - fights between males for a female and for territory, guarding the nest, mating games. For internal motivation, rhythmic processes that occur in the central nervous system are of great importance, first of all. The rhythmic activity of its stem part in vertebrates and of the abdominal nerve structures in invertebrates ensures the orientation of behavior in time. It is known that animals have the so-called "biological clock" - autonomous oscillatory processes that regulate all the rhythms of the body's vital activity. The "biological clock" determines the fluctuations in the external activity of animal behavior, all actions that are repeated with a certain cyclicity. They, as it were, lay the foundation for the instinctive behavior of the animal, and environmental factors make their own adjustments to these rhythms. Changes may be associated with the action of various external stimuli (auditory, visual, etc.), and may also depend on the general physiological state of the animal at the moment. Most often, in the behavior of animals, circadian, or diurnal, rhythms are noted, the period of which is equal to the day. It is interesting to note that the activity of an animal is subject to such rhythmic diurnal fluctuations even in conditions of complete isolation from all environmental factors. For example, an animal can be placed in conditions of full round-the-clock illumination and yet observe an alternation of periods of sleep and wakefulness close to natural. In addition, during the day, short-term rhythms can be noted in the behavior of animals. An example is the observations of the German ethologist W. Schleidt on turkeys. He noted that the clucking of a turkey during the day is repeated with a certain rhythm, which persists even when the bird is completely isolated and deaf. In addition to the orientation of the animal's behavior in time, the "biological clock" orients it in space. For example, migratory birds, when orienting by the position of the sun, must at each moment of time correlate its position with the time of day. This happens when they correlate information about the position of the sun with internal circadian rhythms. Internal factors create a state in the body that precedes the manifestation of one or another instinctive reaction. However, the start of this reaction may depend on the external environmental conditions. For example, a certain level of sex hormones and pituitary hormones stimulates various behavioral responses of an animal associated with reproduction, but the production of these hormones is timed to a certain time of the year. If an animal that lives in the temperate zone of the Northern Hemisphere is kept in short daylight conditions with the onset of spring, the activity of the glands will not appear. On the contrary, if in winter the conditions of a gradually increasing day are created for the animal, hormones will begin to be released, and sexual behavior will manifest itself in the winter season. Internal factors ensure the readiness of the body to perform one or another instinctive movement, external stimuli may not be necessary for the manifestation of an instinctive reaction. The German neurophysiologist E. Holst discovered several zones in the brainstem of a chicken. When these zones are affected by a weak electric current, instinctive movements arise corresponding to one or another zone. It was noted that if one and the same zone is affected for a long time, increasing the strength of irritation, one can observe a whole series of instinctive actions that will be performed in the same order as in natural conditions. For example, a chicken performed the movements that are made when a terrestrial predator approaches: it showed slight anxiety, then rose, flapped its wings, screamed, and then took off. At the same time, the irritant (predator) itself was not within its visibility. Thus, under the influence of exclusively internal factors, not only individual instinctive movements, but also entire instinctive actions can manifest themselves. However, one should not forget that under natural conditions instinctive actions are "triggered" by external factors. The approach of a terrestrial predator, which the chicken would see, would lead to the excitation of the corresponding zone of the bird's brain, which was artificially stimulated under the conditions of the experiment. External factors of instinctive behavior. If the task of internal factors of instinctive behavior is primarily to prepare the body to perform a certain behavioral act, then external factors more often play the role of unique activators of this instinctive action. All instinctive actions are blocked by a special system, which is called the "innate trigger". This is a certain set of neurosensory systems that ensure the confinement of behavioral instinctive acts to a situation in which such behavior will be the most biologically adequate, i.e., to the so-called "starting situation". The innate trigger mechanism reacts to certain external stimuli or their combinations; it is characterized by high selectivity. Each stimulus, signal (or their combination) will be specific to a certain instinctive reaction. The innate trigger recognizes them, analyzes them, integrates the information, and unblocks the response. At the same time, the threshold of irritability of the corresponding nerve centers decreases, and they are activated. Intrinsic motivation "finds a way out", and the instinctive reaction is carried out precisely in those conditions and in that situation when it is biologically significant. The Austrian ethologist K. Lorenz (1903-1989) called this mechanism of "unblocking" the instinctive response an innate response scheme. Instinctive action manifests itself in response to its own set of external stimuli. These stimuli are called "key" or "sign". The external signal in this case is correlated with the key, which is ideally suited to the lock (an innate trigger). For example, during the breeding season for male birds, stimuli characteristic of females of the same species will be key, these stimuli will cause instinctive actions in males associated with courtship, mating, etc. The key stimuli can be simple physical or chemical features, their spatial relationships (eg size correlation) or vectors. Carriers of key stimuli can be not only other individuals, but also plants, as well as various objects of inanimate nature. The German ethologist F. Walter noted that in antelope cubs, any vertical object is the key stimulus that determines the choice of a resting place. The key stimulus performs a guiding function here. Sign stimuli are also extremely diverse in nature: they can be visual, acoustic, chemical, etc. For example, in the sexual behavior of many insects, amphibians, and some mammals, chemicals (sex attractants, pheromones) serve as key stimuli. Sound stimuli include a variety of cries, songs specific to a certain type of animal. Visual key stimuli are called "releasers". These include various morphological features (body color features, crests, crests in birds, growths). For example, for mallard females, releasers are "mirrors" on the flight feathers of drakes. There are also specific species-specific sets of movements that can act as sign stimuli (postures of submission, threatening postures, greeting rituals, mating rituals). The animal is able to recognize the key stimulus even at the first presentation. For example, a red spot on a gull's beak elicits a "begging" response in chicks. To explain the principle of operation of this stimulus, the analogy with a key and a lock is often used. There are also tuning key stimuli. Their action is different from sign stimuli. These stimuli lower the irritability threshold of the nerve centers and direct key stimuli. The existence of key stimuli and their role in the development of instinctive reactions have been proven by many observations and experiments. N. Tinbergen studied the food reaction of chicks of herring gulls and thrushes when a parent individual appeared by the method of mock-ups. The natural reaction of a hungry gull chick to its parent is to peck at the red spot on the adult bird's (yellow) beak. Tinbergen used several layouts in his experiments. Only one model exactly repeated the appearance of the head of an adult herring gull. On the rest of the layouts, individual details were excluded, and gradually the layout became less and less like a seagull's head. The last layout was a flat red object with an oblong ledge. However, the reaction of the nestlings to this object was not only not weaker than the reaction to the first model, but even exceeded it. The reaction of the chick to the layout in the form of a thin white stick with transverse dark red stripes became even more intense. From this we can conclude that the key stimuli for the appearance of the "begging" reaction in herring gull chicks are the red color and the oblong shape. In experiments with XNUMX-day-old thrush chicks, flat disks were used as models. If the thrush chicks were offered a circle, they reached for its upper part, where the head of the parent bird was assumed. If a small circle was attached to a large circle, the chicks began to reach for it, and when two small circles of different sizes were attached, the relative size of the circles became decisive. With a large body size, the chicks were drawn to an additional circle of large sizes, with a small one, to a smaller one. Thus, the key irritants in this case are the relative position and relative size of the layout details. Experiments on studying key stimuli in birds were carried out by Russian ornithologists G.L. Skrebitsky and T.I. Bibikova. During the experiments, the relationship of a seagull to its eggs was studied. The researchers moved eggs from one nest to another, replacing them with eggs of other bird species, and other objects of different shapes, sizes, and colors. Seagulls willingly began to “hatch” other people’s eggs, as well as eggs of other birds, differently colored dummies made of different materials (glass, clay, etc.), and foreign objects (balls, potatoes, stones). The birds did not refuse to roll even heavy stone balls into the nest, i.e., this reaction was not determined by the weight of the “egg.” G.L. Skrebitsky wrote: “... seagulls sitting on such objects presented a very original picture, but the spectacle became especially extraordinary when a bird driven from the nest returned to it and, before sitting down, carefully adjusted multi-colored balls, pebbles or potatoes with its beak ". [8] Birds refused to incubate objects that did not have a rounded shape, such as stones with sharp protrusions or cubes. The scientists concluded that the key stimuli for the seagull were the roundness of the object, the absence of protrusions and indentations on it. If a seagull was offered two eggs of different sizes, it began to roll a larger one into the nest. The researchers even observed such a situation when a seagull tried to incubate a wooden model of an egg of such gigantic size that it could hardly climb onto it. In this situation, a super-optimal response takes place. The animal encounters a superstimulus that has superoptimal features of the key stimulus, and begins to react to it more strongly than normal. Thus, the key stimuli are subject to the law of summation: with an increase in the parameters of the stimulus, the instinctive reaction increases proportionally. This phenomenon may explain the increased reaction of herring gull chicks to a stick cross-striped with red stripes. N. Tinbergen drew attention to the quantitative side of the action of sign stimuli when studying the female chasing reaction in male velvet butterflies during the breeding season. Observations have shown that the male takes off not only at the approach of individuals of his own species, but also at the sight of other flying insects, as well as small birds and even leaves falling from trees. The scientist concluded that for marigold in this situation, some visual key stimuli are of paramount importance. Chemical stimuli in this case cannot be symbolic, because the direction of flight of males is in no way connected with the direction of the wind, which means that they are not guided by smells. Tinbergen and his assistants made models of butterflies out of paper and fixed them on a thin line tied to a long fishing rod. Each series of layouts had only one characteristic external feature: color, size, a certain shape. When the rod was twitched, the model butterfly began to move, which evoked a persecution response in the male marigolds. The intensity of the reaction was recorded by observation. The results of the experiment showed that the reaction of pursuit was caused by models of all colors, but the most active males followed black "butterflies" - the reaction to them was even more pronounced than when they saw brown models, which corresponded to the natural color of the marigold female. In this case, one should speak of an increase in the visual stimulus - a dark color. A similar picture was obtained when comparing the intensity of the reaction to the size of the layout. The males were most active in pursuing models larger than the natural size of the female. Such a stimulus as the shape of the object's body turned out to be not so important for marigolds. Males responded to models of all shapes, with long rectangular models being the least effective. However, observations showed that this was due to a violation of the nature of the movement of such "butterflies": it became less "dancing". Tinbergen also drew attention to another feature of the action of key stimuli, which he called the incentive adder. The scientist wrote: "...a weakly attractive white model will cause the same percentage of reactions as a black one if it is shown at a shorter distance than the black one. The effectiveness of the small white model is also noticeably enhanced if it is made to 'dance.' Thus, the insufficient effectiveness of one parameter can be compensated by the increased attractiveness of a completely different parameter... incentives are added up in a kind of “stimulation adder”, which forces the marigold to react accordingly.” [9] In addition, Tinbergen noted that the state of the male determines which stimuli are currently included in this adder. For example, under normal conditions, the males reacted only to the color tone of the layout (dark or light), i.e., the colors themselves were not included in the adder. When feeding on mock-ups painted in bright colors, the males reacted exclusively to blue and yellow models, i.e., color became a sign stimulus. The response to a key stimulus is not always adequate to the situation and may not lead to the desired result. Thus, Tinbergen describes a phenomenon called “misfire.” A misfire in an animal’s behavior occurs when it encounters a “super-stimulus.” An example of such a “failure” is the feeding of a cuckoo chick by songbirds. The key stimuli that cause the parent bird to feed the chick are the chick's large beak and brightly colored throat. Both of these signs in the cuckoo have a “supernormal” expression. Tinbergen writes: “It is quite possible that many songbirds not only feed the cuckoo chick, but also take pleasure in its huge and attractive mouth.” [10] A misfire can also occur in the relationships between representatives of different classes of animals. A case is described when a cardinal bird fed insects to goldfish in a pool for several weeks. The bird reacted to the wide open mouth of the fish, which is a key stimulus for it when feeding the chicks. In conclusion, it should be noted that the instinctive behavior of animals is most often determined not by individual factors, but by their complex. This requires a combination of external and internal factors. Pigeons, for example, feed their chicks by regurgitating "crop milk" rich in proteins. The very process of education in the goiter "milk" is stimulated by the release of the hormone prolactin (internal stimulus). However, the regurgitation reaction is caused not by the filling of the goiter, but by external stimulation from the side of the chick, which, with its weight, presses on the goiter of the parent. In winter, even with a goiter filled with food, the pigeon does not have such a reaction, because there is no external stimulation. Structure of instinctive behavior. Back at the beginning of the 1918th century. American researcher W. Craig (“Attractions and aversions as components of instinct,” XNUMX) showed that any instinctive action consists of separate phases. Craig identified two phases, which were named: the search (preparatory) phase, or appetitive behavior, and the final phase (final act). Craig showed that under natural conditions, animals look for those key stimuli or their combinations (starting situations) that are necessary for the implementation of a certain instinctive reaction. For example, animals are looking for food, individuals of the opposite sex during the breeding season, nesting places, etc. Craig called these search behaviors appetitive, and the state of the animal at that moment appetence. Intermediate stimuli perceived at the search phase of behavior are not a goal for the animal; they are necessary only to lead to the perception of the key stimuli of the final behavior. The final phase of instinctive behavior is the very consumption by the animal of the elements of the environment it needs, it is this phase that is directly instinctive behavior. The final phase is hereditarily determined, species-typical, it contains the biological meaning of all instinctive action. This phase of behavior consists of a small number of movements, always performed in a clear sequence. It is stereotyped, determined by the structure of the body of the animal. In this phase, only minor individual variations in behavior are possible, which are determined genetically. The acquired components of behavior practically do not play a role in the final act, and most often they are completely absent. K. Lorentz called the final acts of behavioral reactions endogenous movements, they are species-typical, hereditary and do not require special training. In contrast to the final act, the search phase is more variable and adaptive in relation to conditions, although it is also typical of the species. It intertwines innate and acquired forms of behavior, the individual experience of the animal. The exploratory activity of the animal is characteristic of search behavior. It is through changes in appetitive behavior that instinctive reactions can be plastic. The preparatory phase is always divided into several stages. Its end comes when the animal reaches a situation in which the next link in this chain of reactions can take place. For example, the choice of a nesting territory by a male sometimes requires only a return to the old, last year's territory, and sometimes it may require a long search and even a fight with other males. According to K. Lorenz, the search phase of a behavioral act should be referred to as goal-directed behavior. At this stage, various actions are performed, but they are all subordinated to a specific goal. The exploratory phase is very important and is for the animal the same vital necessity as the consumption in the final phase. It is appetitive behavior that is a means of individual adaptation of animals to a changing environment. This phase of the behavioral act includes manifestations of the elementary rational activity of animals. To achieve a certain ultimate goal, the animal chooses a path, while it operates with concepts and laws that connect objects and phenomena of the outside world. Craig built the concept of two phases of instinctive behavior on data obtained as a result of studying the feeding behavior of animals. The predator, experiencing a feeling of hunger, begins to look for prey. However, at first he does not have information about her whereabouts and therefore his search activity is still undirected. Soon the predator sees a potential prey, from which comes the first key stimulus, such as size and color details, and its search behavior moves to the next stage, which already has a certain direction. The predator begins to specify the location, the speed of movement of the prey, while focusing on other key incentives. Then the predator pursues the prey or sneaks up on it unnoticed, after which it seizes and kills. If this is necessary, the victim is dragged to another place, where he is cut into pieces. Only after this, the behavior of the animal enters the final phase, which includes the direct consumption of prey. All actions of the animal related to the search, catching and killing of the victim are related to appetitive behavior. All of them have an instinctive basis, but to a large extent depend on the process of individual learning, the experience of the animal and the situation. Each stage of search behavior has its own preparatory and final phases. The end of one stage is a signal for the beginning of the next, and so on. Successive stages often have several degrees of subordination, so a complex structure of animal behavior is formed. For example, search behavior may lead not to the final phase of a behavioral act, but to a combination of stimuli that stimulates the next phase of search behavior. An example is the search behavior of birds during the breeding season. The first step is to select a territory for the nest. When she is found, the next stage of search behavior begins - building a nest, then the next - courting the female, etc. Animal behavior largely consists of cycles, which in turn consist of a series of repeated simple acts. For example, a bird busy building a nest does this according to a certain pattern. First, she goes in search of building material, then, having found it, evaluates its suitability. If the bird is satisfied with the material, it carries it to the nest, otherwise it throws it away and looks for a new one. Having flown to the nest, the bird weaves the brought materials into its structure with certain movements, forms the shape of the nest, and then flies off again in search. This cycle begins spontaneously and continues as long as the bird has a need to complete the nest. Switching to each subsequent stage of the behavioral reaction occurs upon perception of a certain external stimulus. N. Tinbergen gives an example with female hymenoptera insects - philanthus (bee wolves), who feed their larvae with honey bees. The wasp, in order to make supplies, flies to places where bees gather, where it flies randomly until it meets a suitable victim. Having noticed a flying insect, the wasp flies up to it from the leeward side and stops about 70 cm. If after this the wasp catches the scent of a bee, which will be the key stimulus for the transition to the next stage of the behavioral reaction, it will grab the bee. If a bee is deprived of its scent using ether, the wasp will not grab it. The next stage of the wasp's behavior will be to paralyze the victim with a blow from the sting. To begin this stage, a stimulus associated with touching the victim is required. If you present a wasp with a model of a bee that does not look like it to the touch, but has the same smell, the wasp will not sting such a model. Thus, as an animal goes through various stages of a behavioral reaction, the stimuli that are key for it at the moment change. The state of appetence occurs under conditions of very high excitability of the nerve centers that coordinate certain physiological reactions. K. Lorenz introduced the concept of "specific potential (energy) of action". This potential is accumulated under the influence of a number of external (temperature, light) and internal factors (hormones) in the nerve centers. Having exceeded a certain level, the accumulated energy is released, after which the search phase of the behavioral act begins. With an increased accumulation of "specific energy of action", the final act can be carried out spontaneously, that is, in the absence of appropriate stimuli, this is the so-called "idle reaction." To explain the neurophysiological mechanism of these phenomena, Lorentz proposed his own theory. The data of the German physiologist E. Holst served as the basis for this theory. Holst focused his experiments on the rhythmic activity of the central nervous system. He noted that in the isolated abdominal nerve cord of an earthworm, rhythmic discharges of impulses could be observed that exactly corresponded to the contraction of the worm's segments. In further research, Holst studied the swimming mechanism of the eel. It fixed the middle segments of his body and prevented them from contracting. According to the reflex theory, in this case, the posterior segments of the body will not receive irritation, and therefore will also not be able to contract. However, in reality they begin to move after a certain period of time. If the dorsal roots of the eel's spinal cord are cut, thereby disrupting the transmission of sensory information, the eel will retain the ability to swim, and their coordination will not be impaired. Thus, the movements of the eel’s body are performed not according to the mechanism of a reflex arc (depending on external stimuli), but in accordance with the rhythmic discharges of impulses in the central nervous system. Experiments by other scientists have confirmed this. For example, it has been noted that in decerebrate (with the cerebral hemispheres removed) cats, antagonistic leg muscles may contract rhythmically, completely devoid of sensory nerves. Tadpoles and fish with one intact sensory nerve retain the ability to swim and normal coordination of movements. This means that the central nervous system is characterized by endogenous automaticity, which does not depend on external stimuli. In this case, a minimum level of afferent impulses is necessary to maintain excitation (“specific action energy”) in the corresponding nerve centers at a certain level. The works of E. Holst and his colleagues confirmed that the level of excitation in the corresponding nerve centers affects the nature of the course of instinctive reactions. The experiments were carried out on chickens, which were irritated by the current of the brain stem structures. Depending on the localization of the irritated structure, researchers noted elementary behavioral reactions (turning the head, pecking) or complex acts of behavior (courtship). And if simple reactions always proceeded in approximately the same way, regardless of the parameters of irritation and environmental conditions, then complex behavioral reactions depended on these factors. So, with a weak current strength, a rooster pounced on a stuffed ferret, and with an increase in current, even on the researcher's hand (nonspecific stimulus). Hydraulic model of K. Lorenz. Lorenz proposed a hypothetical model for the implementation of instinctive reactions. The scientist borrowed the general principles of its operation from hydraulics, which is why it was called the “hydraulic model.” "Specific energy of action" is represented in this model by water, which gradually fills the reservoir (energy is accumulated) through an open tap, which indicates a continuous flow of potential energy generated during the life of the organism. Water (energy) enters the reservoir (organism) as long as the body feels the need for this form of behavior. The pressure of the liquid inside the tank is constantly increasing, creating a certain voltage in the system. The outflow of water from the tank, indicating the activity of the animal, occurs through pipes, it is prevented by a valve (central braking mechanism). The valve can open in two situations: with a large pressure of water that has accumulated in the tank, or under the influence of the weight of a load suspended from the valve. Load denotes the influence of external stimuli specific to a given behavioral act. Increasing water pressure (accumulation of specific energy of action) and the severity of the load (strength of external stimuli) summarize their effect on the valve. The stronger the stimulus, the less energy is required. And vice versa, the more energy accumulated, the less force of the external stimulus is needed for the realization of the instinctive reaction. If the energy level is very high, the valve may open without external stimulus due to water pressure. This corresponds to the "idle reaction" (according to Lorentz, "reaction in the void"). So, Lorentz described the behavior of a hungry starling, which, in the absence of any stimulus from the external environment, such as an insect, fixes it with a glance and “catches” it in the air. An inclined tray with holes located at different levels indicates different types of animal motor activity during a behavioral act. The lowest hole corresponds to motor activity with the lowest threshold, the remaining holes correspond to forms of activity with a higher threshold. If the valve is only slightly opened, water will flow out in a small amount and enter only the area of the lower hole. If the valve opens more and the intensity of the water flow increases, it will also enter the following holes. When the reservoir is emptied ("specific energy of action" runs out), this behavioral act stops. The Lorenz model well explains the situation when the threshold for performing an action decreases with a long non-performance (water accumulates in the reservoir to such a level that it takes a small load to open the valve), and the possibility of reactions to non-specific stimuli (accumulation of water in the reservoir to such a level, when no weight is needed to open the valve). The hydraulic model has been repeatedly criticized because of the mechanistic construction and sketchiness. The concepts of "specific energy of action" and "key stimuli" in modern zoopsychology correspond to the concept of "specific motivation". Hierarchical theory of instinct by I. Tinbergen. It is noted that stereotypical motor reactions are in a certain relationship. Sometimes instinctive movements appear together, and an increase in the threshold of one of them causes an increase in the threshold of the second. From this we can conclude that both of them depend on one functional “center”. There is some regularity in the sequence of manifestations of actions in complex instinctive reactions. An example would be aggressive fish collisions when dividing territory. In fish of the cichlid family, direct confrontations are preceded by a special display of intimidation. In some species of cichlids, demonstrations are short-lived, and the fish almost immediately proceed to attack. In other cichlids, collisions with wounds occur only when the males are equally strong, and demonstrations are very complex and lengthy. There are also cichlids in which there are no fights at all, and a ritualized ceremony of intimidating the enemy is performed until one of the males is exhausted and retreats. Such rituals are sequential actions, starting with the display of the sides of the body, then the dorsal fins are raised vertically, followed by tail strokes. Opponents can evaluate the strength of such a blow using the side line, which perceives the vibrations of the water. Then the opponents stand in front of each other, and in some species mutual thrusts begin with open mouths, while in others the opponents bite each other in the open mouths. The rituals continue until one opponent gets tired, in this case his color fades and he swims away. All motor reactions during a ritual demonstration are strictly stereotypical and clearly follow one another. Thus, tail strikes cannot begin before the dorsal fin rises, and mutual thrusts occur only after tail strikes. On the basis of such facts, N. Tinbergen developed a hierarchical theory of instinct (a diagram of the organization (hierarchy) of instinct). This concept is based on the idea of a hierarchy of centers that control individual behavioral responses. The concept of "center" in this case is not anatomical, but functional. Tinbergen interprets instinct as a complete hierarchical system of behavioral acts. This system responds to a specific stimulus with a well-coordinated set of actions. In this case, the change in the excitability of the centers under the influence of external and internal influences occurs in a certain order. A “block” is removed from each center, which protects this center from exhaustion. First of all, the excitability of the center of the search phase of behavior increases, and the animal enters the state of searching for stimuli. When the stimulus is found, the center that controls the implementation of the final act "discharges"; this center is at a lower level of the hierarchy. Thus, the main meaning of the scheme is that the block (inhibition) of impulses is removed in the centers in a certain sequence, which stimulates the next stage of the animal's behavior. As an illustration, Tinbergen gives a diagram of the hierarchy of the reproductive instinct centers of the male three-spined stickleback. The higher reproductive center of the stickleback male is activated by an increase in day length, hormonal and other factors. Impulses from the higher center remove the block of appetitive behavior lying near the center. This center discharges, and the male begins to search for suitable conditions for building a nest (corresponding temperature, territory, necessary soil, vegetation, shallow water). After choosing such a territory, inhibition is removed from the subordinate centers, they are discharged, and the construction of the nest itself begins. If another male penetrates the territory of this male, the excitability of the center of aggressive behavior increases (the block is removed from it), and an aggressive reaction begins in relation to the opponent. When the rival is expelled and the female appears, the block is removed from the center of sexual behavior, courtship of the female and mating (the final act) begin. A contribution to the study of the hierarchical organization of instinct was made by the English zoopsychologist of the XNUMXth century. R. Hynd. Using the example of the stereotypical actions of the great tit, he showed that it is not always possible to arrange these actions in the form of a hierarchical scheme. Some actions may be characteristic of several kinds of instincts, and in some cases they will be the final acts, and in others they will only be a means to create conditions in which the final act can occur. The hierarchy of instinctive behavior is finally formed only in an adult animal. In young individuals, isolated motor acts may appear, devoid of meaning at this age, which, at a more mature age, are integrated into a complex functional set of movements. N. Tinbergen's scheme provides for the possibility of interaction between the "centers" of various types of behavior, for example, in a situation where one center suppresses another. Thus, if a male's hunger intensifies while courting females, he interrupts mating demonstrations and begins to search for food. As a special case of the interaction of "centers" Tinbergen considers conflict behavior that arises in a situation of simultaneous tendency to different (often opposite) forms of behavior. At the same time, none of the forms completely suppresses the others, and the incentives for each of them are extremely strong. As an example, the scientist cites observations of male three-spined sticklebacks and different types of gulls. In a situation where one male stickleback invades the territory of another male, the owner of the territory attacks. He pursues a stranger, and he quickly swims away. When the escaping male enters his territory, they will switch roles, now the pursuer will begin to flee. If the clash of males occurs at the border of their territories, both males will have elements of both attack and flight responses in their behavior. The closer the male is to the center of his territory, the stronger the elements of attack will be expressed in his behavior. When moving away from the center of the territory, these elements will be suppressed, and the elements of flight will intensify. In male black-headed gulls, threatening behavior during a collision at the border of territories includes five postures. Each of them expresses a certain degree of internal conflict between opposite feelings: aggressiveness and fear. Sometimes, in such conflict situations, animals exhibit so-called "replacement movements": there occurs, as it were, a shift in the animal's activity. For example, when a starling meets with an opponent, instead of attacking, it begins to intensively sort out its plumage with its beak. When meeting on neutral territory, male herring gulls assume a menacing posture, and then suddenly begin to clean their feathers. A similar reaction can be observed in other birds, for example, white geese in such a situation make movements, as when bathing, gray geese shake themselves off, and roosters peck grass. Activity shift responses are innate. Another type of behavior in a conflict situation is "mosaic behavior". The animal begins to perform several actions at the same time, but does not complete any of them. For example, a seagull rises to its feet in front of an opponent, raises its wings to strike, opens its beak to peck, but freezes in this position and does not move further. The third type of behavior in a conflict situation is "redirected reaction". The animal directs its actions not to the object that causes the reaction, but to another. For example, a thrush, at the sight of an opponent, begins to peck branches furiously. Sometimes an animal addresses the aggression of a weaker individual, for example, a gray goose attacks not its rival, but a young gosling. Variability of the structure of an instinctive behavioral act. The structure of instinctive behavior is extremely complex. The search phase is not always a reaction to searching for any environmental agents; it can also be negative. In this case, the animal avoids certain stimuli and avoids them. In addition, certain stages of search behavior may drop out altogether, in which case this phase is shortened. Sometimes the search phase does not fully manifest itself because the final act comes too quickly. The direction of search behavior may go astray, and then an “alien” final act is possible. In some cases, the search phase takes the form of a termination phase, while the actual termination phase is also retained. Then the actions in both phases look the same, but have qualitatively different motivations. In a number of cases, the final phase is not achieved at all, then the instinctive act does not proceed to completion. In animals with a highly developed psyche, the goal of a behavioral act may be the search for stimuli itself, i.e., the intermediate stages of search behavior (complex exploratory behavior). Instinctive behavior and communication. Communication is physical (biological) and mental (exchange of information) interaction between individuals. Communication is certainly expressed in the coordination of the actions of animals, therefore it is closely related to group behavior. When communicating, animals necessarily have special forms of behavior that perform the functions of transmitting information between individuals. In this case, some animal actions acquire signaling significance. Communication in this understanding is absent in lower invertebrates, and in higher invertebrates it appears only in rudimentary form. It is inherent in all representatives of vertebrate animals to one degree or another. The German ethologist G. Tembrok studied the process of communication in animals and its evolution. According to Tembroke, it is possible to talk about real animal communities in which individuals communicate with each other only when they begin to live together. When living together, several individuals remain independent, but together they carry out homogeneous forms of behavior in different areas. Sometimes such joint activity involves the division of functions between individuals. The basis of communication is communication (information exchange). To do this, animals have a system of species-typical signals that are adequately perceived by all members of the community. This ability to perceive information and to transmit it must be genetically fixed. The actions by which the transmission is carried out and the assimilation of information takes place are hereditarily fixed and instinctive. Forms of communication. According to the mechanism of action, all forms of communication differ in the channels of information transmission. There are optical, acoustic, chemical, tactile and other forms. Among the optical forms of communication, the most important place is occupied by expressive postures and body movements that make up "demonstrative behavior." This behavior consists of showing the animal certain parts of its body, which, as a rule, carry specific signals. These can be brightly colored areas, additional structures such as combs, decorating feathers, etc. At the same time, some parts of the animal's body can visually increase in volume, for example, due to ruffled feathers or hair. The signal function can also be performed by special movements of the body or its individual parts. By performing these movements, the animal can demonstrate colored areas of the body. Sometimes such demonstrations are carried out with exaggerated intensity. In the evolution of behavior, special motor acts appear, which are separated from other forms of behavior by the fact that they have lost their primary function and acquired a purely signal value. An example is the claw movement of a fiddling crab, which it performs when courting a female. Such movements are called "allochthonous". Allochthonous movements are species-typical and stereotypical, their function is the transmission of information. Their other name is ritualized movements. All ritualized movements are conditional. They are very rigidly and clearly fixed genetically, they are typical instinctive movements. It is this conservatism of movements that ensures the correct perception of signals by all individuals, regardless of living conditions. Most often and in the largest number of ritualized movements are observed in the field of reproduction (first of all, these are mating games) and struggle. They transmit information to one individual about the internal state of another individual, about its physical and mental qualities. Instinctive movements and taxis. Taxis are innate, hereditarily determined reactions to certain components of the environment. By their nature, taxis are similar to instinctive movements, but they also have a difference. Instinctive movements always arise in response to key stimuli, while taxises are manifested under the action of directing key stimuli. This special group of stimuli is in itself not capable of causing the beginning or end of any instinctive movement. Directing key stimuli stimulate only a change in the direction of this reaction. Thus the taxises produce a general orientation of instinctive movements. Taxis are closely related to innate motor coordinations and, together with them, constitute instinctive reactions or their chains. In addition to taxis, there are kinesis. With kinesis, there is no orientation of the animal's body relative to the stimulus. In this case, stimuli either cause a change in the speed of movement of the animal, or a change in the frequency of body turns. In this case, the position of the animal relative to the stimulus changes, but the orientation of its body remains the same. With taxises, the body of the animal takes a certain direction. Taxis can be combined with movement, in which case the animal will move towards or away from the stimulus. If the motor activity is directed towards favorable environmental conditions for the animal, the taxis will be positive (the animal's activity is directed towards the stimulus). If, on the contrary, the conditions are not valuable for the animal or are dangerous, taxis will be negative (the animal's activity is directed away from the stimulus). Depending on the nature of external stimuli, taxises are divided into phototaxis (light), chemotaxis (chemical stimuli), thermotaxis (temperature gradients), geotaxis (gravity), rheotaxis (liquid flow), anemotaxis (air flow), hydrotaxis (environmental humidity) and others There are several types of taxis (according to G.S. Frenkel and D.L. Gunn; Fraenkel GS, Gunn DL "The Orientation of Animals", 1940). 1. Clinotaxis. In clinotaxis, for the orientation of the body relative to the stimulus, the ability of the receptor to determine the direction of the source of irritation is not necessary. The animal compares the intensity of stimulation from different angles by simply turning the organs bearing the receptors. An example is the establishment of the trajectory of movement towards the light of a fly larva. The photoreceptors of the larva are located at the front end of the body; when crawling, it deflects its head first to one side, then to the other. Comparison of the intensity of stimuli on both sides determines the direction of her motor reaction. This type of taxis is characteristic of primitive animals that do not have eyes. 2. Tropotaxis. The animal compares two simultaneously acting stimuli. A change in the direction of movement in this case occurs at different intensities of stimulation. An example of tropotaxis is the orientation of aquatic animals when swimming with the dorsal side up. 3. Telotaxis. The animal chooses one of the two sources of irritation and moves towards it. An intermediate direction is never selected. Thus, the influence of one of the stimuli is suppressed. For example, bees from two light sources choose one, to which they move. 4. Menotaxis ("light compass reaction"). The animal is oriented at a certain angle to the direction of the source of irritation. For example, ants, returning to the anthill, are partially guided by the position of the sun. 5. A. Kühn ("Die Orientierung der Tiere im Raum", 1919) distinguishes, in addition, mnemotaxis. In this case, the animal is guided by the configuration of stimuli, their relative position. An example is the orientation of hymenoptera when returning to a burrow. Observations by N. Tinbergen and V. Kruyt showed that philantine wasps (bee wolves), when returning to the burrow, react to the position of the entrance to it relative to the surrounding elements of the terrain. The degree of complexity of taxises and their functions depend on the level of evolutionary development of animals. Taxis are present in all forms of behavior: from the simplest instinctive reactions to complex forms of behavior. For example, when nestlings of songbirds are oriented in relation to the parent, the key stimulus will be the very appearance of the object (adult bird), the guiding key stimulus is the relative position of the object’s parts, and taxis is the spatial orientation of the chicks towards this stimulus. As mentioned above, for the gull chick, the key stimulus is the red color of the beak of an approaching object, which elicits a "begging" feeding response. The guiding key stimulus will be the location of the red spot on the beak, this stimulus will direct the feeding reaction of the chick. The very orientation of the nestling towards the beak of the object will be a positive phototaxis. K. Lorenz and N. Tinbergen carried out joint studies of the relationship between instinctive motor coordination and taxis. They studied the reaction of rolling eggs into the nest in the greylag goose. For this bird, the key stimulus is the sight of a rounded object without protrusions on the surface, which is located outside the nest. This stimulus causes the geese to roll in. This innate reaction is a repeated movement of the beak towards the bird's chest, which will stop after the object being rolled in touches it. If a cylinder was placed in front of the goose, she immediately rolled it into the nest. However, when an egg was presented to her, which rolled in different directions, the female began to make additional lateral movements of the head, which gave the movement of the egg the correct direction to the nest. The guiding stimulus for taxis lateral movements of the head is the type of deviation of the egg. Thus, in higher animals, taxises orient the instinctive movements of both individual parts of the body and organs of the body. Taxis are observed in the animal's behavioral acts both at the stage of the final act and in search behavior. In the search phase, taxises are supplemented by various orienting reactions, thanks to which the body continuously receives information about the parameters and changes in all components of the environment. Authors: Stupina S.B., Filipechev A.O. << Back: Zoopsychology as a science (History of zoopsychology. Subject, tasks, methods and significance of zoopsychology) >> Forward: Behavior. Basic forms of animal behavior
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