The main provisions of the concept of K. Lorenz, The structure...

The main provisions of the concept of K. Lorenz

The structure of the behavioral act

In the process of creating your working hypothesis of behavior K. Lorentz not only relied on his own experimental material, but creatively comprehended and brought in a single system of presentation of his predecessors. His undoubted merit was the clarification and unification of the terminology used to describe the behavior of his predecessors. In addition, he was introduced and a number of currently used terms.

As a unit of instinctive behavior, Lorentz identifies hereditary coordination, or, as he later called them, endogenous movements, i.e. Specific, congenital, patterned motor acts are fixed complexes of actions (Fixed action patterns).

Fixed Action Complexes are species-specific (the same for all individuals of this species), congenital (ie, manifested in finished form, without pre-workout), template (i.e. stereotyped in order and form of execution) motor acts.

To. Lorentz in the basis of his original concept put the division of behavior into two categories: innate (actually instinctive) and acquired (formed due to individual experience, learning). However, he pointed out that such a fragmentation in most cases is conditional. Each sequence of behavioral acts was considered by Lorentz as a complex interaction of instincts and learning.

When studying the formation of behavior, ethologists rely on the idea of ​​ the structure of the behavioral act, proposed back in the early 1920's. American researcher W. Craig and received further development in the works of K. Lorenz.

Behavioral act consists of several consecutive stages. Initially, the animal develops a state of one or another specific motivation (food, sex, etc.) in a certain period. Under its influence, the so-called exploratory behavior, is formed, as a result of which the animal searches for a key stimulus, reaction to which in the form The final act ends this stage of the chain of behavioral actions.

Most often, instinctive behavior is a whole chain of behavioral acts developing according to the scheme of the search phase - the key stimulus is the final act.

Let's consider this situation in more detail on the example of the behavior associated with the reproduction of the usual fly-bird - flycatcher (Figure 5.1). These birds nest in hollows and willingly occupy a variety of artificial bird houses. Flycatchers-gadgets fly in the spring from the place of wintering and after a while start to multiply. The most important factor for the beginning of this behavior is the launch of the process of producing sex hormones, which in turn is regulated through the corresponding structures of the central nervous system, namely through the hypothalamic-pituitary complex. In this complex, by regulation of the hypothalamic nervous structures, the activity of the major endocrine gland of the organism - the pituitary gland, which controls the activity of the gonads - is regulated.

Fig. 5.1. Pied Flycatcher

Increasing the length of daylight and increasing air temperature stimulate the hypothalamic-pituitary complex, which contributes to the beginning of the process of producing sex hormones. When the concentration of sex hormones in the blood of a bird reaches a certain value, it forms the "dominant instinct" in the brain; (according to Ukhtomsky), which triggers the corresponding behavior, which develops in accordance with the scheme of the behavioral act structure.

At its first stage, an animal that has entered a state of specific readiness for some kind of activity (for example,

readiness for reproduction), actively looking for incentives, under the action of which this activity could be carried out. Thus, a male flycatcher-flyer goes in search of a hollow. This hollow can be both natural and artificial - a birdhouse or a houseboat. Finding a hollow, the male flycatcher-mongrel begins to sing about him, demonstrating to other males of his species that this place is occupied. The singing of the male near the hollow attracts a female of the same species, the search behavior of which is directed to the search for a singing male. Lorenz calls this phase of the behavioral act search (or appetitive - from English, appetitive). Search behavior can vary widely , often it is a complex set of reactions and is characterized by "spontaneity", since it manifests itself mainly under the influence of internal stimuli.

For example, a male flycatcher's choice of a nesting territory is sometimes limited to flying to a certain previously used place, and in other cases requires long searches, fighting other males, and in case of defeat, choosing a new site. According to Lorentz, it is the search phase of the behavioral act that belongs to the category of purposeful behavior, since the actions performed are subordinated to a specific goal that can be achieved in different ways.

The search phase is built on an innate basis, which in the course of ontogeny is supplemented by the acquired reactions. Search behavior is a means of individual adaptation of animals to the environment, and this adaptation is infinitely diverse in its forms. The basis for the formation of search behavior in ontogeny is such processes as habituation and learning in all its diverse forms. It is to the search phase of the behavioral act that most of the manifestations of the rational activity of animals are used, when in order to achieve the goal, the animal in the new situation operates with concepts that have been formed before it and the empirical laws captured by it, connecting objects and phenomena of the external world.

In the flycatcher, the role of training can be manifested, for example, in the fact that the sites and places for nests chosen by adult experienced males are usually better than in birds newly involved in reproduction.

The end of this phase occurs when the animal reaches a situation in which the next link of the given chain of reactions can be realized. Thus, the stage of the exploratory behavior of the male flycatcher-moth ends when he finds a suitable hollow. From this moment the second stage of the given link of the behavioral chain of the process of reproduction begins.

This phase of instinctive behavior manifests itself only in response to strictly defined stimuli called key. In this case, the key stimulus for the male flycatcher is the hollow, and for the female - singing near the hollow of the male. Key stimuli promote the development of instinctive reactions in birds in the form of courtship and mating, which are carried out strictly in accordance with the species-specific stereotype. Thus, the entire second stage of the development of instinctive behavior develops according to a specific pattern - a fixed set of actions. This stage is called the final phase. It completes the first link of a complex chain of behavior associated with reproduction.

Mating of birds leads to a change in their hormonal background, which stimulates the beginning of a new instinctive behavioral link. The first - the search stage of this link is the construction of the nest. Each species of birds builds a nest according to a certain pattern and from more or less constant material. Therefore, an experienced naturalist on the found empty nest can almost unmistakably determine the species belonging of his masters. Pied flycatchers, the nest base in a hollow is made of small and soft dry leaves, pine and birch bark films. The inner lining of the nest is built from dry grass and animal hair. The building material for the bird nest is collected in different places. A solid role in this process is played by their previous experience. The material itself can also vary somewhat, so that birds can use and not quite typical materials. So, for example, in the middle of the last century, a large number of nests of fly-fly moths in the Moscow forest park Losiny Ostrov were investigated. It turned out that as a building material for nests located close to the final stop of the tram, birds often used tramway tickets. In the nests, located near the winter New Year's festivities, were found scraps of ribbons serpentine.

The construction of the nest is always completed by the manufacture of the inner lining of the nest. By this time on the abdomen of the female, a so-called spot (a section of hyperemic skin) is formed, which in the future should contribute to a better heating of the eggs in the nest. The nerve endings of the patch mark the central nervous system of the female about the completion of the nest building process. The finished inner lining serves as a key stimulus for the next, final phase - the laying of eggs and their incubation. Egg laying is performed until they fill the bowl of the nest. The nest filled with eggs serves as a signal to the end of laying and the beginning of incubation. It is interesting that if after laying the first egg the nest is filled with other eggs or even with their models, then the female will start hatching, and the egg laying process will be braked. This fact confirms the role of the filled nest as a key stimulus. Nasizhivanie completes the second link in the chain of instinctive acts, which constitute a complex of behavior associated with reproduction.

We traced the development of only the first two stages of this complex. Further, it is possible to identify the links associated with the feeding of chicks in the nest, then with the feeding of slets etc.

H. Tinbergen was offered a summary table showing the influence of various natural factors on canary propagation. This table (Figure 5.2) shows a complete analogy with the development of the instinctive behavior of the flycatcher.

Incentives that control canary propagation (according to N. Tinbergen, 1978)

Fig. 5.2. Incentives that control canary propagation (according to N. Tinbergen, 1978)

Congenital resolution mechanism

So, many instinctive actions are manifested only under the influence of strictly defined key, or sign, stimuli, which animals are recognized already at the first presentation, without any individual experience. These stimuli remove the blocking mechanisms in the nervous system of the male and female and promote the appearance of a corresponding instinctive reaction in the form of a courtship procedure, mating, building a nest, and so on. This mechanism for the removal of the block of Lorentz was called an innate response scheme ( angeborene auslosende Schema).

At the present time, the term innate resolving mechanism (English innate releasing mechanism) is more commonly encountered by English ethologists. To explain the principle of its operation, the analogy with the key and the lock is often used. The sign stimulus is compared with a key that perfectly fits the lock - an innate resolving mechanism that removes inhibition from the centers providing the appropriate reaction.

Thus, the key ones are such stimuli, under the action of which the innate resolving mechanism triggers. They are very diverse in nature and can be addressed to any of the analyzers. Specific substances - sexual attractants, pheromones caught by sexual partners ready for reproduction, act as key stimuli in the sexual behavior of many insects, amphibians and a number of mammals. In many animals and birds, morphological features-features of body color, deer antlers, crests and crests in birds, bright color of the face skin and buttocks of the baboon, etc., serve as key stimuli for sexual behavior. This type of visually perceived key incentive is commonly referred to as ramie release.

The key stimuli for fixed complexes of instinctive actions in animals can be characteristic for each kind of sound stimuli - singing, cries of threat or courtship. A special category of key incentives are species-specific complexes of movements. Examples include marriage demonstrations, threats and obedience postures, welcome rituals, etc. Certain environmental factors may act as key stimuli. So, for example, it is widely known that the stimulus to the breeding of undulating parakeets that breed well in captivity is the appearance of duplics in the cage. In this case, the same hollow is the key stimulus. The key stimuli for the reproduction of certain species of aquarium fishes are the placement of certain shapes of stones, ceramics, plants of a certain type, as well as changes in the water level or its temperature in the aquarium.

A special group of key incentives are those for which a specific type of training is required - imprinting, or imprinting. Unlike conventional forms of learning that occur throughout the life of an animal, this form of acquiring an individual experience is confined to a strictly defined sensitive period of ontogenesis. During this period, the animal fixes, captures an irritant, to which a certain innate reaction will subsequently take place. This phenomenon most fully described, and most importantly - determined its role in the formation of the behavioral act of K. Lorenz.

Final Act

In contrast to the variable in the form of search behavior, the direct realization of the goal facing the animal, the satisfaction of the motivation leading him occurs in the form of species-specific fixed complexes of actions. They are deprived of the acquired elements and can be improved in ontogenesis only by maturing the brain structures responsible for them, but not at the expense of training. Typical examples of such actions are various forms of threatening and sexual behavior. Stressing the fact that reactions of the type of final acts in all representatives of the species (or a larger systematic category) are the same and manifest in young animals without special training, Lorentz called them endogenous movements. It is the reactions of the type of final acts that constitute, according to Lorentz, the instinct in its pure form, as it was defined above. As already indicated, such reactions may be more stable in phylogenesis than many morphological features.

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