From Big Medical Encyclopedia

DEFENSIVE REACTIONS (synonym reactions of protection) — a complex of the behavioural reactions which are expressed in the form of the separate or combined manifestations of signs of reactions of aggression (rage, anger) and avoiding (fear), directed to preservation of an individual and look in the conditions of action of adverse environmental factors.

The motor reactions (to run away — to attack) specific to manifestation of rage and fear and options of their combined manifestation, reflect biol, O.'s importance of river as policy stroke in reactions of adaptation when manifestations only of aggression or only avoiding give way to the mixed compromise option, the most flexible and reasonable in these conditions. From this point of view of idea of I. P. Pavlov of passive and active defensive reactions reflect one of attempts to emphasize a different ratio of aversivny (izbegatelny) and aggressive tendencies of an animal depending on its individual properties and features of a reinforcement.

Reactions of rage and fear can be considered as the emotional reactions oriented by hl. obr. on control of an external situation, and, therefore, represent the certain standardized ways of response to the most typical situations of the environment.

Fear reactions as phylogenetic ancient forms of adaptive behavior are directed to self-preservation by active avoiding of real or potentially dangerous factor (a predator, toxic agent etc.), and at impossibility to avoid — by the passive adaptation (reaction of dying down, imaginary death, a pose of passive subordination, etc.) allowing to reduce or prevent action of harmful factors. Reaction of aggression — phylogenetic later form of adaptive behavior — is directed to rapprochement with an object for the purpose of achievement of certain benefits by fight against it or for demonstrative actions, for establishment of the hierarchical relations in community etc. Reactions of aggression and fear accompany different forms of behavior — food, sexual, maternal, etc. At nek-ry types manifestation of aggression is optional (e.g., at rodents in lack of the competition because of food), but at predators it becomes necessary means of survival and joins as a necessary link in pshtsedoby-vatelny behavior.

O.'s manifestation by the river is defined by numerous external and internal factors. At animals with dominance rather rigid, inborn, programs of behavior of O. of river can be caused so-called key, or starting, by irritants (a silhouette of a bird of prey for a chicken, shout of caution and alarm, etc.). At children (and at young animals) the river in the form of fear is shown by O. on any new and rather strong irritant, including on jumps in activity of internals.

At mature animals the possibility of manifestation of O. of river in the form of aggression raises at increase in animal numbers in population, at starvation, sexual excitement, i.e. in the presence of any expressed biol, requirements or conditions of a stress. The person O. has a river in the form of unmotivated irritability and the causeless conflicts can be caused by poverty of impressions, monotony and monotony of work, long stay in small collective. Therefore completing of groups for long stay in conditions of relative isolation is usually carried out with the obligatory accounting of psychological compatibility in the conditions of deficit of touch information.

At early stages of ontogenesis of O. of river at the person and animals have character of specialized stereotypic reflexes like otdergivaniye, otryakhivaniye, vyplevyvaniye bitter and, therefore, potentially toxic agents. Aged — 8 months at the child are developed rather resistant stereotypes connected with the procedure of feeding, taste of food, the mode, etc. Therefore the withdrawal pains of the established stereotype, napr, during the room in a day nursery (garden), can cause reaction of a protest, or frustration (failure from new food, negative attitude to the new person). As M. Ya. Studenikin, Yu. A. Makarenko showed, H. N. Burmistrova (1979), an emotional stress at children in connection with receipt in new collective and restriction of contacts with mother is followed by essential changes of metabolism, nonspecific protective mechanisms of thermal control and is one of the factors reducing resistance to infections.

The central mechanisms participating in simple stereotypic O.' implementation by the river (otdergivany extremities, otryakhivany, etc.), are located at the level of back and a myelencephalon. Purposeful O. of river form in the course of training and are carried out with the participation of a neocortex and frontal lobes. Experiments with selective switching off of certain structures of a brain allowed to reveal nek-ry funkts, distinctions between them. So, destruction of ventromedialny kernels of a hypothalamus strengthens the manifestation of a phobotaxis and change of behavior reminding running wild; damage of a zone crinkle and medial departments of a thalamus slows down reaction of active avoiding, strengthening passive forms O. of river like dying down.

The question of availability of biologically active agents (hormones, mediators, peptides) which are selectively changing O. to river finally is not solved. At the same time the essential role of M - and N-cholinergic structures of a brain in origins of O. of river is shown. An impression about a role of monoaminoyergichesky structures of a brain in O.'s integration by the river was gained by a new explanation: it is revealed that at introduction of a number of neurotropic means to a brain along with the general increase in activity the animal has strengthening of aggressive tendencies. On the other hand, many tranquilizers promote reduction of fear and alarm, practically without changing thresholds of reaction of aggression and most stimulation.

The nature of manifestation of O. of river is znachichitelno modified under the influence of hormones. In particular, at animals strengthening of aggressive tendencies at increase in level of androgens at males and prolactin at females is observed. Hormones of a thyroid gland increase aggression at animal both floors. The actions of AKTG and steroid hormones of bark of adrenal glands given about mechanisms are less clear. Introduction by sick AKTG or a cortisone in the therapeutic purposes causes unpredictable changes of mood; assume that the nature of emotional reactions at the same time depends on a reference emotional state. G. Selje is the author of the concept about the general adaptation syndrome as nonspecific reaction of an organism to a stress factor — put forward idea of katataksichesky and syntactic hormones, to-rye it considers respectively as fabric analeptics and tranquilizers, and conditionally allocated active, offensive (katatoksichesky) and passive, conciliatory (syntactic), options of behavior, recommending the last as more preferable to preservation of health.

O.'s disturbances by the river, having various origin, hl are shown. obr. in selective strengthening or weakening of alarm and fear or aggression. Children of early age in the conditions of a touch deprivation and deficit of social communication can have peculiar defense reactions in the form of the persistent aspiration to suck fingers, rhythmic movements of the head and trunk. Children of more advanced age have ways of protection against excessive guardianship of parents or strict requirements of teachers can be shown by negativism and a number of addictions (biting of nails, wrest of hair, tics, etc.). In some cases at children, and also the expressed fear reaction causes a mosaic of the symptoms inherent in emotionally unripe subjects phylogenetic to ancient forms of protection — a motive storm or an emotsiogenny stupor, catalepsy — i.e. reactions like «animal hypnosis». At the adult of reaction of the expressed fear are followed by decrease in perceptual, mnemonic and other mental functions (e.g., reduction in the rate of processing of information, reduction of capacity of touch channels) that finally complicates adoption of the adequate decision. To the contrary, emotions of active sthenic type, aspiration to self-affirmation, so-called sports rage, etc., as a rule, increase efficiency of different types of activity.

It is necessary to emphasize that unlike aggressive reactions of fear reaction and alarm hardly give in to an ugasheniye and quite often act as an obligatory symptom at nek-ry forkhma of psychosomatic pathology. Fear, e.g., arising as natural reaction to sudden change in activity of internals (an attack of bronchial asthma, arrhythmia, etc.), is fixed further in memory and can provoke approach of somatic frustration on the mechanism of a vicious circle.

Various O. of river (attacks of displeasure, unmotivated fear, malignancy, rage or even aggression) can be symptoms of organic lesion of separate structures of a brain, in particular amigdaloidny area (see).

The form and frequency of manifestation of O. of river characterize behavior of the individual. The sociological analysis of relationship in small groups showed that the leader in microcollective, as a rule, possesses an initiative, activity and self-checking. In animal community the most aggressive and physically strong male becomes the leader.

Quantitative assessment of O. of river is used at certain types of the prof. of selection for the characteristic of behavior in the nek-ry critical situations demanding active and adequate actions (activity of the pilot, dispatcher, builder-spiderman, etc.). Such prof. selection is made by means of the complex of methods including questionnaires, psychological tests, a number of the special receptions imitating falling, accidents and also researches on special exercise machines.

Pilot studies of O. of river on animals are conducted by creation of conflict situations, by means of nociceptive stimulation or stimulation of protective belts of a brain. Reaction of aggression, e.g., can be reproduced by introduction of high doses of Phenaminum or caffeine, and also the ways imitating nek-ry natural situations (the test of the open field, the test for «social domination», etc.) - About - are widely used by R-at ethological methods of observation, in particular during the studying of the hierarchical organization in population of animals etc.

Bibliography: Anokhin P. K. Biology and neurophysiology of a conditioned reflex, M., 1968; Berezin F. B., Miroshnikov M. P. and Ugly face N of e of c of R. V. Metodik of a multilateral research of the personality, M., 1976; Wald-man A. W., Kozlovskaya M. M. and Medvedev O. S. Pharmacological regulation of an emotional stress, M., 1979; To about cm about molts y F. P. An emotional stress during the work in extreme conditions, M., 1976; Makarenko Yu. A. System organization of an affective behavior, M., 1980; Milner P. Physiological psychology, the lane with English, M., 1973; With t at d e-nikin M. Ya., M and to and r e of N to about Yu. A. and Burmistrov H. H. Adaptation of children to conditions of the environment, Vestn. USSR Academy of Medical Sciences, No. 10, page 20, 1979; Ecological human physiology, Adaptation of the person to extreme conditions of preschool institution and a medical hospital, under the editorship of O. G. Gazenko, etc., page 625, M., 1979; Experimental psychology, under the editorship of P. Fress and. Piaget, the lane with fr., century 3, M., 1975.

Yu. A. Makarenko.