Individual differences associated with the features of the functional asymmetry of the brain, as well as with the properties of temperament, are one of the factors that determine the specificity and strength of emotional experience. The dimensions of temperament most closely associated with emotions include anxiety, strength — weakness of arousal processes, extraversion — introversion, impulsiveness, emotionality.
Extroverts have a lower threshold for positive social stimuli and therefore respond more frequently with emotions of joy and interest. They are more sensitive to reward, while introverts are more sensitive to punishment. Measurement of local blood flow in the brain in introverts, in contrast to extroverts, revealed an increase in blood flow in the temporal regions. This difference is explained by stronger connections of the cortex of introverts with the limbic system (amygdala) — the structure responsible for fear reactions. It is known that destruction of the amygdala or temporal cortex reduces emotional reactions of fear and stimulates orienting-exploratory behavior, which is normally suppressed by defensive reactions.
Persons with high personal anxiety prefer to respond more often even to neutral stimuli with anxiety, anxiety, and fear. Increased anxiety of the subject correlates with high heart rate and suppression of vascular and respiratory rhythmic modulations of the RR interval in the heart rate, i.e. with a vegetative pattern indicating the predominance of sympathetic regulation, usually observed during stress (Danilova N.N. et al., 1995).
The existence of a genetic predisposition to social fear, in particular, manifested in the fear of the audience, is shown. J. Kagan (Kagan J., 1989), focusing on behavioral characteristics, distinguishes inhibited and disinhibited types of temperament. Children with a disinhibited type of behavior are distinguished by stable sociability, talkativeness, and spontaneously arising emotions. Children with inhibited temperament are shy, shy, and quiet. They are distinguished low threshold for fear of novelty in the social environment. The stability of the complex of these behavioral characteristics in one study was traced up to the age of 21 months, in another up to 7,5 years. Severely inhibited children showed a higher blood level of cortisol, the hormone of stress and negative emotional reactions, compared to normal children. Higher than normal levels of cortisol persisted even during sleep.
The study of infants’ reactions to pain and social isolation revealed stable individual differences in the severity of negative emotions — pain, anger, sadness. Individual features of emotional reactions persisted throughout the entire observation period up to 4 months of age.
Based on the study of the behavior of monkeys, the researchers concluded that the degree of readiness of the animal to respond with fear to external stimuli is genetically programmed. Animals vary activation thresholds of the fear system. Laboratory animals, unlike their wild relatives, do not show fear at the sight of a snake, but quickly learn to react with fear when looking at other monkeys. But among them there are monkeys who cannot be taught to be frightened at the sight of a snake.
Emotional communication largely depends on the individual ability to transmit and receive emotional signals of the interlocutor through facial expressions, posture, gestures, intonation of speech, i.e. from individual manifestations of the mechanism of encoding and decoding emotions. P. Salavey and J. Mayer (Salovey R., Mayer JD, 1990) in their socially oriented concept of the emotional mind (emotional intelligence) insist on the need to highlight individual differences that are manifested in the totality of such properties as the ability for emotional expression, emotional perception and empathy. The importance of these qualities of mind for business communication is reflected in the rule followed by many managers — to hire on the basis of intelligence quotient (IQ), and to promote in position on the emotional quotient (EQ), which characterizes the ability of a person to communicate emotionally.
The most successful attempt to integrate numerous facts testifying to the influence of different personality traits on the emotional sphere of a person was made by P.V. Simonov in his concepts about the system of four brain structures (Simonov P.V., Ershov P.M., 1984). According to this theory, the individual characteristics of the interaction frontal cortex, hippocampus, hypothalamus and amygdala form the basis not only for the types identified by Hippocrates — Pavlov, but also for the properties of extraversion / introversion and neuroticism — the main dimensions of temperament in the concept of G. Eysenck and his followers. The system of four structures also explains the individual preference to respond more often to a certain emotion (Fig. 43).
According to P.V. Simonov, the predominance of the functions of the frontal cortex and hypothalamus in the subject will determine the frequent actualization of needs and purposeful behavior aimed at its satisfaction. In this case, the subject will ignore everything that distracts him from the intended goal. These behaviors are characteristic of choleric temperament — strong and excitable type, according to I.P. Pavlov. The interests of the choleric are constant, stable, and he is stubborn in achieving the goal.
The functional predominance of the hippocampus-amygdala system means that it is ready to respond to a wide range of signals, including those of little significance. If it is difficult to single out the dominant motive (the amygdala), the behavior of such a subject is characterized by indecision, endless fluctuations with its increased sensitivity to stimuli and a tendency to overestimate the importance of events. This characteristic matches the description melancholic — weak type, according to I.P. Pavlov.
The predominance of the hypothalamic-hippocampal system creates a combination of dominant need with generalized responses to signals of unlikely events and unknown destination. This picture is in line with the typical sanguine — strong, balanced, mobile type.
The dominance of the amygdala-frontal cortex system determines well-balanced needs without much emphasis on one of them. A subject with similar properties ignores many events and reacts only to highly significant signals. This behavior is typical for phlegmatic — strong, balanced and inert type.
In the four structure model, their relationship to extraversion and introversion is described as follows. The predominance of the functions of information structures — the frontal cortex and the hippocampus — determines the subject’s primary orientation to the external environment and its dependence on the events taking place in it. Such features are characteristic of extrovert. The predominance of motivational systems — the hypothalamus and the amygdala — creates introvert with its stability of internal motives, attitudes and their low dependence on external influences. An introvert is unsociable, shy, strives for order.
Thus, according to the concept of four structures, each type of nervous system is associated with a certain group of emotions. According to this model, the behavior of a choleric person is purposeful to satisfy a stable dominant need. It has the features of overcoming, fighting, so the dominant emotions are anger, rage, aggressiveness. The behavior of the melancholic is characterized by indecision and tends to be defensive. Emotions of fear, uncertainty, confusion are the most typical for him. More often than others, positive emotions are experienced by a sanguine person (a strong, mobile type). He is distinguished by curiosity, openness, interest in events. The phlegmatic also gravitates toward positive emotions, since his inner world is well arranged, his needs are balanced, and his control system is developed.
Behavioral changes that occur as a result of simultaneous damage to the anterior cortex and hippocampus coincide with an increase in introversion subject. The destruction of the frontal cortex and part of the nuclei of the hypothalamus is comparable to a shift from emotional stability to neuroticism.
Researchers are increasingly identifying features of the functioning of the modulating system of the brain as a natural determinant of individuality. Measurements of personality based on the modulatory system of the brain are based on the assumption that there are more or less stable individual differences in the level of activation (arousal). Some individuals are constantly in a state of high activated™, while others are characterized by a constantly low level of activation. This led to the allocation of such a concept as an individual level of activation. It is usually understood as the level of non-specific activation and functional state that is most often observed in this particular individual during wakefulness.
In the works of M. Zuckerman, the individual level of activation was studied as a person’s tendency to seek or avoid new, complex and intense experiences, as well as the desire for physical and social risk. This trend is called sensation seeking (SS). M. Zuckerman emphasizes that SS contains something related to the property activated, which manifests itself in response to stimuli of moderate and high intensity. To measure the individual need for stimulation and activity, M. Zuckerman developed a special questionnaire that allows you to assess the tendency to «search for sensations». The fifth version of the M. Zuckerman test includes a general scale and four subscales that are part of the general scale: 4 subscales were identified based on factor analysis. Among them:
- Factor TAS (Thrill and Adventure Seeking) — the search for nervous excitement and adventurous adventures — reflects a person’s desire for dangerous sports, various types of physical activity with a risk to life;
- Factor ES (Experience Seeking) — the desire for a variety of experiences that are associated with travel, music, art, communication with friends;
- Factor DIS (Disinhibition) — disinhibition, characterizing the search for social and hedonic stimulation through parties, through sexual diversity, alcohol consumption, participation in games;
- Factor BS (Boredom Susceptibility) — sensitivity to boredom — reflects individual instability to monotonous and stereotyped situations and people, as well as impatience when such situations cannot be avoided;
- Factor G (General) — represents the total score for 4 factors (subscales), or the Sensation Seeking Scale as a whole (Sensation Seeking Scale — SSS).
In a number of studies, SS indicators were studied simultaneously with various components of the orientation reflex in the form of measuring skin resistance and heart rate (HR). The most interesting results have been obtained with respect to heart rate, which makes it possible to differentiate the orienting reflex from the defensive reflex. With the orienting reflex, a decrease in heart rate is observed immediately after the stimulus for several seconds, while the appearance of a defensive reflex is expressed in a short-term phasic increase in heart rate. It was found that individuals with a low level of SS respond to a high-intensity sound with the appearance of defensive reactions in the form of a phasic increase in heart rate. Subjects with a high level of SS respond to the same sound intensity by an indicative type — a short-term decrease in heart rate. Evidence has been obtained that various SS factors are differently associated with orienting and defensive reflexes. The general (general) factor G and the TAS factor correlate with the orienting response to novelty, while the DIS factor is differently associated with orienting and defensive responses to intense stimulation.
According to M. Zuckerman, the individual level of SS has its own biochemical mechanisms. The SS value negatively correlates with the content of the enzyme monoamine oxidase (MAO) in the brain, as well as endorphins (endogenous morph-like peptides) and the level of sex hormones.
Individuals with a high SSS score have a low level of MAO, while subjects with a weak desire to seek sensations and experiences have a high level of MAO in neurons.
Similar results were obtained in monkeys. Individuals with a high content of MAO spend more time alone, while monkeys with a low content of MAO are more socially active, more often show aggressive, sexual and playful behavior.
The neuronal enzyme MAO is found in the mitochondria of neurons. The primary function of MAO is the suppression of neurotransmitters: norepinephrine, dopamine, serotonin inside the neuron. If the content of MAO in neurons for some reason turns out to be reduced, this is combined with a decrease in the biochemical control of the level of neurotransmitters. As a result, the level of catecholamines (NA, DA) and serotonin in the brain increases. Substances that reduce the content of MAO are often used in the clinic as a remedy for depression, which is associated with a deficiency of catecholamines and serotonin.
To substantiate the proposition about the existence of relatively stable individual differences in the level of activation, J. Gray (1964) introduced the concept activation (arousability). In individuals who are highly activated, the stimulus causes a higher level of activation (arousal) in the nervous system than in subjects with low activation.
The property of activation, according to E.A. Golubeva (1993) and her collaborators, can be measured using a range of bioelectric parameters. One of the main indicators of high individual activation is the appearance of high harmonics in the assimilation reaction when low-frequency light flickers are used.
J. Strelay (Strelay J., 1994) considers the property of activation as a common component of many dimensions of temperament, which are distinguished from the positions of various concepts of temperament. These include the properties of extraversion — introversion, neuroticism — stability, emotionality, the strength of excitation processes, reactivity, anxiety, impulsivity, amplification — reduction, inhibition — disinhibition and a tendency to approach — failure. J. Strelyau analyzes these qualities according to their relation to a high or low level of activation, according to their connection with the property of activation.
According to J. Strelyau, introverts, neurotics, highly emotional individuals who avoid searching for additional sensations, with a weak nervous system, highly reactive and highly anxious subjects, low-impulsive, “amplifiers” (augmentors), according to A. Petri (Petrie A.) have the property of high activation , reducers, according to M. Buchsbaum (Buchsbaum MS), with inhibited temperament and a tendency to refuse interaction. Persons with similar temperamental traits are more likely to experience negative emotions, anxiety, and fear.
Individuals with opposite properties of temperament, measured according to the scales discussed above, are characterized by low activation, and, accordingly, their emotions are distinguished by a positive hedonic tone.
The concept of activation is associated with individual differences, determined by the natural ratio of the orienting and defensive reflexes. The sign and characteristics of the individual’s emotional experiences depend on the balance of these two reflexes.
There are reciprocal relationships between these reflexes. This is manifested primarily in the opposite changes in their vegetative components. For the first time, the opposite type of connection between the orienting and defensive reflexes and heart rate was described by F. Graham (Gracham FK, 1979). The phasic orienting reflex is represented by a decrease in heart rate for several seconds after the stimulus that caused it. During the defensive reflex, the heart rate increases. The vessels of the head also react in the opposite way: they narrow during the defensive reflex and expand during the indicative one (Sokolov E.N., 1958). With the advent of the orienting reflex, the defensive reflex is suppressed.
A strong stimulus, applied for the first time, usually causes not a defensive, but an orienting reaction, consisting, as indicated above, in the expansion of the vessels of the head and the narrowing of the vessels of the finger. However, if this strong stimulus is repeated several times, the orienting reaction is replaced by a defensive one, and the stimulus begins to evoke a defensive reaction, a concomitant constriction of the vessels of the arm and head, and this reaction does not fade for a long time upon repetition. The defensive reflex can be inhibited by a new unusual stimulus. So, if electrical stimulation causes a friendly constriction of the vessels of the arm and head (defensive reaction), a new stimulus — a call — causes a typical orienting reaction. If, after the call, the previous electrocutaneous stimulation is applied, then the vessels react not according to the defensive, but according to the indicative type. As the painful stimulus is repeated, a return to the defensive reaction is again observed.
The reciprocal relations of the two reflexes are also manifested in the inhibition of defensive behavior by exploratory behavior. In classical experiments, N.Yu. Vaytonis (see: Sokolov E.N., 1958), rats overcame a wire under current, trying to explore the space lying behind it. B. Siegfried et al. (Siegfried B. et al.) showed that moving rats to a new environment for them leads to analgesia, measured by an increase in the threshold of pain reaction to a thermal stimulus.
The relationship between orienting and defensive reflexes was investigated as the relationship between focused attention and emotions. In adult subjects, it was found that a person’s self-report of the ability to control their attention is associated reciprocally with negative emotions.
M. Posner and colleagues (Posner ML, Rothbart MK, Thomas-Thrapp L., 1997) studied in infants aged 3-4 to 6 months. the ability to slow down attention, block the state of distress. Distress was created with strong light and loud sounds. Then the child was presented with various interesting objects (visual and auditory). The distraction of attention to them was accompanied by an interruption of the negative emotional state, which, however, was restored again with the removal of the object or with getting used to it. The authors found that the very fact of removing the object of attention is not the cause of distress, which is restored only if it was previously present.
S. Maltzman (S. Maltzman) comes to the conclusion that the absolute and relative novelty of the stimulus activates the pituitary-adrenal system. One of the components of the orientation response to novelty is the activation of beta-endorphins (one of the endogenous morphines produced in the central nervous system of vertebrates and exerting an analgesic effect by binding to opiate receptors).
The connection of the orientation reflex with the release of endorphins explains the reinforcing function of the orientation reflex. Consideration of the release of neuropeptides as one of the components of the orienting response opens a new page in the study of those positive emotional reactions that are associated with orienting-exploratory behavior.
In the experiments of R. Butler and G. Harlow (Butler RA, Harlow HF) (see: Sokolov E.N., 1958), the possibility of developing subtle sound differentiations using an orienting reaction as a reinforcement was convincingly shown. A positive reinforcement of the monkey’s correct reaction to sound was the opportunity to open the window and observe what was happening in the laboratory. The inclusion of endorphins in the system of components that form the orienting reaction makes it possible to explain the desire for novelty, which manifests itself in the active search for new stimuli. Finding a new stimulus, leading to the release of endorphins, forms a link in the «self-reinforcement» of the orienting reaction.
The orienting response includes a number of components: eye movement, alpha rhythm depression, slowing of the heart rate, vascular changes, galvanic skin response, and finally the release of endorphins. At the same time, the magnitude of these reactions and the rate of their extinction are different in different individuals. It can be assumed that, depending on the degree of participation of the endorphin component, the positive reinforcing effect of novelty may be different. Weak individual reactivity of the endorphin component reduces the self-reinforcing effect of orientation and research activities.
It seems that an important parameter that determines a positive attitude towards the educational process and creativity is precisely the endorphin component of the orienting reflex, which inhibits negative emotions.
The existence of various types of activation and associated emotional subjective experiences caused by orienting and defensive reflexes is consistent with the idea of heterogeneity of the brain modulating system. Identification of several modulation subsystems makes it possible to link the orienting reflex with the functions of brain information systems. The defensive reflex expresses mainly the activation of the limbic system of the brain. In the passive form of the defensive reflex, the amygdala makes the main contribution to the reaction. At the same time, anxiety and fear become dominant emotions. The active form of the defensive reflex is manifested in the emotion of anger, aggression, which, according to the model of «four structures» P.V. Simonov, is determined by the functions of the frontal cortex and hypothalamus.