Why did we decide to start talking about sleep? Most health problems:

1. overweight

2. metabolic disorder

3. disruption internal organs

4. infectious and inflammatory processes

5. problems with the musculoskeletal system

Our body decides when it rests, and the main rest occurs at night during sleep.

Good, healthy sleep has a primary impact on our health, since it is at night that the body’s tissues are restored. During the day, we only give the body an impulse to move towards health and better well-being. If a person does not have healthy and sufficient sleep, this threatens the future serious problems with health. The effectiveness of our daytime wellness treatments also directly depends on the kind of sleep we have.

Every person spends a third of his life in sleep, which is accompanied by a lack of consciousness and the presence of dreams. The ancient sages spoke correctly about sleep. For example, Hippocrates wrote the following about sleep:

“Whoever has a correct understanding of the signs that appear in sleep will find that they have great power for every thing. Indeed, the soul, while it serves the waking body, is divided between several occupations and does not belong to itself, but gives a certain shares its activity with each activity of the body: hearing, seeing, touching, walking, all bodily activities; thus, the mind does not belong to itself, but when the body is at rest, the soul, moving and running through the parts of the body, controls its own dwelling and performs all bodily activities. Indeed, the sleeping body does not feel, but the soul is awake, cognizes, sees what is seen, hears what is heard, walks, touches, grieves, ponders. Thus, whoever knows how to judge this sensibly, we know more. part of wisdom..."

Sleep is a vital need for the body, more important than food. A person can go without food for about two months, but he cannot live without sleep for more than two weeks.

Physiology of sleep

According to modern research, sleep is a diffuse inhibition of the cerebral cortex that occurs as cells spend their bioenergetic potential during wakefulness. Increased heat production resulting from daily activities leads to heating of all body tissues, and heat causes active tissue destruction.

Partially destroyed tissues, especially nerve cells, cannot fully perform their own functions, and therefore they need a period of relative rest and a decrease in temperature (which is observed in sleep) to restore structures and accumulate energy. In addition, a person’s field form during sleep can leave the physical body and travel in the surrounding space, but at the same time it is glued to the body with the help of a “silver thread”.

Sleep is a functional state of the brain and the entire body of humans and animals. During sleep, the central nervous system operates in a certain mode, the activity of internal organs at night also differs from daytime characteristics, while the active interaction of the body with the environment is inhibited and conscious mental activity is incompletely stopped (in humans).

Features of the functioning of the body in different phases of sleep

During different phases and stages of sleep, significant changes occur in the activity of the brain and the whole organism as a whole. Studies of the activity of individual neurons during FMS (slow-wave sleep) have shown that the average frequency of impulses in most brain structures decreases, although in some of them, which actively ensure the onset and progression of sleep, it increases compared to the waking state.

During REM sleep, the activity of neurons in most parts of the brain increases, reaching the level of wakefulness or even exceeding it. The excitability of neurons also changes and in the FMS, compared to wakefulness, it decreases and decreases even more in the FBS.

Despite the general decrease in motor activity during sleep, various movements are observed - from small ones (in the form of twitching of the muscles of the face, torso and limbs that occur when falling asleep and become more frequent during the period of FBS). To more massive ones (in the form of a change in position in bed) observed in all stages of sleep and often preceding a change in stages.

Cerebral blood flow in the FMS does not change significantly compared to wakefulness, but only increases in some structures. In FBS it increases significantly, exceeding that of quiet wakefulness, and at the same time the brain temperature rises. These data, as well as the characteristics of neural activity, indicate high functional activity of the brain during sleep.

When falling asleep and the first stage, the FMS actually decreases arterial pressure, the heart rate decreases and breathing becomes less frequent. In deeper stages of FMS, the heart rate and breathing rate increase slightly, which may occur for compensation and is necessary to maintain an optimal level of systemic blood flow and pulmonary ventilation due to a decrease in blood pressure and a decrease in the depth of breathing.

In the FBS, the performance of the cardiovascular and respiratory systems increases sharply. At the same time, along with an increase in blood pressure, heart rate and respiration, their greater dynamism is noted, manifesting noticeable arrhythmias of the pulse and respiration.

A dream similar to the one that occurs in humans occurs only in higher vertebrates - birds, mammals. In humans and many animals, there is a daily periodicity of sleep and wakefulness - the so-called circadian rhythm.

In addition to normal sleep, a distinction is also made between narcotic sleep - caused by the administration of various sleeping pills, hypnotic sleep - caused by suggestion, and pathological sleep - associated with disruption of the functioning of certain parts of the brain.

Dreams. As a rule, in dreams a person sees the same things that he sees during the day, but in other, sometimes unusual combinations. Dreams are explained by the fact that during sleep, not the entire cortex is inhibited - some of its areas continue to remain excited and create certain sensations. Dreams last a short time, most of the sleep is dreamless.

Theory and nature of sleep

The most common theories of the origin of sleep.

1. Chemical theory of sleep - explains the development of sleep by the accumulation of specific substances in the body.

2. The theory of sleep centers - connects sleep with periodic changes in the activity of the subcortical centers of sleep and wakefulness.

3. Cortical theory of sleep, according to which sleep occurs as a result of irradiation along the cortex of an inhibitory process that can descend to subcortical formations. This theory was most fully developed by I.P. Pavlov and his students.

It is assumed that during sleep, the brain processes information received during the day, redistributes it to the appropriate memory registers and fixes a memory trace. It has been proven that the latter process occurs during brain activation during REM sleep.

There are a number of theories explaining the occurrence of sleep and its functional significance. There is no single generally accepted concept on this issue yet. In particular, the information concept of sleep suggests that its function is to process information received during the waking state, unload the brain from excess, unnecessary information, and include its biologically important part in memory mechanisms.

Close to this concept is a psychological concept that considers sleep as a state during which psychological processing of an individual’s experience occurs, the emotional sphere is stabilized and psychological protection is provided.

There is an anabolic theory of sleep, which considers sleep as a restorative process during which the energy reserves of the brain and the body as a whole are restored. This is consistent with the data obtained on the occurrence of biochemical processes during sleep (protein synthesis and a number of others). A theory has been put forward that considers sleep as one of the types of instinctive behavior of animals and humans.

The sleep of humans and animals is organized cyclically. In humans, the duration of one cycle is 1.5–2 hours (3–5 cycles are observed per night). Each cycle consists of separate stages of FMS and FBS. The first appearance of FBS occurs 1 – 1.5 hours after falling asleep, following the FMS stage. Delta sleep is typical for the first two sleep cycles, while the duration of FBS is maximum during 3–4 cycles (usually in the early morning hours). On average, in a young and middle-aged person, FMS accounts for 75–80% of the duration of total sleep. FBS occupies, respectively, 20–25% of sleep duration. These values ​​differ significantly from similar indicators in newborn children, as well as in old and senile age.

In parallel with the characteristic EEG changes, such changes are observed.

1. Galvanic skin response changes.

2. Electrocutaneous resistance changes.

3. Sweating and skin temperature change.

4. The activity of the endocrine system changes.

5. The activity of hormone secretion changes.

Mental activity in individual stages and phases of sleep also has its own specifics. The drowsiness stage is characterized by peculiar visual images. When people awaken from deeper stages of FMS, it is often possible to receive reports of thought-like mental activity, sometimes of vague visual images that do not have the brightness and emotionality that is characteristic of typical dreams arising in FMS.

Despite the fact that there is an assumption about the presence of sleep centers in the brain, this hypothesis has not been confirmed. There are a number of brain formations known, the active activity of which ensures the occurrence and progression of sleep as a physiological process.

Obviously, it is still more correct to consider the functional state of sleep comprehensively. In the process of evolution, the simple function of sleep (ensuring rest), as it is at the lower stages of development of living organisms, becomes many times more complicated, ensuring the regulation of all functions of the body, aimed at its most effective interaction with the environment in the waking state.

Throughout life, a person's sleep patterns change. For example, in old age and old age there is a reduction in the duration of night sleep, the period of falling asleep is extended, and a person wakes up more often at night.

The reason for changes in the organization of sleep in a person in old age is biological and social factors affecting his physical and mental state.

NREM and REM phases of human sleep

There are 2 phases of sleep - slow-wave sleep (FMS) and rapid eye movement sleep (REM), sometimes the REM sleep phase is called paradoxical sleep. These names are due to the characteristic features of the rhythm of electroencephalography during sleep. Slow activity is observed in the FMS and faster activity in the FBS.

Physiology of non-REM sleep

With slow-wave sleep, there is a decrease in breathing rate and heart rate, muscle relaxation and slow eye movement. As slow-wave sleep deepens, the total number of movements of a sleeping person becomes minimal. At this time it is difficult to wake him up. When awakening during slow-wave sleep, a person usually does not remember dreams.

During slow sleep, the field uniform floats above human body not far away, so the physical body is motionless and calm, but waking a person is much easier than during REM sleep.

From a physiological point of view, during the slow-wave sleep phase, the physical body is restored (that is, minor repairs of internal organs). In the slow-wave sleep phase, the brain analyzes signals coming from internal organs, and based on these signals, the processes of healing the body are launched.

FMS (phase of slow-wave sleep) is divided into 4 stages with differing bioelectrical characteristics and awakening thresholds, which are objective indicators of sleep depth.

First stage(drowsiness) is characterized by the absence of an alpha rhythm on the EEG, which is a characteristic sign of human wakefulness. During this phase, slow eye movement is observed.

Second stage(slow sleep) is characterized by the rhythm of “sleep spindles” with a frequency of 13–16 per second. At the same time, the amplitude of the background EEG rhythm increases, while its frequency decreases compared to the first stage.

For third stage The appearance of slow rhythms in the delta range on the EEG is characteristic. At the same time, “sleep spindles” continue to appear quite often.

Fourth stage(behaviourally the deepest sleep) is characterized on the EEG by a high-amplitude slow delta rhythm. The third and fourth stages of FMS constitute the so-called delta sleep.

Physiology of REM sleep

During REM sleep, on the contrary, physiological functions are activated: breathing and heart rate quicken, the sleeper’s motor activity increases, the movement of the eyeballs becomes fast - this indicates that the sleeper is dreaming. If you wake him up 10 - 15 minutes after the end of rapid eye movements, he will talk about the dream he had.

During REM sleep, a person’s field form “travels” and all its activities through the silver umbilical cord are reflected in the movements of the physical body. It is because of this that the human body is much more relaxed than during slow-wave sleep and it is much more difficult to wake him up (for the reason that the field form needs time to return back from its journey).

But, despite the relatively greater activity of physiological functions in REM sleep compared to slow sleep, the muscles of the body are more relaxed during this period, and it can be much more difficult to wake up a sleeping person. If a person is artificially deprived of REM sleep (woke up during the period of rapid eye movements), then, despite the sufficient total duration of sleep, after 5 - 7 days he will develop mental disorders.

According to most modern experts, in the REM sleep phase the brain processes information received during the day, that is, this sleep phase is necessary for the evolution and adaptation of a person to changing conditions environment. For example, everyone knows that Dmitry Mendeleev dreamed of the periodic system of chemical elements - so this extremely important event for the world of science occurred during the REM sleep phase. Everyone knows the recommendation of psychologists - “sleep with a problem” - this recommendation is also given with the expectation that in the REM sleep phase, the brain, based on an analysis of the available facts, will find solutions to the problem facing a person.

FBS (phase of rapid eye movement sleep) is distinguished by low-amplitude EEG rhythms, and in the frequency range by the presence of both slow and higher-frequency rhythms (alpha and beta rhythms). Characteristic signs of this phase of sleep are the so-called sawtooth discharges with a frequency of 4–6 per second, rapid eye movements, as well as a decrease in the amplitude of the electromyogram or a complete drop in the tone of the muscles of the diaphragm of the mouth and neck muscles.

Natural factors affecting human sleep

It has been found that intense physical and mental activity in the evening increases the duration of delta sleep, and prolonged physical inactivity causes sleep disturbances up to severe insomnia. Emotions have a great influence on the regulation of sleep, which, depending on the body’s individual reaction to them, can disrupt night’s sleep or cause changes in its structure.

Significant changes in sleep are associated with a sharp change in time zones and the daily cycle of lighting. With a rapid change of time zones in the first day, the connection between the wakefulness-sleep cycle and the circadian rhythm may be disrupted. The internal structure of sleep also changes. The first stage is shortened, the number of transitions from a deeper stage to a more superficial one decreases, and the relative duration of delta sleep increases.

Subjective and objective changes in the sleep structure of residents of mid-latitudes under unusual conditions of the polar night and polar day were noted.

The state of the Earth's magnetosphere also has a certain influence on the course of sleep. During magnetic storms Certain sleep disorders may occur.

1. A person spends a third of his life sleeping.

2. The longest period of wakefulness lasted 18 days 21 hours and 40 minutes. The record was recorded at a competition for sitting in a rocking chair. The winner paid for his achievement with hallucinations, speech and vision disorders, and memory loss.

3. The birth of a child takes 400 - 750 hours of sleep from parents.

4. 12% of people only dream in black and white. Others dream in color.

5. There are several groups of dreams that everyone sees without exception: situations at school or at work, an attempt to escape persecution, a fall from a height, the death of a person, teeth falling out, flying, failing exams, accidents.

6. 8 hours is the optimal time for sleep for a middle-aged person. Children and teenagers need 10 hours of sleep daily, and older people need about 6 hours.

7. Every second adult on Earth experiences one or more symptoms of a sleep disorder, and 13% of disorders are chronic.

8. 20% of car accidents occur due to fatigue and lack of sleep of drivers.

9. People who are blind after birth can see dreams in the form of pictures.

10. People who are blind from birth do not see pictures, but their dreams are filled with sounds, smells and tactile sensations.

11. 90% of dreams are forgotten within 10 minutes after waking up.

12. Somniphobia is a disease in which a person is afraid to sleep.

13. A person does not dream when he snores.

14. 40,000,000 prescriptions for sleeping pills are issued per year in the United States.

15. Over the past 100 years, people have begun to sleep 20% less.

Having the necessary theoretical knowledge, you can properly organize your night's rest. You can read about this Sleep Rules

Additional articles with useful information

Basic rules for healthy sleep

Sleep is an intimate and highly individual process. Many people have their own ritual of falling asleep and waking up, and there is nothing wrong with that. It is much worse when a person regularly violates the physiological laws of sleep, thereby causing great harm to his health.

Features of sleep in children

Parents need to know that the child’s body lives according to its own laws, which are not typical for adults. A child’s sleep is significantly different from an adult’s.

One of necessary conditions Normal human activity is sleep. Its role in maintaining and strengthening health, performance, and mental well-being has been known since ancient times.

Sleep is a physiological state that periodically replaces wakefulness and is characterized by the absence of conscious mental activity and a significant decrease in reactions to external stimuli.

Sleep is one of the main states of the body, in which a person spends up to one third of his life. Sleep deprivation causes deterioration of memory, attention, decrease in the level of functionality of the body, anxiety and depression, and even mental disorders.

There are two functions of sleep:

The first is restoration of the functional state of the body. During sleep, muscles relax, breathing slows down, and the activity of the cardiovascular system decreases. At the same time, the functioning of almost all parts of the brain decreases to a minimum, body temperature drops, that is, all the vital processes of the body occur at a reduced level. A state of complete rest ensues.

The second function of sleep is the active activity of the brain in processing information accumulated during the day. The information received is analyzed, the necessary part of it is stored in long-term memory, while the other, which has no value, is “erased” from the brain.

For many people, sleep is one of the most effective means combating nervous overload. The famous American scientist, father of modern cybernetics Norbert Wiener wrote that The best way to get rid of severe anxiety or mental confusion - sleep on them.

In 1953, American scientists E. Azerinsky and N. Kleitman discovered the phenomenon of “rapid eye movement” sleep and marked the beginning of a new era in the study of sleep and the brain in general.

It has been established that sleep is not a homogeneous state of the brain and body, but consists of at least two qualitatively different components - “slow” and “fast” sleep. When falling asleep, a person first falls into slow-wave (orthodox) dreamless sleep. It is characterized by a qualitative change in the electrical activity of the brain and a decrease in the intensity of certain processes: changes in muscle tone, slowing of breathing and pulse, and lack of eye movement. This type of sleep is divided into four stages, differing in the electrical activity of the brain and the depth of sleep:

Stage 1 is the stage of falling asleep, or drowsiness;

Stage 2 - superficial sleep;

Stages 3 - 4 - delta - sleep, characterized by the depth of the corresponding processes.

When waking up from slow-wave sleep, a person usually notices the absence of dreams.

REM (paradoxical) sleep is sleep with dreams. It is characterized by increased cerebral blood flow, heart rate and respiration. At different periods of its duration, rapid movements of the eyeballs with closed eyelids and muscle twitching occur. The awakening threshold in REM sleep ranges from very high to low. The feeling of rest in the morning, after waking up, depends on its quality. Healthy people experience dreams during this phase of sleep.

The structure of night sleep as a whole is determined by the ratio of alternating sleep phases. All sleep consists of 4-5 cycles, the duration of which in healthy people is approximately the same, relatively stable and amounts to 30-100 minutes. NREM sleep, which is deepest in the first half of the night, lasts about 45-90 minutes. The stages of REM sleep during this period are relatively short. Closer to the morning, orthodox sleep becomes shorter and more superficial, and paradoxical sleep becomes longer.

NREM sleep usually occupies 75-80% of the total duration of the night cycle, REM sleep - 20-25%. Deviations in the duration of the phases of rapid and slow sleep, especially delta sleep, and constant lack of sleep negatively affect a person’s health, his ability to work and his emotional state.

The usual amount of sleep is from 5 to 10 hours. This is an individual characteristic of sleep, which directly depends on the character of a person, his temperament, age, gender and lifestyle.

There is evidence that short sleepers are energetic people who actively overcome life’s difficulties and are not inclined to fixate on unpleasant experiences, while long sleepers are very sensitive to troubles and are prone to short-term anxious and depressive reactions. Scientists suggest that increasing the duration of sleep allows these people to remain within the boundaries of the mental norm.

The quality of sleep is significantly affected by the ratio of mental and physical activity during the day. A sedentary lifestyle interferes with normal sleep, and physical activity and slight muscle fatigue contribute to falling asleep quickly and restful deep sleep. The emotional intensity of the day is also of great importance, any changes in which can cause disruption.

One of the most complex manifestations of brain activity during sleep is dreams. The brighter and more imaginative the dreams, the more complete the sleep. Scientists believe that in the slow-wave sleep phase, information processing occurs, and in the fast sleep phase, mental activity and protection from external irritations occur.

The total duration of dreams is 1.5-2 hours. At the beginning of the night the dreams are shorter, towards the end they are longer. Sometimes I dream about the same plot intermittently. Moreover, its duration often coincides with the duration of the event that makes up the plot. Vivid dynamic dreams are accompanied by rapid eye movements performed in both the horizontal and vertical planes.

Every person sees several dreams per night. To remember them, the time of awakening is important. Waking up immediately after the REM sleep phase, almost everyone remembers the content of the dream plot well; after a few minutes, fewer people remember it; after 5-10 minutes, as a rule, no one manages to remember the dream.

The nature of dreams is related to profession, gender and age. They usually intertwine fantastic pictures and memories of childhood, the distant past and the present. There are many known cases when music, poetry were created at night while sleeping, new ideas were born, the solution of which a person worked on.

It is assumed that in dreams conflict situations are “resolved” in a unique way, and the less active a person is, the more dreams he has. Dreams can be the first harbingers of developing diseases.

The most common sleep disorders include hypersomnia (drowsiness) and insomnia (insomnia). Drowsiness is observed in people who have suffered severe infectious diseases (influenza, meningitis, etc.), with anemia and functional disorders of the nervous system. Insomnia is expressed in shallow, restless sleep with frequent and early awakenings, and a difficult process of falling asleep. Its causes may be a forced violation of the sleep pattern (night work, late classes), an unusual place to sleep, an excited psycho-emotional state, or high physical activity. Insomnia can be caused by insufficient muscle activity, age, sudden changes in the circadian rhythm introduced by electric lighting, and information overload. Insomnia is the primary symptom of incipient somatic and mental diseases: neuroses, psychoses, organic diseases of the brain, diseases of the internal organs and the endocrine system.

Sleepwalking (somnambulism, or sleepwalking) is also one of the sleep disorders. Most often it affects children with an unbalanced nervous system. With age, these phenomena subside and the medical prognosis, as a rule, is favorable. In some cases, treatment is required. A person in a somnambulistic state is well oriented in the surrounding environment, extracts from long-term memory memories of actions known to him, information about objects. You can get an answer from him and get orders fulfilled. Memories of the action taken in the morning are completely absent, since the transition from short-term to long-term memory was blocked. Any case of sleep disturbance requires a thorough examination and consultation with a doctor.

Russian New University

Faculty of Psychology and Pedagogy

Course work

Topic: Psychophysiological basis of sleep

and dreams

Completed:

student Silantiev V.L.

Course 3 Weekend group Scientific supervisor:

D. ped. Science Denisenko S.N.

Moscow 2006

Introduction………………………………………………………………………………….……..3

Chapter 1. Physiological basis of sleep……………………………….…….5

1.1 Theories and hypotheses……………………………………………………………….…..5

1.2 Modern theories of sleep………………………………………..…..6

1.3 Types of sleep……………..……………………………………………………………....9

1.4 Stages of sleep………………………………………………………………………………11

1.5 Need for sleep…………………………………………….…14

1.6 Physiological changes during sleep………………………...16

1.7 The nature of REM sleep………………………………………………………17

Chapter 2. Dreams as a mental aspect of paradoxical sleep..........19

2.1 Physiological basis of dreams……………………………..19

2.2 Mental foundations of dreams……………………….……...…..22

Conclusions……………………………………………………………………………….……26

Conclusion………………………………………………………………………………..27

List of references…………………………………………………………….28

Introduction

Since ancient times, the human mind has been occupied by questions: what is sleep, what causes it, and why do all people and animals experience an irresistible need for it? By studying the phenomena occurring in the body during sleep, its beneficial effects were established. It has been experimentally proven that during sleep the body does not freeze but recovers after prolonged wakefulness. Sleep is especially necessary to restore the functions of the nervous system, mainly the brain.

During sleep, a person's breathing becomes deeper and rarer, and the heart beats slower. All organs rest and restore their functions. Only the brain enjoys relative peace during sleep. The biological significance of sleep is to restore the performance of the body that is tired during wakefulness. What is sleep and what causes it?

In the middle of the last century, many scientists considered sleep the result of “bleeding the brain.” Numerous experiments have been carried out with the scale bed. The person was placed on a special bed and balanced. When a person fell asleep, the side of the bed where his head was went up, that is, his head became lighter during sleep. At first, it was concluded that during sleep the head loses some of its weight due to the drainage of blood from the human brain. From this experience it was completely unclear whether sleep is the cause of the blood flow or, on the contrary, the blood flow is the cause of sleep. Some scientists, on the contrary, believed that the cause of sleep is the overflow of blood in the brain. There are some brain diseases that are caused by blood flow to the brain. In this case, patients also experience sleep, but it has nothing in common with the usual sleep of healthy people. At that time, the theory of so-called “sleep poisons” was very widespread. It was created by French scientists R. Legendre and A. Pieron.

These scientists believed that sleep occurs because toxic metabolic products accumulate in the blood - hypnotoxins. They suppress the activity of the nervous system. This hypothesis emerged after a series of experiments with animals. Blood serum was taken from an animal that had been deprived of sleep for several days and injected into the blood of another animal. This animal immediately fell into a deep sleep. However, observations of natural animal sleep refute this theory.

Soviet scientists, observing the Siamese twins Ira-Galya and Dasha-Masha, came to the conclusion that the theory of “sleep poisons” is untenable. Siamese twins have two various nervous systems and one circulatory system. If the theory of “sleep poisons” were correct, then Siamese twins should have slept and woken up at the same time. Observations have shown that this is not the case. There were moments when one girl was asleep, the other was awake.

There are other data that do not confirm the correctness of the theory of self-poisoning of the body. It is known that a person can actively resist the desire to sleep, and sometimes does not feel the need to sleep at all. There is a theory of the nerve centers of sleep by the Swiss scientist W. Hess and the Austrian scientist K. Economo. According to this theory, sleep is controlled by special centers that are located under the cerebral cortex.

All these theories explained only some aspects of sleep, but did not answer the main question: what is sleep?

Object of study- sleep and dreams.

Subject of study- psychophysiological foundations of sleep and dreams.

Task- study with an example scientific research described in the literature, the psychophysical foundations of sleep and dreams.

Hypothesis- a dream is based mainly on mental foundations, sleep - on physiological foundations.

Target- identify the relationship between sleep and dreams and their influence on human behavior.

1. Physiological basis of sleep

1.1. Theories and hypotheses

Today there are many theories of sleep. All of them describe sleep as a special state of the body caused by prolonged physical and psychological stress. IN modern science The most widely recognized doctrine of sleep was developed by I. P. Pavlov and his followers.

The theory of sleep by I.P. Pavlova is based on the theory of conditioned reflexes. The results of numerous experiments and observations on animals and people led him to the conclusion that in higher animals and humans, sleep and wakefulness are associated with the work of the higher parts of the central nervous system - the cerebral cortex. The work of the brain is based on two nervous processes - excitation and inhibition; they arise under the influence of external and internal stimuli. Excitation forces the body to work, and inhibition delays the activity of organs and turns off the process in the nerve cell itself.

Small animals, such as a rabbit, at the sight of a boa constrictor, instead of running away and thereby saving their lives, remain in place and become prey. This phenomenon is based on an inhibitory process widespread throughout the brain tissue. I.P. Pavlov found that if you stop reinforcing an established conditioned reflex, it will disappear. This extinction of the conditioned reflex occurs due to the development of inhibition of nerve cells in the brain. If external stimuli that contribute to the occurrence of inhibition in the cerebral cortex continue to act for a long time, then inhibition gradually covers more and more extensive areas of the cortex, and when the entire cortex is completely in a state of inhibition,

deep dream.

Thus, sleep is one of the types of inhibition that covers the cerebral cortex and its underlying parts. Whenever nerve cells are threatened with exhaustion or overexcitation, they develop so-called protective inhibition, that is, a protective reaction of the cortex to external stimuli.

So, everything that reduces the performance of nerve cells in the brain - fatigue, exhaustion, a serious illness - increases the need for sleep, increases drowsiness. If you carry out observations, you can be sure that as a result of irritations affecting the brain during the day, fatigue develops in the evening, and with it the desire to sleep - a signal of the body’s persistent desire to rest.

The study of inhibition of the cerebral cortex showed that it does not simply prevent further work of nerve cells. During this apparently passive state of the cell, active metabolic processes take place, brain cells restore their normal composition, and gain strength for further active work. In sleep, when the overwhelming mass of the brain is inhibited, the most favorable conditions not only to restore the functionality of the nerve cells of the brain, which are most in need of such a respite, but also to relax the whole organism.

1.2.Modern theories of sleep

Currently, most of the existing hypotheses regarding the functional purpose of sleep and its individual stages can be reduced to three main types: 1) energetic, or compensatory-restorative, 2) informational, 3) psychodynamic.
According to the “energy” theory, during sleep the energy expended during wakefulness is restored.

A special role is given to the so-called delta sleep, the increase in duration of which follows physical and mental stress. Any load is compensated by an increase in the proportion of delta sleep. It is at the delta stage of sleep that the secretion of neurohormones that have an anabolic effect occurs.
Morphological formations related to sleep regulation were identified.
The reticular formation controls initial stage sleep. The hypnogenic zone, located in the anterior part of the hypothalamus, also has a regulatory effect on the functions of sleep and wakefulness.
Theory P.K. Anokhina attaches decisive importance to the functions of the hypothalamus in this process. With prolonged wakefulness, the level of vital activity of the cells of the cerebral cortex decreases, so their inhibitory effect on the hypothalamus weakens, which allows it to “turn off” the activating effect of the reticular formation.

Information theories claim that sleep is the result of a decrease in sensory flow to the reticular formation. A decrease in information entails the activation of inhibitory structures. There was also a point of view that it is not cells, not tissues, not organs that need rest, but mental functions: perception, consciousness, memory. The perceived information can “overwhelm” the brain, so it needs to disconnect from the outside world (which is the essence of sleep) and switch to a different operating mode.

Sleep is interrupted when the information is recorded and the body is ready for new experiences.

According to the famous psychoneurologist A.M. Wayne, the information theory does not contradict the energy concept of restoration, because the processing of information in a dream does not replace the processing during wakefulness, but complements it.

Recovery in the broadest sense of the word is not peace and passive accumulation of resources, or rather not only peace, which is sufficient in sleep, but, above all, a kind of brain activity aimed at reorganizing the perceived information. After such a reorganization, a feeling of relaxation, physical and mental, arises.

According to "psychodynamic " According to sleep theories, the cerebral cortex has an inhibitory effect on itself and on subcortical structures.
Psychodynamic theories include the homeostatic theory of sleep. In this case, homeostasis refers to the entire complex of processes and states on which optimal brain function is based. According to his theory, there are two types of wakefulness - calm and tense.
Calm is supported by the activity of the reticulo-thalamocortical system (activating the impulses that the reticular formation sends, prompting the thalamus and cerebral cortex to work harder), and tension, in addition, by the activity of the limbic system.
The combination of these two systems provides tense wakefulness is a necessary basis for coordinated reactions. During REM sleep, only the limbic system works: emotions are excited and coordinated reactions are paralyzed. Judging by the activity of brain structures, REM sleep is an analogue of not calm, but intense wakefulness.

It can also be noted that sleep refers to one of the types of cyclic rhythms of human brain activity. Cyclicity underlies our existence, which is ordered by the rhythmic change of day and night, seasons, work and rest. At the level of the organism, cyclicity is represented by biological rhythms, primarily the so-called circadian rhythms, caused by the rotation of the Earth around its axis.

1.3. Types of sleep.

In humans and many animals, the period of sleep and wakefulness is confined to the daily cycle of day and night. This kind of sleep is called monophasic. If the change of sleep and wakefulness occurs several times a day, sleep is called polyphasic. An adult's periodic daily sleep, as a rule, is monophasic, sometimes diphasic (twice a day); a small child has a polyphasic type of sleep.
A number of animals also experience seasonal sleep (hibernation), due to environmental conditions unfavorable for the body: cold, drought, etc.
In addition to those listed, there are several other types of sleep: narcotic(caused by various chemical or physical agents), hypnotic And pathological. The last three types of sleep are usually considered as a consequence of non-physiological effects on the human or animal body.
Drug sleep can be caused by various types of chemical influences: inhalation of ether vapor, chloroform, introduction of various types of drugs into the body, for example, alcohol, morphine and others. In addition, this dream can be caused by electronarcosis (exposure to an intermittent electrical current of weak strength).
Pathological sleep occurs with brain anemia, brain injury, the presence of tumors in the cerebral hemispheres, or damage to certain areas of the brain stem. This also includes lethargic sleep, which can occur as a reaction to severe emotional trauma and can last from several days to several years. The phenomena of pathological sleep should also include somnambulism, the physiological mechanisms of which are still unknown.

Of particular interest is hypnotic sleep, which can be caused by the hypnotic effect of the situation and the influence of the hypnotist. During hypnotic sleep, it is possible to turn off voluntary cortical activity while maintaining partial contact with the environment and the presence of sensorimotor activity.
The alternation of sleep and wakefulness is observed at all stages of the evolutionary ladder: from lower vertebrates and birds to mammals and humans. There is no doubt that such a universal organization of rhythmic alternation of activity and rest has a deep physiological meaning. It is well known that significant physiological changes in the functioning of the central nervous system occur during sleep, autonomic nervous system and other systems and functions of the body.
The basic laws of human mental activity include the cyclic alternation of sleep and wakefulness.
However, it should be noted that there are frequent disturbances in the rhythm of sleep, which include insomnia and the so-called irresistible sleep (narcolepsy), which occurs during passive driving, when performing monotonous work, as well as when managing various vehicles: by car, electric locomotive, metro.

1.4. Stages of sleep

Human sleep has a regular cyclic organization. There are five stages of sleep. Four stages of slow wave sleep and one stage of rapid wave sleep. It is sometimes said that sleep consists of two phases: slow And fast th. A completed cycle is considered to be a period of sleep in which there is a sequential change from the stages of slow-wave sleep to rapid sleep. On average, there are 4 - 6 such cycles per night, lasting approximately 1.5 hours each.

Based on these provisions, V. M. Kovalzon proposes the following definition of sleep: “sleep is a special genetically determined state of the human body (and warm-blooded animals, i.e. mammals and birds), characterized by a natural sequential change of certain printing patterns in the form of cycles, phases and stages" (Kovalzon, 1993).

Sleep studies are carried out through polygraphic recording of physiological indicators. Using EEG recording, significant differences were revealed both between the stages of sleep and between the stages of sleep and wakefulness. Based on a comprehensive study of sleep using EEG, EMG, ECG, EOG and pneumography by W. Dement and N. Kleitman in 1957

proposed a sleep pattern that has become classic. Eight to nine hour sleep is divided into five to six cycles, interspersed with short intervals of awakening, which, as a rule, do not leave any memories for the sleeper.

Each cycle includes two phases: the phase of slow (orthodox) sleep and the phase of rapid (paradoxical) sleep.

The diagrams above show that the change in stages of slow-wave sleep is characterized by a gradual increase in the amplitude and decrease in the frequency of EEG waves, a change from rapid eye movements to slow ones, up to complete disappearance; progressive decrease in EMG amplitude. In paradoxical sleep, the EEG is the same as during wakefulness, the EOG shows rapid eye movements, and the EMG is almost not recorded.

First stage is a transition from the state of wakefulness to sleep, which is accompanied by a decrease in alpha activity and the appearance of low-amplitude slow theta and delta waves. The duration of the first stage is usually no more than 10-15 minutes. At the end of this stage, short bursts of so-called sleepy spindles, clearly visible against the background of slow-wave activity. However, for now spindles sleep does not reach a duration of 0.5 seconds, this period is considered the first stage of sleep. In behavior, this stage corresponds to a period of dozing with half-asleep dreams; it may be associated with the birth of intuitive ideas that contribute to the success of solving a particular problem.

Second stage takes up slightly less than half of the total sleep time at night. This stage is called the “sleep spindle” stage, because its most striking feature is the presence in the EEG of fusiform rhythmic activity with an oscillation frequency of 12-16 Hz. The duration of these "spindles", clearly distinguished from the background high-amplitude EEG with a mixed frequency of oscillations, ranges from 0.2 to 0.5 seconds.
Third stage is characterized by all the features of the second stage, to which is added the presence in the EEG of slow delta oscillations with a frequency of 2 Hz or less, occupying from 20 to 50% of the recording epoch. This transition period lasts only a few minutes.
Fourth stage characterized by a predominance in the EEG of slow delta oscillations with a frequency of 2 Hz or less, occupying more than 50% of the recording time of night sleep. The third and fourth stages are usually combined under the name delta sleep. Deep stages delta sleep more pronounced at the beginning and gradually decrease towards the end of sleep. At this stage, it is quite difficult to wake a person. It is at this time that about 80% of dreams occur, and it is at this stage that attacks are possible sleepwalking and nightmares, but the person remembers almost none of this. The first four stages of sleep normally occupy 75-80% of the entire sleep period.

Fifth stage of sleep . The fifth stage of sleep has a number of names: the stage of “rapid eye movements” or abbreviated REM, “rapid eye movement sleep”, “paradoxical sleep”. During this stage, the person is completely immobile due to a sharp drop in muscle tone, and only the eyeballs under closed eyelids make rapid movements with a frequency of 60-70 times per second. The number of such movements can range from 5 to 50. Moreover, a clear connection was discovered between rapid eye movements and dreams. Thus, healthy people have more of these movements than patients with sleep disorders. It is typical that people who are blind from birth dream only of sounds and sensations. Their eyes are motionless.

It is believed that the intensity of REM can be used to judge the vividness and emotionality of dreams. However, eye movements during sleep differ from those characteristic of viewing objects while awake.
In addition, at this stage of sleep, the encephalogram acquires signs characteristic of the waking state. The name “paradoxical” arose from the apparent discrepancy between the state of the body (complete rest) and brain activity. If you wake up a sleeping person at this time, then in approximately 90% of cases you can hear a story about a vivid dream, and the accuracy of the details will be significantly higher than when waking up from slow-wave sleep
The paradoxical stage of sleep is present in many species of mammals and even in some species of birds. It was also noted that in animals the proportion of paradoxical sleep tends to increase with increasing degree of cortical development. However, paradoxical sleep occurs differently in animals and humans. A person in paradoxical sleep is motionless (only the eyes move). Animals' whiskers, ears, and tail move, paws twitch, blinking and sucking movements occur, and even squeals are heard in dogs.
Periods of REM sleep occur at approximately 90-minute intervals and last on average about 20 minutes. In normal adults, this stage of sleep takes up approximately 20-25% of the time spent asleep. In infants this proportion is significantly higher; In the first weeks of life, about 80% of all very long sleep time is paradoxical sleep.

1.5. Need for sleep.

This vital need depends on age. Thus, the total duration of sleep for newborns is 20-23 hours a day, at the age of 6 months to 1 year - about 18 hours, at the age of 2 to 4 years - about 16 hours, at the age of 4 to 8 years old - 12 hours, from 8 to 12 years old - 10 hours, from 12 to 16 years old - 9 hours. Adults sleep on average 7-8 hours a day.

As a result of observations, it was found that people over 60 years of age suffering from various diseases usually sleep less than 7 hours a day. At the same time, practically healthy people of this age sleep more than 8 hours a day. With an increase in sleep duration, older people who sleep little experience an improvement in their well-being. According to some data, the sleep duration of Caucasian centenarians ranges from 9 to 16-17 hours a day. On average, long-livers sleep 11-13 hours. In other words, as a person ages, the duration of sleep should increase.

A person deprived of sleep dies within two weeks. Sleep deprivation for 3-5 days causes an irresistible need for sleep. As a result of 60-80 hours of sleep deprivation, a person experiences a decrease in the speed of mental reactions, mood deteriorates, disorientation in the environment occurs, performance sharply decreases, and rapid fatigue occurs during mental work. A person loses the ability to concentrate, various disorders of fine motor skills may occur, hallucinations are possible, and sometimes sudden memory loss and slurred speech are observed. With longer sleep deprivation, psychopathy and other mental disorders may occur.
Changes in autonomic functions during prolonged insomnia are very small; there is only a slight decrease in body temperature and a slight slowdown in heart rate.
Science has described several cases of prolonged lack of sleep, which, along with the phenomena of somnambulism (sleepwalking) and lethargic sleep no explanation has yet been found. Most often, these cases were associated with severe mental shock.

Slow-wave and paradoxical sleep are equally necessary for the body. So, if you wake a person every time a paradoxical sleep occurs, the tendency to fall into a paradoxical sleep will increase. After a few days, the person will move from wakefulness to paradoxical sleep without an intermediate phase of normal sleep.
Thus, the stages of sleep form a unique system in which an impact on one link entails a change in the state of another link.

1.6 Physiological changes during sleep.

The most characteristic symptoms of sleep include a decrease in the activity of the nervous system and cessation of contact with the environment due to the “switching off” of the sensorimotor sphere.
The thresholds of all types of sensitivity (vision, hearing, taste, smell and touch) increase during sleep. The threshold value can be used to judge the depth of sleep.

In the first four stages, perception thresholds increase by 30-40%, while in REM sleep - by 400%. Reflex function during sleep is sharply weakened. Conditioned reflexes are inhibited, unconditioned reflexes are significantly reduced. However, some types of cortical activity and reactions to certain stimuli may persist during normal periodic sleep. For example, a sleeping mother hears the sounds of a sick child moving. This phenomenon is called partial wakefulness.
Most muscles are in a relaxed state during sleep, and a person is able to maintain a certain body position for a long time. At the same time, the tone of the muscles that close the eyelids is increased. As you fall asleep, your heart and breathing rhythms slow down and become more even.
Slow-wave sleep is accompanied by a decrease in autonomic reactions - the pupils narrow, sweating increases, the activity of the cardiovascular, respiratory, digestive and excretory systems decreases, the breathing rate decreases, which leads to a limitation of the volume of oxygen entering the blood and a slower removal of carbon dioxide, i.e. the intensity of pulmonary gas exchange decreases. This is why the heart rate decreases at night, and with it the speed of blood flow.
It should be emphasized that, although in general the level of metabolism decreases during sleep, at the same time the processes of restoring the functionality of all cells of the body are activated, their reproduction is intensive, and proteins are replaced.
In contrast, during paradoxical sleep, a “vegetative storm” occurs. Breathing becomes irregular, unrhythmic, varying in depth. Stopping breathing is also possible (for example, in a nightmare).

Throughout the night, the growth of hair and nails is activated in a person. A person's body temperature decreases during sleep. Similar daily temperature fluctuations - a decrease at night and an increase during the day - are also observed in the absence of sleep or when daytime sleep and night wakefulness.

1.7. The nature of REM sleep.

There are a number of theories and hypotheses about the nature and meaning of paradoxical sleep. Unlike slow-wave sleep, REM sleep has a pronounced active nature. Paradoxical sleep is triggered from a strictly defined center located in the back of the brain, in the area varolieva bridge And medulla oblongata. During this stage of sleep, brain cells are extremely active, but the process of transmitting information from the senses to the brain centers, as well as from them to the muscular system, is blocked.

Some researchers believe that these are periods of cell restoration, others believe that paradoxical sleep plays the role of a “safety valve”, allowing excess energy to be discharged while the body is completely deprived of movement; according to others, paradoxical sleep helps to consolidate in memory information received during wakefulness. Some studies even indicate a close connection between a high level of intellectual development and a long total duration of periods of paradoxical sleep in many people.

There is a very interesting hypothesis by Jouvet, according to which, in REM sleep, hereditary genetic information related to the organization of holistic behavior is transmitted to neurological memory.

REM sleep itself can be divided into two stages. Against the background of desynchronization, lasting from 5 to 20 seconds and accompanied by rapid eye movements, the rapid development of the theta rhythm begins, generated hippocampus. This is the emotional stage of REM sleep. Then, the theta rhythm weakens, and meanwhile in the new cortex, especially in its sensorimotor area, the alpha rhythm increases. Then the alpha rhythm weakens and hippocampus the theta rhythm increases again. Both stages alternate several times during sleep, with the first always longer than the second. An increase in the theta rhythm in REM sleep is accompanied by the same vegetative phenomena that accompany intense wakefulness, saturated with strong emotions.

In general, we can conclude that main function slow sleep is recovery homeostasis brain tissue and optimization of control of internal organs. It is also well known that sleep is necessary to restore physical strength and optimal mental state. As for paradoxical sleep, it is believed that it facilitates the transfer of information from short-term memory to long-term memory, storage of information and its further reading.

2. Dreams as a mental aspect of paradoxical sleep

2.1 Physiological basis of dreams.

One of the main features of paradoxical sleep is, of course, dreams. Perhaps none of the phenomena of human consciousness has as many theories and idle inventions as dreams. Dreaming from the dawn of human culture to today appears as the border between the real and the other world. AND

not surprisingly, dreams are often very vivid, sometimes brighter than everyday reality. But Aristotle already approached the interpretation of dreams from a more scientific position, highlighting the role of sensations and emotions in the mechanism of the occurrence of dreams. However, only in the 19th century. belief in the supernatural nature of dreams began to wane. Modern dream theories emphasize that dreams are an extension of the waking state. In the 20th century The study of dreams began to focus on two aspects: the physiological process of dreaming and their content. Researchers have identified physiological signs that confirm that a person is dreaming. The main period of dreaming, characterized by a combination of rapid eye movement (REM), the appearance of brain waves similar to those observed in the waking state, and increased physiological activity, is, as mentioned above, called “rapid eye movement” sleep, or sleep with dreams. Subjects who were awakened outside of REM sleep were less likely to report having dreams and had greater difficulty recalling them.

Extreme behavioral manifestations such as nightmares, enuresis, sleepwalking has been found to often be unrelated to normal dreams.

Over the age of 10 and until the mid-sixth decade of life, people spend about a quarter of their total sleep time in a state of REM sleep. Although the presence of a phase of "rapid" sleep indicates, with a high degree of probability, that a person is dreaming, the content of the dream is directly accessible only to the sleeper himself. To study the content of dreams, researchers must rely on the person's testimony after waking up. Unpleasant feelings in dreams, according to the subjects, occur twice as often as pleasant ones. Apparently, the content of most dreams is directly related to ideas about people and events familiar to the sleeper. Obviously, the feeling of something unfamiliar in a dream is the result of sharp disturbances in time and space of the events occurring in the dream. There are the following main forms of dreams observed during sufficiently deep sleep:

1. dream-desire, based on the desire for self-preservation and reproduction, operating in the subconscious;

2. a fear dream, based on the fear of pain, suffering, etc. and on the (never completely disappearing) feeling of fear of life or of the world;

3. dream-past, reproducing scenes and episodes of childhood;

dream-mononeir (from the Greek monos - unique and oneiron - dream) - completely incomprehensible and meaningless images that at first glance have nothing to do with the sleeping person; they are the true subject of dream interpretation; These images are of particular interest to surrealists;

4. a dream bearing the stamp of “collectivity”; here we are talking about experiences that cannot be comprehended by the consciousness of a waking individual; in these dreams, the sleeper joins the treasury of experience of his ancestors or all of humanity.

Dreams served as a source for solving intellectual and emotional problems and the emergence of artistic ideas. Experiences in dreams are also amazing in their power.

It has been noted since ancient times that there is a paradox of time in dreams. In a moment that passes in a dream, events are experienced that in reality have a much longer duration. To this day, dream books are extremely popular.

The doctrine of higher nervous activity, and in particular the disclosure of the features of the inhibition process, helped to fully comprehend the internal mechanism and physiology of dreams. Experiments have shown that the transition of a nerve cell from a state of excitation to complete inhibition and back occurs through a series of intermediate, so-called hypnotic phases. When sleep is deep, there are no dreams, but if for one reason or another the strength of the inhibitory process in individual cells or areas of the brain weakens and complete inhibition is replaced by one of the transition phases, we see dreams. The paradoxical phase is especially interesting. Cells in this phase respond to weak stimuli much more strongly than to strong ones, and sometimes stop responding to the latter altogether. For cortical cells in the paradoxical phase, the imprint of a long-standing experience or impression can play the role of a weak irritant, and then what seemed long forgotten awakens in our brain an image that we see as if in reality.

Against the background of various inhibitions during sleep, those smoldering excitations in our brain that are associated with desires and aspirations that persistently occupy us during the day often flare up brightly. This mechanism (which physiologists call the revival of dormant dominants) underlies those frequent dreams when we see actually fulfilled what we only dream about in reality.

“An unprecedented combination of past impressions” is what the famous Russian physiologist Ivan Mikhailovich Sechenov called dreams.

This image reflects well one important feature dreams. It is impossible to see in a dream something that was not once perceived by our brain.

During sleep, only what once left its trace in the nerve cells of the brain can come to life in our brain, in our consciousness in the form of a bright picture. It is well known that people who are blind from birth do not dream visual images. In fact, in dreams very often there is a realization of events that could not be realized in reality. Dreams come from the area of ​​the unconscious, precisely from the area where our problems, our undisclosed essence and our negative emotions are repressed. Transforming and overlapping each other, they come in the form of repeating symbols, events and unusual situations. Here we come to the concept of the psychic aspect of dreams.

2.2 Mental foundations of dreams.

One of the first who tried to analyze dreams as a manifestation of unwanted factors repressed into the subconscious was Sigmund Freud.

Sigmund Freud suggested that dreams symbolize a person's unconscious needs and concerns. He argued that society requires us to suppress many of our desires. We cannot influence them and sometimes we are forced to hide them from ourselves. This is an unhealthy and subconscious desire to find balance, to present one's desires to the conscious mind in the form of dreams, thus finding an outlet for suppressed needs.

At first glance, devoid of practical significance, dreams, as well as erroneous actions, becoming the object of psychoanalysis, revealed many new, interesting patterns in the functioning of the psyche. Firstly, experiments with dreams have proven that they are a way of responding to stimuli acting in a dream, coming both from the outside and from the inside. From this, the second conclusion unifying dreams is made that this is a mental phenomenon, a product and manifestation of someone who dreams in response to stimuli interfering with sleep. The third unifying conclusion is that dreams are experienced primarily in visual images, accompanied by thoughts and feelings relating to various organs, which are sometimes difficult to convey in words after waking up.

The dream as a whole is a distorted substitute for something else, the unconscious, and the task of dream interpretation is to find this unconscious. Elements of a dream are understood as substitutes for something else, like the intention of an erroneous action. The dreamer knows about this, but this knowledge is unconscious. Thanks to free associations, you can find out the hidden content of a dream.

Analysis revealed that the distortion is not a manifestation of the essence of dreams. The dream is direct, undisguised wish fulfillment the dreamer, and the function of a dream is not to disturb sleep, but to protect it.

The main characteristic of a dream, according to S. Freud, is that the dream is prompted by a desire, and the fulfillment of this desire is realized through the content of the dream. That is, a dream is the elimination of stimuli that disturb sleep through the hallucinatory experience of wish fulfillment. The processes through which the explicit content of a dream is formed from hidden dream thoughts, somatic stimuli, and remnants of daytime impressions use four main mechanisms - condensation, displacement, secondary processing and figurative representation of thoughts.

Thickening- the merging of various ideas into one component - the mechanism of the dream, which is a way of functioning of mental processes, for example, with wit at the level of words (neologisms). Censorship uses thickening for their own purposes, because Condensation makes it difficult to interpret obvious mental contents. Thickening is expressed in the fact that the explicit story of a dream is only a short translation of its hidden content. Therefore, S. Freud made the assumption that in order to understand the meaning of a dream, you need to ask a person, because the dreamer knows what his dream means, even if he does not remember it. He just doesn't know about his knowledge.

Bias- the mechanism of dreaming, when the feeling of tension, significance, importance of any idea passes over other, initially weaker ideas associated with the first chain of associations.

Secondary processing- consists of regrouping and linking the elements of a manifest dream into a more or less harmonious whole.

Figurative representation of thoughts- turning thoughts into visual images. To express individual elements of a dream, there is a visual representation of words, especially abstract concepts.

What is told about a dream is called the manifest content of the dream, and what is arrived at as a result of analysis is called the hidden thoughts of the dream. The relationships between these contents can be different. Of the entire large and complex psychic structure of unconscious thoughts, only a particle, like a fragment, penetrates into a manifest dream. The task of interpretation is to reconstruct the whole from the parts.

When working with dreams, it is also necessary to take into account Freud's position that the content of dreams comes from real experiences. During sleep, it is only reproduced and remembered, although after waking up a person can deny that this knowledge belongs to his awareness. That is, a person in a dream knows something that he does not remember in the waking state. One of the sources from which a dream draws material is childhood, which a person may not remember in the waking state. There is a reference from 3. Freud to the research of Piltz, who proved that at night in deep sleep impressions of the last time are reproduced, and in the morning - earlier ones. In psychoanalysis, it is generally accepted that dreams are never occupied with trifles, because... supposedly innocent dreams turn out to be serious after interpretation.

Freud's Swiss colleague Carl Gustav Jung saw various dream images as symbols full of meaning, each of which could be interpreted differently according to the overall context of the dream. He believed that during the waking state the subconscious mind perceives, interprets and learns from events and experiences, and during sleep communicates this “inner” knowledge to the conscious mind through a system of simple visual images. He tried to classify dream images according to their symbolic meaning. He believed that the symbols in the dream imagery system are inherent to all humanity, that they were formulated during the evolutionary development of the human brain and were passed down through generations.

Since the advent of computers, psychologists have compared the brain to a computer that performs tasks according to a set of commands—a program. Reprogramming can be carried out at a time when the computer is not busy with its daily tasks - that is, at night, at rest. During sleep, the influx of new information into the brain drops significantly, so sleep is the right time in order for the brain to review and group new information and reprogram itself accordingly.

In light of recent advances in brain research, all of these theories are increasingly being rejected as simplistic, and experiments are being conducted to try to scientifically determine the function, if any, of sleep and dreaming.

The theoretical biologist Francis Crick, who became famous for his discovery of the double helical structure of DNA in 1953 with James D. Watson, turned his attention to the study of the brain. He rejects computer analogies, but suggests that human brain and computers can operate in a similar way in organizing information in parallel (in many places at the same time, as the brain does). When overloaded with data, they react by building a “pseudo-memory” made up of real memory units. The brain can use pseudomemory - dreams - as a way to reduce memory overload.

However, examples of how the subconscious mind “helps” solve certain problems in a dream remain unexplained. Chemist F.A. Kekule, who discovered chemical structure benzene, went to bed one night in a state of anxiety because I could not solve the problem of the molecular structure of benzene. He dreamed of a snake with its tail in its mouth - an ancient image, according to K.G. Jung, found in mythologies around the world, including ancient Egyptian mythology. After this, he proved that the molecular structure of benzene is a ring.

The analysis of the literature showed that the last word has not yet been said in the science of dreams. Only one thing is absolutely clear: sleep is an integral part of human life. Sleep has a physiological basis, but its course is influenced by many factors, including mental ones.

Many mechanisms of dreams are still not understood. Dreams are a reflection of a person’s physical and mental reality. By analyzing them, you can discover unknown secrets of the human unconscious. By studying the symbolism that appears in a dream, one can diagnose a disease that has not yet manifested itself on the physical plane. Dreaming is a wonderful tool for

knowledge of hidden human problems. The main thing is to learn how to use this tool.

Conclusion

Subsequent studies indicate the important adaptive-programming role of sleep in the life of the body. That is why the effects obtained in some phases of natural sleep are persistent and have a great influence on behavioral programs in the subsequent state of wakefulness.

Thus, traditionally modern psychologists distinguish two periodic states of the psyche, inherent in all people: wakefulness - a state characterized by active interaction between a person and outside world, and sleep is a state considered primarily as a period of rest.

There is a lot of scientific evidence indicating that sleep is by no means a passive inhibitory state that only contributes to the restoration of strength and energy; sleep is a specific, active state of the brain that promotes the full use of existing experience and acquired information in the interests of more perfect adaptation of the body during wakefulness .

This is the vital function of REM sleep and its integral component - dreams.

List of used literature

1. Grimak L.P. "Reserves human psyche". Politizdat, 1989.

2. "Psychology and pedagogy." Edited by Radugin A.A.: textbook, 1997.

3. E. I. Chazov "Emergency conditions and emergency medical care."

4. A. G. Khripkova “The World of Childhood: Youth”.

5. L. L. Rokhlin “Sleep, hypnosis, dreams.”

6. A.N. Bakulev, F.F. Petrov "Popular Medical Encyclopedia".

7. I. P. Pavlov PSS t 3-4.

8. D.Z. Kapustin “Men’s Health” translation from English.

9. P. A. Samsonov “The Male Body” translation from English.

10. Bosnak R. “In the world of dreams” Moscow ed. "Tree of Life" 1991

11. Stanley K. “Secrets of Sleep” ed. "Veche" Moscow 1997

12. Samuel Dunkell “Night Body Language” “Arnica” 1994

13. Godefroy J. “What is psychology” Moscow “Mir” 1992 volume No. 1

14. Freud Z. “Interpretation of Dreams” St. Petersburg ed. "Aletheia"

15. T.M. Maryutina, O.Yu. Ermolaev "Introduction to psychophysiology"

16. K. Jung “Favorites” Minsk 1998 ed. "Medley"

Sleep is a physiological state that is characterized primarily by the loss of active mental connections of the subject with the world around him. Sleep is vital for higher animals and humans. A third of a person’s life passes in a state of periodic sleep.

Biological significance of sleep. For a long time it was believed that sleep is a rest necessary to restore the energy of brain cells after active wakefulness. However, in Lately the biological significance of sleep is considered much more widely. First, it turns out that brain activity during sleep is often higher than during wakefulness. It has been found that the activity of neurons in a number of brain structures increases significantly during sleep. In addition, during sleep, activation of a number of autonomic functions is observed. All this made it possible to consider sleep as an active physiological process, an active state of vital activity.

Objective characteristics (signs) of sleep. Sleep is characterized primarily by a loss of active consciousness. A person who sleeps deeply does not react to many environmental influences unless they are excessive. Reflex reactions during sleep are reduced. Sleep is characterized by phase changes in IRR, which are especially pronounced during the transition from wakefulness to sleep.

During the transition from wakefulness to sleep, the following phases are observed:

Equalization,

Paradoxical,

Ultra-paradoxical,

Narcotic.

Typically, conditioned reflex reactions obey the law of strength: to a stronger conditioned stimulus, the magnitude of the conditioned reflex reaction is greater than to a weak stimulus. The developmental phases of sleep are characterized by disturbances in power relations. Equalization phase characterized by the fact that animals begin to respond with conditioned reflex responses of the same magnitude to conditioned stimuli of varying strength.

During paradoxical phase a conditioned reflex reaction of a larger magnitude is observed to weak conditioned stimuli than to strong stimuli. Ultraparadoxical phase characterized by the disappearance of conditioned reactions to positive conditioned signals and the appearance of a conditioned reflex response under the influence of inhibitory conditioned stimuli. IN narcotic phase animals cease to respond with a conditioned reflex reaction to any conditioned stimuli.

Another indicator of sleep status is the loss of the ability to engage in active, goal-directed activities.

Objective characteristics of the sleep state are clearly detected on the EEG and when recording a number of vegetative indicators. During sleep, a number of changes occur in the EEG, occurring in several stages. In a state of wakefulness, low-amplitude, high-frequency EEG activity (beta rhythm) is characteristic. When you close your eyes and relax, this activity is replaced by a low-amplitude alpha rhythm. During this period, a person falls asleep, he gradually plunges into an unconscious state.

During this period, awakening occurs quite easily. After some time, alpha waves begin to form “spindles.” After 30 minutes, the “spindle” stage is replaced by the stage of high-amplitude slow theta waves. Awakening at this stage is difficult. This stage is accompanied by a number of changes in vegetative parameters: heart rate decreases, blood pressure, body temperature, etc. decrease. The theta wave stage is replaced by the stage of high-amplitude ultra-slow delta waves. As unconsciousness deepens, delta waves increase in amplitude and frequency. Delta sleep is a period of deep sleep. Heart rate, blood pressure, and body temperature reach minimum values ​​during this phase.

The described EEG changes constitute the “slow wave” stage of sleep, it lasts 1-1.5 hours. This stage is replaced by the appearance on the EEG of low-amplitude, high-frequency activity characteristic of the state of wakefulness (beta rhythm). Since this stage appears during the deep sleep phase, it is called “paradoxical” or “rapid wave” sleep.

Thus, according to modern ideas the entire period of one sleep cycle is divided into two states that replace each other (this change occurs 6-7 times during the night) and differ sharply from each other:

Slow wave or slow wave (orthodox) sleep;

REM or paradoxical sleep.

The slow-wave sleep stage is accompanied by high-amplitude slow delta waves in the EEG, and the REM sleep stage is accompanied by high-frequency low-amplitude activity (desynchronization), which is characteristic of the EEG of the brain of a waking animal, i.e., according to EEG indicators, the brain is awake and the body is asleep. This gave rise to calling this stage of sleep paradoxical sleep.

If you wake up a person in the phase of paradoxical sleep, he reports dreams and conveys their content. A person waking up in the slow-wave sleep phase most often does not remember dreams.

The paradoxical phase of sleep turned out to be important for normal life. If a person is selectively deprived of only the paradoxical phase of sleep during sleep, for example, by waking him up as soon as he enters this phase, then this leads to significant disturbances in mental activity. This indicates that sleep, and especially its paradoxical phase, is a necessary state of preparation for normal, active wakefulness.

Theories of sleep.

Humoral theory: The cause of sleep is considered to be special substances that appear in the blood during wakefulness. The proof of this theory is an experiment in which a awake dog was transfused with the blood of an animal that had been deprived of sleep for 24 hours. The recipient animal immediately fell asleep. Currently, it has been possible to identify some hypnogenic substances, for example, a peptide that induces delta sleep. However, the presence of hypnogenic substances is not a fatal sign of sleep development.

This is evidenced by observations of the behavior of two pairs of unseparated twins. In these twins, the embryonic separation of the nervous system occurred completely, and the circulatory systems had many anastomoses. These twins showed different attitude to bed: one girl, for example, could sleep, while the other was awake. All this indicates that humoral factors cannot be considered as the absolute cause of sleep.

The second group of theories is neural theories of sleep. Clinical observations have shown that with various tumor or infectious lesions of the subcortical, especially brain stem formations, patients experience various sleep disorders - from insomnia to prolonged lethargic sleep. These and other observations indicated the presence of subcortical sleep centers.

It was experimentally shown that when the posterior structures of the subthalamus and hypothalamus were irritated, the animals immediately fell asleep, and after the irritation stopped, they woke up. These experiments indicated the presence of sleep centers in the subthalamus and hypothalamus.

In the laboratory of I.P. Pavlov it was established that when a long-term and persistently unreinforced conditioned stimulus was used or when a subtle differential conditioned signal was produced, the animals, along with the inhibition of their conditioned reflex activity, fell asleep. These experiments allowed I.P. Pavlov to consider sleep as a consequence of the processes of internal inhibition, as a deepened, diffuse inhibition that spread to both hemispheres and the nearest subcortex. This is how the cortical theory of sleep was substantiated. However, a number of facts could not be explained by either the cortical or subcortical theories of sleep.

Firstly, observations of patients who lacked almost all types of sensitivity showed that such patients fall into a state of sleep as soon as the flow of information from the operating sense organs is interrupted. For example, in one patient, of all the sense organs, only one eye was preserved, the closure of which plunged the patient into a state of sleep. The patient, with preservation of sensitivity only on the dorsum of the forearm of one hand, was constantly in a state of sleep. She woke up only when they touched areas of her skin that remained sensitive.

Secondly, it remained unclear why hemispheric animals and newborn children, whose cortex is not yet sufficiently differentiated morphologically, sleep.

Many questions of the central organization of sleep processes were explained with the discovery of the ascending activating influences of the reticular formation of the brain stem on the cerebral cortex. It has been experimentally proven that sleep occurs in all cases of elimination of the ascending activating influences of the reticular formations on the cerebral cortex.

Along with this, descending influences of the cerebral cortex on subcortical formations were established. The influence of the frontal parts of the cerebral cortex on the limbic structures of the brain and hypothalamic sleep centers is especially important. In the waking state, in the presence of ascending activating influences of the reticular formation on the cerebral cortex, neurons of the frontal cortex inhibit the activity of neurons in the sleep center of the posterior hypothalamus. In a state of sleep, when the ascending activating influences of the reticular formation on the cerebral cortex decrease, the inhibitory influences of the frontal cortex on the hypothalamic sleep centers decrease.

An important circumstance that has direct relation to the nature of sleep, was the establishment of the fact of reciprocal relationships between the limbic-hypothalamic and reticular structures of the brain. When the limbic-hypothalamic structures of the brain are excited, inhibition of the structures of the reticular formation of the brain stem is observed and, vice versa.

Consequently, states of wakefulness and sleep are characterized by specific architectonics, a peculiar “layout” of cortical-subcortical relationships.

During wakefulness, due to afferentation flows from the sense organs, the structures of the reticular formation of the brain stem are activated, which have an ascending activating effect on the cerebral cortex. In this case, the neurons of the frontal cortex exert descending inhibitory influences on the sleep centers of the posterior hypothalamus, which eliminates the blocking influence of the hypothalamic sleep centers on the reticular formation of the midbrain.

In a state of sleep, with a decrease in the flow of sensory information, the ascending activating influences of the reticular formation on the cerebral cortex are reduced. As a result, the inhibitory influences of the frontal cortex on the neurons of the sleep center of the posterior hypothalamus are eliminated. These neurons, in turn, begin to inhibit the reticular formation of the brain stem even more actively. Under conditions of blockade of all ascending activating influences of subcortical formations on the cerebral cortex, a slow-wave stage of sleep is observed.

Hypothalamic centers, due to morphofunctional connections with the limbic structures of the brain, can have ascending activating influences on the cerebral cortex in the absence of influences from the reticular formation of the brain stem.

The mechanisms discussed above constitute cortical-subcortical theory of sleep, proposed by P.K. Anokhin. This theory made it possible to explain all types of sleep and its disorders. It proceeds from the leading postulate that whatever the cause of sleep, the sleep state is associated with the most important mechanism - a decrease in the ascending activating influences of the reticular formation on the cerebral cortex.

The development of sleep is explained by a decrease in the ascending activating influences of the reticular formation due to inhibition of the activity of its neurons during electrical stimulation of the posterior hypothalamus.

The sleep of cortical-free animals and newborn children is explained by the weak expression of the descending influences of the frontal cortex on the hypothalamic sleep centers, which under these conditions are in an active state and have an inhibitory effect on the neurons of the reticular formation of the brainstem. A newborn's sleep is periodically interrupted only by the excitation of the hunger center located in the lateral nuclei of the hypothalamus, which inhibits the activity of the sleep center. In this case, conditions are created for the entry of ascending activating influences of the reticular formation into the cortex. The newborn wakes up and stays awake until the activity of the hunger center decreases due to the satisfaction of food needs.

It becomes clear that in all cases of severe limitation of sensory information, which occurred in some patients, sleep arose as a result of a decrease in the ascending activating influences of the reticular formation of the brain stem on the cortex.

The cortical-subcortical theory of sleep explains many sleep disorders. Insomnia, for example, often occurs as a result of overexcitation of the cortex under the influence of smoking or intense creative work before bedtime. At the same time, the descending inhibitory influences of frontal cortex neurons on the hypothalamic sleep centers are enhanced and the mechanism of their blocking effect on the reticular formation of the brain stem is suppressed.

Shallow sleep is observed with partial blockade of the mechanisms of ascending activating influences of the reticular formation on the cerebral cortex. Prolonged, for example, lethargic sleep can be observed when the sleep centers of the posterior hypothalamus are irritated by a vascular or tumor pathological process. In this case, the excited cells of the sleep center continuously exert a blocking effect on the neurons of the reticular formation of the brain stem.

The concept of “sentinel points” as partial wakefulness during sleep is explained by the presence of certain channels of reverberation of excitations between subcortical structures and the cerebral cortex during sleep against the background of a decrease in the bulk of the ascending activating influences of the reticular formation on the cerebral cortex. The “sentinel point” or focus may be determined by signaling from internal organs, internal metabolic needs and external vital circumstances.

For example, a nursing mother may sleep very soundly and not respond to strong enough sounds, but she quickly wakes up when her newborn baby moves slightly. Sometimes “watchdog points” can have prognostic value. For example, in the case of pathological changes in a particular organ, increased impulses from it can determine the nature of dreams and be a kind of prognosis of the disease, subjective signs which are not yet perceived in the waking state.

The hypnotic state can be defined as partial sleep. Perhaps the hypnotic state is created due to the excitation of limbic-thalamic structures against the background of the remaining part of the ascending activating influences of the reticular formation on the cerebral cortex” that determine behavioral activity.

Selective activation of the limbic structures of the brain is observed when the brain is exposed to electrical current pulses during so-called electrosleep, and a hypnosis-like state is formed.

Sleep, as a special state of the body and, above all, the state of the brain, is characterized by specific cortical-subcortical relationships and the production of special biologically active substances, and is used in the treatment of neurotic, asthenic conditions, relieving psycho-emotional stress and in a number of psychosomatic diseases ( early stages hypertension, heart rhythm disturbances, ulcerative lesions of the gastrointestinal tract, skin and endocrine disorders).

Pharmacological sleep is inadequate in its mechanisms to natural sleep. Various “sleeping pills” limit the activity of different brain structures - the reticular formation of the brain stem, the hypothalamic region, and the cerebral cortex. In this case, the natural mechanisms of the formation of sleep stages, its dynamics, and awakening are disrupted. In addition, during pharmacological sleep, the processes of memory consolidation, processing and assimilation of information, etc. may be disrupted. Therefore, the use of pharmacological agents to improve sleep should have sufficient medical justification.

Modern ideas about the physiological architecture of a behavioral act (functional system of behavior). Any activity of the body is adaptive and is aimed at achieving a useful adaptive result for the body. The basis of this adaptive activity is the formation of functional systems, i.e., a set of processes and mechanisms that dynamically develop to achieve a useful result for the body. Consequently, the formation of functional systems is subordinated to obtaining a certain, useful adaptive result. An insufficient result can completely reorganize the system, forming a new one with a more perfect interaction of components that ensure a useful result.

Stages (nodal mechanisms) of the formation of a functional system. The concept of functional systems postulates the idea that the environment of existence influences the organism even before the conditioned stimulus acts. Consequently, when implementing a conditioned reflex, the conditioned stimulus acts against the background of the so-called pre-launch integration, which is formed on the basis various types afferent excitations.

1. Situational afferentation - the sum of afferent excitations that arise in the specific conditions of the existence of an organism and signal the situation in which the organism resides.

2. Situational afferentation acts on the body at the moment when it has one or another level of motivational arousal (motivation), which is in a state of hidden dominance. Dominant motivation is formed on the basis of a leading need, with the participation of motivational centers of the hypothalamus. From several needs, the most relevant one is selected, on the basis of which the dominant motivation arises. At the stage of afferent synthesis, the dominant motivation activates memory.

3. Any behavioral reaction, including a conditioned reflex, occurs faster if a similar situation has already occurred in life, i.e. if there are traces of past experience - memory. The significance of memory at the stage of afferent synthesis is that it extracts information related to the satisfaction of the dominant motivation.

These three types of excitations: motivational, memory and situational afferentation create pre-launch integration, against which the fourth type of afferentation operates - triggering afferentation(trigger stimulus, conditioned signal). These four types of excitations interact and ensure the formation of the First stage, the first nodal mechanism of the functional system behavior - afferent synthesis(Fig. 34).

Fig.34. Diagram of the functional system of a behavioral act (according to P.K. Anokhin).

The main condition for the formation of afferent synthesis is the simultaneous meeting of all four types of afferentations. These types of afferentations must be processed simultaneously and jointly, which is achieved due to the convergence of all types of excitations on convergent neurons. The stage of afferent synthesis leads the body to decide what kind of result should be produced in this moment, it provides the setting of a goal to which all further implementation of the functional system will be devoted.

The second stage of the functional system is decision-making(goal setting).

This stage is characterized by the following features:

Decision making is carried out only on the basis of complete afferent synthesis.

Through decision making, one specific form of behavior is adopted that corresponds to an internal need, previous experience and the environment.

At the decision-making stage, the body is freed from excess degrees of freedom, i.e., out of hundreds of possibilities after the decision is made, only one is realized. The remaining degrees of freedom make it possible to economically carry out exactly the action that should lead to the programmed result.

The decision-making stage contributes to the formation of the integral of efferent excitations; during this period, all types of excitations acquire an effector, executive character.

The third stage of a functional system is the formation action programs. At this stage, a specific goal of action and ways of its implementation are formed. Simultaneously with the formation of the action program, a copy of it is formed, which is stored in the nervous system, in the acceptor of the results of the action.

The fourth stage in the formation of a functional system is the formation acceptor of action results. This is a very complex apparatus of brain activity, which must form subtle nervous mechanisms that allow not only to predict the signs (parameters) of the result required at the moment, but also to compare (compare) them with the parameters of the actually obtained result. Information about the latter comes to the acceptor of action results thanks to reverse afferentation. It is this apparatus that allows the body to correct behavioral errors or bring imperfect behavioral acts to perfect ones. An acceptor of the results of an action is an ideal image of the future results of an action.

It is this model that is the standard for assessing reverse afferentations. Evidence has been obtained that this nervous complex, which has a high degree of multiconvergent interaction, receives excitations not only of afferent, but also of efferent nature. It's about about the collateral branches of the pyramidal tract, which, through a chain of intermediate neurons, carry “copies” of efferent messages (commands) going to the effectors. These efferent excitations converge on the same intermediate neurons of the sensorimotor area of ​​the cortex, which receive afferent excitations that transmit information about the parameters of the actual result.

Thus, the moment of decision making and the beginning of the release of efferent excitations from the brain is accompanied by the formation of an extensive complex of excitations, consisting of afferent signs of the future result and collateral copies of efferent excitations arriving along the pyramidal tract to the working apparatus. After a certain time, this same complex of excitations is joined by excitations from the parameters of the actual result obtained. The process of assessing the actually obtained result is carried out from a comparison (comparison, juxtaposition) of the predicted parameters and the parameters of the actually obtained result.

If the results do not correspond to the forecast, then a mismatch reaction occurs in the comparison apparatus, activating an orienting-exploratory reaction, which raises the associative capabilities of the brain to a higher level. high level, thereby helping active selection additional information. It is this general activation of the brain, realized in the orienting-exploratory reaction, that directs the body to search for additional information. On its basis, a more complete afferent synthesis is formed, a more adequate decision is made, which in turn leads to the formation of a more adequate program of action and to action that allows one to obtain the programmed result.

When the desired useful result is achieved, a coordination reaction is formed in the acceptor of action results. The stage of afferent synthesis receives sanctioning afferentation, signaling the satisfaction of motivation. At this point the functional system ceases to exist.

The processes of coordination and mismatch that arise when comparing the parameters of the actually obtained result with those programmed in the acceptor of action results are accompanied by general reactions - a feeling of satisfaction and dissatisfaction, i.e. positive and negative emotions.

Consequently, the main stages, key mechanisms of the functional system are:

Afferent synthesis.

Decision-making.

Formation of an action program.

Formation of an acceptor of action results.

Action and its result.

Comparison of the result parameters with their model in the action result acceptor, carried out using reverse afferentation.

The synthesis of such diverse excitations is carried out on convergent neurons. It is to them that situational and triggering afferentations and excitement from motivational centers come. On these same neurons, the synthesis of these excitations with traces of previously occurring processes (memory) is carried out. The neurons on which the mechanisms of the functional system are formed are located in all structures of the central nervous system, at all its levels. The integration of these processes determines the holistic multi-level, multi-component adaptive activity of the organism.

Sleep is a physiological state that is characterized primarily by the loss of active mental connections of the subject with the world around him. Sleep is vital for higher animals and humans. A third of a person’s life passes in a state of periodic sleep.

BIOLOGICAL SIGNIFICANCE OF SLEEP. For a long time it was believed that sleep is a rest necessary to restore the energy of brain cells after active wakefulness. However, recently the biological significance of sleep has been considered much more widely. First, it turns out that brain activity during sleep is often higher than during wakefulness. It has been found that the activity of neurons in a number of brain structures increases significantly during sleep. In addition, during sleep, activation of a number of autonomic functions is observed. All this made it possible to consider sleep as an active physiological process, an active state of vital activity.

OBJECTIVE CHARACTERISTICS (SIGNS) OF SLEEP. Sleep is characterized primarily by a loss of active consciousness. A person who sleeps deeply does not respond to many environmental influences; as long as they are not excessively forceful. Reflex reactions during sleep are reduced. Sleep is characterized by phase changes in IRR, which are especially pronounced during the transition from wakefulness to sleep. During the transition from wakefulness to sleep, the following phases are observed:

* equalizer,

* paradoxical,

* ultraparadoxical,

* narcotic.

Typically, conditioned reflex reactions obey the law of strength: to a stronger conditioned stimulus, the magnitude of the conditioned reflex reaction is greater than to a weak stimulus. The developmental phases of sleep are characterized by disturbances in power relations. The equalizing phase is characterized by the fact that animals begin to respond with conditioned reflex responses of equal magnitude to conditioned stimuli of varying strength. During the paradoxical phase, in response to weak conditioned stimuli, a larger magnitude of conditioned stimuli is observed. During the narcotic phase, animals respond with a conditioned reflex reaction to any conditioned stimuli.

Another indicator of sleep status is the loss of the ability to engage in active, goal-directed activities.

Objective characteristics of the sleep state are clearly detected on the EEG and when recording a number of changes occurring in several stages. In a state of wakefulness, low-amplitude, high-frequency EEG activity (beta rhythm) is characteristic. When you close your eyes and relax, this activity is replaced by a low-amplitude alpha rhythm. During this period, a person falls asleep, he gradually plunges into an unconscious state. During this period, awakening occurs quite easily. After some time, the alpha waves form “spindles.” After 30 minutes, the “spindle” stage is replaced by the stage of high-amplitude slow theta waves. Awakening at this stage is difficult. This stage is accompanied by a number of changes in vegetative parameters: the heart rate decreases, blood pressure, body temperature, etc. decrease. The theta wave stage is replaced by the stage of high-amplitude ultra-slow delta waves. As unconsciousness deepens, delta waves increase in amplitude and frequency. Delta sleep is a period of deep sleep. Heart rate and blood pressure reach minimum values ​​during this phase.

The described EEG changes are " slow wave" part of sleep, it lasts 1-1.5 hours. This stage is replaced by the appearance in the EEG of low-amplitude, high-frequency activity characteristic of the state of wakefulness (beta rhythm). Since this stage appears during the deep sleep phase, it is called “paradoxical” or “fast wave” sleep.

Thus, according to modern concepts, the entire period of one sleep cycle is divided into two states, which replace each other (such a change occurs 6-7 times during the night) and differ sharply from each other:

slow wave or slow (orthodox) sleep;

fast wave or paradoxical sleep.

Slow stage sleep is accompanied by high-amplitude slow delta waves in the EEG, and the REM sleep stage is accompanied by high-frequency low-amplitude activity (desynchronization), which is characteristic of the EEG of the brain of a waking animal, i.e., according to EEG indicators, the brain is awake and the body is asleep. This gave rise to calling this stage paradoxical sleep.

If you wake up a person in the phase of paradoxical sleep, he reports dreams and conveys their content. A person who wakes up during the slow-wave sleep phase most often does not remember dreams.

The paradoxical phase of sleep turned out to be important for normal life. If a person is deliberately deprived of the paradoxical phase of sleep during sleep, for example, by waking him up as soon as he enters this phase, then this leads to significant disturbances in mental activity. This indicates that sleep, and especially its paradoxical phase, is a necessary state of preparation for normal, active wakefulness.

DREAM THEORIES.

Humoral theory: the cause of sleep is considered to be special substances that appear in the blood during wakefulness. The proof of this theory is an experiment in which a awake dog was transfused with the blood of an animal that had been deprived of sleep for 24 hours. The recipient animal immediately fell asleep. Currently, it has been possible to identify some hypnogenic substances, for example, a peptide that induces delta sleep. However, the presence of hypnogenic substances is not a fatal sign of sleep development. This is evidenced by observations of the behavior of two pairs of unseparated twins. In these twins, the embryonic division of the nervous system occurred completely, and the circulatory systems had many anastomoses. These twins showed different attitudes towards sleep: one girl, for example, could sleep, while the other was awake. All this indicates that humoral factors cannot be considered as the absolute cause of sleep.

Second group of theories - nervous sleep theories. Clinical observations have shown that with various tumor or infectious lesions of the subcortical, especially brain stem formations, patients experience various sleep disorders - from insomnia to prolonged lethargic sleep. These and other observations indicated the presence of subcortical sleep centers.

It was experimentally shown that when the posterior structures of the subthalamus and hypothalamus were irritated, the animals immediately fell asleep, and after the irritation stopped, they woke up. These experiments indicated a presence in the subthalamus. and hypothalamus sleep centers.

In the laboratory of I.P. Pavlov it was established that when a long-term and persistently unreinforced conditioned stimulus was applied or when a subtle differentiated conditioned signal was produced, the animals, along with the inhibition of their conditioned reflex activity, fell asleep. These experiments allowed I.P. Pavlov to consider sleep as a consequence of the processes of internal inhibition, as a deepened, diffuse inhibition that spread to both hemispheres and the nearest subcortex. This is how the cortical theory of sleep was substantiated.

However, a number of facts could not be explained by either the cortical or subcortical theories of sleep.

Firstly, observations of patients who lacked almost all types of sensitivity showed that such patients fall into a state of sleep as soon as the flow of information from the operating sense organs is interrupted. For example, in one patient, of all the sense organs, only one eye was preserved, the closure of which plunged the patient into a state of sleep. The patient, who retained sensation only on the dorsum of the forearm of one hand, was constantly in a state of sleep. She woke up only when they touched areas of her skin that remained sensitive.

Secondly, it remains unclear why hemispheric animals and newborn children, whose cortex is not yet sufficiently differentiated morphologically, sleep.

Many questions of the central organization of sleep processes were explained with the discovery of the ascending activating influences of the reticular formation of the brain stem on the cerebral cortex. It has been experimentally proven that sleep occurs in all cases of preservation of the ascending activating influences of the reticular formation on the cerebral cortex.

Along with this, descending influences of the cerebral cortex on subcortical formations were established. The influence of the frontal parts of the cerebral cortex on the limbic structures of the brain and hypothalamic sleep centers is especially important. In the waking state, in the presence of ascending activating influences of the reticular formation on the cerebral cortex, neurons of the frontal cortex inhibit the activity of neurons in the sleep center of the posterior hypothalamus. In a state of sleep, when the ascending activating influences of the reticular formation on the cerebral cortex decrease, the inhibitory influences of the frontal cortex on the hypothalamic sleep centers decrease.

An important circumstance directly related to the nature of sleep was the establishment of the fact of reciprocal relationships between the limbic-hypothalamic and reticular structures of the brain. When the limbic-hypothalamic structures of the brain are excited, inhibition of the structures of the reticular formation of the brain stem is observed and vice versa.

Consequently, the states of wakefulness and sleep are characterized by specific architectonics, a kind of “layout” of cortical-subcortical relationships.

During wakefulness, due to afferentation flows from the sense organs, the structures of the reticular formation of the brain stem are activated, which have an ascending activating effect on the cerebral cortex. In this case, neurons of the frontal cortex exert descending inhibitory influences on the cerebral cortex. In this case, the neurons of the frontal cortex exert descending inhibitory influences on the sleep centers of the posterior hypothalamus, which eliminates the blocking influence of the hypothalamic sleep centers on the reticular formation of the midbrain.

In a state of sleep, with a decrease in the flow of sensory information, the ascending activating influences of the reticular formation on the cerebral cortex are reduced, as a result of which the inhibitory influences of the frontal cortex on the neurons of the sleep center of the posterior hypothalamus are eliminated. These neurons, in turn, begin to inhibit the reticular formation of the brain stem even more actively. Under conditions of blockade of all ascending activating influences of subcortical formations on the cerebral cortex, a slow-wave stage of sleep is observed.

Hypothalamic centers, due to multifunctional connections with the limbic structures of the brain, can have ascending activating influences on the cerebral cortex in the absence of influences from the reticular formation of the brain stem.

The mechanisms discussed above constitute the cortical-subcortical theory of sleep proposed by P.K. Anokhin. This theory made it possible to explain all types of sleep and its disorders. It proceeds from the leading postulate that whatever the cause of sleep, the sleep state is associated with the most important mechanism - a decrease in the ascending activating influences of the reticular formation on the cerebral cortex.

The development of sleep is explained by a decrease in the ascending activating influences of the reticular formation due to inhibition of the activity of its neurons during electrical stimulation of the posterior hypothalamus.

The sleep of cortical-free animals and newborn children is explained by the weak expression of the descending influences of the frontal cortex on the hypothalamic sleep centers, which under these conditions are in an active state and have an inhibitory effect on the neurons of the reticular formation of the brain stem. The newborn's sleep is periodically interrupted only by the excitation of the hunger center located in the lateral nuclei of the hypothalamus, which inhibits the activity of the sleep center. In this case, conditions are created for the entry of ascending activating influences of the reticular formation into the cortex. The newborn wakes up and stays awake until the activity of the hunger center decreases by satisfying nutritional needs.

It becomes clear that in all cases of severe limitation of sensory information, which occurred in some patients, sleep arose as a result of a decrease in the ascending activating influences of the reticular formation of the brain stem on the cortex.

The cortical-subcortical theory of sleep explains many sleep disorders. Insomnia, for example, often occurs as a result of overexcitation of the cortex under the influence of smoking or intense creative work before bedtime. At the same time, the descending inhibitory influences of frontal cortex neurons on the hypothalamic sleep centers are enhanced and the mechanism of their blocking effect on the reticular formation of the brain stem is suppressed.

Shallow sleep is observed with partial blockade of the mechanisms of ascending activating influences of the reticular formation on the cerebral cortex. Prolonged, for example, lethargic sleep can be observed when the centers of the posterior hypothalamus are irritated by a vascular or tumor inflammatory process. In this case, the excited cells of the sleep center continuously exert a blocking effect on the neurons of the reticular formation of the brain stem.

The concept of “sentinel points” as partial wakefulness during sleep is explained by the presence of certain channels of reverberation of excitations between subcortical structures and the cerebral cortex during sleep against the background of a decrease in the bulk of the ascending activating influences of the reticular formation on the cerebral cortex. The "sentinel point" or focus may be determined by signaling from internal organs, internal metabolic needs and external vital circumstances. For example, a nursing mother may sleep very soundly and not respond to strong enough sounds, but she quickly wakes up when her newborn baby moves slightly. Sometimes "watchdogs" can have prognostic value. For example, in the case of pathological changes in a particular organ, increased impulses from it can determine the nature of dreams and be a kind of prognosis of a disease, the subjective signs of which are not yet perceived in the waking state.

The hypnotic state can be defined as partial sleep. Perhaps the hypnotic state is created due to the excitation of limbic-thalamic structures against the background of the remaining portion of the ascending activating influences of the reticular formation on the cerebral cortex, which determine behavioral activity.

Selective activation of the limbic structures of the brain is observed when the brain is exposed to electrical current pulses during so-called electrosleep, and a hypnosis-like state is formed.

Sleep, as a special state of the body and, above all, the state of the brain is characterized by specific cortical-subcortical relationships and the production of special biologically active substances, is used in the treatment of neurotic, asthenic conditions, relieving psycho-emotional stress and in a number of psychosomatic diseases (early stages of hypertension, heart rhythm disorders , ulcerative lesions of the gastrointestinal tract, skin and endocrine disorders).

Pharmacological sleep is inadequate in its mechanisms to natural sleep. Various "sleeping pills" drugs limit the activity of different brain structures - the reticular formation of the brain stem, the hypothalamic region, and the cerebral cortex. In this case, the natural mechanisms of the formation of sleep stages, its dynamics, and awakening are disrupted. In addition, during pharmacological sleep, the processes of memory consolidation, processing and assimilation of information, etc. may be disrupted. Therefore, the use of pharmacological agents to improve sleep should have sufficient medical justification.