At every moment of our life we find ourselves in one of the two basic states of our existence: wakefulness or sleep. In reality, we have full contact with the outside world and the senses provide us with a huge amount of information permanently. After being processed by the brain, we react to them with gestures, actions or words.
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The mysterious activity of the brain during sleep .
During sleep, while closing the eyes, we block visual stimuli. The brain is excluded from its activity by extinguishing the impending senses. Our movements are limited to the minimum necessary and speech blocked. At that time, the brain deals with its internal activity, which until today is still shrouded in mystery.
Sleep is the regeneration and ordering of information and experiences?
More and more often it is stated that sleep plays the role of regeneration time of the central nervous system and the whole organism. In our "central computer" there is probably an erasure of accidental and irrelevant information and the transfer of records from short-term memory to non-volatile memory - to "hard disk". Thus, many aspects of this complex disorder - extremely important to our mental ability - are manifested in the sleep disorders or insomnia.
Neurophysiology studies of sleep
Physiologists have examined the depth of human sleep with "standardized noise" and have stated that the deepest sleep is made by people at the beginning of the night. Later, with the passage of hours, the sleeper wakes up much lighter noise. In the twenties of the twentieth century, Hans Berger studied the bioelectric activity of the brain. Saving it in the form of long graphs from various parts of the human skull is now called electroencephalography (EEG).
The states of sleep and wakefulness can be characterized by the three most important registrations - physiological signals: bioelectrical activity of the brain, eye movements and muscular activity.
Research on brain processes during sleep
The bioelectric activity of the brain consists of the resultant discharge of a tiny electric charge produced by billions of nerve cells from which our brain is built. These changes in functional bio-currents are captured by electrodes placed on the skin of the skull, and then reinforced by an electroencephalograph, recorded on a long ribbon of paper and after digital processing recorded in the computer's memory. American Nathaniel Kleitman in 1939 was a forerunner of polysomnography, and his pupil Eugene Aserinsky described in 1952 the phenomenon of rapid eye movement during sleep (REM). Eye movements also cause changes in functional currents and therefore it is possible to record them in the form of an electrocoagulogram. Tensions and muscle arousal are in turn recorded in the form of an electromyogram. Usually, the polysomnographic recording is performed during sleep and wakefulness, sometimes on a round-the-clock basis, and appropriate computer programs enable the analysis of the sleep and wakefulness of a given patient.
Other physiological processes during sleep
Of course, during the sleep the rhythms and work of the heart and breath are also recorded, because during sleep sometimes there is paroxysmal apnea as well as cardiac arrhythmias.
A full-fledged and defective dream
Neurophysiological research reveals some basic findings, one of the most important is the statement of the REM sleep phase and the dreaming phenomena associated with it. Some people have the impression that they never dream, others retain foggy memories of their dreams, and yet others sometimes remember some of their dreams.Sleep with fewer REM phases or lack of these phases is a defective sleep, or a kind of insomnia. So in order not to suffer from insomnia, not only do we have to fall asleep, but also the "prescribed" amount of time to experience dreams.
The sleep phases - Rem and not - and the feelings and behavior of the sleeper
It was found that people awakened during the period of REM reported the emergence of rich dreams at the same time. It was found that rapid eye movements, in the sleep phase called REM, are associated with the complexity of dreamed-up dream images. Also observed during this time traces of facial vibrations in the subjects. Today we know that man's dream has a complicated nature - including several phases of the so-called nieREM, so-called 'K' and 'sleep spindles'. After them, the REM period lasts from a few to several minutes. The REM period ends one sleep cycle. For a healthy, or natural, sleep, it must have about 4-5 such cycles, each of which ends with the REM phase.
Biochemical record of the sleep rhythm
Human biological rhythms, including the rhythm of sleep and wakefulness, are generated by periodic changes in biochemistry in the central nervous system. The rhythms of sleep and wakefulness are maintained by activity in the supra crucifers of the hypothalamus under the influence of external lighting conditions in a 24-hour cycle. In people who are in the dark (cave experiments) or in blind people who do not have the perception of light, there is a disorder of many circadian rhythms, eg melatonin, cortisol, body warmth and phases of sleep - vigil. It was found that differences in the secretion of the pineal hormone melatonin reach a fourfold increase in the night. Thus, the change in the sleep and wakefulness cycle is the basic regulator of melatonin secretion. The highest secretion of this hormone occurs in man at night. In addition, it has been shown that the intensity of its secretion significantly decreases with age.
Sleep rhythm regulator - melatonin
The circadian rhythm of the pineal gland - melatonin - is about 6 years old. The peak of excretion of nocturnal melatonin takes place between the fourth and the tenth year of life. After this period there is a decrease in its secretion and about 45 years of age it is most pronounced. It is sometimes called "melatoninopauza". In people around 70, it is several times smaller than before puberty. This can also explain the difficulty of sleeping in older people. Therefore, this hormone has been used to treat certain types of sleep disorders.
When work norms are exceeded and sleep is lacking...
In recent years, the Glasgow clinic dealing with sleep testing has done a lot of interesting research. With the help of Holter-like equipment, polisomnographic records of professional truck drivers were recorded on a daily basis. It turned out that when work norms are exceeded and the time spent by drivers on the road in their records appears, so-called "Elements of the microsound". These repetitive short, usually second, falling asleep occur while driving. The car is able to travel about 50 meters during this time and cause a serious accident due to lack of control. It seems that "Holter" sleep tests of drivers and other employees will find a wide application in the future.
Harmfulness of insomnia
Experiments on sleep deprivation (forced insomnia) have shown how harmful real insomnia is. After a time (individual for each person) from 50 to 500 hours of insomnia, various (fortunately transient) mental disorders appeared in the subjects. They were delusions, hallucinations and depersonalization.
Symbolic poetic motto of the text:
A dream? - ah, this world is silent, deaf, mysterious,
Life of the soul, is it not worth researching people!
Who will take his place, who will count his time!
A. Mickiewicz. Forefathers cz. AND
Doctor of Medicine Janusz Krzyżowski
Psychiatrist
Private office tel. 22 833 18 68
00-774Warszawa, Dolna 4 lok. 15
