The interest in studying the effects of sleep deprivation (deprivation) is based on evidence that people who have been deprived of sleep for a long time often develop disorders of thinking and perception, similar to those observed in schizophrenia.
Full deprivation.
After 24–28 hours of complete sleep deprivation, the electrical activity of the brain decreases and electroencephalogramsbecomes about the same as when falling asleep, although the person looks awake and moves with his eyes open.People who are deprived of sleep are able to maintain effective activity for a very short time;if they work for a long time, they make a large number of mistakes, especially in conditions of limited time.
On the first night, when the subject is allowed to fall asleep after three or four days of complete sleep deprivation, there is a significant increase in the duration of the 4th stage, with a relative reduction in the phase with rapid eye movements .In the following nights, a compensatory increase in the duration of sleep occurs with rapid eye movements .At the same time, after a long sleep deprivation (from eight to ten days) on the first restorative night, the duration of both sleep with rapid eye movements and stage 4 increases .
Under conditions of limiting the duration of sleep, but not completely depriving it, lengthening of the 4th stage occurs due to the reduction of other stages of sleep withoutrapid eye movements , predominantly of the 3rd stage.
Selective deprivation.
If a person is selectively deprived of only the 4th stage, then later, as soon as he is allowed to sleep without interference, its compensatory lengthening occurs.When a person is awakened only during sleep with rapid eye movements , then falling asleep again, he will more often plunge into this phase of sleep.This effect is becoming more pronounced on each subsequent night of deprivation.As soon as the subject is allowed to sleep through the rest of the night, he will experience a significant increase in the total duration of sleep with rapid eye movements .It is now established that sleep deprivation with rapid eye movements does not lead to pronounced mental changes.
SLEEP DISORDERS
Sleepwalking and night terrors
associated with impaired activation and most often occur at the beginning of the night, when the 3rd and 4th stages prevail.Both of these disorders usually last only a few minutes.When diving, a person often wanders around the same place, confusion is written on his face, and actions are uncoordinated .Previously it was widely believed that the lunatic seemed to lose its vivid dreams, but sleepwalking usually occurs during sleep withoutrapid eye movements (in the 3rd and 4th stages).Night terrors are accompanied by a piercing cry, motor and autonomic arousal.The heart rate rises sharply, sometimes a man with a mad look, screaming, quickly rushes out of the room.Children usually forget these episodes completely, and in adults only fragmentary memories remain.Both types of disorders are more common in childhood and are likely to be associated with delayed maturation of the central nervous system.
Nightmares
– occurring at night, states of intense anxiety and fear associated with vivid, emotionally intense dreams.This is a common cause of sleep disorders, as people wake up from a nightmare, do not sleep for a long time, afraid to fall asleep again or analyze what they see in a dream.Nightmares, which in essence are dreams, arise during sleep with rapid eye movements and are different from nighttime fears associated with the 3rd and 4th stages.Nightmares in children are a manifestation of their emotional maturation, they reflect temporary difficulties in distinguishing reality and fantasy.Nightmares in adults are more often associated with psychological factors.
Nocturnal enuresis ,
or urinary incontinence during sleep, also occurs in the sleep phase withoutquick eye movements .Although the omissionurine is possible at any time of the night, most often it is observed in its first third, when the 3rd and 4th stages predominate.Most episodes occur in the 4th stage, and urination begins at the moment of transition to the 2nd or 1st stage.If a person at this moment wakes up and changes his underwear, he cannot tell about any dreams and, having fallen asleep again, will have a normal sleep pattern.If it remains wet, then the 3rd and 4th stages do not appear for several hours, and if a person wakes up in a subsequent period with rapid eye movements , he may recall fragments of dreams related to incontinence.
Narcolepsy, hypersomnia , sleep apnea.
Disorders characterized by pathological drowsiness include narcolepsy and various options for hypersomnia , including sleep apnea.Narcolepsy is manifested by short-term sudden bouts of irresistible sleepiness.In most cases, patients also have cataplexy (sudden muscle relaxation), and attacks of falling asleep are accompanied by an appearance on electroencephalogramSame changes as during sleep with quick eye movements .
Unlike narcolepsy, with hypersomnia, periods of increased daytime sleepiness and bouts of falling asleep are usually longer and last from one to several hours.This disorder is due to both psychological and organic factors.The most studied form of periodichypersomnia – Kleine-Levine syndrome;it occurs more often in young men and is accompanied by increased appetite.Hypersomnia may also be associated with impaired brain function due to a tumor, vascular lesion, encephalitis, toxic encephalopathy, endocrine or metabolic disorders.
Apnea (respiratory arrest) in sleep is characterized by a complete cessation of gas exchange, lasting more than 10 s, sometimes over 1 min.The exact cause of this condition is unknown, but it may be due to the cessation of chest movements, impaired upper airway patency, or a combination of these factors.It is often accompanied by increased daytime sleepiness.In mild cases, sleep apnea can be eliminated with drugs and weight loss.In severe cases, surgery is sometimes required.
Insomnia (insomnia).There are three types of insomnia : the first of them (the most frequent) falls asleep, the second – maintaining sleep, while the third is marked by an early final awakening.The causes of insomnia are multiple.It can occur in response to transient stress, chronic emotional conflict, or physical illness.Insomnia is often caused by psychostimulants and even caffeine contained in coffee or coca-cola, and sometimes a violation of the usual regime.Sleep disorder often occurs also in the aging process.the development of chronicInsomnia is promoted by various factors, including emotional conflicts, an abnormal (non-adaptive) reaction to stress, the constant expectation of poor sleep, and the associated anxiety.Effective treatment of chronic insomnia requires an integrated approach and includes psychotherapy, behavioral therapy and, as an additional measure, the rational use of drugs.
DREAM AND DISEASES OF THE INTERNAL BODIES
Heart Disease.
With severe stress or emotional stress, patients with coronary heart disease often develop angina pectoris – a sudden intense chest pain.A study of sleep in these patients showed that 82% of strokes at night occurs during sleep with rapid eye movements .Dreams preceding arousal with pain in the heart usually fall into two related categories: they reflect either intense physical exertion or fear, anxiety and depression.Patients who can reproduce the content of the dream, often note the feeling of pain in the chest during sleep.
Duodenal ulcer.
It has been shown that in patients with duodenal ulcer at night, 3–20 times more hydrochloric acid is secreted in the stomach than in healthy people, and a significant increase in gastric secretion often occurs during sleep with rapid eye movements .In healthy people, such changes in secretion during sleep with rapid eye movements do not occur.This fact may explain the nocturnal deterioration of the condition, which often occurs in patients with duodenal ulcer.The study of these patients, as well as patients with coronary heart disease, shows that sleep with rapid eye movements is a very stressful period, at least in certain diseases.
Bronchial asthma.
Patients with asthma at night often develop asthma attacks, which leads to sleep disturbance.Asthma attacks can occur at any stage of sleep.Patients have a significant increase in wakefulness due to frequent nighttime awakenings and an early final awakening;in addition, they have shortened the 4th stage of sleep – possibly due to repeated awakenings.
DRUGS AND DREAM
Sleep disorders cause the majority of psychoactive , i.e.affecting mental activity.These include central nervous system stimulants (for example, amphetamine ), antidepressants, sedatives (for example, hypnotics and tranquilizers).The stimulating effect of nicotine can also disrupt sleep.Awakening at night and can cause alcohol.
Especially adverse effect on sleep has the abuse of sleeping pills.Most hypnotics retain their therapeutic effect if the period of their use does not exceed two weeks, but they are often taken for months and even years.With constant use, addiction to these drugs develops, which is why it is necessary to gradually increase the dose to a value that violates the structure of sleep, which further upsets sleep in general.In patients who are trying to stop taking benzodiazepine drugs, insomnia may increase (recoil).When you try to stop taking sleeping pills after several days of their use, there may be an increase in sleep periods with rapid eye movements and nightmares.