What is sleep
As soon as most researchers came to the conclusion that during sleep the human brain rests, as neurologists appeared methods of electrophysiology, and scientists were able to record the activity of neurons in the cerebral cortex. It turned out that during sleep, neurons not only do not rest, but, on the contrary, work even more actively. What for? Maybe in a dream a person is looking for answers to questions that torment him? No, scientists are sure that everything is much more prosaic. While we sleep, the brain is busy … repairing the body. It establishes relationships with internal organs1.
Don’t believe? But in vain! After all, everyone knows that even with a cold, bed rest is prescribed and more sleep is recommended. Sleep is necessary to restore spent strength and energy, strengthen the nervous and immune systems, normalize metabolism, and reduce the risk of developing many diseases. And lack of sleep, like excess sleep, is harmful.
The average sleep rate for an adult is 7-8 hours a day. Scientists have precisely established that saving on night rest will come out sideways: less than 5 hours a day increases the risk of heart attacks by 45%. And when you switch to a 4-hour sleep, the body begins to absorb glucose more slowly, so the risk of diabetes increases.
What else is known about sleep, the mysterious state in which the human body recovers? It consists of two main parts: slow and fast2. These phases alternate, with REM sleep predominating in babies, and slow sleep in adults. During sleep, blood pressure decreases, heart rate decreases, breathing becomes less frequent, body temperature decreases by a few tenths of a degree2. But it’s all about slow sleep.
REM sleep, on the other hand, differs significantly in its characteristics: the muscles are as relaxed as possible, while the encephalogram resembles a picture of wakefulness.2. It is upon awakening at this moment that most people recall vivid, often emotionally rich dream pictures.
How much do we remember? Doctors say not much. In healthy adults, REM sleep consists of 4–6 episodes and lasts 20–25% of total sleep time. In this case, one cycle of fast or slow sleep lasts for 90 minutes.
When do we have dreams that we consider prophetic? Mostly before dawn. And the reason for this is that the deep stages of sleep prevail in the first half of the night, and REM sleep in the second.
All people are able to dream, but they can not always remember them after waking up. Some dreams are remembered as dull and discolored, while others, on the contrary, are bright and saturated. For a long time, night “pictures” have been associated with the other world, and the priests interpreted them according to special dream books, looking for an encrypted message in dreams. As psychology and physiology began to develop in the late 19th century, interest in dream interpretation took on a scientific context. True, most researchers agreed that dreams are still a stream of the unconscious.
But the father of psychophysiology, Sigmund Freud, found a rational grain in this and suggested using the method of associations to interpret dreams. Behind all the dream pictures, Freud saw a desire repressed by the mind, usually sexual3. Carl Gustav Jung proposed his own version, calling sleep the unconscious life of the soul.
Today’s somnologists call for memorizing the smallest details of dreams. If you have been watching a dream television series at night for several days, months and even years (maybe not even on the same topic, but with the obligatory presence of the same character, object, scene), then they must be considered together, compare, pay attention to similarities and differences. Dreams are, in a way, an intense workout for the body.
Why does a person need sleep
As our expert explains psychologist-consultant, member of the Russian Psychological Society Elena Akhromeeva, sleep helps the human body in several ways at once:
1. To be slim
Lack of sleep reduces insulin sensitivity. This, in turn, threatens to change the absorption of glucose from the blood. It turns out this situation: the cells do not respond to the presence of glucose in the blood. The body receives the signal “I’m hungry”, and the person experiences a feeling of hunger. Therefore, chronically sleep deprived people are often overweight.
2. To prevent type 2 diabetes
Sleep deprivation is also linked to type XNUMX diabetes. Due to a malfunction, the cells send a signal that there is not enough insulin in the body, so the pancreas begins to produce it in excess. In the end, the gland “gets tired”, its function is depleted, so a person is forced to receive insulin from the outside – for example, by injection.
3. To have a strong immune system
When a person sleeps in the dark, his body produces the hormone melatonin, which has a positive effect on the functioning of the immune system.
4. To release growth hormone
Growth hormone is important not only for children. In adults, this hormone is responsible for tissue repair and healing. By the way, antibodies after vaccination are better produced during sleep.
5. To process information
Neuroscientists have proven that sleep is essential for information processing. It is during sleep that information from short-term memory passes into long-term memory.
6. To be mentally healthy
Due to lack of sleep, mental stress increases in a person, mood decreases, and disorders of the autonomic nervous system occur.
Why do we dream
As our expert explains, dreams are associated with REM sleep (aka REM sleep). During the night, a person manages to go through this phase several times – in total, no more than 3 hours.
During the REM phase, the brain forms new neural connections, creates new associative pathways. That is why it is very important for a person in an emergency situation (after an accident, a man-made accident, a plane crash, during military operations, etc.) to stabilize from shock, return to the “here and now” state, talk with a specialist before the first sleep. The fact is that during sleep, all impressions of the event, all difficult, not fully experienced feelings will be “processed” and deposited in the subcortex of consciousness. With unfavorable development, this threatens with post-traumatic stress disorder.
– During sleep, the work of the prefrontal cortex of the brain is suppressed, and the preconscious and unconscious functions of the psyche are activated. That is why we see dreams in which we commit insane, shameless acts, we feel something that does not correlate with the plot of the dream. That’s why Freud said that “dreams are the royal road to the unconscious.” During sleep, both hemispheres work. The left is responsible for the storyline. The right one is for the visualization of sleep and emotional coloring, – says psychologist Elena Akhromeeva.
Popular questions and answers
Is it possible to learn in a dream, how to remember colorful dreams and other popular questions are answered by our expert – a psychologist-consultant, a member of the Russian Psychological Society Elena Akhromeeva.
Is it possible to study in a dream?
How to remember your dreams?
What happens if you don’t sleep at night?
Sources of:
- Sleep is brainwashing. Danilenko K.V. Science First Hand Journal, 2014. https://cyberleninka.ru/article/n/son-promyvaet-mozgi/viewer
- Modern concepts of “slow” and “REM” sleep and their role in the genesis of Alzheimer’s disease (literature review). Madaeva I.M., Berdina O.N. Journal Acta Biomedica Scientifica, 2017
- Exploration of dreams. Gemenetzis Constantine. HORIZON magazine. Phenomenological research, 2016. https://cyberleninka.ru/article/n/razvedyvanie-snovideniy