In the world of dreams: what actually happens to your brain at night
Every time you go to sleep, your brain remains awake, doing several important things at once: recharging its “batteries”, fixing what you have experienced and learned in a day (including trying to get rid of the worst memories), and , finally, organizes for you unique “movie screenings” - dreams.
We propose to spy on the sleeping mind along with the BBC Future and find out what is going on in it at different stages of sleep.
1st hour after bedtime: REM sleep
When we begin to fall asleep, the body “turns off” and a kind of paralysis sets in, which provides us with a state of rest. At this stage, the brain puts the body into sleep mode, turning off the centers of activity one by one.
But sometimes during this process there are failures or "glitches", causing extremely unpleasant sensations. For example, “exploding head syndrome” - when, due to a sudden outbreak of activity in the areas responsible for sound processing, it seems to you that all brain cells are simultaneously firing, so that an “explosion” occurs in your head.
Or another common disorder: it seems to you that you are not sleeping, but you cannot move . By the way, both of these syndromes can explain some "supernatural visions", for example, ghosts and UFOs.
2nd hour: immersion into the deepest sleep
Johann Fussley's famous nightmare, 1781
If you sleep only for 6 hours for 12 nights in a row, then a sleepy “intoxication” will occur - just like a person with real blood alcohol. That is, the language will become stupid, coordination and memory problems will begin.
3rd hour: return to the first, drowsy stage
“Sleep caused by the flight of a bee around a pomegranate, a second before awakening”, Salvador Dali, 1944
At this time, as a rule, dreams. They are often crumpled and chaotic - this is a sign that your brain is gathering disjointed thoughts and memories together, trying to fix them in your memory.
This also explains why hallucinations begin in a sleepless person. When there is no possibility to organize memory in a dream, night visions penetrate into reality, and it becomes difficult for a person to separate one from the other.
5th hour: exit from the deep phase, light sleep
It's time for lunatics walking in a dream. Somnambulism is rare and mostly in young people with mental disabilities. But it can also be transmitted by inheritance: the probability that a person will be a lunatic is 10 times higher if one of his close relatives walks in a dream.
Lunatics often speak in their sleep, but they are not able to respond to you and generally engage in dialogue. Usually they do not remember what they did and what they said in their dreams.
6th hour: the deepest slow sleep
This is the most important hour for memory to work perfectly, and one of the main reasons why you should sleep at all: the slow fluctuations of the electrical activity of the brain help to unite and organize the memories of the past day. In addition, in a dream, it is easier to survive unpleasant and painful moments and, as they say, “clear your head”. No wonder there is a saying “the morning of the evening is wiser”.
7th hour: again, fast sleep with dreams
Engraving by Francisco Goya "The Sleep of Reason Produces Monsters", ca. 1799
Over the course of the night, the phases of REM sleep become longer, therefore the dreams seen in the morning are best remembered. And then nightmares are more likely.
After 8 hours of sleep
A full night's sleep helps to improve mood and strengthen memory. In theory, you should wake up after another light stage of sleep - then it will be easier for you to get up and you will feel cheerful and fresh.