Deep sleep without any dreams has long been equated with a state of unconsciousness, but research by the University of British Columbia shows that this is not entirely true. Consciousness does not turn off completely, even when sleep is especially deep.
Sleep without dreams, relatively speaking, can be divided into three stages. One of them involves the appearance in a dream of thoughts and even certain images, however, you do not take the same part in what is happening as when you see a dream. Another involves recognizing ambient sounds, such as an alarm ringing. And finally, the third is that a person, even if he does not understand this, realizes that he is sleeping.
Therefore, as you can see, everything is not as simple as it seemed initially. Sleep, in principle, is a rather complex mechanism, and therefore everything is not so unambiguous that you fall asleep, fall out of reality for a certain time, and then wake up again. Also, scientists intend to find out what exactly happens in the brain when a person starts walking in a dream. And they are absolutely sure that the discoveries made will be of great help to them in this and will help them get closer to solving all the processes occurring in the body in a dream.
Semenenko Kirill