Sleep riddles. From insomnia to lethargy

Dream and dreams have always enveloped a secret inaccessible to the understanding of a person. Why does a living creature lose contact with the outside world every day? Why sleep? Should I attach importance to dreams and why do people see them at all? Sleep riddles were looking for explanations - both mystical and philosophical, and physiological and medical. The emergence of the latest methods of studying the processes occurring in the brain, modern experimental opportunities made it possible to learn a lot about why, how and how much we actually sleep. What today"s science knows about dreams - as well as about states such as Insumonia, lethargic sleep, conscious dreams and much more - and is told in this book