About the book: 1970 / The book by Professor A. M. Vein is devoted to an important and little-studied problem: the role and significance of sleep and wakefulness in human life. It examines the causes of sleep and wakefulness and the mechanisms of these conditions, as well as the regulation of sleep and wakefulness. The author seeks to give an idea of ​​the history and current state of science studying this problem. Much attention is paid to the description of two phases of sleep: slow (orthodox) and fast (paradoxical, or sleep with dreams). The features of mental activity during sleep, the main forms of sleep and wakefulness disorders and methods of regulating disorders are examined. The book in a popular form introduces readers to the research of the author and other scientists on this problem. It is intended for a wide range of teachers, students, and researchers.