The author is writing for the interested layman as well as the specialist, presenting the current status of experimental research on psychological aspects of sleep. Several recently published popular accounts of sleep research have emphasized the physiological work. It is a little disappointing that the first chapter fails to convey the great excitement generated in the whole field of sleep research by the nature of recent findings, and the formulation that there are two entirely different kinds of sleep, so different physiologically that some researchers prefer to think of one of them—REM [rapid eye movement] sleep—as a "third state of existence."
The second and third chapters deal with mental activity, during REM sleep, and the fourth and fifth deal with mental activity during NREM sleep. The book definitely picks up in the second chapter, which is a clear and compelling review of research findings regarding the association of dreaming and