We often hear that humans spend one third of their lives sleeping—and most of us would up that fraction if we could. Whether we’re curling up for a brief lunchtime catnap, catching a doze on a sunny afternoon, or clocking our solid eight hours at night, sleeping is normally a reliable way to rest our heads and recharge our minds. And our bodies demand it: without sufficient sleep, we experience changes in mood, memory loss, and difficulty concentrating. Symptoms of sleep deprivation can be severe, and we know that sleep is essential for restoring and rejuvenating muscles, tissue, and energy. And yet, although science is making remarkable inroads into the workings and functions of sleep, many aspects still remain a mystery.   In The Science of Sleep , sleep expert Wallace B. Mendelson explains the elements of human sleep states and explores the variety of sleep disorders afflicting thousands of people worldwide. Mendelson lays out the various treatments that are available today and provides a helpful guide for one of life’s most important activities. By offering the first scientific yet accessible account of sleep science, Mendelson allows readers to assess their personal relationships with sleep and craft their own individual approaches to a comfortable and effective night’s rest.   Addressing one of the major public health issues of the day with cutting-edge research and empathetic understanding, The Science of Sleep is the definitive illustrated reference guide to sleep science.  In this attractive, artistic, informative, engaging, and lucidly written book, Mendelson provides an excellent introduction to sleep science and sleep medicine. He very effectively communicates with personal insights and perspectives not possible in published meta-analyses, regulatory prescribing information, and formal clinical guidelines. (David N. Neubauer MD, sleep specialist, in Sleep and Vigilance)The book is really well written, easy to understand and I would recommend to anyone working in the field of sleep as well as those who just simply have an interest in finding out more. The book is divided into really clear chapters so its easy to pick and choose which areas of interest I wanted to read about.(Kathryn Pinkham, Founder Of The Insomnia Clinic, Chiltern Hospital, Bucks, UK) Sleep is one of the most important health issues of our day, and so many of us want to better understand it and use science to guide our choices and habit changes. Wallace Mendelson's book is a beautiful and digestible summary of the latest scientific understanding of sleep, perfect for nerding out on this most vital topic. Ellen Vora MD, Psychiatrist, New York Wallace B. Mendelson, M.D.,  has more than forty years of experience in sleep research and clinical care. He is retired professor of psychiatry and clinical pharmacology and former director of the Sleep Research Laboratory at the University of Chicago, and former president of the Sleep Research Society. The Science of Sleep What It Is, How It Works, and Why It Matters By Wallace B. Mendelson The University of Chicago Press Copyright © 2017 Wallace B. Mendelson All rights reserved. ISBN: 978-0-226-38716-1 Contents INTRODUCTION, ONE HUMAN SLEEP, TWO SLEEP IN ANIMALS, THREE THE EFFECTS OF SLEEP DEPRIVATION, FOUR CIRCADIAN RHYTHMS AND SLEEP, FIVE A LIFETIME OF SLEEP, SIX HORMONES AND SLEEP, SEVEN SLEEP DISORDERS, EIGHT INSOMNIA, GLOSSARY, SELECTED BIBLIOGRAPHY, INDEX, ACKNOWLEDGMENTS, CHAPTER 1 HUMAN SLEEP We can measure our lives on many different levels. A life, for instance, could be considered the period in which a person's heart beats a certain number of times (perhaps 3 billion), or enjoys Saturday nights (about 3,600), or experiences periods of peacefulness (all too few), or feels the joy of love (hopefully at least once). In the same way, sleep, which occupies perhaps one-third of our existence, can be viewed on a number of different levels. It is a process that can be measured physiologically while at the same time understood as a psychological experience, and even a social behavior. In this book we will explore some of these aspects of sleep. Human sleep is a reversible period of decreased consciousness and responsiveness, comprised of two distinct states known as rapid eye movement (REM) and non-rapid eye movement (NREM) sleep. Although the modern era of sleep research began in the 1950s with the description of REM sleep, its roots go back to the 1920s with the discovery of the human electroencephalogram, or EEG. Our growing understanding of sleep has been influenced by some remarkable individuals who (sometimes while looking for something else) made crucial observations about sleep, by developments in psychology and technology, and even by world events. WHAT IS SLEEP? The many qualities of sleep Sleep is a period of recurring behavioral quiescence, which has several qualities, including decreased awareness of and responsiveness