William C. Dement, M.D., Ph.D., is the world's leading authority on sleep, sleep deprivation, and the diagnosis and treatment of sleep disorders. In 1970 he founded the world's first sleep disorders center at Stanford University. In 1975 he launched the American Sleep Disorders Association and served as president for its first twelve years. Each year since 1971 he has taught the popular "Sleep and Dreams" course at Stanford University and has written the first undergraduate textbook in the field. He was also chairman of the National Commission on Sleep Disorders Research, whose final report led directly to the creation of a new agency within the National Institutes of Health, the National Center on Sleep Disorders Research. He lives with his family in northern California.

Christopher Vaughan is the author of How Life Begins: The Science of Life in the Womb, named as one of the best books of 1996 by the National Association of Libraries. He lives in Palo Alto, California, with his wife and two children.