Kleitman, father of sleep research

Nathaniel Kleitman (Ph.D., ’23), Professor Emeritus in Physiology, pioneer in sleep research and co-discoverer of REM sleep, died in Los Angeles Friday, Aug. 13, at the age of 104.

The world’s first scholar to concentrate entirely on sleep, Kleitman is universally recognized as the father of sleep research. Before him, few scientists had systematically investigated the intricacies of sleep, which previously had been dismissed as a state of quiescence.

“Nathaniel Kleitman was the first scholar of sleep,” said Allan Rechtschaffen, Professor Emeritus in Psychiatry and former director of the University’s Sleep Research Laboratory. “He was the first to take a deep, complete, absorbing interest in sleep, the first to compile the existing knowledge of sleep into a unified text, and with his students, the first to map out the multiple discreet stages of sleep.”

“Kleitman put sleep on the map,” said Dr. William Dement, director of the Sleep Disorders Clinic at Stanford University and one of Kleitman’s former students. “He never really got the spotlight because he chose to specialize in an area that was seen as a backwater at the time, but there are now nearly six billion people on earth. They all spend one-third of their lives asleep, and for that rather substantial side of humanity, he stands alone as the major figure. Without Kleitman getting the rest of us interested in sleep research, millions of lives would have been adversely affected.”

Kleitman joined the University faculty in 1925 and established the world’s first sleep laboratory, filled with measuring devices designed and built by himself and his students. In 1939, he published the first major textbook on sleep, Sleep and Wakefulness, which rapidly became the bible of sleep researchers everywhere.

In September 1953, as a result of work in his laboratory, Kleitman and one of his students, the late Eugene Aserinsky, reported the discovery of rapid eye movements during sleep and suggested the association of these eye movements with dreaming. This discovery is often described as the beginning of modern sleep research for it demonstrated that there were at least two major kinds of sleep and that sleep included active brain processes.

In the 1950s, Kleitman and Dement refined the techniques of all-night sleep recording, including measurements of eye motion and EEGs of brain activity. These measurements then were used to chart the sequence of sleep patterns, including dreaming, over the course of a night.

Later, Kleitman proposed the existence of a basic rest-activity cycle, or BRAC, during both sleep and wakefulness.

Kleitman often used himself, friends and family as research subjects for his many experiments, keeping precise records of his two daughters’ sleep habits from infancy through college. He once kept himself awake for 180 consecutive hours to study the effects of sleep deprivation. He and an associate spent more than a month 150 feet underground in Mammoth Cave, Ky., to chart their daily fluctuations in wakefulness and body temperature. They chose Mammoth Cave as their research site to be free from the regulating influence of sunlight and daily schedules and to determine how altering the normal 24-hour routine of sleep and wakefulness affected mental performance.

Kleitman was born in Kishinev, Russia, in 1895, arrived in the United States in 1915 and became a naturalized citizen in 1918. He received his B.S. from the College of the City of New York in 1919, his A.M. from Columbia University in 1920 and his Ph.D. summa cum laude from the University of Chicago in 1923.

Kleitman is survived by two daughters and their husbands: Hortense Kleitman Snower and William Snower Jr. of Kansas City, Mo., and Esther Kleitman and Steven A. Moszkowski of Los Angeles.