Nathaniel Kleitman was Professor Emeritus in Physiology

Physiology

Physiology is the science of the function of living systems. This includes how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system. The highest honor awarded in physiology is the Nobel Prize in Physiology or...

 at the University of Chicago

University of Chicago

The University of Chicago is a private research university in Chicago, Illinois, USA. It was founded by the American Baptist Education Society with a donation from oil magnate and philanthropist John D. Rockefeller and incorporated in 1890...

. Author of the seminal 1939 book Sleep and Wakefulness, he is recognized as the father of American sleep research. Kleitman, along with his student Eugene Aserinsky

Eugene Aserinsky

Eugene Aserinsky , a pioneer in sleep research, was a graduate student at University of Chicago in 1953 when he discovered REM sleep. He made the discovery after hours spent studying the eyelids of sleeping subjects...

, was the first to discover rapid eye movement (REM) sleep and demonstrate that it was correlated with dreaming and brain activity. Nathaniel Kleitman was born in Kishinev, Russia, in 1895. He emigrated to the United States in 1915, obtained a PhD from the University of Chicago's Department of Physiology in 1923 (thesis "Studies on the physiology of sleep"), and joined their Faculty in 1925. Two of his students later became well known sleep researchers themselves: the aforementioned Eugene Aserinsky and William Charles Dement

William C. Dement

William Charles Dement is a pioneering US sleep researcher, and founder of the Sleep Research Center, the world's first sleep laboratory, at Stanford University. He is a leading authority on sleep, sleep deprivation, and the diagnosis and treatment of sleep disorders such as sleep apnea and...

.