Nathaniel Kleitman

Nathaniel Kleitman  (April 26, 1895 - August 13, 1999) was Professor Emeritus in Physiology at the University of Chicago.

He is recognized as the father of sleep research and is credited as the first scholar to study sleep. Kleitman, along with his student Eugene Aserinsky, was the first to discover REM sleep (Rapid Eye Movement) 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, joined the University Faculty in 1925 and opened their first sleep laboratory.