National Geographic : 1987 Dec
scientists who thought about sleep at all were likely to agree with the renowned Rus sian physiologist Ivan Pavlov, who held that the brain sort of tuned down during sleep. Then Dr. Nathaniel Kleitman, a professor of physiology at the University of Chicago and the father of modern sleep research, asked Eugene Aserinsky, a graduate stu dent, to investigate the relationship between eye movements and sleep. As a first subject, Aserinsky installed his eight-year-old son, Armond, in a room bor rowed from the physiology department, then hooked him up to an antique brain wave recording machine rescued from the basement. Electrodes taped near Armond's eyes transmitted their movements to the machine, which reposed on a table beneath "a terrible light"-as Aserinsky will never forget-"in the shape of a gargoyle with a horrific face and bright eyes." For two years Aserinsky made his pains taking observations. "The twitchings had A THREE-MONTH-OLD infant spends about 40 percent of a 14-hour sleep budget in REM. An adult sleeps about 7.5 hours, with 20 percent of that in REM. In the 70s, totalsleep time has decreased to about six hours, but the proportionof REM stays at about 20 percent. PAINTINGBY DAVIS MELTZER been noted before," he says, "but nobody stayed up all night and recorded them objec tively. Armond's eyes moved as if he was looking around, as if he was awake." What really surprised Aserinsky was regularity. "Suddenly there were movements; they would disappear for a time, then reappear." The discovery swept aside Pavlov's the ory by demonstrating forevermore that the so-called sleeping brain was charged with activity. Pursuing the study of the eye move ments with the EEG brain-wave machine, Kleitman and William C. Dement, a medi cal student, delineated the architecture of sleep. The proverbial "good night's sleep," they found, actually consists of two sleeps: rapid eye movement, or REM, sleep, a name both Dement and Aserinsky claim to have coined, and non-REM. Our nightly repose begins with about 90 minutes of non-REM, during which our brain waves gradually lengthen through four distinct (Continued on page 802) AWAKE AWAKE AWAKE What Is This Thing Called Sleep?