Eugene Aserinsky, PhD, never wanted to study sleep. He tried being a social worker, a dental student, and even did a stint in the army as an explosives handler. He enrolled at the University of Chicago to pursue organ physiology, but all potential supervisors were too busy to take him on. His only choice was Nathaniel Kleitman, PhD, a middle-aged professor whom Dr. Aserinsky described as “always serious.” Dr. Kleitman was doing research on sleep and so, grudgingly, Dr. Aserinsky had followed suit.
Two years later, in 1953, the duo published a paper that shattered the way we saw sleep. They described a weird phenomenon Dr. Aserinsky later called REM sleep: periods of rapid eye movements paired with wakefulness-like activity in the brain. “We are still at the very beginning of understanding this phenomenon,” Mark Blumberg, PhD, professor of psychological and brain sciences at University of Iowa, Iowa City, said in an interview.
Before Dr. Aserinsky had walked into Dr. Kleitman’s lab, the widespread belief held that sleep was “the antithesis of wakefulness,” as Dr. Kleitman wrote in his seminal 1939 book, “Sleep and Wakefulness.” Others saw it as a kind of a coma, a passive state. Another theory, developed in the early 20th century by French psychologist Henri Piéron, PhD, held that sleepiness is caused by an accumulation of ‘hypnotoxins’ in the brain.
In his 1913 study that would likely fail a contemporary ethics review, Dr. Piéron drew fluid from the brains of sleep-deprived dogs and injected it into other dogs to induce sleep. As he explained in an interview with The Washington Times in 1933, he said he believed that fatigue toxins accumulate in the brain throughout the wakeful hours, then slowly seep into the spinal column, promoting drowsiness. Once we fall asleep, Dr. Piéron claimed, the hypnotoxins burn away.
From blinking to rapid eye movement
In 1925 when Dr. Kleitman established the world’s first sleep laboratory at the University of Chicago, sleep was a fringe science that most researchers avoided with a wide berth. Yet Dr. Kleitman was obsessed. The Moldova-born scientist famously worked 24/7 – literally. He not only stayed long hours in his lab, but also slept attached to a plethora of instruments to measure his brain waves, breathing, and heartbeat. At one point, Dr. Kleitman stayed awake for 180 hours (more than a week), to check how forced sleeplessness would affect his body (he later compared it to torture). He also lived 2 weeks aboard a submarine, moved his family north of the Arctic Circle, and spent over a month 119 feet below the surface in a cave in Kentucky, fighting rats, cold, and humidity to study circadian rhythms.
Dr. Kleitman was intrigued by an article in Nature in which the author asserted that he could detect the approach of slumber in train passengers by observing their blink frequencies. He instructed Dr. Aserinsky to observe sleeping infants (being monitored for a different study), to see how their blinking related to sleep. Yet Dr. Aserinsky was not amused. The project, he later wrote, “seemed about as exciting as warm milk.”
Dr. Aserinsky was uncertain whether eyelid movement with the eyes closed constituted a blink, then he noticed a 20-minute span in each hour when eye movement ceased entirely. Still short of getting his degree, Dr. Aserinsky decided to observe sleeping adults. He hauled a dusty clanker of a brain-wave machine out of the university’s basement, and started registering the electrical activity of the brain of his dozing subjects. Soon, he noticed something weird.
As he kept staring at the sleeping adults, he noticed that at times they’d have saccadic-like eye movements, just as the EEG machine would register a wake-like state of the brain. At first, he thought the machine was broken (it was ancient, after all). Then, that the subjects were awake and just keeping their eyes shut. Yet after conducting several sessions and tinkering with the EEG machine, Dr. Aserinsky finally concluded that the recordings and observations were correct: Something was indeed happening during sleep that kept the cortex activated and made the subjects’ eyes move in a jerky manner.