The Enduring Mysteries of Sleep and Insomnia

Article Tools

Print

E-mail

Comments

RSS

Hartley and his contemporaries considered sleep necessary but intrinsically bad. Oversleeping (or, heaven forbid, enjoying sleep) demonstrated a character flaw; it was a symptom of sloth and low intelligence. By the 19th century, theories had evolved yet not progressed. Many people believed that sleep was caused by mysterious toxins in the blood. Long popular, the "hypnotoxin" theory suggested that fatigue was a poisonous substance that built up over the day, finally causing sleep at night, when the poison was eliminated.

In a series of experiments in the 1920s, a young Russian-American doctor, Nathaniel Kleitman, first studied the effects of sleep deprivation, disproving the long-held hypnotoxin theory in the process. His research led to two brilliant and simple conclusions. First, people who stayed up all night were more alert in the morning than they'd been in the middle of the sleepless night (as most insomniacs can attest). Second, after about 60 hours of being awake, the ill effects of sleeplessness on a person's health and behavior appeared to level off. Both findings contradicted the belief that fatigue-inducing poisons progressively accumulated in the body.

The hypnotoxin myth was one of many that Kleitman, a University of Chicago physiologist, debunked over a 50-year career. Kleitman, in fact, revolutionized the study of sleep. He established the first clinical sleep laboratory, where he experimented on animal and human subjects, including himself. He made seminal discoveries about the sleep cycle, dreams, sleep deprivation, and sleep disorders. In 1939 he published Sleep and Wakefulness, a classic that remains in print today.

Kleitman is often called the dean of sleep research, yet the image I have of him evokes a very different title. In an enlarged photocopy of a grainy 1938 newspaper photograph that hangs above my desk, he is emerging from Mammoth Cave in Kentucky, where he and an assistant had spent 32 consecutive days as part of a primitive experiment. A tall bearded man in black robes, Kleitman materializes from darkness, followed by a second bearded man, B.H. Richardson, in the same flowing attire. Kleitman's face is bleached as white as the Druidic hood covering his head. Stunned by flashbulbs, he looks like he's been captured against his will. Most details are lost to the inky blackness, yet there's a wild look in his eyes—the look of a man who has been to the underworld and back. It is Hypnos himself, together with Morpheus.

Kleitman and Richardson lived in nearly total darkness, silence, and isolation, seeking nothing less than to challenge the "cosmic forces," as Kleitman put it, that mandate a 24-hour day—that is, the planetary cycle of day and night that dictates when and how long we tend to sleep. They were attempting to adjust to a 28-hour schedule—19 wakeful hours and 9 in bed. Richardson successfully adapted to the 28-hour day, offering proof in Kleitman's mind that cosmic forces were not invincible. His own experience was very different—he slept well only when it coincided with his usual schedule. They both quickly resumed normal 24-hour patterns after they emerged.

RSS | Comments | E-mail | Print