Science 101

The Science of Sleep

The sleep research field is essentially in its infancy. Here’s how it’s grown and where it’s going.


Before the 1950s, scientists didn’t spend much time researching sleep because, well, they just didn’t think there was much to study. The prevailing theory was that during the daytime, our brains were bombarded with sensory stimulation. When the sun went down and there wasn’t much going on, our brains just shut off for a few hours. A sleeping brain was essentially a lightbulb that had been turned off—and who wants to study an unlit bulb?

Then, in 1953 Dr. Nathaniel Kleitman and one of his students at the University of Chicago, Eugene Aserinsky, used polysomnography—hooking people up to EEG machines to measure their brain waves, heart rate, and breathing—to discover rapid eye movement (REM) sleep. They also suggested the eye movements were associated with dreaming.

“That link to dreaming can’t be overstated in what it did to create the field of sleep research,” says Michael Grandner, Ph.D., director of the Sleep and Health Research Program and an assistant professor in the Department of Psychiatry at the University of Arizona College of Medicine in Tucson. “People knew about the eye movements before; they just didn’t care about them.”

“The idea that there was a biological link to dreaming, which was in the realm of psychoanalysis, got a lot of people interested in studying sleep.”

Then all of a sudden, they did care. A lot. After all, in the mid-50s, Freudian psychoanalysis was still a big deal. “The idea that there was a biological link to dreaming, which was in the realm of psychoanalysis, got a lot of people interested in studying sleep.” Soon, another of Kleitman’s students, William Dement, figured out the 90-minute sleep cycle. Every 90 minutes we move through three stages of non-rapid eye movement (NREM) sleep, and one stage of rapid eye movement (REM) sleep (where dreaming occurs).

By the 1970s and 80s, a growing field of scientists were discovering and investigating sleep disorders like insomnia, narcolepsy, and obstructive sleep apnea (OSA)—and learning how to treat them with inventions like CPAP (continuous positive airway pressure) therapy and CBTI, a form of cognitive behavioral therapy for insomnia. The connections between circadian rhythms and sleep were becoming clearer. Sleep scientists also discovered that narcolepsy, a sleep disorder that causes disturbances in sleep-wake cycles, has a genetic link. 

In 1993, a large study found that an alarming number of people had OSA (but didn’t know it), and that people who had the condition but didn’t get it treated died sooner, from heart attacks and strokes, says Grandner.  Around the same time, a large national survey found Americans were sleeping 20 percent less than they had a century before, that 40 million people suffered from chronic sleep disorders, and that sleepiness was wreaking havoc on the nation's highways, in schools and in the workplace. It was a wake up call that sleep was critical to health.

“Suddenly, you had people from public health and cardiology and all these other fields coming to sleep medicine,” Grandner says. The National Commission on Sleep Disorders Research was created in 1994 to help fund and coordinate sleep research nationwide. Instead of hundreds, the field grew to thousands.

How is Sleep Tested?

Scientists have learned a lot about sleep in the past 70 years, but their methods haven’t changed much. “Polysomnography is more expensive, all digital, the electrodes are better, but the principles and scoring rules are mostly the same,” says Grandner.

If your doctor prescribes a sleep study to find out the cause of your poor sleep, you go to a lab that’s set up a bit like a hotel room, with a bed and TV. The big difference between the lab and the Hilton (besides the lack of room service)? An EEG monitors your sleep stages and REM cycles to look for any disruptions in your sleep patterns. Sensors placed on your head and body measure your eye movements, breathing rates, oxygen levels, body movements and if you snore. Video cameras record your sleep.

Even if you don’t get a full night’s sleep hooked up to the wires, there’s typically enough data (usually over 1,000 pages worth, according to the National Sleep Foundation) to help your doctor identify any issues that may be keeping you up at night.

The Future of Sleep Research

With advances in technology, at-home sleep studies may be more common in the future, says Grandner. Already, there are FDA-approved portable devices to measure sleep brain wave activity, asses leg movements and monitor breathing. Do-at-home tests are about $1,000 cheaper than those done in the lab, but they can’t pick up as many conditions.

Scientists have learned a lot about sleep in the past 70 years, but their methods haven’t changed much.

Another way to see a sleep doctor without taking off your pajamas is telemedicine. “Telemedicine is ideal for sleep medicine, since doctors rarely need to touch patients during the exam; they just look at their airways, and that can be done with a phone,” says Grandner. This technology already exists: The American Academy of Sleep Medicine SleepTM platform  lets you connect with a sleep specialist through an app. 

Sleep labs may utilize more environmental data one day, too. Already, at-home sensors are available that track your sleep and talk to other smart gadgets (to say, dim the lights or adjust your bedroom’s temperature). “I wouldn’t rely on it right now but as this technology gets better and more accurate, it may allow us to measure things in different ways.”  Beds could also be potentially embedded with technology to measure things like body movements, but the investment isn’t there yet says Grandner.

What do Sleep Researchers Want to Learn Next?

Over the past 10 years, there’s been a big focus on sleep health, as studies have consistently showed a link between poor sleep and disease and mortality, says Grandner. Scientists will use emerging technology and data to continue to dig into those connections. 

Other hot research areas involve how sleep consolidates memory, the genetics of sleep disorders, and whether school start times should be adjusted to improve students’ sleep, says Grandner. Sleep researchers are also looking for innovations in treatment, including developing new, non-sedative medications for insomnia. One, Suvorexant, a drug that blocks orexin, a neurotransmitter that causes wakefulness, is already available. “The explosion in innovation is really exciting,” says Grandner.

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