Dreamland: Adventures in the Strange Science of Sleep (21 page)

What many older adults call insomnia may in fact be an ancient survival mechanism. Carol Worthman, an anthropologist at Emory University in Atlanta, has argued that the modern comforts of silence, deep foam mattresses, and climate control have given us the expectation that sleep should always come easily. The wiring of our brains hasn’t caught up with the comforts of our bedrooms, however. With no sharp claws or teeth to scare off potential predators, early humans were at their most defenseless when they laid down on the ground for several hours in the middle of the night.

Sleeping patterns that change as we age show that our brains expect us to be living and sleeping in a group, Worthman says. To illustrate this idea, she noted that the three basic stages of adulthood—teenage, middle age, old age—have drastically different sleep structures. Teenagers going through puberty find it impossible to fall asleep early and would naturally sleep past ten in the morning if given the choice. Their grandparents often fall asleep early in the night, but then find that they can’t stay that way for more than three or four hours at a time. Middle-aged adults typically fall between the middle of these two extremes, content to fall asleep early when circumstances allow it, yet able to pull an all-nighter when a work project calls for it. These overlapping shifts could be a way to ensure that someone in the family is always awake and keeping watch, or at least close to it. In this ancient system, it makes sense that older adults who are unable to move as fast as the rest of the family are naturally jumpy, never staying in deep sleep for long, simply because they were the most vulnerable to the unknown.

Those survival instincts are of little help when life takes place in a condo in Boca Raton. One 2003 poll by the National Sleep Foundation found that nearly seven out of every ten adults aged fifty-five to eighty-four reported frequent sleep problems. When sleeping pills or sleep apnea masks aren’t the answer, what is left is perhaps the newest branch of sleep medicine: the science of how to naturally get a good night’s rest.

12

Mr. Sandman

I
t started as a way to get a better grade. In the fall of 2003, Jason Donahue, then a junior at Brown University, sat listening in his living room to a friend who had just come back from a psychology lecture and was eager to share what he had learned. In class that day, his professor had discussed the concept of sleep inertia. Roughly speaking, the higher-functioning aspects of the brain—making decisions, recalling important facts, directing precise movements of the body—are compromised if a person is woken up during certain stages of sleep. Just like the physics of a moving object, the brain resists changes to its current state.

This phenomenon is most pronounced when the brain is suddenly taken from deep, slow-wave sleep and faced with the complexities of navigating life. Logic becomes fuzzy, reactions slow down, and the brain typically wants nothing more than to fall back to sleep. The first scientists who noticed the condition called it sleep drunkenness. It often takes its most extreme form when a person is woken up from deep sleep during the first part of the night. In studies, subjects rustled from this stage of sleep were confused and disoriented by their surroundings, leading to strange behaviors like picking up a lamp next to the bed and talking into it as if it were a phone without realizing their error.

Sleep inertia is a well-known—and much-feared—consideration in aviation safety. Pilots who wake up suddenly from a cockpit nap are more likely to make poor decisions that cost lives. In May of 2010, Zlatko Glusica was the captain of an Air India Express plane carrying 166 passengers from Dubai to Mangalore, a bustling port city on India’s southern coast. Among pilots, the city’s airport is known for its short runway, making for a notoriously difficult landing. Glusica, fifty-three, was a veteran who had logged over ten thousand hours of flying time. More importantly, he had previously landed nineteen flights at Mangalore. Voice recordings recovered from the cockpit picked up the sound of Glusica snoring for much of the three-hour flight across the Arabian Sea. As the Boeing 737 approached the landing, Glusica woke up and took over the controls from his copilot. It was clear almost immediately that Glusica was in no condition to complete the task safely. His copilot warned him repeatedly that he was coming in at the wrong angle and that he should pull up and try again. But Glusica, groggy from sleep inertia, didn’t process the red flags and went ahead with his flight path. The last sound on the cockpit recorder was the copilot screaming that they didn’t have any runway left. The plane overshot its landing and burst into flames. Only eight people survived.

Back at Brown University, the college juniors had a very different set of considerations when it came to sleep inertia. Donahue recalled times when he had stayed up late studying for an exam, only to wake up the next morning foggy-headed and unable to concentrate for what seemed like hours. The information he knew the night before was lost and his test grades suffered. In his living room, Donahue began wondering whether it would be possible to time his sleep cycle perfectly so that he woke up at the ideal moment, effectively hacking his body’s rhythms and tweaking them for his benefit. He began hanging out around Brown’s School of Engineering, looking for someone who could develop a cheap and portable way to track the stages of sleep that wouldn’t require the onerous wires and equipment found in professional sleep labs. That’s when he met Ben Rubin. A fellow junior, Rubin was intrigued by the idea of capturing the unseen activity of the brain and using this information to improve his life.

With money won from a business competition, Donahue and Rubin set to work on a prototype of a device that would track the stages of sleep and wake a person up at an optimal moment in the sleep cycle. The concept they developed was relatively simple. It consisted of a brain wave–tracking monitor worn around the forehead during sleep that took a snapshot of the brain’s activity every thirty seconds and estimated what stage of sleep a person was in. Before going to bed, a user would program what time he or she needed to be awake the next morning. The machine’s alarm would go off up to a half hour before the deadline if there was a window of light sleep that allowed for a smooth transition into the new day. In the showdown between sleeping versus waking up, getting out of bed earlier won if it meant sidestepping sleep inertia.

Their first users, however, came away with an altered view of the product’s function. As soon as they saw their total sleep time and the minute-by-minute account of their sleep cycles, they no longer cared about the alarm clock aspect of the device. “Our friends were the first testers, and some of them started freaking out when they saw that they were waking up eight times a night and couldn’t remember it,” Donahue told me. Tracking and analyzing the quality and quantity of sleep was more appealing than waking up at the perfect time. Donahue and Rubin went back to the drawing board and redesigned the product to focus on data collection.

Six years later, they launched the device as a consumer product. Now called the Zeo Personal Sleep Coach, it offered to unlock the mysterious hours of sleep to anyone who was willing to wear a black fabric headband that places a hard plastic square just above the eyebrows. Inside the square are three monitors that pick up electrical activity in the brain and lateral movements of the eyes. Together, they are on the look-out for the biological markers of sleep. When plugged into a base station that doubles as an alarm clock, the Zeo displays a graph that gives a precise breakdown of the prior night’s sleep. The appearance of sleep spindles—two- to three-second bursts of voltage that rise and fall rapidly—on the graph hints that a person is at the shallowest portions of the roughly ninety-minute cycle. Long, slow waves signal the deepest sleep. And brain-wave activity resembling waking thought that comes at the same time as rapid movement of the eyes suggests that a person is dreaming. After wearing a Zeo headband all night, users can pinpoint that they were in dreaming sleep between 1:45 and 2:10, say, or that they woke up briefly at 3:30 and again an hour later.

But it is the second function of the Zeo that is revolutionary. Using an algorithm that takes into account the number of times a person wakes up, the time spent in deep sleep, and the total time spent sleeping, the Zeo rates each night of sleep and spits out a figure, known as a ZQ, that ranges from 0, for the worst sleep imaginable, to 120, the ideal sleep. With the advent of the ZQ rating, sleep entered the world of data and tracking. Implicit in any quantifiable scale comes the promise of improvement. Just like cholesterol levels, body weight, and blood pressure, sleep could now be translated into a numbered path that offered guideposts to personal betterment. Over time, a user can compare one night of sleep to another without resorting to intuition. “Measurement by itself isn’t the end goal,” Rubin told me. “The end goal is improvement, whether it’s something that tracks running or sleeping or weight loss. Measurement allows you to do that in new ways.”

Numbers are one way to fulfill an ambition that eludes nearly all of us. We each want perfect sleep. But getting there is much harder said than done. A thicket of studies have shown that humans, as a rule, do a terrible job of judging not only how they slept on any particular night but also what goes into making them sleep better. Accurately estimating how long it took to fall asleep and contrasting one night of sleep with another are two skills that are simply beyond our capacity. Sleep science, for much of its short history, offered little direction. With researchers understandably focused on disorders such as sleep apnea and parasomnias, the field of sleep medicine has spent more time researching why a night of sleep went wrong than why another went right.

Only recently has science figured out what goes into a good night of sleep. Falling asleep, and staying that way throughout the night, appears to be a battle with two fronts. The first takes place in the head. Between the time when a person lays his or her head on a pillow and the time when the brain sends out the first sleep spindles marking the onset of sleep, the mind must put aside its focus on its immediate surroundings and daily concerns. This process requires a person to give up direct control of his or her thoughts. At the same time, the body must be comfortable enough that the brain essentially forgets that they are attached. When something gets in the way of either, the end result is often insomnia.

These dual tracks toward good sleep are rarely recognized by the average person. Instead, many assume that physical comfort is the only thing standing between them and a good night’s rest. Mattresses, for this reason, are perhaps the most basic consumer purchase and the least understood. Many people who walk into a mattress store have only vague notions of what they think they will like. It’s no surprise, then, that the number of questions
Consumer Reports
fields about purchasing a new bed ranks only behind the number concerning buying a new car.

The biggest question—whether a bed should be hard or soft—has a long and confusing history. In an 1833 article in an Irish newspaper called the
Dublin Penny Journal
, for instance, a writer known as the Celebrated Doctor Abercrombie suggested that “the mattress, or bed, on which we lie, ought to always be rather hard. Nothing is more injurious to health than soft beds; they effeminate the individual, render his flesh soft and flabby, and incapacitate him from undergoing any privation.” In the 1970s and 1980s, a rebellion against firm mattresses accounted for the brief popularity of waterbeds. Sales of these heavy, leak-prone mattresses peaked at 3.8 million in 1988 and then plummeted. Waterbeds have since been rebranded as flotation mattresses, though the name change hasn’t done much to revive sales. In 2008, the medical journal
Spine
seemed to settle the question of firmness. It found that there was little difference in back pain between those who slept on hard mattresses and those who slept on softer ones. How hard a person likes his or her bed is a personal preference and nothing more.

In fact, the bed that you find the most comfortable will most likely be the one that you are already sleeping on. This inclination toward the routine was first noticed in a research study conducted in the 1950s. In it, subjects were asked to rate the firmness of their mattress at home and their overall sleep quality. They then slept on three mattresses in a lab—one hard, one soft, and one in-between—over three separate nights. At the end of the study, researchers matched overall satisfaction with each type of mattress. The biggest factor that influenced the rankings was how closely each bed matched the one that a subject had at home. Fifty years later, researchers at a German hospital again decided to search for the perfect mattress. With a half century of research into sleep at their side, they reasoned that they could identify the ideal firmness that would allow the maximum level of comfort for every patient in the hospital. But the human body wasn’t as efficient as they had hoped. “There was no global preference for any of the beds tested,” the German team found. They continued, with a pang of resignation. “Each individual seemed to develop its own sleep pattern which meant that results could be only compared for the same subject.” Just as in the study from the 1950s, patients liked what was the most familiar.

A comfortable surface isn’t always necessary for quality sleep. In the late 1960s, William Dement—one of the premier researchers in the history of sleep science who you may remember from an earlier chapter—received a commission from a company that had recently built a prototype of a high-tech mattress. Inside of it, warm air flowed through billions of tiny, ceramic beads. The end result was the feeling of a cushion built out of heated mud. “Everyone in our lab agreed that it was the most comfortable bed they had ever lain on,” Dement later noted. The company that hired him asked Dement to determine how well people slept on its product, which was expected to retail for several-thousand dollars, compared with a conventional mattress. To make the final result more dramatic, Dement decided to include a third option in his study: sleeping on a concrete floor with no padding. Volunteers gamely spent a night on each of the three, and Dement’s team later evaluated the results. “We were absolutely flabbergasted,” he wrote. There were no significant differences in the quality of a volunteer’s sleep or the total number of hours spent sleeping on the three surfaces. Given the option between a concrete floor and a high-tech mattress, subjects in the study experienced roughly the same night of sleep either way.

While a comfortable mattress may have little impact when it comes to sleep quality, there are several other aspects of the bedroom that do. Taken together, they form what specialists call sleep hygiene. Most are common sense. It is obviously not a good idea to drink coffee in the evening if it keeps you up at night. Nor is drinking alcohol before bedtime a smart move. Alcohol may help speed the onset of sleep, but it begins to take its toll during the second half of the night. As the body breaks down the liquid, the alcohol in the bloodstream often leads to an increase in the number of times a person briefly wakes up. This continues until the blood alcohol level returns to zero, thereby preventing the body from getting a full, deep, restorative sleep.