I lie about to fall asleep . . .
In the slot between waking and sleep
a large letter tries to get in without quite succeeding.
—Tomas Tranströmer, Nocturne
Sleep that knits up the raveled sleave of care
The death of each day’s life, sore labor’s bath
Balm of hurt minds, great nature’s second course,
Chief nourisher in life’s feast.
—William Shakespeare, Macbeth
I’m having my head measured and divided into quadrants, and my scalp marked with a red pencil: I’m like a side of beef being marked up by a butcher. The marks will be the locations for the electrodes that will record my brain activity overnight. David Morgan, the PhD student who will be monitoring my sleep from a control room up the corridor, scrubs at points on my scalp with an earbud dipped in abrasive gel, to clean the skin of dead cells and tenderize it for the electrode. “Do behind the ears really well,” advises Morgan’s supervisor, Jakke Tamminen. “There will be a lot of bacteria there.” To me he says, “No offense, most people don’t wash behind their ears.”
I end up with an electrode grid that will pick up signals from the frontal, temporal, and parietal lobes of my brain; as well as next to my eyes, to measure their roving movement when I’m in REM (rapid eye movement sleep—see below); and my jaw, to measure muscle tone: during REM sleep the body is paralyzed, to stop you acting out your dreams. A final electrode is stuck Hindu-like in the center of my brow, like a bindi; for all I know, it’s the chakra site of my third eye. The wires are gathered in a kind of cyborg ponytail, tied behind me, and plugged into a wall-mounted unit that will receive and amplify the signals, my brain waves.
We say “I’ve had a brain wave” to describe the sudden genesis of an idea, but brain waves really exist, and come in different sizes, just like the waves in the ocean. They are the electrical activity of neurons in the brain, and when we are asleep, they synchronize enough to make discernible patterns. I’m in a sleep lab in the department of psychology at Royal Holloway, University of London, to find out what mine look like.
Sleep is something of an anomaly in this book. It is perhaps the least well understood of all the traits I’m investigating, having been scientifically studied for only a relatively short time. What is it for, exactly? We know that cellular repair and maintenance go on during sleep, and this is part of its restorative function. It also plays a role in memory storage. But how does it do this?
It’s also odd in this book because it’s not clear, at first glance, what it means to be a good, let alone superhuman, sleeper. Is it someone who sleeps only five hours a night and still feels great? Or is it someone who sleeps more than ten hours but is at the peak of their profession? We’ll look at examples of both types, and we’ll also meet someone who thrives by customizing her sleep and breaking it into chunks sprinkled throughout each twenty-four-hour period. We’ll meet people, too, who can control one of the most celebrated aspects of sleep: dreaming. Despite the uncertainty, I’ve included sleep as a category because, quite simply, it is universal—not just to humans, but to all life-forms that we know of—and because ultimately it is vital that we sleep well. Happily, unlike some of the other traits, sleep is something we can all excel at.
When Tamminen is satisfied that the electrodes stuck to my head are recording properly, they bid me goodnight and disappear into the control room. It’s around 11 p.m., and through the intercom they say they will wake me at 7 a.m. the next day. Now, they tell me, in a similar manner to how I implore my daughter, please go to sleep.
• • •
Sometimes incidents in life lead you down peculiar and unexpected paths. In 1892 Hans Berger, a trainee soldier in the cavalry of the German Empire, was thrown from his horse into the path of a horse-drawn cannon. You can imagine that heart-stopping feeling, when time seems to slow down in the face of approaching death. In this instance it was in the guise of stomping horses dragging artillery. But death didn’t come—the cannon stopped in time and Berger survived. Here’s a weird coincidence: many miles away his sister had an intense feeling that her brother Hans was in danger. She begged her father to send Hans a telegram, checking on his safety, and when Hans received it, he was understandably stunned. How could she have known? He became obsessed with discovering how his brain could have possibly transmitted a signal to his sister.
Berger became a psychiatrist. In his career he was driven all the time by the desire to understand the energy of the brain, and in 1924 he recorded the first human electroencephalogram (EEG). EEGs have been somewhat overshadowed by MRI scanners, which can show at a high resolution what’s going on deep in the brain, but the advantage of EEG (aside from its much lower cost) is that it allows researchers to watch changes in brain activity each millisecond, something not currently possible with MRI. It’s also much easier to sleep overnight with EEG than in the growling, immobilizing coffin of an MRI scanner.
And indeed I slept quite well in the sleep lab. The electrodes all over my scalp and face didn’t really bother me—it was only the wailing of drunken students outside, and an unfamiliar pillow, that disrupted my slumber. I had a few peculiar dreams that I remembered after waking from some student singalongs in the middle of the night. It hadn’t bothered me that there were people monitoring me as I slept, but in the morning, when I was shown my night’s sleep on the computer, I realized how intimate an insight the scientists had into me. “You fell asleep quite quickly,” says Tamminen, scrolling through the EEG traces showing my brain activity. “You are drifting off here. There’s a disturbance here, but that’s just you moving around for some reason.” I met the man only yesterday, and he already knows how I sleep.
There are five stages of sleep, numbered 1 to 4; the fifth is REM sleep. Throughout the night we cycle through the stages and start again at stage 1. The proportion of time we spend in each stage varies throughout the night, and for any number of other reasons, such as our age and whether we’re intoxicated or on medication or disturbed by something. Stage 1 is light sleep, and the transitional stage between waking and sleep. Usually I pass quickly from this stage, but in the sleep lab I was tossing and turning as noises from outside dragged me back to the surface. Tamminen shows me the long tail of oscillations before more interesting things start happening. What he’s looking for is a spindle. Spindles are the sign that I’ve gone into stage 2.
In the mass of jumps and oscillations that make up a night’s sleep as recorded on an EEG, you see odd, particular bursts of activity lasting half a second or so, always in the frequency range of 12–14 hertz. These are spindles, and originate from some brain spasm in the thalamus, deep in the center of the brain. Spindles might have something to do with the integration of new information into the brain, because they seem to make the brain more plastic, that is, more agreeable to the acceptance of new data.
Tamminen explains that as we learn new things in the day, they are quickly encoded by the hippocampus. This acts as a short-term memory store, but at night the information needs to be consolidated. It is conveyed to the neocortex, a large and important region of the brain that looks after language acquisition and sensory perception; a region, basically, that is highly active when we are thinking. Spindles may act as gatekeepers to this region. There is some suggestion that people with spindles of slow duration are more intelligent,1 so I am a little crestfallen when Tamminen says my spindle isn’t a very good one.
We carry on scrolling through the electrical output of my unconscious mind. It’s amazing what Tamminen can read into what to me are chaotic spikes and scratches. We find a nicer spindle. My brain waves, he says, are starting to slow. These are delta waves, and they first appear in stage 3 sleep. We carry on, into stage 4, and the waves become more prominent. This is slow wave sleep, and stages 3 and 4 are together called deep sleep. The waves are now gently rolling, and even my untrained eye can see the undulations. Here I am dead to the world. It’s hard to rouse someone from deep sleep, and if you manage it, they are often disoriented and bleary. It’s like they’ve come back from a strange land—looking at this readout, a strange ocean would be more apt—and the reason they are bleary is because they are rebooting their operating system. It takes a while to get back online.
We continue scrolling, paddling, through the waves of my night. Soon the EEG starts to change again, and Tamminen says I am entering REM sleep. The electrodes wired to my eyes start showing peaks and troughs, indicating that my eyes are rolling around under my lids. I always wondered, are the eyes just unmoored during this time, or are they looking toward things you see in dreams? The answer is probably the former, as dreams can occur, we now know, in non-REM sleep, and it’s not clear that we’re always dreaming when we are in the roiling stage of REM sleep. The EEG wired to my jaw goes flat, indicating that my body is now paralyzed.
Deep sleep tends to happen more in the first half of the night, and periods of REM sleep get longer in the second half. Sleepers tend to wake momentarily after cycles of REM sleep, and Tamminen, the Morpheus of this sleep lab, points out a sudden burst of activity on my EEG.
“You’re awake here.” He checks the time stamp. “It’s about five in the morning. Do you remember this?”
I do, actually. I’d woken up and could hear blackbirds singing outside, and I thought it might be time to get up. I’d been dreaming of sailing on a ferry to Liverpool and seeing the Liver birds on the Royal Liver Building at the waterfront. I soon went back to sleep.
“You’re getting restless now,” Tamminen the Sandman says, as we approach the end of the night and the ocean gets choppy. “You’ll wake up soon.”
• • •
Back at home after my night in the sleep lab, I’m staring out the window, watching a fox curled up on the grass in the garden, dozing in the sun. His ears twitch as car doors bang in the nearby street, and he looks up when children shout in the neighboring gardens. He’s never going to go into deep sleep, is he? He can never relax. I look out again a bit later and the fox is still asleep, but has shifted position under the apple tree so as to avoid the shade and track the warmth of the sun.
Foxes sleep in snatched periods of time across a twenty-four-hour cycle: their sleep is polyphasic, as opposed to our monophasic sleep. Many mammals sleep like this, especially those with small body masses, because they burn energy so quickly, even while sleeping, that they need to wake up and forage. Dogs and cats are similar, and it was the example of such animals, along with the prolific number of flights he was taking and the sheer amount of stuff he wanted to do, that inspired the American inventor and architect Buckminster Fuller to adopt a polyphasic sleep pattern.
Fuller, who died in 1983 aged eighty-seven, was a man who marched to his own drumbeat. When he was in his thirties, Fuller would work, eat, and live—but mainly work—in four six-hour blocks, taking a thirty-minute nap in between. He called this hellish schedule Dymaxion sleep and supposedly kept it up for two years, but even when sleeping like a regular person he was known for being tireless, driven, and productive. There’s no doubt that he achieved a huge amount in his life—he published more than thirty books, and among his many inventions, the geodesic dome is perhaps his most well known. Indeed, when a sleep researcher mentioned his name, my first thought went to the football-shaped sixty-atom carbon molecules named buckminsterfullerene because they resemble his geodesic domes. As well as his inventions, Fuller was inspirational and forward-thinking, coining the term “Spaceship Earth” to capture the idea that we are all living together on the planet, and that we must use our energy and resources renewably.
Fuller was undoubtedly a superhuman sleeper. Few of us will contribute to humanity as much as he did. How did he do it? Did he force that sleep pattern on himself through strength of will? Or was there an inner drive that enabled him to work, that sourced him with energy despite the lack of sleep—was it, indeed, some inner energy that stopped him sleeping for very long?
Even if our goals are more modest, we’d like to contribute more to society, to ourselves and our friends and families; we’d like to have Fuller’s tirelessness. We want that extra time. His example has helped inspire a community of sleep hackers, who insist that the eight-hour-a-night standard is unnatural, or is holding us back. Or at the very least they conclude that it is not for them.
Fuller is long gone to the eternal sleep, but modern pioneers of polyphasic sleeping carry his torch. Marie Staver, now a project manager in Boston, adopted what she named the Uberman system when she was a student, struggling with essays and revision and constant tiredness. She was also troubled by insomnia. Inspired by Fuller, she decided that the regular monophasic way of sleep just wasn’t for her. If “Uberman,” by the way, sounds a bit like “Übermensch,” that’s because the latter is what Staver and a friend originally called it. Perhaps they were trying to reclaim the word from association with Hitler. In any case, they eventually settled on the marginally less Nietzschean “Uberman.” The system entails sleeping in six 20-minute naps, one every four hours. You get a total of two hours’ sleep in each twenty-four-hour cycle—a superhuman twenty-two hours’ waking time altogether. Staver says that the initial adjustment to this radical sleep pattern is monstrous, with symptoms of flu, headaches, and bouts of anxiety and depression. But once you are used to it, after a couple of weeks, it pays off because you become much more productive and you feel more rested. “It took some work to maintain, but considering the benefits, it was definitely worth it.” You have to set an alarm to get you up after the twenty-minute nap, but she says she’d wake up at nineteen minutes, on the nose.
Staver is no longer an Übermensch—she could keep that up only for six months before what she calls “social factors” got in the way. But for the last nine years she’s been on a differently patterned polyphasic system called Everyman 3. Under this regimen, you get three hours’ sleep in a block at night, and then three twenty-minute naps throughout the day. It gives you four more hours of waking time than the rest of us in each twenty-four-hour cycle.
Staver says it’s hard to say whether Everyman is easier than Uberman. Perhaps it’s like asking an ultrarunner if a twenty-four-hour track race is easier than a one-hundred-mile mountain run. “For most people, Everyman 3 fits the most easily into a regular schedule, so it requires a less jarring lifestyle modification [than Uberman].” If you are on Everyman 3, Staver says, you can work a nine-to-five job, as long as you can get a nap at lunch. Because it has a core three-hour sleep, it involves milder sleep deprivation at first, but takes longer to adapt to overall. “For me, right now E3 is easier because I still don’t have the kind of lifestyle in other ways that would support a Dymaxion schedule—but I’m working on it, and the second I do, I’m switching,” she says. “I love E3 compared to monophasic. I have four additional hours per day and I feel more rested.”
I do get the sense that she feels E3 is cheating, somehow. “I love the pure polyphasic schedules best,” she admits. “I suppose they are more challenging, but aren’t all awesome things?”
As I have with many of the people I’ve met in this book, I feel I am a long way from Staver’s ability. I’m a boring old monophasic sleeper. People talk about “pulling all-nighters,” but I remember doing this properly only once, when I was writing up my PhD. I worked through the night in the lab, and met my friends at the regular departmental coffee break the next morning, wearing the same clothes. Then I staggered home and flatlined for hours. I can’t imagine how much effort it is to keep to a polyphasic sleep pattern, but Staver says that she found it to be a lot of effort just to maintain monophasic sleep.
She can easily sleep in odd locations such as cars, on spare couches, even outside. She does experience the sensation of falling asleep as soon as her head hits the pillow when she is adapting to a new schedule, but says that once she’s adapted, she drops off in around five minutes. A five-minute sleep latency, as they call the time it takes you to fall asleep, is just about healthy and normal, but five minutes out of a twenty-minute nap time is a significant lost chunk. Does she really feel awake and alert on this schedule? “I wake rested and don’t usually experience any tiredness until it’s almost the next nap time. I certainly don’t feel like I really need sleep any more often, in fact much less often, than I did while I was monophasic.” It’s hard to judge this independently, as we don’t meet, and only communicate by email.
I do wonder about loneliness.
“It took a little getting used to, being awake for so much time that others were sleeping,” Staver says. “But it’s very productive time, and if I need human interaction, it’s easy enough to find things to do with people during weird hours.”
She calls her extra time non-people hours, and says she mostly uses them for writing, and for taiji practice. Taiji is the Chinese Taoist meditative practice which is the basis of the martial art tai chi. Taiji means something like “supreme extreme” or “great ultimate” and refers to a state of infinite potential; maybe I’m primed to make the connection, but it sounds to me quite similar in tone to Nietzsche’s Übermensch.
Staver is quite an evangelist for polyphasic sleep. While of course she doesn’t advocate it for everyone, neither does she think monophasic sleep is for everyone. There is a large and enthusiastic internet community of polyphasic diehards. And many people clearly experience a chronic lack of sleep. A US survey between 2004 and 2007 of 66,000 civilian workers found that 30 percent reported sleeping six hours or less per night. For people in senior management, the figure was 40 percent. Staver feels that the answer to this ever-increasing societal pressure to work is not to stop bringing smartphones into the bedroom, or to educate people on the need and the benefits of at least seven hours of uninterrupted sleep, but to look at other options to hack the system: “Being long-term sleep deprived or constantly desynchronized is terribly unhealthy. We know this, and yet as a society we do very little, or nothing, to help encourage people to get good restful sleep, or to give them options when ‘be unconscious for eight-plus hours’ isn’t a viable one.”
It’s almost as if there’s a monophasic tyranny forcing the majority of us to sleep in eight-hour blocks. There are all these people who need more sleep, and we’re putting more and more pressure on each other to be awake and productive all the time.
She’s right of course that it is unhealthy to be sleep deprived. And we definitely all need more sleep. But my biggest concern about polyphasic sleeping is the health consequences. Doesn’t it take a toll on you?
“The adaptation process does take a toll on one’s system, and I certainly don’t recommend optimizing sleep schedules to the sick or frail,” Staver says. “But after you’re adapted, nothing I’ve seen makes me think that being polyphasic is doing any damage. Both Bucky Fuller and I have seen doctors regularly while and after being polyphasic, and we were in excellent health.”
Polyphasic sleep is studied professionally. NASA knows that astronauts tend to manage only six hours’ sleep per night,2 and experiments have showed that naps can help boost working memory. The yachtswoman Ellen MacArthur had to adopt a polyphasic sleep pattern when she sailed around the world. She was advised by neurologist Claudio Stampi, who runs the Chronobiology Research Institute in Newton, Massachusetts. Stampi specializes in helping solo sailors cope without sleep.
There was a key difference between MacArthur’s sleep during that time and the precise timing of Staver’s system. MacArthur grabbed sleep when she could, but often had to leap up to see to something. “The biggest thing that affects your sleep is the amount of adrenaline that is pumping through your body,” MacArthur told me. Her journals from the record attempt are full of entries about how her veins are so full of adrenaline she can’t sleep, her mind is whirring, but she is exhausted. “At any point during the round-the-world, with a few exceptions, you could capsize that boat anytime, and you sleep with the ropes in your hands,” she said. “So when you sleep it’s five minutes, nine minutes, occasionally you sleep for twenty minutes, very rarely one hour.”
When I met her, she was clear about the single hardest thing about sailing the round-the-world on her own: “It’s not that it’s not physically hard, but it’s the sleep deprivation. Sometimes you can’t sleep at all. It is too dangerous.”
It’s one thing to sleep polyphasically for the duration of a space mission, or if you are a fighter pilot, or even if you are sailing around the world on your own. It’s quite another to try to do it as the norm, and the fact is that we just don’t know what it might do in the long term, because we don’t know enough about what sleep does. Time to visit some more sleep scientists.
• • •
To find the Guy’s Hospital Sleep Disorders Centre you have to turn down an easily missed alley opposite Borough Market in London. I hear someone describe it as Diagon Alley. I meet Guy Leschziner, consultant neurologist and clinical lead for sleep. Also present is Meir Kryger, a legendary sleep scientist at the Yale School of Medicine who happens to be based at Guy’s Hospital when I visit. Kryger was the first to diagnose sleep apnea in North America, and has published many books and hundreds of papers about sleep. For good measure we are joined by Adrian Williams, a consultant sleep physician at Guy’s and founding member of the British Sleep Foundation. “If you want to find out what sleep does,” he intones, “you deprive animals of sleep.”
At the turn of the last century the Russians did this with dogs. They found that the dogs died within three days; if deprived of water, they lasted eight or nine days. “So sleep is more important than water,” Williams says. He delivers this remarkable sentence as a simple matter-of-fact statement, like “rain falls from the clouds.”
He tells me of some classic experiments conducted in the 1980s by the American sleep pioneer Allan Rechtschaffen, of the University of Chicago.3 Rechtschaffen found that if you deprive rats of sleep completely, they’ll die in about two weeks. If you deprive them of REM sleep, they’ll die in four weeks. As the rats become more sleep deprived, their behavior changes. The males become hypersexual. “They were mounting rocks,” Williams says, dry as sand.
I recall the case of Randy Gardner, who was a teenager in San Diego in 1964. On a whim, he decided to stay awake for as long as he could. That turned out to be an extremely long time: 264 hours, which amounts to just over eleven days. He holds the record for the longest time that anyone has intentionally gone without sleep without using drugs.
By some accounts Gardner was fairly unaffected during his nonsleep, although some observers reported that his short-term memory was shot, and that he hallucinated, became moody and paranoid. He was monitored during his record attempt by a US Navy psychiatrist, John Ross.4 This is from Ross’s report of Gardner on day eleven:
Expressionless appearance, speech slurred and without intonation; had to be encouraged to talk to get him to respond at all. His attention span was very short and his mental abilities were diminished.
In a serial sevens test, where the respondent starts with the number 100 and proceeds downward by subtracting seven each time, Gardner got back to 65 (only five subtractions) and then stopped. When asked why he had stopped he claimed that he couldn’t remember what he was supposed to be doing.
He was, however, fine after he’d caught up on his sleep, and showed no long-term problems.
We all know how lack of sleep makes us moody. Ellen MacArthur’s support team saw this regularly during her round-the-world attempt. It happens because the connection starts to break down between the decision-making parts of our brain in the prefrontal cortex and the mysterious and intimidating amygdala, which is the master of our fear and emotions. But the sleep-deprived rats didn’t die of moodiness.
“In the totally sleep-deprived rats,” Williams says, “they die in a very bad state, their temperature is falling, their appetite has gone up but they’re losing weight, they lose their fur and the bowel disintegrates.”
I’m at a bit of a loss to respond to this. Kryger helps me out. “They have a horrible death. And it seems to be a metabolic death. These poor rodents were under horrible stress.”
Once you get over the horror of the experiments, in which rats were housed in cages with rotating floors that would plunge them into water if they fell asleep, it’s interesting to note that merely depriving them of REM sleep still caused them to die, if not so quickly. So what does this tell us about the function of sleep?
There are some hypotheses that it is about the practicing of complex motor behaviors; we know sleep is essential for consolidating memories5 and has a function in restoring cell function.6 This might be why babies have more REM sleep, because they are learning to control their movement.
“Babies spend twelve hours a day in REM sleep,” says Kryger. “But we don’t know if they dream, or if they do, what they’re dreaming of.”
Adults, too, vary in the amount of REM sleep they get.
“We see patients on antidepressants, which dramatically reduce or in some cases abolish REM sleep,” says Leschziner. “We don’t know how important the function of REM sleep is in later life. It may have a very important function in babies or children that is of less significance in later life.”
It may be to do with processing emotions experienced in the day. There remain some fundamental unknowns and we don’t know whether the functions of different stages of sleep alter as we go through life. “It may be that we were designed to die at forty, so the function of REM sleep after forty is of no consequence from an evolutionary perspective,” says Leschziner.
We might not know the function of REM sleep, but we all know about one of its most celebrated consequences.
• • •
Read these words: “Scrambled eggs—oh my darling how I love your legs.” Did you automatically insert a melody? No? How about this: “Yesterday—all my troubles seemed so far away.”
The melody for the most recorded song of all time came to Paul McCartney in a dream in a hotel room in 1964. On waking he knew he had something and improvised the first lines that came into his head so he wouldn’t forget it. When George Martin first heard the demo it had the working title “Scrambled Eggs.”
Cut to another hotel room, a year later. Keith Richards wakes from a dream with what would become one of the most famous guitar riffs of all time in his head. He picks up a guitar and plays “(I Can’t Get No) Satisfaction” into a cassette machine before he goes back to sleep. Richards later said that you can hear him snoring on the tape.
I like the way that both men, McCartney and Richards, are happy to attribute their most enduring works to dreams, as if shirking responsibility for them. There are dozens more examples. The structure of the periodic table of elements came to Dmitri Mendeleev in a dream, and Otto Loewi dreamed the idea that led to the discovery of neurotransmitters and a Nobel Prize.7 But while we have probably all been inspired by dreams, you have to be in a special place creatively to achieve a breakthrough on the level of “Yesterday” as the result of a dream. I am, however, counting the ability to dream as a component of the ability to sleep: superhuman dreamers qualify for inclusion in this chapter. Some people really can dream better than others, and the ability has positive, real-life consequences.
Michael Schredl had kept a dream diary from the age of twenty-two. When he was thirty-four, he tried something different. He started asking himself, five to ten times a day, “Am I dreaming or am I awake?” He would scan the world around him and check for signs that he was in the real world. If there was something incompatible with reality, he would know he was in a dream.
If this sounds like extreme paranoia, or the start of a Christopher Nolan film, it isn’t. Schredl was practicing a method known to increase the probability of lucid dreaming—the state when you are in a dream but become aware of it and are able to take control. You may well have experienced it. About 50 percent of people have a lucid dream at least once in their lives. Sometimes, when it’s happened to me, it’s enabled me to stay calm in the dream when something terrifying is happening, like being eaten by a monster, or stabbed, or falling off a cliff. I won’t die, I’ve told myself, because I know this is a dream. In more pleasurable lucid dreams I’ve been able to fly or levitate (though sometimes these become “unlucid” and gravity drags me down).
Around a fifth of the population have lucid dreams once a month or more. “Not only does the frequency of lucid dreaming vary a lot between different people, but so does the ability to affect dream content,” says Schredl, who grew up to become a professor in the sleep laboratory of the Central Institute of Mental Health at Heidelberg University in Germany. “So there are naturally good lucid dreamers.” Let’s meet one.
Michelle Carr’s first lucid dream happened when she was nineteen and a college student, studying psychology at the University of Rochester, New York.
“I was sleep deprived and often took naps after early morning classes,” she says. “After one morning nap, I had a false awakening where I sat up in my bed, and then realized that my body was still asleep in bed, and I was in fact dreaming. I floated around my bedroom briefly before waking up.”
That was her first lucid dream. After that she read up on them and practiced techniques to induce them. She found that morning naps were good times to go lucid: “I would sometimes be able to wake up briefly from the nap and then consciously fall asleep into a lucid dream.”
This is the wake-induced lucid-dreaming technique. It’s about keeping grasp of the transitional stage between waking and sleeping known as hypnagogia, and bringing some conscious awareness with you into the dream state. “I believe this technique worked for me because I was likely having more REM sleep and a lighter sleep in these naps than I have during the night,” Carr says.
She now has lucid dreams about once a week, and has done for years. She uses them for fun (flying is always a favorite) and if the need arises, she will use them to deal with nightmares, “Such as confronting one recurring monster who ended up representing a friend with whom I had recently had a fight.” During one dream incident, she remembers scrabbling to escape a monster only to realize it was a nightmare, and one she’d been in before. She took control, turned around in the dream and faced the monster. Carr uses lucid dreams as the rest of us might use spare time. She meditates, practices French (without the social anxiety she would have if doing so when awake), and explores her consciousness, to see what it is capable of creating.
Her lucid dreams were a huge influence on the career that she pursued. After her undergraduate degree she went on to do a PhD at the Dream and Nightmare Laboratory at the University of Montreal, and she now works on dreams and emotional memory at the Swansea University Sleep Laboratory in the UK. Her years of practice in lucid dreaming, and the fact that she thinks about it a lot in the day, too, means she experiences them regularly. She can maintain the lucid state for ten to fifteen minutes, and is able to control herself during that time.
Martin Dresler of Radboud University in the Netherlands, and colleagues at the Max Planck Institute of Psychiatry in Munich, managed to scan the brain of one person who was able to go into lucid dreaming while in the coffin-like confines of the fMRI machine. Based, admittedly, on this single data point, Dresler found that lucid dreaming occurs during REM sleep but shows activity in brain regions normally shut down in that stage of sleep. This, the researchers suggest, could explain why lucid dreamers are able to access cognitive abilities such as self-control and access to memories that are beyond us in normal dreams. The biggest difference between lucid and nonlucid REM sleep was seen in the precuneus, part of the brain involved in self-referential processing, agency, and first-person perspective.8
This fits with Carr’s experience of lucid dreaming. In such dreams, she has self-awareness and control over her own movements, but not absolutely over the dreamscape. “I still run into resistance from the dream,” she says. “For instance, I am not really able to change the environment around me at will, although I can decide to move through it.”
I’ve occasionally met dead relatives in my dreams. In these dreams I’m aware that the person I’m with is dead in the real world, not least because they appear younger than they were when they died, but I don’t guide the conversation; the encounter takes its own course. This is a common feature of lucid dreams. They aren’t always about creating elaborate plots; they can just unfold, with the dreamer as the passive but lucid observer. With dead people—not that I see dead people all the time, but when I do—I don’t steer dream conversations around to particular subjects (“Tell me where you hid the diamonds, Grandma!”); the conversations and the encounters are unguided. They would be mundane if it weren’t for the fact that one of the characters is dead. When I wake I am left with an odd feeling of pleasure and affection at having spent some time with a loved one who is now dead, even though the experience was entirely imaginary. It is this emotional quality which makes the dream memorable, as we saw in Chapter 2. Lucid dreams are pleasurable, and even beneficial. Evelyn Doll, for example, from the Medical University of Vienna, found that regular lucid dreamers had better mental health than normal dreamers.9
It’s instructive that the characters who pop up in a lucid dream usually retain their autonomy, because it tells us which regions in the brain are important for consciousness. In Carr’s dreams, too, characters remain beyond her control. “I might approach someone and ask them for information, but they either ignore me or respond in gibberish. Sometimes I am unable to open doors or to approach certain characters,” she says. “So I think that my techniques still require a lot of practice.”
Michael Schredl’s work points to what can be achieved with practice. For researchers, there’s an extraordinary benefit to studying lucid dreaming: you are able to communicate with people in the unconscious world. The dreamer, of course, is asleep, usually in REM sleep, but as they achieve lucidity, they can signal to the scientist with their eyes. Kristoffer Appel, at Osnabrück University in Germany, has exploited this by teaching Morse code to lucid dreamers and having them send messages back from the dream world. An eye motion to the left is a dash; to the right is a dot. Appel sends the dreamer arithmetic to perform by playing sequences of beeps that the dreamer incorporates into the dream.10 The dreamer is then able to compute the answer and signal it back using Morse code.
Schredl has taken this further, and uses the lucid dream as an arena for training. This leads to the remarkable proposition that you could intentionally practice something while sleeping, in order to improve your skill. In one study of 840 athletes, 57 percent said they’d experienced at least one lucid dream in their lives, and 24 percent had one at least once a month.11 Nine percent of the lucid-dreaming athletes practiced their sport in the dream and said their athletic skill improved as a result. It’s a small sample, and entirely anecdotal, so Schredl and colleagues decided to try to test the idea. They brought lucid dreamers into the sleep lab and had them practice darts while dreaming. Yes, darts. We are in a Martin Amis novel written by a neuroscientist.
Schredl and his team had a group of test subjects play darts, then fall asleep in the lab. Volunteers who were able to go into lucid dreaming performed three consecutive left–right eye movements to signal the onset of dream control. First they had to “assemble”—that is, dream into existence—the board and the darts necessary for the trial. The boards used were the kind with a red bull’s-eye at the center, surrounded by nine concentric black and white rings. Then they began to play darts. The trials required subjects to throw six sets of five darts, and to signal to the waking world after every fifth dart.
At the end of the thirty throws, the dreamers had to try to wake up. They then provided the researchers with a detailed dream report. The next morning, lucid dreamers and control subjects who had not tried to practice darts in their sleep were tested again with a real dartboard, and scored for their ability.
Just as with any kind of practice, distractions detract from its quality and efficiency. Some lucid dreamers were able to practice darts without distraction, but others had to deal with obstacles, such as a pesky dream character interfering with the task (“the doll kept throwing darts at me”) or changes to objects in the dream environment (“at some point I threw pencils”). Sometimes the dream got away from them, and the dreamer’s grip on lucidity started to fail (“I noticed it was getting somewhat unstable . . . I performed another eye signal . . . I managed three or four more throws and then I woke up”). The scientists tried to account for distractions in the dream reports obtained from the dreamers.
You can imagine the difficulties in obtaining a good sample size under these trying conditions, and Schredl emphasizes that this is a pilot study. Given that caveat, they found that if dreamers weren’t distracted, their darts score improved after they practiced in the dream. Given that almost a quarter of German athletes apparently have regular lucid dreams, Schredl wonders if dream practice might become part of athletic training.
He told me about reports from amateur athletes who improved their skills during lucid dreams. There is a springboard diver who used lucid dreams to practice twists and somersaults. She could slow down time in the dream so the sequence unfurled more slowly, allowing her to understand the movements going on at each point. There’s also a snowboarder who practices tricks that he can’t yet do in the real world. The practice has helped him improve, he says.
It makes me think of the training philosophy of marginal gains. It’s arguably been responsible for some of the huge success in British cycling over the last decade or so. The idea is that you try to improve every possible factor so as to reap a greater benefit. Such as painting the floor of the team truck white, in order to better spot any dust that might impair bike performance, or finding the best pillow for sleep and bringing it to team hotels.
On its own, each adjustment permits a tiny, maybe unnoticeable improvement. But make enough of them and the gains mount up. Sports psychologists already place a lot of emphasis on getting a good night’s sleep. Should dream-training be added to the list?
For sports such as cycling, where strength training is key, it probably won’t work, says Schredl. “But for more artistic sports, like platform diving and freestyle skiing, this does seem plausible.” It’s why mental training and rehearsal while you’re awake has a benefit: think of the track and the race-line memorizing we saw in Formula 1 drivers. Direct transfer of information during sleep has been achieved in rats, but this has required the highly invasive implantation of electrodes. Dream-training may work only if you can achieve a lucid state, but it’s possible to learn this, and at an elite level, any small improvement is worth pursuing.
• • •
LeBron James is one of the greatest basketball players of all time. He is a double Olympic gold medalist, has won the US National Basketball Association championship three times and has been voted Most Valuable Player four times. There are many reasons for his phenomenal athleticism and his success, but one jumps out at me: he sleeps eleven to twelve hours per night.12
Cheri Mah, who now works in the Human Performance Center at the University of California, San Francisco (the lab where ultrarunner Dean Karnazes was tested), investigated the effect of longer sleep on college basketball players. She and her colleagues recruited eleven men from the Stanford University team, with an average age of nineteen, and trained them to extend the amount of time they slept. The men all managed to sleep longer (by an average of almost two hours), and their sprint speed, shooting accuracy, and free-throw percentages all improved. Extending sleep time, Mah’s team concluded, improves athletic performance, reaction time, and sprint time, as well as mood and vigor. Peak performance can occur only when sleep is optimal, she suggests.13
There’s only one LeBron James, but anyone can extend their sleep time. You just need to make sure you don’t drink alcohol or caffeine too late in the day (and preferably not at all), nor should you eat dinner too late. Both things keep your metabolic rate high and can disturb your sleep. Make sure your bedroom is cool, dark, and quiet, and that you won’t be interrupted or disturbed. Don’t go to bed too late, and try not to binge-read on electronic devices or check work emails before you do. Wind down at least half an hour before bed, crank the lights down low, read a novel. Embrace sleep as your restorative friend rather than something to resist.
There will, however, always be the resistors. Some will sleep six hours or fewer from pressure of work, and some will insist they don’t need sleep. It’s at this point in the chapter that we bow to the inevitable and mention Margaret Thatcher and Donald Trump. Both politicians are often cited for their ability to get by on little sleep. “Trump brags that he only needs four hours a night,” Meir Kryger told me, “and it shows, in my opinion, because he has many of the symptoms of sleep deprivation.”
These symptoms include moodiness, lack of alertness, confusion, and problems making decisions. In Trump’s case, the garbled “covfefe”14 tweet springs to mind. Long-term lack of sleep has been linked to an increase in risk of stroke and diabetes, and can cause depression and weight gain. The US National Sleep Foundation’s latest, updated sleep duration figures recommend seven to eight hours’ sleep per night for adults.15 Recent work at the Sleep Research & Treatment Center at Penn State College of Medicine in Hershey, Pennsylvania, suggests there are side effects to short sleep.16 If you are already at risk for cardiovascular disease, short sleep can increase the risk. Julio Fernandez-Mendoza also found that there are some short sleepers who might not even be aware they are short sleepers. Typically they think they get more sleep than they actually do. “In other words, they are not aware that when they spent eight hours in bed and think they got seven and a half hours they actually got six,” he says. These kinds of short sleepers don’t seem to suffer any ill effects, such as hypertension, diabetes, or depression, but they do experience a decrease in processing speed. This is the part of cognitive function that determines how quickly you are able to understand, react to, and complete a mental task.
Some of the claims made by people who say they only need four hours’ sleep are bravado; they are what business people and politicians (people in these roles are especially prone to the tendency) think they ought to say. “Some people are short sleepers and are macho about it,” says Kryger. “They don’t perform really well, they think sleep is a waste of time. They’d rather be awake or making money and being productive rather than sleep.” On the other hand, there really are people who don’t suffer the cognitive hangover most of us get if we miss out on sleep. Businesswoman Martha Stewart seems to be one of these.17 She has complained that there’s not enough time in the day and says she needs only four hours a night.
“Some of the claims people make are true,” says Kryger. Some short sleepers seem to escape the negative consequences. These are the people we’ll investigate now.
The Sleep-Wake Center at the University of Utah, like most sleep units around the world, mostly sees people who have problems sleeping. They are busy fielding patients with sleep apnea, daytime drowsiness, restless leg syndrome, and, of course, insomnia. But in the early 2000s, its director, Christopher Jones, started pondering why some people are morning larks, and some skew much more to the night owl end of the sleep spectrum. He realized that understanding this better might inform treatments for people who don’t sleep well, so he put out a call for volunteers for a study. He was interested in habitual early risers, and a sixty-eight-year-old woman got in touch. The woman told Jones that she needed only six hours’ sleep, that she had been like that as long as she could remember, and that it had never done her any harm. What’s more, her daughter was the same.
Jones was intrigued and fascinated, especially that the daughter was the same—it hinted that there might be something genetic influencing their sleep. In the early 1990s Urs Albrecht and colleagues at the University of Fribourg in Switzerland had found Per2, a gene in mice that regulates the circadian clock. There’s a version of the gene in families that have advanced sleep-phase syndrome. If you have this, you sleep eight hours but you are skewed wildly out of kilter. These people are extreme morning people, going to bed at six or seven in the evening and waking at three or four in the morning. The Per2 gene, on chromosome 2, influences the circadian pacemaker the body sets its clock by, and variations of it have been linked to certain cancers.18 Ever since this variant had been discovered, says Jones, he’d been hoping to come across a family with highly skewed or unusual sleep patterns. With this mother and daughter pair, he seemed to have found it.
“I had never heard of ‘natural’ short sleepers before,” he says, “and at first just thought they were just very morning people.” However, he had the pair keep sleep logs and wear wrist monitors called actigraphs, which recorded the amount of movement and activity they made. The results confirmed that the pair were going to sleep late (around 10 p.m.) as well as getting up early (at 4 a.m.), which is not generally considered part of the usual “extreme morning person” routine.
Jones took DNA samples from the pair and sent them to Ying-Hui Fu, a colleague at the University of California, San Francisco. Fu specializes in the biology of myelin, which is the fatty insulating material around nerve cells; and sleep behavior. She has a particular interest in genetics, and in the extreme larks of the sleeping world.
When she looked at the gene sequences of the mother and daughter pair referred from Utah, Fu found a mutation in the DEC2 gene on chromosome 12. Suspecting that it was this mutation that was causing the women to wake up so early, Fu made transgenic mice and flies carrying the mutation. The resulting mice slept about an hour less than normal mice, and the flies two hours less. Fu, who published her findings in the journal Science in 2009,19 says if DEC2 was available in a pill, she’d take it so she’d have more time in the day.
Louis Ptacek is a neurogeneticist who works with Fu at UCSF. The key question about people with the DEC2 short-sleeping mutation is whether they gain all the restorative benefits of sleep in only six hours.
“Unfortunately, we know so little about sleep that this question cannot be answered at this time,” was his response. The issue, he says, is whether these people “need” less sleep. In other words, do they accumulate while awake less of whatever it is that must be cleared during sleep? “Do they have the same ‘burden’ from being awake for a certain number of hours but sleep more ‘efficiently’?”
Since finding the mother-daughter pair, the team has gathered genetic information from many more families of short sleepers, and according to Ptacek they have discovered at least one or two, and maybe three, new human sleep genes or mutations. The team is focusing now on people with this short-sleeping ability, and will be able, he says, to get at some of these questions: “All elements of sleep are genetic. And they are all subject to environmental influences.”
• • •
So there are genuine short sleepers. People who naturally get by on less, not those who push themselves because of work or because they have to care for a relative. What are the personality traits of these people?
To find out, Timothy Monk and colleagues at the University of Pittsburgh Medical Center in Pennsylvania recruited short sleepers for a study, making sure they admitted only natural short sleepers. Those selected (nine men and three women) slept for an average of 5.3 hours per night compared with 7.1 hours for a control group of people matched for age and gender who were not short sleepers.
All the subjects completed attitude-to-life questionnaires. If you know someone who is a short sleeper, or if you are one yourself, consider for a moment the personality traits you associate with them. Monk’s results showed that in their small sample, the short sleepers were more energetic and aggressive than the normal sleepers. They were also less anxious and more ambitious. All these traits seem to fit the stereotype of the short sleeper we hear about. In contrast to earlier studies, Monk’s team found no evidence that short sleepers were necessarily more extroverted, but concluded that there is some evidence for “subclinical hypomania” in short sleepers. This is basically an elevated mood that, when it becomes problematic, can tip into bipolar disorder.20
Remember that the short sleepers in this study were not being driven by work. The team had to exclude many applicants who put themselves forward as natural short sleepers but who were found to be sleeping “unwisely”—curtailing sleep for work or caregiving purposes, or because they were unwell either physically or mentally.
“Every now and again I’ll encounter someone who doesn’t sleep much in terms of what we consider to be normal, but is quite productive,” says Meir Kryger. “What we’ll never know is how productive they could’ve been had they actually slept the right amount of time. That’s the dilemma.”
Productivity is one thing, but the evidence is clear that it’s not good to force yourself to sleep less than about seven hours. Napoleon Bonaparte’s pronouncement about the hours of sleep people require—“six for a man, seven for a woman, eight for a fool”—is as backward as it is sexist. Even for those people who genuinely get by on less sleep, such as those being profiled in Ying-Hui Fu’s lab, the long-term costs will eventually outweigh the short-term benefits. We can say this because sleep deprivation seems to make people more vulnerable to developing dementia.21 Several lines of evidence suggest a reason. For one thing, the clean-up cells deployed by the brain are overactive when you are sleep deprived. Michele Bellesi of the Marche Polytechnic University in Italy interrupted the sleep of mice for five days in a row, and found that cells called astrocytes, which perform a pruning function in the brain, were more active, as were microglial cells, which function to locate damaged cells. Other experiments in mice have shown that sleep helps the brain purge itself of debris,22 and that if you prevent animals from getting deep sleep, then amyloid proteins—the hallmarks of Alzheimer’s—build up in the brain.23
Remember that Margaret Thatcher suffered from Alzheimer’s late in life. It seems we are now able to say that her habit of sleeping only four hours a night caught up with her—that there was a causal link between her sleeping and her dementia. “Animal tests would suggest it’s causal,” says Adrian Williams. “Mice get Alzheimer’s if they don’t sleep.”
While it’s clear that a full understanding of all the benefits of sleep, let alone the mechanisms of how it functions, will take many years, we know that a good night’s sleep is essential for our health and well-being. Get some rest. Your happiness depends on it.