You need super-sleep

This is the tyranny of sleep. Every animal on the planet is a junkie hooked on its restorative charms. Scientists have shown that if you keep rats in unrelenting wakefulness they will die within four weeks, a 20th of their normal lifespan. Yet one species has begun an unprecedented mass experiment in defying the natural world’s most ancient instinct. Humans stir themselves in the morning with chemical stimulants and little buzzing devices, and stay up long after sunset with artificial lights and still more little buzzing devices. The orthodox belief is that this is a catastrophic and irreversible problem that is leaving us more tired than we have ever been. But what if it is wrong? What if we could fight back against our sleep addiction and manage with six hours or even significantly less?

“There will,” Benjamin Franklin once said, “be sleeping enough in the grave.” Jim Horne is inclined to agree. In his book Sleeplessness, which will be published in October, the Loughborough University sleep scientist argues that the modern obsession with spending eight hours out of every 24 in a state of catatonia is misguided. What matters is not so much how long we sleep as how well and efficiently we do it. It is time, he says, to approach rest with the same thirst for economy we bring to all our other activities in the 21st century.

“Judging sleep by its duration is like judging a plate of food by the total number of calories on it rather than the fats, proteins and carbohydrates,” Professor Horne said. “We don’t need to make up all the sleep we’ve lost, it’s the quality of the sleep that’s so important.”

Around the world, hundreds of researchers and maverick amateurs are working on ways to maximise this quality and so minimise the amount of time we have to spend in bed. Some of these paths, such as the American military’s attempt to engineer soldiers capable of fighting for a week without sleep, have proved to be quixotic blind alleys. Others work for a while, but their effects come at a prohibitive biological cost. Some, however, might just give us the benefits of eight hours’ rest in the space of four or five.

The easiest fix is gadgetry. Two years ago Phyllis Zee, professor of neurology at Northwestern University in Chicago, brought 13 people between the ages of 60 and 84 into her sleep laboratory for two consecutive nights. On both evenings her subjects looked at 88 pairs of related words (such as “energy – oil”) and tried to commit as many to memory as they could. Then they put on a pair of earphones and went to bed.

The only difference between the two nights was that one of them was punctuated with bursts of meaningless sound broadcast through the earphones. This “pink noise” is a little like the white noise of TV static, but with the volume of the bass frequencies turned up. You might think of the muffled rumble of an old-fashioned locomotive running over sleepers in the rain, or the sighing of waves against a pebble beach. “The noise is fairly pleasant, it kind of resembles a rush of water,” Professor Zee said. “It’s just noticeable enough that the brain realises it’s there, but not enough to disturb sleep.”

Beneath the apparent perversity of the experiment was a certain logic. The brain’s rhythms of electrical activity can slip into sync with certain subtle patterns of sound in a phenomenon known as entrainment. In 2012 Chinese researchers had shown that continuous pink noise broke down the complexity of people’s brainwaves as they slept, effectively stabilising the deeper stages of their slumber. Other groups found that entraining the sleeping brain with targeted blasts of sound made the method even more effective.

Even so, Professor Zee’s results, published in the journal Frontiers in Human Neuroscience in March, were astounding. The morning after their pink noise-blighted night, her human guinea pigs performed three times as well in their memory tests as they did on the other day. Their slow-wave activity, the phase of sleep during which the body releases growth hormones while the brain stocks up on energy and consolidates its new neural pathways, was markedly increased. It was, in crude terms, super-sleep.

Then there are the brain-zappers. Every great culture has had its bioelectricity fad. In the first century AD Scribonius Largus, court physician to the Roman emperor Claudius, was in the habit of treating gout and migraines by applying a live electric torpedo fish to the affected spot. The Victorians used “electropathic” belts to boost the virility of feeble men. Today we have transcranial direct current stimulation (TDCS). These clunky headsets are designed to pass a weak electrical field through a particular brain region, making it easier or harder for the neurons to chatter with one another. They have been used as experimental treatments for depression, chronic pain and belief in God. It was always going to be only a matter of time before scientists would test their capacity for sleep enhancement.

Last year, Fabiana Ruggiero and her team presented the results of a study involving 26 patients between the ages of 19 and 86. Two were stroke survivors; others had Parkinson’s disease, eating disorders and paraparesis, a rare inherited syndrome that causes cramps and spasms in the lower legs. Dr Ruggiero, a neurologist at the Policlinico of Milan, one of Italy’s oldest hospitals, gave her patients individually tailored doses of electricity to the skull for 20 minutes a time on five consecutive days. It worked a treat. On average, their sleep quality scores improved by 13 per cent and they felt they were sleeping 22 per cent better. Most strikingly, the efficiency of their normal sleep rose by 17 per cent.

The experiment was small and tentative, but it was by no means a one-off. Months earlier, scientists at Freiburg Medical University revealed that TDCS reduced the amount of time 19 healthy people needed to sleep by 25 minutes a night on average. In another 2016 paper, researchers in Tehran showed that TDCS treatment raised the probability of slow-wave sleep in six insomnia patients by about 20 per cent and increased the overall efficiency of their sleep by roughly half that margin. “Our preliminary results,” they wrote in the Journal of Sleep Research, “suggest a sleep-stabilising role for the intervention, which may mimic the effect of sleep slow wave-enhancing drugs.”

These technological tricks are impressive but need to be handled with care for the time being, according to Russell Foster, professor of circadian neuroscience at the University of Oxford. Setting aside the unappealing prospect of trying to nod off with a crackling electronic diadem wrapped around your temples, the research is still at an early stage and has only involved a few dozen patients. “It’s tricky,” Professor Foster said. “I think the jury is still out on these methods.”

Another, even stranger approach to “sleep-hacking” is loosely based on natural history rather than drugs or machinery. Today most westerners tend to get their rest in a single block of sleep each night, but this is very much a deviation from the norm. In a landmark 2005 book called At Day’s Close: Night in Times Past, the American historian Roger Ekirch showed that from the dawn of literature in ancient Greece until well into the Industrial Revolution it was customary for us to snooze for a few hours, wake and toddle around doing chores in the middle of the night, and then go back to bed until morning. “It’s likely that our ancestors did have a first sleep and then go and visit the neighbours or do things in the house and then have a second sleep,” said Malcolm von Schantz, professor of chronobiology at the University of Surrey.

Humans, like the great apes, instinctively prefer to doze in two phases. Winston Churchill, who famously got by on five or six hours of sleep, was one of the best-known modern nappers. “You must sleep sometime between lunch and dinner,” he once said. “Take off your clothes and go to bed. That’s what I always do . . .You will be able to accomplish more. You get two days in one. Well, at least one and a half.”

The polyphasic sleep movement is napping on steroids. Taking their cue from the way babies and the majority of other animal species break their sleep up into even smaller chunks, thousands of people have quietly abandoned the long goodnight altogether. On internet chat forums such as Reddit they swap tips about intimidating schedules with names like the Everyman, the Uberman and the Dymaxion. Buckminster Fuller, the American polymath and inventor, earned notoriety for his ability to drop off within 30 seconds and to sleep in 30-minute bursts every six hours. Even Dame Ellen MacArthur has tried her hand at the technique, sleeping as little as one-and-a-half hours a day in a series of micro-naps during her record-breaking circumnavigation of the world in 2005.

Steve Pavlina, a self-help writer from the US, used the method to nap for 20 minutes every four hours, totalling only two hours of sleep each day over five-and-a-half months. “Adapting to polyphasic sleep took many days, and I felt like a zombie the first week,” he wrote. “At one point I just sat on the couch staring at a wall for 90 minutes, unable to form any thoughts. But eventually I was able to adapt, and it was one of the most unusual experiences of my life.” The trick is to get to the rapid-eye movement stage, when dreams occur, in a matter of minutes. And it worked. Pavlina said the sole reason he had given up was to see more of his wife and children. “The rest of the world,” he said, “simply isn’t polyphasic.”

The science, however, is dubious. Attempts to test the approaches in a systematic way have foundered on the tendency of participants to drop out in large numbers as they find they cannot stand the punishing strain. Researchers say that the only reason polyphasic sleep appears to be more efficient is because the brain is effectively on a permanent war footing, duped into fighting for its survival. In the end it may have disastrous consequences for health. “I would say generally that it’s not something that any of us would recommend to anybody unless they absolutely have to,” Professor von Schantz said. “To sleep less than you feel you need to is likely to be harmful to you in the medium and long term.”

There may be a better way. Sleep needs vary enormously across the animal kingdom. Some bat species roost for as much as 21 hours out of 24, but according to a paper published in March African elephants may sleep for less than two. While their counterparts in zoos rest for as much as seven hours a day, the wild elephants were found to dream only once every three or four days.

Vladyslav Vyazovskiy, one of Professor Russell’s Oxford colleagues, thinks they may hold the key not only to discovering more efficient ways of sleeping but also to a more fundamental understanding of what sleep is. “You start wondering why on earth such a big animal as an elephant hardly sleeps at all,” he said. “It must have found a way to fulfil this function by other means.” Humans already sleep about two hours less each night than chimpanzees, our closest relatives. Margaret Thatcher and Donald Trump have claimed to get by on four hours a night. Harriet Green, the IBM executive and former head of Thomas Cook, says she manages with three. What do they do that the rest of us don’t?

In a remarkable study that came out last year, Dr Vyazovskiy and his colleagues experimented with mice that ran voluntarily on a wheel for hours at a stretch, sometimes covering several miles in the course of a night. When the scientists examined the animals’ brains they found something bizarre. Some of the mice’s neurons completely stopped firing as they exercised. The activity in the motor and sensory processing regions dropped by more than a third.

More curious still, the mice spent considerably more time awake than their sedentary peers. Something about the rhythmic, repetitive drumming of their feet on the wheel seemed to send parts of their brains to sleep, enabling them to refresh themselves on the go. “This state,” Dr Vyazovskiy wrote in a recent article, “may even allow the brain to rest without entering deep sleep and provide some of the same benefits.” Much as migrating birds can snooze on the wing with only half of their brains, at least one mammal species appears to be able to drift into a mode that blends active wakefulness with the healing power of sleep.

Mice, it must be stressed, are not humans. But there is tantalising evidence that we may have similar abilities. Traditional Buddhist meditation practices, involving a balance between concentration and relaxation, are known to profoundly alter how the brain works. Their aim, according to Willoughby Britton, an expert on the psychology of meditation at Brown University in Providence, Rhode Island, is the cultivation of a “vigilant awareness in every waking moment [that extends] beyond the waking state to sleep states as well”.

The religion’s ancient writings suggest that proficient meditators should end up sleeping about four hours a day. This is fairly counterintuitive, as the paradoxical Buddhist state of slumberous alertness turns out to drastically increase the amount of time spent in the shallows of sleep at the expense of the deeper, slow-wave phases. Yet 70 per cent of the participants in one study of a three-month Theravada retreat ended up sleeping about two hours less than normal, while a controlled experiment involving Indian master-meditators showed that they slept only 5.2 hours a night compared with 7.8 for a group of non-meditators.

Waking and sleeping; sleeping and waking. The two may not be quite the mutually estranged realms we once took them for. If it is possible to blur the hardest boundary in our cognitive experience by jogging or even simply by adopting the right habits of thought, then drugs or electronic devices guided by our emerging knowledge of neurobiology could one day have effects on our sleep that would have been indistinguishable from magic half a century ago. For now, this science is in its speculative childhood. The imperium of sleep will not be broken any time soon.

Oliver Moody