Register Thursday | June 20 | 2019

The Science of Shut-Eye

Please stop bragging about getting four hours of sleep

Everybody knows the waking life is where it’s at. Not that we hate sleep, mind you. It’s just that we’re addicted to wakefulness. We feel no remorse in shaving an hour off our slumber in order to reclaim the time stolen from us by our daytime commitments. And we take the consequences in stride—buying ear-splitting alarm clocks to drag us into the light, guzzling Slurpee-sized coffees to kickstart our brains.

And why not? Less sleep, after all, equals more free time; and more free time equals increased productivity. But what if we could wrestle control of our consciousness from nature and bend the laws of sleep to our wills? What if we could just stay awake?

When it comes to the science of sleep, there are limitless theories, remedies, studies, superstitions and experiments, and yet the true nature of this universal pastime has eluded us. On this planet, we are nearly alone in our habit of sleeping for one consolidated period per day. Known as “monophasic sleep,” this practice is limited to humans and a select few other mammals like squirrel monkeys. The rest of the animal kingdom exhibits a more “polyphasic” approach to sleeping—breaking up forty winks into smaller portions (say, five to nine winks apiece), taken throughout the day.

As any parent can testify, polyphasic tendencies do exist in humans. At birth, we are pure polyphasic, achieving our sleep quota with substantial naps occurring about every four hours. It is only as we mature that our sleep periods amalgamate, settling relatively quickly into a monophasic nighttime schedule. It’s almost a metaphor for how our species moved toward consolidated sleep.

Polyphasic behaviour increases with the volatility of an environment and the frequency with which a species feeds. When early human societies abandoned the risks of hunting and foraging for more stable, community-based food production, they required longer periods of wakefulness. As in our individual lives, there came a time when monophasic sleep simply made more sense.

This theory of a gradual, evo-
lutionary shift is supported (in some respects) by the research of Thomas Wehr, an American pioneer in body-clock studies. In one study, he attempted to simulate prehistoric sleep conditions by removing his subjects from artificial light for fourteen night-hours per day for several weeks. The subjects began moving toward a pattern of broken slumber, sleeping for four hours before a two-to-three-hour interval of “rest and reflection.” Subjects would then fall back to sleep for another four hours before waking for the day.

If, as this experiment suggests, our tendency toward consolidated sleep is a learned one, is there the possibility that we may be able to fragment our sleep patterns? Further, might there be a hidden mechanism in this apparent flexibility that could unlock a world of waking wonder?

It’s an attractive prospect and, unsurprisingly, an ancient one. Leonardo da Vinci claimed that he’d whittled down his total sleep hours to a trim ninety minutes per day, with no loss of performance or wakefulness. By napping for fifteen minutes, every four hours, he claimed that the recuperative effects of a full night’s sleep could be achieved. In other words, a day’s worth of multiple naps could achieve the same restorative results as a single period of merged sleep.

Since the idea entered the twentieth century, it has taken on many names. “Überman sleep,” a popular moniker, suggests that one could metamorphose into a superhuman, bestowed with gifts of efficiency and productive inspiration beyond the limits of snoozing mortals. Da Vinci, for example, claimed that his creativity received a great boost from this method. A 1990 study performed by Italian chronobiologist Claudio Stampi managed to recreate this pattern for a limited time, and on a limited scale, by reducing total sleep duration in subjects to three hours per day with few detrimental effects. Polyphasic sleep strategies, wrote Stampini, “appear[ed] to be the only way to achieve sleep reduction with little to no loss in performance.”

The überman sleep method maintains that the vital stages of sleep may be shuffled, cut and dealt like playing cards. Sleep, as we know it, occurs in five stages: a non-REM phase (comprised of four stages said to be important to tissue repair, regeneration and growth) is followed by an REM (rapid eye movement) phase (during which we dream, and said to be vital to learning ability and memory function). We sequentially pass through these stages a number of times during a night of normal sleep. However, as Stampi’s subjects were adapting to the überman schedule, he noticed something interesting: the stages of sleep, rather than being skipped or abandoned, simply began to distribute themselves evenly throughout the naps. This lent support to the notion that überman sleep, if not yet a valid concept, was at least a plausible one.

Plausible or not, discussions of ultra-short sleep strategies have been relegated to anecdote, rumour and the alleyways of culture: in one Seinfeld episode, Kramer tries to replicate da Vinci’s sleeping system and falls asleep at inopportune moments—hilarity ensues.

In fact, more recent studies have implied that there are fundamental problems with the nap strategies laid out by da Vinci. After identifying the significant effects of cumulative sleep debt, British researcher Jim Horne had to revise his own estimates of “core sleep”—the minimum amount necessary for restoration to take place—from four hours to six. And University of Pennsylvania clinical psychologist David Dinges recently challenged the idea that sleep reduction was possible with “little to no performance loss.” Dinges proposed that while “working memory performance benefit[s] from the naps, vigilance and basic alertness [do] not benefit very much.”

But perhaps the biggest obstacle to employing the überman method is logistical. Unless we are unemployed, self-employed or part-time-employed, it’s unlikely that the working environments of our waking lives would respond favourably to an inflexible schedule of frequent napping.

Our daily pattern of sleepiness and wakefulness is the result of two forces: our circadian rhythms and our sleep drive. Like every living thing, we’ve evolved according to the orbital mechanics of our planet. As the light–dark boundary dividing the earth scrolls across the continents from east to west, it triggers the biological clocks of animals passing into the sunlight. These clocks, embodied by two small structures in the brain (called the suprachiasmatic nucleus or SCN), control our circadian rhythms—a surprisingly varied spectrum of biological and neurobehavioural fluc-
tuations in alertness, body temperature, problem-solving ability and short-term memory performance. Generally, it can be said that the SCN tries to promote wakefulness during the light hours and restorative sleep at night.

The other force is our sleep drive, a process that independently attempts to balance the length of our waking time with the amount of sleep we’ve accumulated. How much shut-eye we’ve banked is what dictates whether or not our need for sleep will surpass our ability to stay awake. Someone who hasn’t slept in days can still experience stages of lucidity and near-normal performance, as their circadian rhythms ebb and flow, but ultimately the sleep drive—a biological obligation—will trump these highs and lows. The consequences of reaching this point can be severe.

When we’ve exceeded our capacity to stay awake, our sleep drive can trigger an attack of instant or “micro” sleep. This may sound exotic, but the symptoms of this phenomenon will be familiar to many of us and read like a dance card for the undead: the blank stare, the head snap, the drooping eyes, environmental non-responsiveness and, more seriously, the collapse. These occurrences can last from a few seconds to several minutes—often unbeknownst to the sufferer. The everyday ramifications for pilots, truckers, security personnel or anyone responsible for the safety of the public are clear.

We exercise an illusion of control over our sleeping patterns. Unable to muck about with our circadian rhythms, we instead toy maliciously with our sleep drives: pulling all-nighters and chipping away at those vital hours, trading our sleep for cash, for entertainment, for personal time. We have all heard the claim (or made it) that “I can get by on four hours of sleep.” This is, quite simply, a dangerous illusion. We don’t adapt to less sleep; we adapt to operating at a level of impairment, oblivious to the cognitive deficits we’re amassing.

The cost of disobedience can be harsher than many of us even know: physical weakness, drowsiness, increased appetite, changes in metab-
olism, impaired immune functions, decreased glucose tolerance, delayed reaction time, impaired problem-solving and decision-making skills, decreased motor functions, deterioration of mood and social ability, loss of short-term memory, an inability to learn new skills or maintain concentration, blurred vision, slurring of speech, bizarre or uncharacteristic behaviour and hallucinations. This is just a partial list.

These symptoms all mean the same thing: eventually, the tyrant must exercise control over its disobedi-
ent subject. When the demands of a twenty-four-hour society meet the physical realities of our biological sleep requirement, the consequences are more and more alarming. Disasters such as Chernobyl, Three Mile Island, Challenger, Bhopal and Exxon Valdez have officially been attributed to errors in judgement induced by fatigue. In a time when the actions of a very small number of people, or even a single individual, can have direct and dramatic consequences on large populations, the idea that we may be living in a sleep-deprived culture is a disturbing one.

We want to cheat the system, if only to serve the society we’ve created. But it would appear that, as yet, there is no “official” loophole. There’s only one way to be an über-productive and über-efficient member of society: you need to get a good night’s sleep.