Work, friendships, exercise, parenting, eating, reading — there just aren’t enough hours in the day. To live fully, many of us carve those extra hours out of our sleep time. Then we pay for it the next day. A thirst for life leads many to pine for a drastic reduction, if not elimination, of the human need for sleep. Little wonder: if there were a widespread disease that similarly deprived people of a third of their conscious lives, the search for a cure would be lavishly funded. It’s the Holy Grail of sleep researchers, and they might be closing in.
As with most human behaviours, it’s hard to tease out our biological need for sleep from the cultural practices that interpret it. The practice of sleeping for eight hours on a soft, raised platform, alone or in pairs, is actually atypical for humans. Many traditional societies sleep more sporadically, and social activity carries on throughout the night. Group members get up when something interesting is going on, and sometimes they fall asleep in the middle of a conversation as a polite way of exiting an argument. Sleeping is universal, but there is glorious diversity in the ways we accomplish it.
Different species also seem to vary widely in their sleeping behaviours. Herbivores sleep far less than carnivores — four hours for an elephant, compared with almost 20 hours for a lion — presumably because it takes them longer to feed themselves, and vigilance is selected for. As omnivores, humans fall between the two sleep orientations. Circadian rhythms, the body’s master clock, allow us to anticipate daily environmental cycles and arrange our organ’s functions along a timeline so that they do not interfere with one another.
Our internal clock is based on a chemical oscillation, a feedback loop on the cellular level that takes 24 hours to complete and is overseen by a clump of brain cells behind our eyes (near the meeting point of our optic nerves). Even deep in a cave with no access to light or clocks, our bodies keep an internal schedule of almost exactly 24 hours. This isolated state is called ‘free-running’, and we know it’s driven from within because our body clock runs just a bit slow. When there is no light to reset it, we wake up a few minutes later each day. It’s a deeply engrained cycle found in every known multi-cellular organism, as inevitable as the rotation of the Earth — and the corresponding day-night cycles — that shaped it.
Human sleep comprises several 90-minute cycles of brain activity. In a person who is awake, electroencephalogram (EEG) readings are very complex, but as sleep sets in, the brain waves get slower, descending through Stage 1 (relaxation) and Stage 2 (light sleep) down to Stage 3 and slow-wave deep sleep. After this restorative phase, the brain has a spurt of rapid eye movement (REM) sleep, which in many ways resembles the waking brain. Woken from this phase, sleepers are likely to report dreaming.
One of the most valuable outcomes of work on sleep deprivation is the emergence of clear individual differences — groups of people who reliably perform better after sleepless nights, as well as those who suffer disproportionately. The division is quite stark and seems based on a few gene variants that code for neurotransmitter receptors, opening the possibility that it will soon be possible to tailor stimulant variety and dosage to genetic type.
Around the turn of this millennium, the biological imperative to sleep for a third of every 24-hour period began to seem quaint and unnecessary. Just as the birth control pill had uncoupled sex from reproduction, designer stimulants seemed poised to remove us yet further from the archaic requirements of the animal kingdom.
Any remedy for sleepiness must target the brain’s prefrontal cortex. The executive functions of the brain are particularly vulnerable to sleep deprivation, and people who are sleep-deprived are both more likely to take risks, and less likely to be able to make novel or imaginative decisions, or to plan a course of action. Designer stimulants such as modafinil and armodafinil (marketed as Provigil and Nuvigil) bring these areas back online and are highly effective at countering the negative effects of sleep loss. Over the course of 60 hours awake, a 400mg dose of modafinil every eight hours reinstates rested performance levels in everything from stamina for boring tasks to originality for complex ones. It staves off the risk propensity that accompanies sleepiness and brings both declarative memory (facts or personal experiences) and non-declarative memory (learned skills or unconscious associations) back up to snuff.
It’s impressive, but also roughly identical to the restorative effects of 20 mg of dextroamphetamine or 600 mg of caffeine (the equivalent of around six coffee cups). Though caffeine has a shorter half-life and has to be taken every four hours or so, it enjoys the advantages of being ubiquitous and cheap.
For any college student who has pulled an all-nighter guzzling energy drinks to finish an essay, it should come as no surprise that designer stimulants enable extended, focused work. A more challenging test, for a person wired on amphetamines, would be to successfully navigate a phone call from his or her grandmother. It is very difficult to design a stimulant that offers focus without tunnelling – that is, without losing the ability to relate well to one's wider environment and therefore make socially nuanced decisions. Irritability and impatience grate on team dynamics and social skills, but such nuances are usually missed in drug studies, where they are usually treated as unreliable self-reported data. These problems were largely ignored in the early enthusiasm for drug-based ways to reduce sleep. (...)
One reason why stimulants have proved a disappointment in reducing sleep is that we still don’t really understand enough about why we sleep in the first place. More than a hundred years of sleep deprivation studies have confirmed the truism that sleep deprivation makes people sleepy. Slow reaction times, reduced information processing capacity, and failures of sustained attention are all part of sleepiness, but the most reliable indicator is shortened sleep latency, or the tendency to fall asleep faster when lying in a dark room. An exasperatingly recursive conclusion remains that sleep’s primary function is to maintain our wakefulness during the day. (...)
The Somneo mask is only one of many attempts to maintain clarity in the mind of a soldier. Another initiative involves dietary supplements. Omega-3 fatty acids, such as those found in fish oils, sustain performance over 48 hours without sleep — as well as boosting attention and learning — and Marines can expect to see more of the nutritional supplement making its way into rations. The question remains whether measures that block short-term sleep deprivation symptoms will also protect against its long-term effects. A scan of the literature warns us that years of sleep deficit will make us fat, sick and stupid. A growing list of ailments has been linked to circadian disturbance as a risk factor.
Both the Somneo mask and the supplements — in other words, darkness and diet — are ways of practising ‘sleep hygiene’, or a suite of behaviours to optimise a healthy slumber. These can bring the effect of a truncated night’s rest up to the expected norm — eight hours of satisfying shut-eye. But proponents of human enhancement aren’t satisfied with normal. Always pushing the boundaries, some techno-pioneers will go to radical lengths to shrug off the need for sleep altogether.
As with most human behaviours, it’s hard to tease out our biological need for sleep from the cultural practices that interpret it. The practice of sleeping for eight hours on a soft, raised platform, alone or in pairs, is actually atypical for humans. Many traditional societies sleep more sporadically, and social activity carries on throughout the night. Group members get up when something interesting is going on, and sometimes they fall asleep in the middle of a conversation as a polite way of exiting an argument. Sleeping is universal, but there is glorious diversity in the ways we accomplish it.Different species also seem to vary widely in their sleeping behaviours. Herbivores sleep far less than carnivores — four hours for an elephant, compared with almost 20 hours for a lion — presumably because it takes them longer to feed themselves, and vigilance is selected for. As omnivores, humans fall between the two sleep orientations. Circadian rhythms, the body’s master clock, allow us to anticipate daily environmental cycles and arrange our organ’s functions along a timeline so that they do not interfere with one another.
Our internal clock is based on a chemical oscillation, a feedback loop on the cellular level that takes 24 hours to complete and is overseen by a clump of brain cells behind our eyes (near the meeting point of our optic nerves). Even deep in a cave with no access to light or clocks, our bodies keep an internal schedule of almost exactly 24 hours. This isolated state is called ‘free-running’, and we know it’s driven from within because our body clock runs just a bit slow. When there is no light to reset it, we wake up a few minutes later each day. It’s a deeply engrained cycle found in every known multi-cellular organism, as inevitable as the rotation of the Earth — and the corresponding day-night cycles — that shaped it.
Human sleep comprises several 90-minute cycles of brain activity. In a person who is awake, electroencephalogram (EEG) readings are very complex, but as sleep sets in, the brain waves get slower, descending through Stage 1 (relaxation) and Stage 2 (light sleep) down to Stage 3 and slow-wave deep sleep. After this restorative phase, the brain has a spurt of rapid eye movement (REM) sleep, which in many ways resembles the waking brain. Woken from this phase, sleepers are likely to report dreaming.
One of the most valuable outcomes of work on sleep deprivation is the emergence of clear individual differences — groups of people who reliably perform better after sleepless nights, as well as those who suffer disproportionately. The division is quite stark and seems based on a few gene variants that code for neurotransmitter receptors, opening the possibility that it will soon be possible to tailor stimulant variety and dosage to genetic type.
Around the turn of this millennium, the biological imperative to sleep for a third of every 24-hour period began to seem quaint and unnecessary. Just as the birth control pill had uncoupled sex from reproduction, designer stimulants seemed poised to remove us yet further from the archaic requirements of the animal kingdom.
Any remedy for sleepiness must target the brain’s prefrontal cortex. The executive functions of the brain are particularly vulnerable to sleep deprivation, and people who are sleep-deprived are both more likely to take risks, and less likely to be able to make novel or imaginative decisions, or to plan a course of action. Designer stimulants such as modafinil and armodafinil (marketed as Provigil and Nuvigil) bring these areas back online and are highly effective at countering the negative effects of sleep loss. Over the course of 60 hours awake, a 400mg dose of modafinil every eight hours reinstates rested performance levels in everything from stamina for boring tasks to originality for complex ones. It staves off the risk propensity that accompanies sleepiness and brings both declarative memory (facts or personal experiences) and non-declarative memory (learned skills or unconscious associations) back up to snuff.
It’s impressive, but also roughly identical to the restorative effects of 20 mg of dextroamphetamine or 600 mg of caffeine (the equivalent of around six coffee cups). Though caffeine has a shorter half-life and has to be taken every four hours or so, it enjoys the advantages of being ubiquitous and cheap.
For any college student who has pulled an all-nighter guzzling energy drinks to finish an essay, it should come as no surprise that designer stimulants enable extended, focused work. A more challenging test, for a person wired on amphetamines, would be to successfully navigate a phone call from his or her grandmother. It is very difficult to design a stimulant that offers focus without tunnelling – that is, without losing the ability to relate well to one's wider environment and therefore make socially nuanced decisions. Irritability and impatience grate on team dynamics and social skills, but such nuances are usually missed in drug studies, where they are usually treated as unreliable self-reported data. These problems were largely ignored in the early enthusiasm for drug-based ways to reduce sleep. (...)
One reason why stimulants have proved a disappointment in reducing sleep is that we still don’t really understand enough about why we sleep in the first place. More than a hundred years of sleep deprivation studies have confirmed the truism that sleep deprivation makes people sleepy. Slow reaction times, reduced information processing capacity, and failures of sustained attention are all part of sleepiness, but the most reliable indicator is shortened sleep latency, or the tendency to fall asleep faster when lying in a dark room. An exasperatingly recursive conclusion remains that sleep’s primary function is to maintain our wakefulness during the day. (...)
The Somneo mask is only one of many attempts to maintain clarity in the mind of a soldier. Another initiative involves dietary supplements. Omega-3 fatty acids, such as those found in fish oils, sustain performance over 48 hours without sleep — as well as boosting attention and learning — and Marines can expect to see more of the nutritional supplement making its way into rations. The question remains whether measures that block short-term sleep deprivation symptoms will also protect against its long-term effects. A scan of the literature warns us that years of sleep deficit will make us fat, sick and stupid. A growing list of ailments has been linked to circadian disturbance as a risk factor.
Both the Somneo mask and the supplements — in other words, darkness and diet — are ways of practising ‘sleep hygiene’, or a suite of behaviours to optimise a healthy slumber. These can bring the effect of a truncated night’s rest up to the expected norm — eight hours of satisfying shut-eye. But proponents of human enhancement aren’t satisfied with normal. Always pushing the boundaries, some techno-pioneers will go to radical lengths to shrug off the need for sleep altogether.
by Jessa Gamble, Aeon | Read more:
Image: Carlos Barria/Reuters
