Demis Hassibis is most creative at 1AM

Google DeepMind CEO says he starts his second workday at 10 p.m. and com... https://t.co/FzwrCTAaYR via @YouTube

— Bill Benzon, BAM! Bootstrapping Artificial Minds (@bbenzon) April 19, 2026

Biphasic Sleep vs. a continuous 8 hours

While the soul of this message is true—we shouldn't pathologize every waking moment—the history is a bit more complex.

- Biphasic sleep was real. Pre-industrial humans did sleep in two shifts. We lost this not to a mattress conspiracy, but to artificial light, which compressed…

— Emeka Sepi Maduka (@Sepiyoung) April 5, 2026

Parent-child co-sleeping is common in Asia [East and West]

Mike Ives, Sharing a Bed With Your Kid? It’s Totally Normal in Asia. NYTimes, July 22, 2025.

In the United States and some other Western countries, many parents wince at the idea of sharing a bed with their young child on a regular basis.

But in other places, long-term bed sharing through infancy, toddlerhood and beyond is seen as totally normal. For many families in Asia, in particular, the question is not whether to do it, but when to stop.

How and where young children sleep is a big deal for the whole family. It can have implications for an infant’s safety and a child’s development. It can also affect parental sleep, intimacy and mental health, and can influence how families configure their homes.

Western practice:

In the West, and especially in the United States, bed sharing tends to be unpopular and contentious. That is partly because the American Academy of Pediatrics and other experts warn that it can be unsafe for infants 6 months of age or younger.

Many Western parents put infants to sleep in cribs or beds in a separate room — often using a practice known as “sleep training,” in which infants are taught to sleep independently. Modern ideas about separating mothers and babies at night have their roots in campaigns by “Victorian-era influencers” in Britain and the United States, according to “How Babies Sleep,” a book published this year by the anthropologist Helen Ball.

Even though there isn’t much scientific literature on bed sharing, studies generally show that the practice is far more common in Asia than in the West. [...]

One multicountry survey of parents of infants and toddlers from 2010 found that bed-sharing rates were over 60 percent in China, Japan and South Korea, and over 70 percent in India and parts of Southeast Asia. The rates in Australia, Canada, New Zealand and the United States ranged from 5 to 15 percent.

Priorities:

In some Asian societies, many couples prioritize the mother-child bond over their own sleep health and marital relationships, said Heejung Park, a professor of psychology at Scripps College in California who has studied bed sharing in the region. [...]

In India, the cultural attachment to bed sharing is so deep that it tends to persist even among urban elites who are exposed to “Western sleep training culture,” said Himani Dalmia, a sleep specialist in New Delhi who runs a support group for parents and shares a bed with her children, 7 and 9.

Singapore is an exception:

One apparent exception in the region is Singapore, a wealthy city-state where reported bed sharing rates are lower than in other East and Southeast Asian countries. Sleep training seems to be increasingly popular there, and some Singaporean parents are reluctant to admit to bed sharing, said Elaine Chow, the president of a local breastfeeding support group.

Ah, those “intimacy” issues:

Some of Ms. Kim’s friends have children who stayed in the family bed until age 12, even at the expense of their parents’ sleep quality and sex lives. That would be too much for her, she said. So she and her husband have decided that their girls will move into what is now their playroom in about two years.

There's more at the link.

Hours of sleep vary inversely with income

Cristián Jara, Francisca Pérez, Rodrigo Wagner, Sleep hours fall as income rises: Macro and micro evidence on sleep inequality around the world, Economics & Human Biology, 2025, 101496, ISSN 1570-677X, https://doi.org/10.1016/j.ehb.2025.101496.

Highlights

• This paper examines global patterns of sleep inequality.
• Full-time, prime-age male workers in the top income quartile sleep around half an hour less per day than those in the lowest quartile.
• At the macro level, average sleep duration decreases as a country’s GDP increases.
• Higher-income individuals allocate more time to other leisure activities, such as social outings and internet usage, substituting sleep.

Abstract: People spend about a third of their lives sleeping. Our paper utilizes detailed time-use data to study sleep inequality by income. Our contribution lies in analyzing this relationship both within and across countries, using a global sample. At the micro level, we find that full-time male workers in the top income quartile sleep around half an hour less per day than those in the lowest quartile. This qualitative result is robust to various alternative tests and measurement of key variables. At the macro level, the average sleep hours decrease as the country’s GDP per capita increases. Interestingly, both our micro and macro estimations, are coherent with an estimated income elasticity of sleep around −0.04. Using this elasticity we replicate the implicit relationships identified in previous single-country studies. Additional results suggest that other leisure activities may be positively correlated to income, such as internet use and social outings, substituting sleep.

Keywords: Sleep inequality; Time allocation; Multinational Time Use Study

* * * * *

H/t Tyler Cowen.

Napping is good

I've believed that since I was quite young. I nap all the time. Now the NYTimes has an article in which experts advise on the proper way to nap. That's a good thing, but I do wonder what has happened that we are so far from the natural rhythms of our body and brain that we need an expert to advise us on napping. I suppose the expertise is necessary to overcome the effects of a misplaced emphasis on the moral value of work, which necessarily precludes napping during the part of the day reserved for work. Anyhow, here's the article:

Alica Callahan, You Deserve a Great Nap, NYtimes, November 23, 2023.

Here's a bit of advice:

Keep expectations low.

You may not fall asleep during your nap — or at least you may not think you have — and that’s OK, Dr. Mednick said. We are often “somewhat conscious” in the early stages of sleep, she said, but “it’s still good rest.”

She pointed to a recent study that found that drifting into the lightest stage of sleep — a sort of twilight zone where your mind wanders in a dreamlike way — for even one minute during a 20-minute rest generated more creativity and better problem-solving in young adults.

Get comfortable.

Settle into a quiet place where you’re unlikely to be interrupted, and put your phone on airplane mode, Dr. Wu said. If you’re lucky enough to have an office or access to a nap room, consider keeping a pillow, eye mask and earplugs at work, said Jessica Payne, a professor of psychology at the University of Notre Dame.

Then, try to tune into your five senses to “get out of your head and into your body,” Dr. Wu said, and let your breathing slow and deepen. “That allows the sleep to come to you.”

There's more advice, all of which makes sense.

Napping is yet another aspect of controlling behavioral mode, which is one of the most important things we need to master.

The benefits of dreaming

Carolyn Todd. REM Sleep Is Magical. Here’s What the Experts Know. NYTimes. Feb 25, 2023.

When we sleep we go cycle through five stages of sleep. We dream during one of those stages. When we dream we move our eyes. Thus dream sleep is called REM sleep – Rapid Eye Movement.

Benefits:

If you’ve ever gone to bed upset about something and woken up noticeably less bothered, it’s likely a result of the emotional processing and memory reconsolidation that happen during REM. There’s evidence that your brain divorces memories from their emotional charge — removing the “sharp, painful edges” from life’s difficulties, said Matthew Walker, a professor of neuroscience and psychology and the founder and director of the Center for Human Sleep Science at the University of California, Berkeley. REM is “like a form of overnight therapy,” he said.

REM also makes us better learners. During this sleep stage, your brain strengthens neural connections formed by the previous day’s experiences and integrates them into existing networks, Dr. Robbins said.

Dr. Walker added: “We take those new pieces of information and start colliding them with our back catalog of stored information. It’s almost a form of informational alchemy.”

These novel connections also make us more creative, he said. “We wake up with a revised mind-wide web of associations” that helps us solve problems. Researchers in Dr. Walker’s lab conducted a small study where people were roused from different stages of sleep and asked to solve anagram puzzles. They found that subjects awakened from REM sleep solved 32 percent more anagrams than subjects who were interrupted during non-REM sleep.

Then, of course, there’s dreaming: The majority of our vivid dreaming takes place during REM. Some experts suspect that dreams are a mere byproduct of REM sleep — the mental manifestation of neurological work. But others think they might help people process painful experiences, Dr. Walker said.

And although most physical processes, like repairing bone and muscle tissues, happen during the non-REM sleep stages, some hormonal changes occur while someone is in REM, Dr. Walker said, like the release of testosterone (which peaks at the onset of the first REM cycle).

If we don't get enough:

But large deficits of REM sleep, no matter your age, can deprive you of its psychological benefits, Dr. Dasgupta said. You may have more trouble learning, processing emotional experiences or solving problems.

Dysregulated REM sleep is also linked with cognitive and mental health issues, like slower thinking and depression, said Dr. Ana Krieger, medical director of the Center for Sleep Medicine at Weill Cornell Medicine. Too little REM, fragmented REM and REM sleep behavior disorder — where muscle paralysis fails to happen and people physically act out their dreams, often by kicking or punching — are associated with neurological issues, from mild forgetfulness to dementia and Parkinson’s disease.

There's more at the link.

The "two-sleep" system (two periods of sleep at night, separated by wakefulness)

Zaria Gorvett, The forgotten medieval habit of 'two sleeps', BBC Future, Jan 9, 2022. Much of the article is apparently based on, Roger Ekrich, At Day's Close: A History of Nighttime.

In the 17th Century, a night of sleep went something like this.

From as early as 21:00 to 23:00, those fortunate enough to afford them would begin flopping onto mattresses stuffed with straw or rags – alternatively it might have contained feathers, if they were wealthy – ready to sleep for a couple of hours. (At the bottom of the social ladder, people would have to make do with nestling down on a scattering of heather or, worse, a bare earth floor – possibly even without a blanket.)

At the time, most people slept communally, and often found themselves snuggled up with a cosy assortment of bedbugs, fleas, lice, family members, friends, servants and – if they were travelling – total strangers.

To minimise any awkwardness, sleep involved a number of strict social conventions, such as avoiding physical contact or too much fidgeting, and there were designated sleeping positions. For example, female children would typically lie at one side of the bed, with the oldest nearest the wall, followed by the mother and father, then male children – again arranged by age – then non-family members.

A couple of hours later, people would begin rousing from this initial slumber. The night-time wakefulness usually lasted from around 23:00 to about 01:00, depending on what time they went to bed. It was not generally caused by noise or other disturbances in the night – and neither was it initiated by any kind of alarm (these were only invented in 1787, by an American man who – somewhat ironically – needed to wake up on time to sell clocks). Instead, the waking happened entirely naturally, just as it does in the morning.

The period of wakefulness that followed was known as "the watch" – and it was a surprisingly useful window in which to get things done. "[The records] describe how people did just about anything and everything after they awakened from their first sleep," says Ekirch.

Under the weak glow of the Moon, stars, and oil lamps or "rush lights" – a kind of candle for ordinary households, made from the waxed stems of rushes – people would tend to ordinary tasks, such as adding wood to the fire, taking remedies, or going to urinate (often into the fire itself).

For peasants, waking up meant getting back down to more serious work – whether this involved venturing out to check on farm animals or carrying out household chores, such as patching cloth, combing wool or peeling the rushes to be burned. One servant Ekirch came across even brewed a batch of beer for her Westmorland employer one night, between midnight and 02:00. Naturally, criminals took the opportunity to skulk around and make trouble – like the murderer in Yorkshire.

But the watch was also a time for religion.

For Christians, there were elaborate prayers to be completed, with specific ones prescribed for this exact parcel of time. One father called it the most "profitable" hour, when – after digesting your dinner and casting off the labours of the world – "no one will look for you except for God”.

Those of a philosophical disposition, meanwhile, might use the watch as a peaceful moment to ruminate on life and ponder new ideas. In the late 18th Century, a London tradesman even invented a special device for remembering all your most searing nightly insights – a "nocturnal remembrancer", which consisted of an enclosed pad of parchment with a horizontal opening that could be used as a writing guide.

But most of all, the watch was useful for socialising – and for sex.

As Ekirch explains in his book, At Day's Close: A History of Nighttime, people would often just stay in bed and chat. And during those strange twilight hours, bedfellows could share a level of informality and casual conversation that was hard to achieve during the day.

For husbands and wives who managed to navigate the logistics of sharing a bed with others, it was also a convenient interval for physical intimacy – if they'd had a long day of manual labour, the first sleep took the edge off their exhaustion and the period afterwards was thought to be an excellent time to conceive copious numbers of children.

Once people had been awake for a couple of hours, they'd usually head back to bed. This next step was considered a "morning" sleep and might last until dawn, or later. Just as today, when people finally woke up for good depended on what time they went to bed.

Ekirch also references bi-phasic sleep in the classical era.

Biphasic sleep is common among among animals as well.

"There are broad swaths of variability among primates, in terms of how they distribute their activity throughout the 24-hour period," says David Samson, director of the sleep and human evolution laboratory at the University of Toronto Mississauga, Canada. And if double-sleeping is natural for some lemurs, he wondered: might it be the way we evolved to sleep too?

The move away from biphasic sleep happened during the Industrial Revolution:

"Artificial illumination became more prevalent, and more powerful – first there was gas [lighting], which was introduced for the first time ever in London," says Ekirch, "and then, of course, electric lighting toward the end of the century. And in addition to altering people's circadian rhythms. artificial illumination also naturally allowed people to stay up later."

However, though people weren't going to bed at 21:00 anymore, they still had to wake up at the same time in the morning – so their rest was truncated. Ekirch believes that this made their sleep deeper, because it was compressed.

As well as altering the population's circadian rhythms, the artificial lighting lengthened the first sleep, and shortened the second. "And I was able to trace [this], almost decade by decade, over the course of the 19th Century," says Ekirch.

I mention multiphasic sleep in other posts, such as:

• Reading The Human Swarm 5: Night-time action and brain-to-brain coupling [Shazam!!]
• Sleep: 8 continuous hours is a cultural convention, not a natural need

H/t Tyler Cowen.

Why we sleep

Unraveling why we sleep https://t.co/lx5VZ6gMXs

— Germán Sierra (@german_sierra) September 19, 2020

Abstract from the linked article (which is not behind a paywall):

Sleep serves disparate functions, most notably neural repair, metabolite clearance and circuit reorganization. Yet the relative importance remains hotly debated. Here, we create a novel mechanistic framework for understanding and predicting how sleep changes during ontogeny and across phylogeny. We use this theory to quantitatively distinguish between sleep used for neural reorganization versus repair. Our findings reveal an abrupt transition, between 2 and 3 years of age in humans. Specifically, our results show that differences in sleep across phylogeny and during late ontogeny (after 2 or 3 years in humans) are primarily due to sleep functioning for repair or clearance, while changes in sleep during early ontogeny (before 2 or 3 years) primarily support neural reorganization and learning. Moreover, our analysis shows that neuroplastic reorganization occurs primarily in REM sleep but not in NREM. This developmental transition suggests a complex interplay between developmental and evolutionary constraints on sleep.

Neural coordination of sleep

It’s great to watch science progress. Three years ago, we had a post a bemoaning that no one understood what a brain region called the claustrum actually does. Now, we finally know that the claustrum coordinates patterns of brain activity that are important for sleep! https://t.co/SHD7zRifFa

— Knowing Neurons (@KnowingNeurons) May 13, 2020

Sleep fallacies

Alexey Guzey critiques Matthew Walker, Why We Sleep (2017).

In the first chapter of Why We Sleep, Walker:

1. completely misrepresents the relationship between sleep and longevity and between sleep and cancer (Section 1)
2. erroneously states that getting a good night’s sleep is always beneficial (Section 2)
3. erroneously states that patients with fatal familial insomnia die because of lack of sleep (Section 3)
4. seems to invent a “fact” that the WHO has declared a “sleep loss epidemic” (Section 4)
5. misrepresents National Sleep Foundation’s sleep recommendations and uses them to misrepresent the number of adults failing to get the recommended hours of sleep (Section 5)
6. calls his book “a scientifically accurate intervention”

Given the density of scientific and factual errors and an apparent invention of new “facts” by Walker, I would caution readers against taking the book’s recommendations at face value.

His conclusion:

If you take one thing away from this entire essay, remember this: as long as you feel good, sleeping anywhere between 5 and 8 hours a night seems basically fine for your health (see Section 1), regardless of whatever Big Sleep wants you to believe.

All of the evidence we have about sleep and long-term health is in the form of those essentially meaningless correlational studies, but if you’re going to use bad science to guide your sleep habits, at least use accurate bad science.

H/t Tyler Cowen.

Reading The Human Swarm 5: Night-time action and brain-to-brain coupling [Shazam!!]

Ch12 of The Human Swarm, “Sensing Others” starts off with two dynamite paragraphs. I say they’re dynamite because they speak to two of my hobby horses, a relatively recent one, and one that goes back to my graduate school days. Let’s dig in (p. 161):

Spend time among hunter-gatherers and you realize sleeping through the night is a modern idea. On my trip to Namibia, I listened as Bushmen conversed under a chiseled Milky Way in voices elaborate as birds, full of clicks, twang, and twitter. Their huts were barely visible in the flicker of family fires as they shared both traditional tales and evens of the day with gusto and moments of dramatic acting. When the sun was up their conversations centered on daily business. Nighttime was story time, with tales conveying the big picture of a proper social life and affirming people’s connections with the greater society.

That’s my recent hobby horse, and it is grounded in my own behavior. While I’m basically an “early to bed, early to rise” guy, in recent years I’ve noticed that in creative phases I may get up once or twice in the night and work (creatively) for an hour or two. Some posts:

• Sleep, NOT, an 8-hour block (9.27.12)
• Sleeping Habits (mine – 11.15.12)
• Sleep Ain’t What It used to Be (1.12.13)
• Sleep: 8 continuous hours is a cultural convention, not a natural need (5.14.14)

Moffett’s second paragraph is about brain-to-brain communication:

Years later their animated storytelling came vividly to mind as I stood behind Uri Hasson, a professor of psychology and neuroscience at Princeton University, while he hunched over a computer displaying a series of brain scans. Hassonhad been observing the cerebral activity of people watching a movie. The snippets he played were open to interpretation: some viewers might suspect the husband in the film was unfaithful while others might conclude the wife was a liar. When Hasson looked at scans of the viewers’ brains, he found they differed accordingly. If, however, audience members talked to each other as they watched a video, their cerebral cortexes synchronized: the same portions of their brains lit up when they began to follow the story line with a unified point of view. Hasson calls this mind-to-mind coupling “a mechanism for creating and sharing a social world.” The pleasure the Bushmen expressed that starry night must have come from such a melding of minds.

Moffett sites an article I’d posted here at New Savanna in 2013, Brain-to-brain coupling: a mechanism for creating and sharing a social world. I’ve posted a number of articles by Hasson. More generally, I’ve got a good many posts on the topics of coupling and synchrony (you’ll find there’s a fair amount of overlap between those two topics). There is now a large and growing literature on the neural activity of people interacting with one another.

My interest in this topic goes back to my graduate school days, when David Hays got me interested in the work of William Condon, who’d taken high-speed video of people intereacting with one another and observed that their movments where synchronized on a scale of 10s of milliseconds. This then became the central conception of my 2001 book on music, Beethoven’s Anvil, where I devoted the second and third chapters to developing the dual notions that, 1) tighly coupled synchronzed movement is central to music-making, and 2) and music-making is central to human society. I developed these ideas in the context of Walter Freeman’s conception of the nervous system as a complex dynamical system.

Now I’ve got to get back to reading Moffett’s book. More later.

Sleep on it! [problem solving]

Kristin E. G. Sanders, Samuel Osburn, Ken A. Paller, Mark Beeman, Targeted Memory Reactivation During Sleep Improves Next-Day Problem Solving, Psychological Science, First published online, October 11, 2019, https://doi.org/10.1177/0956797619873344

Abstract: Many people have claimed that sleep has helped them solve a difficult problem, but empirical support for this assertion remains tentative. The current experiment tested whether manipulating information processing during sleep impacts problem incubation and solving. In memory studies, delivering learning-associated sound cues during sleep can reactivate memories. We therefore predicted that reactivating previously unsolved problems could help people solve them. In the evening, we presented 57 participants with puzzles, each arbitrarily associated with a different sound. While participants slept overnight, half of the sounds associated with the puzzles they had not solved were surreptitiously presented. The next morning, participants solved 31.7% of cued puzzles, compared with 20.5% of uncued puzzles (a 55% improvement). Moreover, cued-puzzle solving correlated with cued-puzzle memory. Overall, these results demonstrate that cuing puzzle information during sleep can facilitate solving, thus supporting sleep’s role in problem incubation and establishing a new technique to advance understanding of problem solving and sleep cognition.

H/t Alex Tabarrok.

The brain likes movement, rock-a-by baby, doodling

Richard A. Friedman, The Neuroscience of ‘Rock-a-Bye Baby, NYTimes, 10 Feb 2019:

Want to fall effortlessly into profound slumber and sleep like a baby? Everyone knows that infants can be lulled to sleep by gentle rocking. Well, now it seems that what works for babies works for adults, too.

New research shows that a slow rocking motion not only improves sleep but also can help people consolidate memories overnight. And this, in turn, tells us something interesting about how much the brain is affected by what seem to be purely physical interventions.

Synchrony:

The researchers found that rocking induced a kind of synchrony in brain wave activity that varied in tandem with the external motion. Rocking also increased the number of brain oscillations specific to sleep, which are critical for memory consolidation and learning. Though the exact mechanism is unclear, the researchers hypothesize that rocking activates motion-sensitive neurons in the inner ear, which then leads to modulation of brain activity.

All this made me wonder: How does physical movement affect the brain more broadly? It’s well known that exercise enhances cognitive functioning, but what about movements like rocking that involve minimal exertion? What effect on the brain do our seemingly purposeless everyday physical movements have — like fidgeting, foot shaking and doodling, among others?

A 2016 study showed that children with A.D.H.D. who were allowed to fidget — bouncing around and moving gently in place — performed better on a concentration task the more they moved.

Another study focused on doodling. Researchers had 40 participants monitor a boring telephone message for the names of people attending a party. Half the group was randomly assigned to doodle — they shaded printed shapes — while listening to the message. The study found that the “doodling group performed better on the monitoring task and recalled 29 percent more information on a surprise memory test.”

Cats too can dream, and when they crash...

When your cat crashes his bicycle in his dream pic.twitter.com/g64Z2pJETN

— Nature is Amazing 🌿 (@AMAZlNGNATURE) January 24, 2018

Sleep in Review

The Fashion and Style section of the NYTimes, of all places, has an article on sleep, "Sleep Is the New Status Symbol", by Penelope Green. It opens:

At M.I.T.’s Media Lab, the digital futurist playground, David Rose is investigating swaddling, bedtime stories and hammocks, as well as lavender oil and cocoons. Mr. Rose, a researcher, an inventor-entrepreneur and the author of “Enchanted Objects: Design, Human Desire and the Internet of Things,” and his colleagues have been road-testing weighted blankets to induce a swaddling sensation and listening to recordings of Icelandic fairy tales — all research into an ideal sleep environment that may culminate in a nap pod, or, as he said, “some new furniture form.”

And goes on from there, sleep research at UCal Berkeley, a sleep appliance start-up in Paris, a body-clock reset device in Australia, to:

The federal Centers for Disease Control and Prevention calls sleeplessness a public health concern. Good sleep helps brain plasticity, studies in mice have shown; poor sleep will make you fat and sad, and then will kill you. It is also expensive: Last year, the RAND Corporation published a study that calculated the business loss of poor sleep in the United States at $411 billion — a gross domestic product loss of 2.28 percent.

Companies now fight “presenteeism,” a neologism that describes the lackluster performance of foggy-brained, sleep-deprived employees, with sleep programs like Sleepio, an online sleep coach, and sleep fairs, like the one hosted last month in Manhattan by Nancy H. Rothstein, director of Circadian Corporate Sleep Programs and otherwise known as the Sleep Ambassador, for LinkedIn.

The "sleep space" was a $32B market in 2012.

“I can see sleep being another weapon in competitive parenting and career-building,” Ms. Salzman said. “If you want your child to succeed, do you have to buy them these sleep devices? Sleep is personal, it’s class, not mass, and now the sleep industry is based on technical services, customized for me. It’s a bizarre marriage of high tech and low tech. Chamomile tea is going to have a resurgence, as the antithesis to the whole pharma thing.”

And so it goes.

WTF!

Think of sleep as something done by/for the mind. All this interest in sleep testifies to the difficulty and importance of learning to regulate your mind. It's in the same ballpark as meditation, mindfulness, and the many forms of psychotherapy.

More on segmented sleep

My friend Barry Solow just alerted me to this, Letter of Recommendation: Segmented Sleep, in the NYTimes:

Back when segmented sleep was common, this period between “first” and “second” sleep inspired reverence. The French called it dorveille, or wakesleep, a hypnotic state. English speakers called it “the watch.” I had usually approached the post-­midnight hours full-sail, by staying up. Waking into them is different, childlike. The time feels freer. The urge to be busy abates. Conversation has a conspiratorial intimacy, as if you’ve sneaked behind the tent to find the only other smoker at the wedding. Though I preferred the name dorveille, because it sounded glamorous, “the watch” was technically more accurate during those early weeks, when I mainly got up and watched Netflix.

In the preindustrial West, most people slept in two discrete blocks and used dorveille for all kinds of purposes. Having sex was popular. Benjamin Franklin liked to “take cold-air baths,” a fancy way of saying “open his windows naked.” Many people wrote in journals or interpreted dreams, which feel more proximate at 3 a.m. than in daylight. You could drink a cup of tea and take a satisfied leak on the embers of your fire. But everyone did something, because dorveille was ubiquitous.

We tend to view our basic patterns, like spending the evening out and then lying unconscious for eight hours straight, as belonging to a natural order. But until streetlights, being up late meant wandering town in butt-­clenching terror, tripping over stray animals until the wind blew out your lantern and you were set upon by armed bandits. So you went home before dark and went to bed early, waking after midnight.

After all, we're not born to sleep thru the night. Teaching/coaxing/cajoling  infants to sleep through the night is one of the major tasks of childhood. As I recall from something I read years ago, we're born to a 3 hour cycle, 90 minutes awake, and the 90s minutes of sleep. That's what has to be shaped to a "normal" sleeping pattern.

More on sleep at New Savanna. & sleep is just one behavioral mode among many.

Microsleep, when parts of the brain nod off during the day

Christoff Koch in Scientific American:

My last column, “To Sleep with Half a Brain,” highlighted the growing realization of sleep researchers that being awake and asleep are not all-or-none phenomena. Just because you're asleep doesn't necessarily imply that your entire brain is asleep. Conversely, as I will describe now, we have also learned that even when you're awake, your entire brain may not be awake.

A case in point for sleep intruding into wakefulness involves brief episodes of sleep known as microsleep. These intervals can occur during any monotonous task, whether driving long distances across the country, listening to a speaker droning on or attending yet another never-ending departmental meeting. You're drowsy, your eyes get droopy, the eyelids close, your head repeatedly nods up and down and then snaps up: your consciousness lapses.

My last column, “To Sleep with Half a Brain,” highlighted the growing realization of sleep researchers that being awake and asleep are not all-or-none phenomena. Just because you're asleep doesn't necessarily imply that your entire brain is asleep. Conversely, as I will describe now, we have also learned that even when you're awake, your entire brain may not be awake.

A case in point for sleep intruding into wakefulness involves brief episodes of sleep known as microsleep. These intervals can occur during any monotonous task, whether driving long distances across the country, listening to a speaker droning on or attending yet another never-ending departmental meeting. You're drowsy, your eyes get droopy, the eyelids close, your head repeatedly nods up and down and then snaps up: your consciousness lapses. [...]

These results paint a more nuanced view of wakefulness and sleep than the prevailing one, in which both conditions were considered to be global, all-or-none states of consciousness. Instead these data [from electrodes implanted in rats], buttressed by single-neuron recordings from patients with implanted microelectrodes, as used occasionally in epilepsy treatment, suggest that even when the subject is awake, the individual's neurons can become tired and occasionally check out. The heavier the sleep pressure, the more likely this will happen simultaneously at many places in cortex. Conversely, after many hours of restful sleep, some of these neurons become decoupled from these brain-wide oscillations and begin to wake up.

Sleep: 8 continuous hours is a cultural convention, not a natural need

T. M. Luhrmann in the NYTimes:

This obsession with eight hours of continuous sleep is largely a creation of the electrified age. Back when night fell for, on average, half of each 24 hours, people slept in phases. In “At Day’s Close,” a remarkable history of night in the early modern West, Roger Ekirch writes that people fell asleep not long after dark for the “first sleep.” Then they awoke, somnolent but not asleep, often around midnight, when for a few hours they talked, read, prayed, had sex, brewed beer or burgled. Then they went back to sleep for a shorter period. Mr. Ekirch concludes, “There is every reason to believe that segmented sleep, such as many wild animals exhibit, had long been the natural pattern of our slumber before the modern age, with a provenance as old as humankind.”

A different regime, for example:

What have we lost with our dismissal of what the writer George Sturt called the “quiet depths of darkness”? In traditional non-Western societies like the Toraja, what happens at night really matters. People pay close attention to their dreams, and because they are awakened more often, they have more opportunity to remember them. When the anthropologist Eduardo Kohn arrived in a small village deep in the Amazon, people slept largely outdoors in an open thatch house, surrounded by other people. They would wake at night to drink tea, because it was cold, or because of the calls of animals. “Thanks to these continuous disruptions,” he writes, “dreams spill into wakefulness and wakefulness into dreams in a way that entangles them both.”

Sleep Ain't What It Used to Be

Back in September I posted a paragraph from a NYTimes op-ed arguing that the 8-hour block IS NOT a 'natural' sleep pattern. It's culturally imposed. There's more where that came from:

* * * * *

Matthew J. Wolf-Meyer. The Slumbering Masses: Sleep, Medicine, and Modern American Life. University of Minnesota Press, 2012.

Jacket copy [boldface mine]:

Americans spend billions of dollars every year on drugs, therapy, and other remedies trying to get a good night’s sleep. Anxieties about not getting enough sleep and the impact of sleeplessness on productivity, health, and happiness pervade medical opinion, the workplace, and popular culture. In The Slumbering Masses, Matthew J. Wolf-Meyer addresses the phenomenon of sleep and sleeplessness in the United States, tracing the influence of medicine and industrial capitalism on the sleeping habits of Americans from the nineteenth century to the present. 

Before the introduction of factory shift work, Americans enjoyed a range of sleeping practices, most commonly two nightly periods of rest supplemented by daytime naps. The new sleeping regimen—eight uninterrupted hours of sleep at night—led to the pathologization of other ways of sleeping. Arguing that the current model of sleep is rooted not in biology but in industrial capitalism’s relentless need for productivity, The Slumbering Masses examines so-called Z-drugs that promote sleep, the use of both legal and illicit stimulants to combat sleepiness, and the contemporary politics of time. Wolf-Meyer concludes by exploring the extremes of sleep, from cases of perpetual sleeplessness and the sleepwalking defense in criminal courts to military experiments with ultra-short periods of sleep. 

Drawing on untapped archival sources and long-term ethnographic research with people who both experience and treat sleep abnormalities, Wolf-Meyer analyzes and sharply critiques how sleep and its supposed disorders are understood and treated. By recognizing the variety and limits of sleep, he contends, we can establish more flexible expectations about sleep and, ultimately, subvert the damage of sleep pathology and industrial control on our lives.

Sleeping Habits

I've been adjusting my sleeping habits.

Like most of us, I grew up believing that one must get eight hours of sleep a night and that those hours had to be in a continuous chunk. The latter was rarely if ever explicitly stated; it was just assumed. Eight hours is eight hours straight.

So, when I found myself nodding off at 8, 8:30, or 9 PM I'd set myself some task that would keep me awake at least until 9:30 or 10. And when I'd waken in the middle of the night I just lay there in bed until I went back to sleep. Sometimes that happened quickly and sometimes it didn't.

And I'd take frequent naps during the day.

Then I read David Randall's article in the NYTimes. Shazaam! You mean it doesn't have to be eight continuous hours? You mean this 8-hours thing is a recent invention, that people routinely awaken in the middle of night and do stuff? That there was a lot of napping in the world, I already knew that, and did it myself. But the other stuff? Hot-diggity-dawg!

Now when I feel sleepy at 8PM I go to bed. And when I awaken at midnight or 1PM or 2PM or whenever, I'll get up and work for an hour or two. No problems.

And the napping continues.