Chapter 14. Biological Rhythms, Sleep, and Dreaming
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By STEPH YIN For animals that hibernate, making it to spring is no small feat. Torpor — the state of reduced bodily activity that occurs during hibernation — is not restful. By the time they emerge, hibernating animals are often sleep-deprived: Most expend huge bursts of energy to arouse themselves occasionally in the winter so their body temperatures don’t dip too low. This back-and-forth is exhausting, and hibernators do it with little to no food and water. By winter’s end, some have shed more than half their body weight. But just because it’s spring doesn’t mean it’s time to celebrate. Spring means getting ready for the full speed of summer — and after spending a season in slow motion, that requires some ramping up. Here’s a look at what different animals have on the agenda after coming out of winter’s slumber. Black bears emerge from their dens in April, but stay lethargic for weeks. During this so-called walking hibernation, they sleep plenty and don’t roam very far. Though they have lost up to one-third of their body weight over winter, they don’t have a huge appetite right away — their metabolism is not yet back to normal. They snack mostly on pussy willows and bunches of snow fleas. In January or February, some females give birth, typically to two or three cubs. New mothers continue to hibernate, but they go in and out of torpor, staying alert enough to respond to their cubs’ cries. When they emerge from their dens, mama bears find trees with rough bark that her cubs can easily climb for safety. “Slowly, the bears’ metabolism gears up to normal, active levels,” said Lynn Rogers, a bear expert and principal biologist at the Wildlife Research Institute, a nonprofit in Minnesota. “When plants start sprouting on the forest floor, that’s when they start really moving around.” © 2017 The New York Times Company
Keyword: Biological Rhythms
Link ID: 23406 - Posted: 03.25.2017
By Diana Kwon Astrocytes, star-shape glial cells in the brain, were once simply considered support cells for neurons. However, neuroscientists have recently realized they have many other functions: studies have shown that astrocytes are involved in metabolism, learning, and more. In the latest study to investigate astrocytes’ roles in the brain, researchers confirmed these cells played a key role in regulating mouse circadian rhythms. The team’s results were published today (March 23) in Current Biology. “Recent results have indicated that [glia] are actively modulating synaptic transmission, the development of the nervous system, and changes in the nervous system in response to changes in the environment,” said coauthor Erik Herzog, a neuroscientist at Washington University in St. Louis. “So circadian biologists recognized that the system that we study in the brain also had astrocytes and have wondered what role that they might play.” In 2005, Herzog’s team published a seminal study linking glia to mammalian circadian rhythms. By investigating rat and mouse astrocytes in a dish, the researchers discovered that these glial cells showed circadian rhythms in gene expression. Since then, several independent groups have reported evidence to suggest that astrocytes help regulate daily rhythms. However, linking astrocytes to circadian behaviors in mice remained difficult. “I had several folks in the lab over many years [who] were unable to find the tools that would allow us to answer the question definitively: Do astrocytes play a role in scheduling our day?” Herzog recalled. “Then, within the last year or so, some new tools . . . became available for us.”. © 1986-2017 The Scientist
USA Today Network Josh Hafner , For college students, new parents and employees dogged by deadlines, the all-nighter is nothing new. But going without sleep leaves you basically drunk, putting you at the equivalent of a .1% blood alcohol content as you drive to work, make decisions and interact with others. “The first thing that goes is your ability to think," said Joseph Ojile, M.D., a board member with the National Sleep Foundation. Judgement, memory and concentration all suffer impairment by the body's 17th hour without sleep, he said. “We know at 17 hours, you're at .08% blood alcohol level," he said, the legal standard for drunk driving. "At 24 hours, you’re at 0.1%." Coordination deteriorates as well in those intervening hours, said Ojile, a professor at Saint Louis University School of Medicine. Irritability sets in, too. Pain becomes more acute and the immune system suffers, he said, leaving the body more open to infection. "Here’s the worst part about the lack of judgement," Ojile said. "The person is unaware of their impairment. How scary is that? ‘I’m fine, I’ll just drive home. I’ll do my work at the nuclear plant, no problem. Or fly the plane, no problem.’" It's not entirely clear how the effects worsen past 24 hours, Ojile said, other than they do. The brain starts shutting down in trance-like microsleeps, 15- to 30-second spells that occur without the person noticing. Eventually, not sleeping results in death.
Link ID: 23404 - Posted: 03.25.2017
Richard A. Friedman Jet lag makes everyone miserable. But it makes some people mentally ill. There’s a psychiatric hospital not far from Heathrow Airport that is known for treating bipolar and schizophrenic travelers, some of whom are occasionally found wandering aimlessly through the terminals. A study from the 1980s of 186 of those patients found that those who’d traveled from the west had a higher incidence of mania, while those who’d traveled from the east had a higher incidence of depression. I saw the same thing in one of my patients who suffered from manic depression. When he got depressed after a vacation to Europe, we assumed he was just disappointed about returning to work. But then he had a fun trip out West and returned home in what’s called a hypomanic state: He was expansive, a fount of creative ideas. It was clear that his changes in mood weren’t caused by the vacation blues, but by something else. The problem turned out to be a disruption in his circadian rhythm. He didn’t need drugs; he needed the right doses of sleep and sunlight at the right time. It turns out that that prescription could treat much of what ails us. Clinicians have long known that there is a strong link between sleep, sunlight and mood. Problems sleeping are often a warning sign or a cause of impending depression, and can make people with bipolar disorder manic. Some 15 years ago, Dr. Francesco Benedetti, a psychiatrist in Milan, and colleagues noticed that hospitalized bipolar patients who were assigned to rooms with views of the east were discharged earlier than those with rooms facing the west — presumably because the early morning light had an antidepressant effect. The notion that we can manipulate sleep to treat mental illness has also been around for many years. Back in the late 1960s, a German psychiatrist heard about a woman in Tübingen who was hospitalized for depression and claimed that she normally kept her symptoms in check by taking all-night bike rides. He subsequently demonstrated in a group of depressed patients that a night of complete sleep deprivation produced an immediate, significant improvement in mood in about 60 percent of the group. © 2017 The New York Times Company
By Torah Kachur, A simple, non-invasive, non-medicinal, safe and cheap way to get a better night's sleep is to play some pink noise, according to a study published on Wednesday in the journal Frontiers in Human Neuroscience. Pink noise has more lower octaves than typical white noise and is hardly soothing. For example, it can be one-second pulses of the sound of a rushing waterfall. The short pieces of quick, quiet sounds would be really annoying if you were trying to fall asleep. But the pink noise isn't trying to get you to fall asleep; it's trying to keep you in a very deep sleep where you have slow brainwaves. This is one of our deepest forms of sleep and, in particular, seems to decline in aging adults. "When you play the pulses at particular times during deep sleep, it actually leads to an enhancement of the electrical signal. So it leads to essentially more of a synchronization of the neurons," said Nelly Papalambros, a PhD student at Northwestern University and the first author on the work. The pulses are timed to coincide with your entry into slow wave sleep. They sound to the same beat as your brainwaves, and they seem to increase the effectiveness of your very valuable and very elusive deep sleep. That slow wave sleep is critical for memory consolidation or, basically, your ability to incorporate new material learned that day with old material and memories. ©2017 CBC/Radio-Canada.
by Laura Sanders If your young child is facing ear tubes, an MRI or even extensive dental work, you’ve probably got a lot of concerns. One of them may be about whether the drugs used to render your child briefly unconscious can permanently harm his brain. Here’s the frustrating answer: No one knows. “It’s a tough conundrum for parents of kids who need procedures,” says pediatric anesthesiologist Mary Ellen McCann, a pediatric anesthesiologist at Boston Children’s Hospital. “Everything has risks and benefits,” but in this case, the decision to go ahead with surgery is made more difficult by an incomplete understanding of anesthesia’s risks for babies and young children. Some studies suggest that single, short exposures to anesthesia aren’t dangerous. Still, scientists and doctors say that we desperately need more data before we really understand what anesthesia does to developing brains. It helps to know this nonanswer comes with a lot of baggage, a sign that a lot of very smart and committed people are trying to answer the question. In December, the FDA issued a drug safety communication about anesthetics that sounded alarming, beginning with a warning that “repeated or lengthy use of general anesthetic and sedation drugs during surgeries or procedures in children younger than 3 years or in pregnant women during their third trimester may affect the development of children’s brains.” FDA recommended more conversations between parents and doctors, in the hopes of delaying surgeries that can safely wait, and the amount of anesthesia exposure in this potentially vulnerable population. |© Society for Science & the Public 2000 - 2017.
Susan Milius Fitbit-style tracking of two wild African elephants suggests their species could break sleep records for mammals. The elephants get by just fine on about two hours of sleep a day. Much of that shut-eye comes while standing up — the animals sleep lying down only once every three or four days, new data show. Most of what scientists previously knew about sleeping elephants came from captive animals, says neuroethologist Paul Manger of the University of the Witwatersrand, Johannesburg. In zoos and enclosures, elephants have been recorded snoozing about three hours to almost seven over a 24-hour period. Monitoring African elephants in the wild, however, so far reveals more extreme behavior. Data are hard to collect, but two females wearing activity recorders for about a month averaged less sleep than other recorded mammals. Especially intriguing is the elephants’ ability to skip a night’s sleep without needing extra naps later, Manger and colleagues report March 1 in PLOS ONE. “The remarkably short amount of sleep in wild elephants is a real elephant in the room for several theories for the function of sleep,” says Niels Rattenborg of the Max Planck Institute for Ornithology in Seewiesen, Germany. Ideas that sleep restores or resets aspects of the brain for peak performance can’t explain animals that sleep only a little and don’t need catch-up rest, says Rattenborg, who wasn’t involved in the elephant study. The results also don’t fit well with the thought that animals need sleep to consolidate memories. “Elephants are usually not considered to be forgetful animals,” he says. |© Society for Science & the Public 2000 - 2017.
Sleeping too much or too little can increase the likelihood of becoming obese, researchers have discovered. The study found abnormal sleeping patterns increased the risk of being overweight for those genetically predisposed to obesity. The effect was seen regardless of diet, health or socio-demographic group. The University of Glasgow study also found no clear link between sleep duration and body weight in those with a low genetic risk of obesity. Researchers looked at the effects of a short sleep of less than seven hours a night and a long sleep - more than nine hours - along with daytime napping and shift work. Negative effect They found that in people with a high genetic risk of obesity, both short-sleep and long-sleep durations further increased risk of carrying excess weight, compared with people who slept for normal durations of between seven and nine hours a night. Long sleepers with a risk of obesity were about 4kg heavier and short sleepers were about 2kg heavier than those with a similarly high genetic obesity risk with normal sleep durations. The negative affect happened irrespective of what subjects ate, their health concerns or socio-demographic factors, the research team said. The findings, based on data from almost 120,000 UK Biobank participants, showed no obvious link between sleep duration and body weight in those considered to be at a low genetic risk of obesity. Dr Jason Gill, from the Institute of Cardiovascular and Medical Sciences, said: "These data show that in people with high genetic risk for obesity, sleeping for too short or too long a time, napping during the day and shift work appears to have a fairly substantial adverse influence on body weight. © 2017 BBC.
Link ID: 23303 - Posted: 03.02.2017
Ian Sample Science editor Dozens of British children who developed narcolepsy as a result of a swine flu vaccine could be compensated after the high court rejected a government appeal to withhold payments. Six million people in Britain, and more across Europe, were given the Pandemrix vaccine made by GlaxoSmithKline during the 2009-10 swine flu pandemic, but the jab was withdrawn after doctors noticed a sharp rise in narcolepsy among those who received it. The sleep disorder is permanent and can cause people to fall asleep dozens of times a day. Some narcoleptics have night terrors and a muscular condition called cataplexy that can lead them to collapse on the spot. In 2015, a 12-year-old boy, known as John for the proceedings, was awarded £120,000 by a court that ruled he had been left severely disabled by narcolepsy caused by the vaccine. He was seven when he had the jab and developed symptoms within months. Because of his tiredness, John became disruptive at school and found it almost impossible to make friends. He takes several naps a day, cannot shower or take a bus on his own, and may never be allowed to drive a car. Despite paying out, the Department for Work and Pensions argued John’s disability was not serious enough to warrant compensation and said the court was wrong to take into account how the illness would affect him in the future. But the high court on Thursday rejected the government’s appeal that only the boy’s disability at the time should have been considered. The ruling paves the way for more than 60 other people to claim compensation. © 2017 Guardian News and Media Limited
By Julia Shaw We all have times of day when we are not at our best. For me, before 10am, and between 2-4pm, it’s as though my brain just doesn’t work the way it should. I labor to come up with names, struggle to keep my train of thought, and my eloquence drops to the level expected of an eight-year-old. In an effort to blame my brain for this, rather than my motivation, I reached out to a researcher in the area of sleep and circadian neuroscience. Andrea Smit, a PhD student working with Professors John McDonald and Ralph Mistlberger at Simon Fraser University in Canada, was happy to help me find excuses for why my memory is so terribly unreliable at certain times of day. Humans have daily biological rhythms, called circadian rhythms, which affect almost everything that we do. They inform our bodies when it is time to eat and sleep, and they dictate our ability to remember things. According to Smit, “Chronotype, the degree to which someone is a “morning lark” or a “night owl,” is a manifestation of circadian rhythms. In a recent study, Smit used EEG, a type of brain scan, to study the interaction between chronotypes and memory. “Testing extreme chronotypes at multiple times of day allowed us to compare attentional abilities and visual short term memory between morning larks and night owls. Night owls were worse at suppressing distracting visual information and had a worse visual short term memory in the morning as compared with the afternoon,” she says. “Our research shows that circadian rhythms interact with memories even at very early stages of processing within the brain.” © 2017 Scientific American
Aylin Woodward Fearful, flighty chickens raised for eating can hurt themselves while trying to avoid human handlers. But there may be a simple way to hatch calmer chicks: Shine light on the eggs for at least 12 hours a day. Researchers at the University of California, Davis bathed eggs daily in light for different time periods during their three-week incubation. When the chickens reached 3 to 6 weeks old, the scientists tested the birds’ fear responses. In one test, 120 chickens were randomly selected from the 1,006-bird sample and placed one by one in a box with a human “predator” sitting visibly nearby. The chickens incubated in light the longest — 12 hours — made an average of 179 distress calls in three minutes, compared with 211 from birds incubated in complete darkness, animal scientists Gregory Archer and Joy Mench report in January in Applied Animal Behaviour Science. Chickens exposed to lots of light as eggs “would sit in the closest part of the box to me and just chill out,” Archer says. The others spent their time trying to get away. How light has its effect is unclear. On commercial chicken farms, eggs typically sit in warm, dark incubation rooms. The researchers are now testing light's effects in large, commercial incubators. Using light exposure to raise less-fearful chickens could reduce broken bones during handling at processing plants, Archer says. It might also decrease harmful anxious behaviors, such as feather pecking of nearby chickens. G. S. Archer and J. A. Mench. Exposing avian embryos to light affects post-hatch anti-predator fear responses. Applied Animal Behaviour Science. Vol. 186, January 2017, p. 80. doi: 10.1016/j.applanim.2016.10.014. © Society for Science & the Public 2000 - 2016
Ah, to sleep, perchance … to shrink your neural connections? That's the conclusion of new research that examined subtle changes in the brain during sleep. The researchers found that sleep provides a time when thebrain's synapses — the connections among neurons—shrink back by nearly 20 percent. During this time, the synapses rest and prepare for the next day, when they will grow stronger while receiving new input—that is, learning new things, the researchers said. Without this reset, known as "synaptic homeostasis," synapses could become overloaded and burned out, like an electrical outlet with too many appliances plugged in to it, the scientists said. "Sleep is the perfect time to allow the synaptic renormalization to occur … because when we are awake, we are 'slaves' of the here and now, always attending some stimuli and learning something," said study co-author Dr. Chiara Cirelli of the University of Wisconsin-Madison Center for Sleep and Consciousness. "During sleep, we are much less preoccupied by the external world … and the brain can sample [or assess] all our synapses, and renormalize them in a smart way," Cirelli told Live Science. Cirelli and her colleague, Dr. Giulio Tononi, also of the University of Wisconsin-Madison, introduced this synaptic homeostasis hypothesis (SHY) in 2003. © 2017 Scientific American
Carl Zimmer Over the years, scientists have come up with a lot of ideas about why we sleep. Some have argued that it’s a way to save energy. Others have suggested that slumber provides an opportunity to clear away the brain’s cellular waste. Still others have proposed that sleep simply forces animals to lie still, letting them hide from predators. A pair of papers published on Thursday in the journal Science offer evidence for another notion: We sleep to forget some of the things we learn each day. In order to learn, we have to grow connections, or synapses, between the neurons in our brains. These connections enable neurons to send signals to one another quickly and efficiently. We store new memories in these networks. In 2003, Giulio Tononi and Chiara Cirelli, biologists at the University of Wisconsin-Madison, proposed that synapses grew so exuberantly during the day that our brain circuits got “noisy.” When we sleep, the scientists argued, our brains pare back the connections to lift the signal over the noise. In the years since, Dr. Tononi and Dr. Cirelli, along with other researchers, have found a great deal of indirect evidence to support the so-called synaptic homeostasis hypothesis. It turns out, for example, that neurons can prune their synapses — at least in a dish. In laboratory experiments on clumps of neurons, scientists can give them a drug that spurs them to grow extra synapses. Afterward, the neurons pare back some of the growth. Other evidence comes from the electric waves released by the brain. During deep sleep, the waves slow down. Dr. Tononi and Dr. Cirelli have argued that shrinking synapses produce this change. © 2017 The New York Times Company
Ian Sample Science editor As an antidote to one of the ills of modern life, it may leave some quite cold. When the lure of the TV or fiddling on the phone keep you up late at night, it is time to grab the tent and go camping. The advice from scientists in the US follows a field study that found people fell asleep about two hours earlier than usual when they were denied access to their gadgets and electrical lighting and packed off to the mountains with a tent. A weekend in the wilds of the Rocky Mountains in Colorado helped reset people’s internal clocks and reversed the tendency of artificial light to push bedtime late into the night. A spell outdoors, the researchers conclude, could be just the thing for victims of social jetlag who find themselves yawning all day long. “Our modern environment has really changed the timing of our internal clocks, but also the timing of when we sleep relative to our clock,” said Kenneth Wright, director of the sleep and chronobiology lab at the University of Colorado in Boulder. “A weekend camping trip can reset the clock rapidly.” To explore the sleep-altering effects of the natural environment, Wright sent five hardy colleagues, aged 21 to 39, on a six day camping trip to the Rocky Mountains one December. They left their torches and gadgets behind, and had only sunlight, moonlight and campfires for illumination. The campers went to bed on average two and a half hours earlier than they did at home, and racked up nearly 10 hours of sleep per night compared with their usual seven and a half hours. Monitors showed that they were more active in the daytime and were exposed to light levels up to 13 times higher than they typically received at home.
Bruce Bower Hunter-gatherers and farming villagers who live in worlds without lightbulbs or thermostats sleep slightly less at night than smartphone-toting city slickers, researchers say. “Contrary to conventional wisdom, people in societies without electricity do not sleep more than those in industrial societies like ours,” says UCLA psychiatrist and sleep researcher Jerome Siegel, who was not involved in the new research. Different patterns of slumber and wakefulness in each of these groups highlight the flexibility of human sleep — and also point to potential health dangers in how members of Western societies sleep, conclude evolutionary biologist David Samson of Duke University and colleagues. Compared with other primates, human evolution featured a shift toward sleeping more deeply over shorter time periods, providing more time for learning new skills and knowledge as cultures expanded, the researchers propose. Humans also evolved an ability to revise sleep schedules based on daily work schedules and environmental factors such as temperature. Samson’s team describes sleep patterns in 33 East African Hadza hunter-gatherers over a total of 393 days in a paper published online January 7 in the American Journal of Physical Anthropology. The team’s separate report on slumber among 21 rural farmers in Madagascar over 292 days will appear later this year in the American Journal of Human Biology. |© Society for Science & the Public 2000 - 201
By Rachael Lallensack Jet lag can put anyone off their game, even Major League Baseball (MLB) players. Long-distance travel can affect specific—and at times, crucial—baseball skills such as pitching and base running, a new study finds. In fact, jetlag's effects can even cancel out the home field advantage for some teams returning from away games. Jet lag is known for its fatigue-inducing effects, most of which stem from a mismatch between a person’s internal clock and the time zone he or she is in, something called “circadian misalignment.” This misalignment is especially strong when a person’s day is shorter than it should be—which happens whenever people travel east—previous research has shown. Just how that affects sports teams has long been debated. A 2009 study of MLB, for example, found that jet lag did decrease a team’s likelihood of winning, if only slightly. But no prior study has ever been able to pinpoint exact areas of game play where the effects of jet lag hit hardest—data that could help coaches and trainers better prepare players for games following travel. To figure out how that might happen, “adopted” Chicago Cubs fan and study author Ravi Allada, a neurobiologist at Northwestern University in Evanston, Illinois, looked at 20 years’ worth of MLB data from 1992 to 2011. He and his team narrowed their data set from 46,535 games to the 4919 games in which players traveled at least two time zones. Then, they broke down offensive and defensive stats from each of those games, including home runs allowed, stolen bases, and sacrifice flies. Finally, they compared how the numbers changed for teams that had traveled east versus those that had traveled west. © 2017 American Association for the Advancement of Science.
Keyword: Biological Rhythms
Link ID: 23140 - Posted: 01.24.2017
by Laura Sanders Most nights I read a book in bed to wind down. But when I run out of my library supply, I read articles on my phone instead. I suspect that this digital substitution messes with my sleep. That’s not good for me — but it’s probably worse for the many children who have screens in their rooms at night. A team of researchers recently combed through the literature looking for associations between mobile devices in the bedroom and poor sleep. Biostatistician Ben Carter of King’s College London and colleagues found that kids between ages 6 and 19 who used screen-based media around bedtime slept worse and were more tired in the day. That’s not surprising: Phones, tablets and laptops make noise and emit blue light that can interfere with the sleep-inducing melatonin. But things got interesting when the researchers compared kids who didn’t have screens in their bedrooms with kids who did have phones or tablets in their rooms but didn’t use them. You might think there wouldn’t be a sleep difference between those groups. None of these kids were up all night texting, gaming or swiping, so neither sounds nor blue light were messing with any of the kids’ sleep. Yet Carter and colleagues found a difference: Kids who had screen-based media in their bedroom, but didn’t use it, didn’t sleep as much as kids without the technology. What’s more, the sleep they did get was worse and they were more tired during the day, the researchers reported in the December JAMA Pediatrics. |© Society for Science & the Public 2000 - 2017
Children who have their tonsils removed to treat chronic throat infections or breathing problems during sleep may get more short-term symptom relief than similar children who don’t get tonsillectomies, two recent studies suggest. Over time, however, the benefits of surgery for chronic streptococcal throat infections appear to go away. Three years after tonsillectomies, children who had these procedures had about the same number of throat infections as those who didn’t get their tonsils taken out, one of the studies in the journal Pediatrics found. “Tonsillectomy, while very common and generally safe, is not completely without risk,” said Sivakumar Chinnadurai, senior author of the strep throat study and a researcher at Vanderbilt University Medical Center in Nashville. “The recognition of risks, and the knowledge that some patients’ infection rate improves over time has led to [strep] infection being a much less common indication for tonsillectomy than it was in the past,” Chinnadurai added by email. “While tonsillectomy remains one of the most common surgeries performed in the United States, the main indication for children has switched to obstructed breathing.” To assess the potential for tonsillectomies to help young people with chronic strep infections, Chinnadurai and colleagues examined data from seven studies of children who had experienced at least three strep infections in the previous one to three years. © 1996-2017 The Washington Post
Link ID: 23127 - Posted: 01.21.2017
By JANE E. BRODY Insomnia is like a thief in the night, robbing millions — especially those older than 60 — of much-needed restorative sleep. As the king laments in Shakespeare’s “Henry IV, Part 2”: O sleep, O gentle sleep, Nature’s soft nurse, how have I frightened thee. That thou no more will weigh my eyelids down, And steep my senses in forgetfulness? The causes of insomnia are many, and they increase in number and severity as people age. Yet the problem is often overlooked during routine checkups, which not only diminishes the quality of an older person’s life but may also cause or aggravate physical and emotional disorders, including symptoms of cognitive loss. Most everyone experiences episodic insomnia, a night during which the body seems to have forgotten how to sleep a requisite number of hours, if at all. As distressing as that may seem at the time, it pales in comparison to the effects on people for whom insomnia — difficulty falling asleep, staying asleep or awakening much too early — is a nightly affair. A survey done in 1995 by researchers at the National Institute on Aging among more than 9,000 people aged 65 and older living in three communities revealed that 28 percent had problems falling asleep and 42 percent reported difficulty with both falling asleep and staying asleep. The numbers affected are likely to be much larger now that millions spend their pre-sleep hours looking at electronic screens that can disrupt the body’s biological rhythms. Insomnia, Dr. Alon Y. Avidan says, “is a symptom, not a diagnosis” that can be a clue to an underlying and often treatable health problem and, when it persists, should be taken seriously. Dr. Avidan is director of the sleep clinic at the University of California, Los Angeles, David Geffen School of Medicine. © 2017 The New York Times Company
By Alan Burdick Some nights—more than I like, lately—I wake to the sound of the bedside clock. The room is dark, without detail, and it expands in such a way that it seems as if I’m outdoors, under an empty sky, or underground, in a cavern. I might be falling through space. I might be dreaming. I could be dead. Only the clock moves, its tick steady, unhurried. At these moments I have the most chilling understanding that time moves in only one direction. I’m tempted to look at the clock, but I already know that it’s the same time it always is: 4 A.M., or 4:10 A.M., or once, for a disconcerting stretch of days, 4:27 A.M. Even without looking, I could deduce the time from the ping of the bedroom radiator gathering steam in winter or the infrequency of the cars passing by on the street outside. In 1917, the psychologist Edwin G. Boring and his wife, Lucy, described an experiment in which they woke people at intervals to see if they knew what time it was; the average estimate was accurate to within fifty minutes, although almost everyone thought it was later than it actually was. They found that subjects were relying on internal or external signals: their degree of sleepiness or indigestion (“The dark brown taste in your mouth is never bad when you have been asleep only a short time”), the moonlight, “bladder cues,” the sounds of cars or roosters. “When a man is asleep, he has in a circle round him the chain of the hours, the sequence of the years, the order of the heavenly bodies,” Proust wrote. “Instinctively he consults them when he awakes, and in an instant reads off his own position on the earth’s surface and the time that has elapsed during his slumbers.” © 2017 Condé Nast.