Chapter 10. Biological Rhythms and Sleep

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By Christina Caron Q: Sometimes my eyelid twitches on and off for days — weeks, even. It’s distracting and irritating. How do I get it to stop? And should I be concerned? Eyelid spasms, while annoying, are “rarely a sign of something serious,” said Stephanie Erwin, an optometrist at Cleveland Clinic’s Cole Eye Institute. The most common type of eye twitch is a series of muscle contractions called eyelid myokymia, which produces involuntary and intermittent contractions of the eyelid, typically the lower one. Only one eye is affected at a time because the twitch originates in the muscle surrounding the eye, and not the nerve that controls the blink reflex, which sends the same message to both eyes simultaneously, Dr. Erwin added. The spasms can last from hours to days to months. “If the twitching persists for a long period of time, or is accompanied by additional symptoms, it is a good idea to be checked by an eye doctor to make sure nothing else is going on,” she said. If the twitching spreads to other muscles in the face or if you notice both eyes are twitching at the same time, those are indications of a more serious problem. Other red flags include a drooping eyelid or a red eye. But if just one eyelid is twitching on and off, it is usually a harmless (and often exasperating) case of eyelid myokymia. As for why it happens: “Nobody knows exactly why,” said Dr. Alice Lorch, an ophthalmologist at Massachusetts Eye and Ear in Boston. But more commonly, it is stress, lack of sleep or excessive caffeine intake that brings on eyelid twitching, the experts said. Dry eye, a common affliction among those who stare at screens most of the day, is another culprit. Studies have indicated that we blink less when looking at digital devices, which makes our eyes feel dry. © 2021 The New York Times Company

Keyword: Vision; Stress
Link ID: 28131 - Posted: 12.31.2021

By Linda Searing Among people who have covid-19, those who have certain sleep disorders (including sleep apnea) face a 31 percent greater chance of developing a severe case that requires hospitalization, or dying from the disease, than do people who have covid-19 and who do not have sleep-disturbed breathing, according to research published in The study links the increase in risk to breathing disorders that can cause oxygen levels to drop during sleep, creating a low oxygen level called hypoxia. The researchers found that having such a sleep-related breathing disorder did not make people more likely to contract the coronavirus. They wrote, however, that having low oxygen levels “may play a role in worse outcomes once the viral illness evolves,” describing hypoxia as an “amplifier” of covid effects. The findings were based on data from 5,402 adults (average age 56) who had undergone sleep studies and coronavirus testing in 2020 through the Cleveland Clinic Health System. For someone with sleep apnea, which is one of the most common sleep disorders, breathing repeatedly stops and starts during sleep, sometimes 30 times or more an hour and often is accompanied by gasping or snorting sounds. This causes hypoxia. Treatment often involves using what is called positive airway pressure (PAP) while sleeping. The person wears a mask, which has a tube connected to a small PAP machine that sits bedside. It pumps pressurized air into the upper airway, keeping it open and allowing normal breathing. The researchers suggested further studies to determine whether such treatment would improve covid-19 outcomes for people with a sleep disorder. © 1996-2021 The Washington Post

Keyword: Sleep
Link ID: 28126 - Posted: 12.29.2021

By Richard Sandomir Allan Rechtschaffen, an indefatigable sleep researcher at the University of Chicago who tested the effects of sleep deprivation, studied dreaming, narcolepsy, napping and insomnia and standardized the measurement of sleep stages, died on Nov. 29 at his home in Chicago. He was 93. His wife, Karen Rechtschaffen, confirmed the death. The University of Chicago was an established center of sleep research when Professor Rechtschaffen arrived on its campus in 1957 as a psychology instructor. Four years earlier, Nathaniel Kleitman, a physiologist, and Eugene Aserinsky, a graduate student, had written a paper that reported the discovery of rapid eye movement, or REM, during sleep, an indication of dreaming. The finding appealed to Professor Rechtschaffen’s fascination with the mind’s effect on the body. “This was a perfect vehicle for studying that issue,” he said in an interview in 2010 with the Sleep Research Society, which he helped start 50 years earlier. “You could conceive of it as the mind turning on with the REM period and turning off with the end of the REM period. So you could see periods of mind and periods of no mind.” REM and other aspects of sleep became the focus of his career. In 1958, he was named director of the university’s sleep research laboratory, where his experiments on animals and humans over the next 41 years helped him define a challenge that he described this way: “If sleep doesn’t serve an absolutely vital function, it is the biggest mistake evolution ever made.” His best-known experiment concerned self-deprivation using rats. As Professor Rechtschaffen and his colleagues reported in the journal Science in 1983, they had placed two rats at a time in a plexiglass box, each with an electrode attached from its head to a computer and each placed on one-half of a divided disk built over shallow water. When the experimental rat tried to sleep, the disk automatically rotated, forcing the animal to stay awake. The control rat was treated similarly but could sleep when the other rat was awake and the disk was not moving. © 2021 The New York Times Company

Keyword: Sleep
Link ID: 28116 - Posted: 12.18.2021

Sofia Moutinho When Thomas Edison hit a wall with his inventions, he would nap in an armchair while holding a steel ball. As he started to fall asleep and his muscles relaxed, the ball would strike the floor, waking him with insights into his problems. Or so the story goes. Now, more than 100 years later, scientists have repeated the trick in a lab, revealing that the famous inventor was on to something. People following his recipe tripled their chances of solving a math problem. The trick was to wake up in the transition between sleep and wakefulness, just before deep sleep. “It is a wonderful study,” says Ken Paller, a cognitive neuroscientist at Northwestern University who was not part of the research. Prior work has shown that passing through deep sleep stages helps with creativity, he notes, but this is the first to explore in detail the sleep-onset period and its role in problem-solving. In this transitional period, we are not quite awake, but also not deeply asleep. It can be as short as a minute and occurs right when we start to doze off. Our muscles relax, and we have dreamlike visions or thoughts called hypnagogia, generally related to recent experiences. This phase slips by unnoticed most of the time unless it is interrupted by waking. Like Edison, surrealist painter Salvador Dalí believed interrupting sleep’s onset could boost creativity. (He used a heavy key instead of a metal ball.) To see whether Dalí and Edison were right, researchers recruited more than 100 easy sleepers. The team gave them a math test that required them to convert strings of eight digits into new strings of seven by using specific rules in a stepwise manner, such as “repeat the number if the previous and next digit are identical.” The volunteers weren’t told that there was an easier way to get the right answers by following a hidden rule: The second number in their final string was always the same as the last number in the same string. © 2021 American Association for the Advancement of Science.

Keyword: Sleep; Attention
Link ID: 28106 - Posted: 12.11.2021

Sophie Fessl Catching some z’s repairs a day’s damage to neurons’ DNA, at least in zebrafish. While the fish are awake, DNA damage accumulates, which, through a buildup of the DNA repair protein Parp1, triggers sleep, according to a study published today (November 18) in Molecular Cell. The study is “pivotal in providing evidence regarding sleep and its role in DNA damage and repair,” writes anesthesiologist Siu Wai Choi of the University of Hong Kong in an email to The Scientist. Choi led an earlier study that established a link between sleep deprivation and DNA damage in doctors but was not involved in the current research. Cells routinely face stress, such as exposure to radiation, that can leave their DNA damaged. Cells therefore have an arsenal of repair proteins to mend the DNA or, if it’s irreparable, trigger cell death. Neuroscientist Lior Appelbaum and his team at Bar-Ilan University in Israel had previously found that DNA damage increases during the day and decreases during the night, suggesting that sleep could help repair this damage. In the new study, they investigated whether DNA damage is the reason why zebrafish—and, by extension, perhaps other animals—sleep. When postdoc David Zada and other authors induced DNA damage in the neurons of zebrafish larvae by inducing neuronal activity or using UV radiation, the fish slept longer. “It makes the fish tired,” says Appelbaum. © 1986–2021 The Scientist.

Keyword: Sleep; Genes & Behavior
Link ID: 28081 - Posted: 11.20.2021

David Robson Michelle Carr is frequently plagued by tidal waves in her dreams. What should be a terrifying nightmare, however, can quickly turn into a whimsical adventure – thanks to her ability to control her dreams. She can transform herself into a dolphin and swim into the water. Once, she transformed the wave itself, turning it into a giant snail with a huge shell. “It came right up to me – it was a really beautiful moment.” There’s a thriving online community of people who are now trying to learn how to lucid dream. (A single subreddit devoted to the phenomenon has more than 400,000 members.) Many are simply looking for entertainment. “It’s just so exciting and unbelievable to be in a lucid dream and to witness your mind creating this completely vivid simulation,” says Carr, who is a sleep researcher at the University of Rochester in New York state. Others hope that exercising skills in their dreams will increase their real-life abilities. “A lot of elite athletes use lucid dreams to practise their sport.” And there are more profound reasons to exploit this sleep state, besides personal improvement. By identifying the brain activity that gives rise to the heightened awareness and sense of agency in lucid dreams, neuroscientists and psychologists hope to answer fundamental questions about the nature of human consciousness, including our apparently unique capacity for self-awareness. “More and more researchers, from many different fields, have started to incorporate lucid dreams in their research,” says Carr. This interest in lucid dreaming has been growing in fits and starts for more than a century. Despite his fascination with the interaction between the conscious and subconscious minds, Sigmund Freud barely mentioned lucid dreams in his writings. Instead, it was an English aristocrat and writer, Mary Arnold-Forster, who provided one of the earliest and most detailed descriptions in the English language in her book Studies in Dreams. © 2021 Guardian News & Media Limited

Keyword: Sleep; Consciousness
Link ID: 28079 - Posted: 11.17.2021

Clare Marie Schneider For some people, waking up early just feels natural. Carla Finley is a baker in Brooklyn, N.Y., who starts her day at 5 or 6 a.m. Finley is what we would call a morning person. "Sometimes it's still dark, which actually I love," she says. "Something about feeling the light come in feels really sacred." This story comes from Life Kit, NPR's family of podcasts to help make life better — covering everything from exercise to raising kids to making friends. For more, sign up for the newsletter and follow @NPRLifeKit on Twitter. Of course, not everyone is as lucky as Finley. Emily Gerard is a writer for the Today show, and she often finds herself waking up at odd hours to prepare for the show, which starts at 7 a.m. "When that alarm goes off, I have a few moments of feeling like I want to die," she says. There are a lot of reasons why we may have to get up early. Maybe it's for work, or maybe it's to get your kids ready for school or take care of a family member. Maybe you just want some time to work on your hobby or take care of errands before a busy day. But if you're not naturally a morning person, how much room do you have to change your wake-up schedule? "We have a fair amount of wiggle room, but it's behavioral," says Dr. Katie Sharkey, an associate professor of medicine and psychiatry and human behavior at Brown University's Alpert Medical School. Basically, your biological clock, which determines your circadian rhythms, is baked into who you are to an extent, but a few habits can help make waking up earlier less of a chore. © 2021 npr

Keyword: Biological Rhythms
Link ID: 28063 - Posted: 11.06.2021

By Diana Kwon It’s nearly that time of the year again: the end of daylight saving, when Americans push their clocks back and rejoice at the gained hour of sleep—or mourn the lost hour of sunlight in the afternoon. This system’s twice-a-year transitions have become increasingly unpopular. Scientists have been calling attention to the damaging effects of the time changes—which include a general reduction in mental and physical well-being, as well as a potential increased risk of serious complications, such as strokes and heart attacks, soon after the shifts. There is also evidence of increases in traffic fatalities and harmful medical errors shortly following when clocks are moved forward in the spring. Advertisement In many countries, this might be the one of the last instances in which people make the adjustment. Governments around the world have been in discussions about scrapping the seasonal clock changes and sticking to one time—either permanent standard time or permanent daylight saving. In the U.S., many states are considering, or have already passed, legislation to adopt one of the two. Hawaii and most of Arizona decided to adopt just standard time more than 50 years ago. Last year the European Parliament voted to abolish the time shifts, but the member states of the European Union have yet to agree on how to implement the decision. Beth Malow, a professor of neurology and pediatrics at Vanderbilt University, spoke with Scientific American about the health effects of this timekeeping practice and what should replace it. © 2021 Scientific American,

Keyword: Biological Rhythms
Link ID: 28062 - Posted: 11.06.2021

By Elizabeth Pennisi Dive among the kelp forests of the Southern California coast and you may spot orange puffball sponges (Tethya californiana)—creatures that look like the miniature pumpkins used for pies. No researchers paid them much mind until 2017, when William Joiner, a neuroscientist at the University of California (UC), San Diego, decided to look into whether sponges take naps. That’s not as silly a question as it seems. Over the past few years, studies in worms, jellyfish, and hydra have challenged the long-standing idea that sleep is unique to creatures with brains. Now, “The real frontier is finding an animal that sleeps that doesn’t have neurons at all,” says David Raizen, a neurologist at the University of Pennsylvania (UPenn) Perelman School of Medicine. Sponges, some of the earliest animals to appear on Earth, fit that description. To catch one snoozing could upend researchers’ definition of sleep and their understanding of its purpose. Scientists have often defined sleep as temporary loss of consciousness, orchestrated by the brain and for the brain’s benefit. That makes studying sleep in brainless creatures controversial. “I do not believe that many of these organisms sleep—at least not the way you and I do,” says John Hogenesch, a genome biologist at Cincinnati Children’s Hospital Medical Center. Calling the restful, unresponsive state seen in jellyfish and hydra “sleeplike” is more acceptable to him. But others in the field are pushing for a much more inclusive view: that sleep evolved not with modern vertebrates as previously assumed, but perhaps a half-billion years ago when the first animals appeared. “I think if it’s alive, it sleeps,” says Paul Shaw, a neuroscientist from Washington University in St. Louis. The earliest life forms were unresponsive until they evolved ways to react to their environment, he suggests, and sleep is a return to the default state. “I think we didn’t evolve sleep, we evolved wakefulness.” © 2021 American Association for the Advancement of Science.

Keyword: Sleep; Evolution
Link ID: 28061 - Posted: 11.03.2021

By Brooke Jarvis Deirdre Barrett’s body was in bed, but her mind was in a library. The library was inside a very old house, with glowing oil lamps and shelves of beautiful leatherbound books. At first it felt snug and secure and timeless, exactly the sort of place an academic like Barrett, who teaches in the psychiatry department at Harvard Medical School and edits the scientific journal Dreaming, might find inviting. But as the dream went on, she remembered later, “I became less able to focus on the library and more overwhelmed by the unseen horror outside.” Beyond the windows of the softly lit library, “a terrible plague was ravaging the world.” When Barrett woke up, it was mid-March of 2020. She had been reading about the novel coronavirus in Wuhan since it began to make headlines, and she wondered, as she often did when she read about events in the news, how this one might be showing up in the dreams of the people who were experiencing it: residents on lockdown in China, overwhelmed doctors and nurses in Italy. The dreamlife of collective catastrophe was something she had studied repeatedly during her academic career — analyzing, for example, the dreams of Kuwaitis after the Iraqi invasion and those of British officers held prisoner by the Nazis during World War II, to see how the dreams compared with one another and with dreams from calmer times. As a child, Barrett was fascinated by her own dreams, which were often vivid. They tended to stay with her well after she woke up, making nights feel like a time for slipping in and out of new worlds and adventures, often ones she’d read about but was now able to interact with and inhabit fully. When she grew up, she decided, she would become a writer of fiction; many of the early stories she wrote were set not just in worlds that she imagined, but also in and out of the various dream worlds of her characters. She was deeply curious about the dream lives of other people: When she started writing for her high school newspaper, she occasionally asked her sources if they’d had dreams related to whatever she was interviewing them about. Dreams were a window, albeit a very strange one, into the way that other people and their minds worked. In college Barrett decided that fiction was not her future (though she did develop a practice of making visual art about what she saw and felt while sleeping). What she wanted was to be a scientist who studied what happened inside dreams. © 2021 The New York Times Company

Keyword: Sleep
Link ID: 28060 - Posted: 11.03.2021

A new study re-emphasises the fact that oversleeping can be harmful for us – and especially for older people Says who? Says Brendan P Lucey, MD. Who? Associate professor of neurology and director of the Washington University Sleep Medicine Center. And lead author of a new study at Washington University School of Medicine (which is neither in Washington DC nor Washington state but St Louis, Missouri, confusingly). Here we go, a new study: what does it say? That it is, in fact, possible to have too much of a good thing. And if that good thing is sleep, how much is too much? Possibly anything over seven and a half hours a night. What?! What about my beauty sleep? Eight hours, absolute minimum. The study monitored 100 older adults, in their mid to late 70s. I am awake now, so tell me what they found. That there’s an association between less than five and a half hours’ sleep and, more surprisingly, more than seven and a half hours’ sleep and reduced cognitive performance for older adults. So how much is right for the over-75s? The “sweet spot” is somewhere in the middle range, between five and a half and seven and a half hours’ kip. What else is associated with cognitive decline in older people? Alzheimer’s is the main cause, contributing to around 70% of dementia cases. “It’s been challenging to determine how sleep and different stages of Alzheimer’s disease are related,” said Lucey. “But that’s what you need to know to start designing interventions.” © 2021 Guardian News & Media Limited

Keyword: Sleep
Link ID: 28056 - Posted: 10.30.2021

Infants who sleep longer through the night and with fewer interruptions may be less likely to become overweight during their first six months of life, according to a study published in the journal SLEEP(link is external). While the research only showed a link – not a cause-effect relationship – between infants’ sleep and weight, the findings suggest that newborns can reap some of the same health benefits that others get from consistent, quality shut-eye. The research emerged from the Rise and SHINE (Sleep Health in Infancy & Early Childhood) study, which analyzes ways sleep may influence a newborn’s growth and development. The five-year study is being supported in part by the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health. “What is particularly interesting about this research is that the sleep-obesity association we see across the lifespan appears in infancy and may be predictive of future health outcomes,” said Marishka K. Brown, Ph.D., director of the National Center on Sleep Disorders Research, located within the NHLBI. Brown noted that multiple studies have shown links between good sleep and improved health. For children, this includes a reduced risk of developing obesity and diabetes, while supporting development, learning, and behavior. In the current study, researchers observed 298 newborns and found that for every hourly increase in nighttime sleep, measured between 7 p.m. and 8 a.m., the infants were 26% less likely to become overweight. Likewise, for each reduction in nighttime awakening, they were 16% less likely to become overweight.

Keyword: Sleep; Obesity
Link ID: 28047 - Posted: 10.23.2021

By Christina Caron For about 1 in 20 people in the northern half of the United States, cooling temperatures and shorter, darker days may signal the onset of seasonal affective disorder, or SAD, a type of depression that typically arrives in the fall or winter, then goes away in the spring. Unlike mild cases of the “winter blues,” SAD symptoms make it difficult to function. It tends to start with so-called “vegetative symptoms”: an increased appetite and a craving for carbohydrates like french fries or ice cream, the urge to sleep longer hours, difficulty getting up in the morning and feeling wiped out at work. Then, in three to four weeks, “the mood plummets,” said Michael Terman, a professor of clinical psychology at Columbia University and an expert in seasonal affective disorder. Patients with SAD develop major depression, which includes persistent feelings of sadness, withdrawal from friends and family and a loss of interest in activities that were once enjoyable. Researchers don’t yet know why some people develop SAD and others do not, but the disorder is believed to run in families and is more common among women. SAD develops in the fall and winter because shorter daylight hours and less sunlight shift the body’s internal clock, and certain mood-regulating hormones, like serotonin, oscillate with the seasons. The good news is that because SAD is tied to the changing seasons, “you can predict its onset and ward it off,” Dr. Terman said. If you have already started experiencing vegetative symptoms — for example you are sleeping longer and having more difficulty waking up — or if you already know you are susceptible to seasonal affective disorder, experts said it’s best to start implementing preventive measures before major depression sets in. © 2021 The New York Times Company

Keyword: Depression; Biological Rhythms
Link ID: 28018 - Posted: 10.02.2021

Annie Melchor After finishing his PhD in neuroscience in 2016, Thomas Andrillon spent a year road-tripping around Africa and South America with his wife. One evening, on a particularly difficult road in Patagonia, his mind began to wander and he ended up accidentally flipping the car. Luckily, no one was hurt. As locals rushed in to help, they asked Andrillon what had happened. Was there an animal on the road? Had he fallen asleep at the wheel? “I had difficulty explaining that I was just thinking about something else,” he remembers. This experience made him think. What had happened? What was going on in his brain when his mind began to wander? In 2017, Andrillon started his postdoctoral research with neuroscientists Naotsugu Tsuchiya and Joel Pearson at Monash University in Melbourne. Shortly after, Tsuchiya and Andrillon teamed up with philosopher Jennifer Windt, also at Monash, to dive into the neural basis of mind wandering. Initially, Andrillon says, they wanted to know if they could detect mind wandering from facial expressions, recalling how teachers claim to be very good at knowing when their students are not paying attention. So they did a pilot experiment in which they filmed their test subjects performing a tedious, repetitive task. After reviewing the videos, one of Andrillon’s students came to him, concerned. “I think we have a problem,” said the student. “[The subjects] look exhausted.” Sure enough, even though all the study participants were awake, they were obviously struggling to not fall asleep, says Andrillon. It was this observation that gave them the idea to broaden their focus, and start looking at the connection between wavering attention and sleep. © 1986–2021 The Scientist.=

Keyword: Attention; Sleep
Link ID: 28016 - Posted: 10.02.2021

By Leigh Weingus I’ve struggled with sleep since I was a teenager, and have spent almost as long trying to fix it. I’ve absorbed countless books and articles on getting better sleep that instructed me to go blue-light free at least two hours before bedtime, take nightly baths to lower my body temperature, keep my phone far from my bedroom and avoid caffeine after 12 p.m. In between all my diligent sleep hygiene work, I couldn’t help but feel like there was a larger force at play. My sleep seemed to change throughout my menstrual cycle, for example, getting worse in the days before my period and significantly better afterward. When I was pregnant, I experienced the best sleep of my life, and when I stopped breastfeeding, I didn’t sleep for days. I finally started to ask myself: When we talk about getting better sleep, why aren’t we talking more about hormones? According to the National Sleep Foundation, the lifetime risk of insomnia is 40 percent higher for women than it is for men. Blaming this discrepancy entirely on hormones oversimplifies it — women also tend to take on the bulk of household worrying and emotional labor, and they tend to experience higher levels of anxiety. But according to Mary Jane Minkin, an obstetrician-gynecologist and clinical professor in the Department of Obstetrics, Gynecology, and Reproductive Sciences at the Yale School of Medicine, anecdotal evidence and studies suggest that hormones likely play a role.

Keyword: Sleep; Hormones & Behavior
Link ID: 28000 - Posted: 09.22.2021

By Sarah Lyall In the winter of 1995, the Brazilian neuroscientist Sidarta Ribeiro moved to New York to pursue his Ph.D. at Rockefeller University. His arrival, he writes in his fascinating, discursive new book, “The Oracle of Night,” precipitated one of the strangest periods of his life. Overcome by a sudden, inexplicable lassitude, Ribeiro did little but attend classes, read and sleep. But his sleep was exciting and revelatory, full of vivid, evocative dreams that enriched his waking hours. “I began to dream in English,” he writes, “and my dreams became even more intense, with representations of epic narratives through unnaturally deserted New York streets on the sunny, icy morning of an endless Sunday.” This period lasted for several months and then abruptly ended. When Ribeiro re-entered the world, as if emerging from hibernation, he was refreshed and alert, energized by a “cognitive transformation” that he felt had been enhanced by his dreaming imagination. He became fascinated by dreams — why do we have them, what do they say about us, what role do they play in our lives? — and embarked on a lifetime of study of this most interesting of topics. (He wears many hats. He got his Ph.D. in animal behavior; he is the founder and vice director of the Brain Institute at the Federal University of Rio Grande do Norte in Brazil.) “The Oracle of Night” makes a resounding case for the mystery, beauty and cognitive importance of dreams. Ribeiro marshals prodigious evidence to bolster his case that a dream is not simply “fragments of memory assembled at random” (as he summarizes Francis Crick’s dismissive position), but instead is a “privileged moment for prospecting the unconscious” — a phenomenon that, in Carl Jung’s words, “prepares the dreamer for the events of the following day.” © 2021 The New York Times Company

Keyword: Sleep
Link ID: 27979 - Posted: 09.08.2021

Rachel Hall Napping has long been a symbol of laziness, but actually it is an essential bodily function that improves our memory, creativity, empathy and problem-solving abilities. Sleep scientists say the gold standard for good physical and mental health is making sure you get between seven and nine hours’ sleep every day, but not necessarily all in one go. “Capitalists in the old days told us that we should do 12 to 16 hours of work for them, and then have eight hours to do what we like, so they wanted us to sleep efficiently in a certain window – that’s where the idea of consolidated sleep comes from,” said Till Roenneberg, a professor of chronobiology at the University of Munich. He has been studying civilisations without electricity, and has observed that people often woke up during the night, took a break and went back to sleep. However, Matthew Walker, a professor of neuroscience at the University of California, Berkeley, and author of Why We Sleep, said people who have trouble falling asleep at night should approach naps with caution, and that everyone should avoid napping after 3pm. “If you nap too late in the day it’s a bit like snacking before main meal, it just takes the edge off your sleep hunger at night,” he said. The ideal length, according to the scientists, is 20 to 25 minutes. Any longer and you’ll fall into a deeper sleep cycle, which lasts for about 90 minutes. This means when you wake up you will experience “sleep inertia”, or grogginess. © 2021 Guardian News & Media Limited

Keyword: Sleep; Biological Rhythms
Link ID: 27965 - Posted: 08.28.2021

By Jillian Kramer Mice are at their best at night. But a new analysis suggests researchers often test the nocturnal creatures during the day—which could alter results and create variability across studies—if they record time-of-day information at all. Of the 200 papers examined in the new study, more than half either failed to report the timing of behavioral testing or did so ambiguously. Only 20 percent reported nighttime testing. The analysis was published in Neuroscience & Biobehavioral Reviews. West Virginia University neuroscientist Randy Nelson, the study's lead author, says this is likely a matter of human convenience. “It is easier to get students and techs to work during the day than [at] night,” Nelson says. But that convenience comes at a cost. “Time of day not only impacts the intensity of many variables, including locomotor activity, aggressive behavior, and plasma hormone levels,” but changes in those variables can only be observed during certain parts of the diurnal cycle, says University of Wyoming behavioral neuroscientist William D. Todd. This means that “failing to report time of day of data collection and tests makes interpretation of results extremely difficult,” adds Beth Israel Deaconess Medical Center staff scientist Natalia Machado. Neither Todd nor Machado was involved in the new study. The study researchers say it is critical that scientists report the timing of their work and consider the fact that animals' behavioral and physiological responses can vary with the hour. As a first step, Nelson says, “taking care of time-of-day considerations seems like low-hanging fruit in terms of increasing behavioral neuroscience research reliability, reproducibility and rigor.” © 2021 Scientific American

Keyword: Biological Rhythms
Link ID: 27953 - Posted: 08.21.2021

By Virginia Hughes In the 1960s, the drug was given to women during childbirth to dampen their consciousness. In the 1990s, an illicit version made headlines as a “date rape” drug, linked to dozens of deaths and sexual assaults. And for the last two decades, a pharmaceutical-grade slurry of gamma-hydroxybutyrate, or GHB, has been tightly regulated as a treatment for narcolepsy, a disorder known for its sudden sleep attacks. Now, the Food and Drug Administration has approved the drug for a new use: treating “idiopathic hypersomnia,” a mysterious condition in which people sleep nine or more hours a day, yet never feel rested. Branded as Xywav, the medication is thought to work by giving some patients restorative sleep at night, allowing their brains to be more alert when they wake up. It is the first approved treatment for the illness. But some experts say the publicly available evidence to support the new approval is weak. And they worry about the dangers of the medication, which acts so swiftly that its label advises users to take it while in bed. Xywav and an older, high-salt version called Xyrem have a host of serious side effects, including breathing problems, anxiety, depression, sleepwalking, hallucinations and suicidal thoughts. GHB “has serious safety concerns, both in terms of its abuse liability and its addictive potential,” said Dr. Lewis S. Nelson, the director of medical toxicology at Rutgers New Jersey Medical School. An estimated 40,000 people in the United States have been diagnosed with idiopathic hypersomnia, but Dr. Nelson said that many more people with daytime drowsiness might wind up with this diagnosis now that it has an F.D.A.-approved treatment. The disorder’s hallmark symptoms — sleep cravings, long naps and brain fog — overlap with many other conditions. The more people who take the drug, the more opportunity for abuse. “The potential for the scope of use to expand is very real,” Dr. Nelson said. “So that is concerning to me.” © 2021 The New York Times Company

Keyword: Sleep; Drug Abuse
Link ID: 27947 - Posted: 08.14.2021

By Katharine Q. Seelye Dr. J. Allan Hobson, a psychiatrist and pioneering sleep researcher who disputed Freud’s view that dreams held hidden psychological meaning, died on July 7 at his home in East Burke, Vt. He was 88. The cause was kidney failure resulting from diabetes, said his daughter, Julia Hobson Haggerty. For some time, sleep was not taken seriously as an academic pursuit. Even Dr. Hobson, who was a professor of psychiatry at Harvard Medical School and director of the Laboratory of Neurophysiology at the Massachusetts Mental Health Center, joked that the only known function of sleep was to cure sleepiness. But over a career that spanned more than four decades, his own research and that of others showed that sleep is crucial to normal cognitive and emotional function, including learning and memory. In more than 20 books — among them “The Dreaming Brain” (1988); “Dreaming as Delirium: How the Brain Goes Out of its Mind” (1999), and “Dream Self” (2021), a memoir — he popularized his research and that of others, including the findings that sleep begins in utero and is essential for tissue growth and repair throughout life. “He showed that sleep isn’t a nothing state,” Ralph Lydic, who conducted research with Dr. Hobson in the 1980s and is a professor of neuroscience at the University of Tennessee, said in a phone interview. “He demonstrated that the brain is as active during R.E.M. sleep as it is during wakefulness,” he added, referring to sleep characterized by rapid eye movement. “We know as much about sleep as we do in part because of him.” One of his most influential contributions to dream research came in 1977, when Dr. Hobson and a colleague, Robert McCarley, produced a cellular and mathematical model that they believed showed how dreams occur. Dreams, they said, are not mysterious codes sent by the subconscious but rather the brain’s attempt to attribute meaning to random firings of neurons in the brain. © 2021 The New York Times Company

Keyword: Sleep
Link ID: 27929 - Posted: 08.04.2021