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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.

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 8: Hormones and Sex
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

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and 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

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 27965 - Posted: 08.28.2021

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

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 4: Development of the Brain
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

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 27929 - Posted: 08.04.2021

By Laura Sanders A brush with death led Hans Berger to invent a machine that could eavesdrop on the brain. In 1893, when he was 19, Berger fell off his horse during maneuvers training with the German military and was nearly trampled. On that same day, his sister, far away, got a bad feeling about Hans. She talked her father into sending a telegram asking if everything was all right. To young Berger, this eerie timing was no coincidence: It was a case of “spontaneous telepathy,” he later wrote. Hans was convinced that he had transmitted his thoughts of mortal fear to his sister — somehow. So he decided to study psychiatry, beginning a quest to uncover how thoughts could travel between people. Chasing after a scientific basis for telepathy was a dead end, of course. But in the attempt, Berger ended up making a key contribution to modern medicine and science: He invented the electroencephalogram, or EEG, a device that could read the brain’s electrical activity. Berger’s machine, first used successfully in 1924, produced a readout of squiggles that represented the electricity created by collections of firing nerve cells in the brain. © Society for Science & the Public 2000–2021.

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 1: Introduction: Scope and Outlook
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 1: Cells and Structures: The Anatomy of the Nervous System
Link ID: 27895 - Posted: 07.08.2021

By Katherine Ellison Remember the line from that old folk song? If living were a thing that money could buy You know the rich would live and the poor would die. Sadly, there’s little “if” about it. On average, the poor live less healthy lives and are more than three times as likely to die prematurely as the rich. That’s true for many well-documented reasons, including less healthy diets with too much processed food, polluted neighborhoods and a lot more toxic stress. In recent years, however, researchers have added one more factor to this mix: It turns out that the poor, as well as socially disadvantaged racial minorities, sleep much less well on average than the rich, which can take a major toll on their physical and mental health. “We used to think that sleep problems were limited to Type A professionals, and they certainly aren’t immune, but low-income individuals and racial minorities are actually at greatest risk,” says Wendy Troxel, a senior behavioral and social scientist at the RAND Corporation, who coauthored an analysis of socioeconomic disparities in sleep and health in the 2020 Annual Review of Public Health. Inadequate sleep among low-income adults and racial minorities contributes to higher rates of illnesses, including cardiovascular disease and dementia, both of which are more common among these groups, Troxel and her coauthors point out. One study they cite attributes more than half of the differences in health outcomes between whites and Blacks, for example, to differences in quantity or quality of sleep. You might think of this as the great sleep divide. © 2021 Annual Reviews, Inc

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 11: Emotions, Aggression, and Stress
Link ID: 27881 - Posted: 06.29.2021

By Anahad O'Connor According to recent studies, the number of people complaining of insomnia skyrocketed during the pandemic, rising from 20 percent of adults last summer to nearly 60 percent in March. If you’re one of those people who’s been plagued by poor sleep, the Well desk is here to help. Recently, we asked our readers to tell us two things: What’s keeping you from getting a good night’s rest? And what are the most pressing questions you would ask a sleep expert? More than 1,200 of you responded. You asked about insomnia, supplements, middle-of-the-night awakenings, snoring bed mates and more. So we collected your most popular questions, brought them to the world’s top sleep experts and shared their answers below. Sometimes I am physically tired but can’t fall asleep. How is that possible? This is what’s known as the tired but wired syndrome. Usually, it’s driven by stress and anxiety. Even if you’re exhausted, a racing mind can activate the “fight or flight” branch of your nervous system, making you alert and unable to fall asleep. “For us to fall asleep and stay asleep, we need to go in the opposite nervous system direction,” said Matthew Walker, a professor of neuroscience and psychology at the University of California, Berkeley, and the author of the best-selling book “Why We Sleep.” “We need to shift over to the calming branch of the nervous system called the parasympathetic nervous system.” © 2021 The New York Times Company

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 27847 - Posted: 06.11.2021

Nicholas Bakalar Many people wear a CPAP machine at night to treat the interrupted breathing of obstructive sleep apnea, a condition that affects an estimated 22 million Americans. But CPAP machines can be noisy, cumbersome and uncomfortable, and many people stop using the devices altogether, which can have dire long-term consequences. Mouth guards may be a more comfortable and easy-to-use alternative for many people with obstructive sleep apnea, according to a new report. The study, published in Laryngoscope, looked at 347 people with sleep apnea who were fitted with a mouth guard by an otolaryngologist. Two-thirds of patients reported they were comfortable wearing the devices, and the devices appeared to be effective in helping to relieve the disordered breathing of obstructive sleep apnea. The lead author of the study, Dr. Guillaume Buiret, head of otolaryngology at Valence Hospital in Valence, France, said that if he had sleep apnea, he would choose an oral appliance first. “It’s easy to tolerate, effective and it costs a lot less than CPAP,” he said. “Thirty to 40 percent of our patients can’t use CPAP, and these patients almost always find the dental appliance helpful. I would recommend it as a first-line treatment” Loud snoring may be the most obvious consequence of sleep apnea, but the condition, if left untreated, can lead to a broad range of complications, including high blood pressure, heart disease, liver dysfunction and Type 2 diabetes. © 2021 The New York Times Company

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 27838 - Posted: 06.02.2021

Veronique Greenwood The hydra is a simple creature. Less than half an inch long, its tubular body has a foot at one end and a mouth at the other. The foot clings to a surface underwater — a plant or a rock, perhaps — and the mouth, ringed with tentacles, ensnares passing water fleas. It does not have a brain, or even much of a nervous system. And yet, new research shows, it sleeps. Studies by a team in South Korea and Japan showed that the hydra periodically drops into a rest state that meets the essential criteria for sleep. On the face of it, that might seem improbable. For more than a century, researchers who study sleep have looked for its purpose and structure in the brain. They have explored sleep’s connections to memory and learning. They have numbered the neural circuits that push us down into oblivious slumber and pull us back out of it. They have recorded the telltale changes in brain waves that mark our passage through different stages of sleep and tried to understand what drives them. Mountains of research and people’s daily experience attest to human sleep’s connection to the brain. But a counterpoint to this brain-centric view of sleep has emerged. Researchers have noticed that molecules produced by muscles and some other tissues outside the nervous system can regulate sleep. Sleep affects metabolism pervasively in the body, suggesting that its influence is not exclusively neurological. And a body of work that’s been growing quietly but consistently for decades has shown that simple organisms with less and less brain spend significant time doing something that looks a lot like sleep. Sometimes their behavior has been pigeonholed as only “sleeplike,” but as more details are uncovered, it has become less and less clear why that distinction is necessary. All Rights Reserved © 2021

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 27825 - Posted: 05.19.2021

By Sofia Moutinho There’s no 9-to-5 for female northern elephant seals. After the winter breeding season, the animals spend more than 19 hours—and up to 24 hours—per day hunting in the northern Pacific Ocean, killing up to 2000 small fish daily to survive, according to a new study of these elusive animals. The work, made possible by cameras and devices attached to the seals’ heads, could also help scientists monitor other deep-ocean life. “This study is fascinating,” says Jeremy Goldbogen, a marine biologist at Stanford University who was not part of the research. “The advanced technology provides unprecedented levels of detail on where and when the elephant seals forage in a deep, dark ocean.” Northern elephant seals (Mirounga angustirostris) are mysterious animals. They appear onshore, on some Pacific Coast beaches, only twice a year: in late December or early January to mate or give birth, and about 2 months later to shed their fur. They spend the rest of their time, almost 10 months, fishing. Males, which can weigh up to 2 tons—about the weight of a small truck—hunt big fish close to the coast. Females, which are only about one-third of the size, hunt smaller fish in a deep-sea region known as the twilight zone. To get food from the zone, which reaches depths of 1500 meters, the females must hold their breath for up to 1.5 hours. “The physiological challenges that these animals face to meet their daily energetic demand is an extraordinary feat,” Goldbogen says. To find out how the females survive on the small fish—some of which are just 2 centimeters long—Japanese and U.S. researchers attached infrared video cameras with depth sensors to the heads of 48 female elephant seals. They also attached GPS trackers and a special device that could count every time a seal opened its mouth. (The researchers called their device the Kami Kami Logger, after the Japanese sound for biting, similar to the English “chomp chomp.”) © 2021 American Association for the Advancement of Science

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 27819 - Posted: 05.15.2021

Linda Geddes It’s a common enough scenario: you walk into your local supermarket to buy some milk, but by the time you get to the till, the milk bottle has turned into a talking fish. Then you remember you’ve got your GCSE maths exam in the morning, but you haven’t attended a maths lesson for nearly three decades. Dreams can be bafflingly bizarre, but according to a new theory of why we dream, that’s the whole point. By injecting some random weirdness into our humdrum existence, dreams leave us better equipped to cope with the unexpected. The question of why we dream has long divided scientists. Dreams’ subjective nature, and the lack of any means of recording them, makes it fiendishly difficult to prove why they occur, or even how they differ between individuals. “While various hypotheses have been put forward, many of these are contradicted by the sparse, hallucinatory, and narrative nature of dreams, a nature that seems to lack any particular function,” said Erik Hoel, a research assistant professor of neuroscience at Tufts University in Massachusetts, US. Inspired by recent insights into how machine “neural networks” learn, Hoel has proposed an alternative theory: the overfitted brain hypothesis. © 2021 Guardian News & Media Limited

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 27818 - Posted: 05.15.2021

By Pam Belluck Could getting too little sleep increase your chances of developing dementia? For years, researchers have pondered this and other questions about how sleep relates to cognitive decline. Answers have been elusive because it is hard to know if insufficient sleep is a symptom of the brain changes that underlie dementia — or if it can actually help cause those changes. Now, a large new study reports some of the most persuasive findings yet to suggest that people who don’t get enough sleep in their 50s and 60s may be more likely to develop dementia when they are older. The research, published Tuesday in the journal Nature Communications, has limitations but also several strengths. It followed nearly 8,000 people in Britain for about 25 years, beginning when they were 50 years old. It found that those who consistently reported sleeping six hours or less on an average weeknight were about 30 percent more likely than people who regularly got seven hours sleep (defined as “normal” sleep in the study) to be diagnosed with dementia nearly three decades later. “It would be really unlikely that almost three decades earlier, this sleep was a symptom of dementia, so it’s a great study in providing strong evidence that sleep is really a risk factor,” said Dr. Kristine Yaffe, a professor of neurology and psychiatry at the University of California, San Francisco, who was not involved in the study. Pre-dementia brain changes like accumulations of proteins associated with Alzheimer’s are known to begin about 15 to 20 years before people exhibit memory and thinking problems, so sleep patterns within that time frame could be considered an emerging effect of the disease. That has posed a “chicken or egg question of which comes first, the sleep problem or the pathology,” said Dr. Erik Musiek, a neurologist and co-director of the Center on Biological Rhythms and Sleep at Washington University in St. Louis, who was not involved in the new research. © 2021 The New York Times Company

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 13: Memory and Learning
Link ID: 27786 - Posted: 04.24.2021

By Laura Sanders Octopuses cycle through two stages of slumber, a new study reports. First comes quiet sleep, and then a shift to a twitchy, active sleep in which vibrant colors flash across the animals’ skin. These details, gleaned from four snoozing cephalopods in a lab in a Brazil, may provide clues to a big scientific mystery: Why do animals sleep? Sleep is so important that every animal seems to have a version of it, says Philippe Mourrain, a neurobiologist at Stanford University who recently described the sleep stages of fish (SN: 7/10/19). Scientists have also catalogued sleep in reptiles, birds, amphibians, bees, mammals and jellyfish, to name a few. “So far, we have not found a single species that does not sleep,” says Mourrain, who was not involved in the new study. Cephalopod neuroscientist and diver Sylvia Medeiros caught four wild octopuses, Octopus insularis, and brought them temporarily into a lab at the Brain Institute of the Federal University of Rio Grande do Norte in Natal, Brazil. After tucking the animals away in a quiet area, she began to carefully record their behavior during the day, when octopuses are more likely to rest. Two distinct states emerged, she and her colleagues report March 25 in iScience. In the first, called quiet sleep, the octopuses are pale and motionless with the pupils of their eyes narrowed to slits. Active sleep comes next. Eyes dart around, suckers contract, muscles twitch, skin textures change and, most dramatically, bright colors race across octopuses’ bodies. This wild sleep is rhythmic, happening every half an hour or so, and brief; it’s over after about 40 seconds. Active sleep is also rare; the octopuses spent less than 1 percent of their days in active sleep, the researchers found. © Society for Science & the Public 2000–2021.

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 27749 - Posted: 03.27.2021

By Penelope Green In 1999, Rosalind D. Cartwright, a renowned sleep researcher, testified for the defense in the murder trial of a man who arose from his bed early one night, gathered up tools to fix his pool’s filter pump, stabbed his beloved wife to death, rolled her into the pool and went back to bed. When he was awakened by the police, he said he had no memory of his actions. His lawyers argued that the man, who had no motive to kill his wife, had been sleepwalking and was therefore in an unconscious state and not responsible for his behavior. Dr. Cartwright, who had successfully served as a witness for the defense in a similar case a decade earlier (working pro bono in both trials), agreed. The jury did not, and the man was sentenced to life in prison. As Dr. Cartwright was leaving the courtroom, however, a bailiff asked for her business card. Abashedly, he told her, “I beat people up in my sleep.” Nicknamed the Queen of Dreams by her peers, Dr. Cartwright studied the role of dreaming in divorce-induced depression, worked with sleep apnea patients and their frustrated spouses, and helped open one of the first sleep disorder clinics. She died at 98 on Jan. 15 at her home in Chicago. Her daughter, Carolyn Cartwright, said the cause was a heart attack. The earlier sleepwalking murder case that hinged on Dr. Cartwright’s testimony was a notorious one, even inspiring a television movie, “The Sleepwalker Killing”: In 1987 a young Canadian man murdered his mother-in-law and brutally attacked his father-in-law after driving from his home to theirs in his pajamas. Like the pool man, he had no motive to kill them. © 2021 The New York Times Company

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 27733 - Posted: 03.17.2021

By Sofia Moutinho In the movie Inception, Leonardo DiCaprio enters into other people’s dreams to interact with them and steal secrets from their subconscious. Now, it seems this science fiction plot is one baby step closer to reality. For the first time, researchers have had “conversations” involving novel questions and math problems with lucid dreamers—people who are aware that they are dreaming. The findings, from four labs and 36 participants, suggest people can receive and process complex external information while sleeping. “This work challenges the foundational definitions of sleep,” says cognitive neuroscientist Benjamin Baird of the University of Wisconsin, Madison, who studies sleep and dreams but was not part of the study. Traditionally, he says, sleep has been defined as a state in which the brain is disconnected and unaware of the outside world. Lucid dreaming got one of its first mentions in the writings of Greek philosopher Aristotle in the fourth century B.C.E., and scientists have observed it since the 1970s in experiments about the rapid eye movement (REM) phase of sleep, when most dreaming occurs. One in every two people has had at least one lucid dream, about 10% of people experience them once a month or more. Although rare, this ability to recognize you are in a dream—and even control some aspects of it—can be enhanced with training. A few studies have tried to communicate with lucid dreamers using stimuli such as lights, shocks, and sounds to “enter” people’s dreams. But these recorded only minimal responses from the sleepers and did not involve complex transmission of information. © 2021 American Association for the Advancement of Science.

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 14: Attention and Higher Cognition
Link ID: 27700 - Posted: 02.19.2021

By Diana Kwon Dreams are full of possibilities; by drifting into the world beyond our waking realities, we can visit magical lands, travel through time and interact with long-lost family and friends. The notion of communicating in real time with someone outside of our dreamscapes, however, sounds like science fiction. A new study demonstrates that, to some extent, this seeming fantasy can be made real. Scientists already knew that one-way contact is attainable. Previous studies have demonstrated that people can process external cues, such as sounds and smells, while asleep. There is also evidence that people are able to send messages in the other direction: Lucid dreamers—those who can become aware they are in a dream—can be trained to signal, using eye movements, that they are in the midst of a dream. Two-way communication, however, is more complex. It requires a person who is asleep to actually understand what they hear from the outside and think about it logically enough to generate an answer, explains Ken Paller, a cognitive neuroscientist at Northwestern University. “We believed that it was going to be possible—but until we actually demonstrated it, we weren’t sure.” For this study, Paller and his colleagues recruited volunteers who said they remembered at least one dream per week and provided them with guidance on how to lucid dream. They were also trained to respond to simple math problems by moving their eyes back and forth—for example, the correct answer to “eight minus six,” would be moving your eyes to the left and right twice. While the participants slept, electrodes attached to their faces picked up their eye movements and electroencephalography (EEG)—a method of monitoring brain activity—kept track of what stage of sleep they were in. © 2021 Scientific American

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 14: Attention and Higher Cognition
Link ID: 27699 - Posted: 02.19.2021

By Valeriya Safronova Jennifer Lopez is wearing them, Kylie Jenner and Rashida Jones are promoting them, and Drew Barrymore is selling them. Blue-light glasses are shaping up to be the accessory of our prolonged screen-mediated moment. But do we need them? Blue-light glasses are fitted with lenses that filter out certain light waves that are emitted by the sun and, to a lesser extent, by digital devices like phones, laptops and tablets. Blue light is not inherently bad; it boosts attention and wakefulness during the day. But it suppresses the natural production of melatonin at night. By limiting exposure to blue light by as little as 20 percent, companies say, a customer could sleep better, experience less eye strain and prevent potential retinal damage. Scientists, however, are not convinced that the glasses are a worthy investment. “Whichever aspect you look at, it’s very hard to justify spending the extra money,” said Dr. John Lawrenson, a professor of clinical visual science at City, University of London. (Prices vary but start at around $20.) After reviewing several studies that tested the effectiveness of blue-light-blocking lenses, he and his colleagues concluded that the glasses are not necessary. Digital eye strain is real, but it’s impossible to say with certainty that the culprit is blue light. “No one has established an independent causal association between blue light coming from the computer and visual symptoms,” Dr. Lawrenson said. He recommended going to an eye doctor for a checkup instead of rushing to buy nonprescription glasses. Regardless, the blue-light category is booming. A quick Google search pulls up several brands that almost exclusively sell “computer glasses” (like Felix Gray, which raised more than $1.7 million in funding in 2020, bringing its total funding to $7.8 million as of September, according to PitchBook), as well as prescription-eyewear companies like Zenni (which sold two million pairs of its Blokz lenses in 2020, according to the company) and Jins (which noted an uptick in online orders last year). If you’ve shopped at Warby Parker recently, you were probably asked if you’d like a blue-light filter added to your lenses. © 2021 The New York Times Company

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 7: Vision: From Eye to Brain
Link ID: 27698 - Posted: 02.19.2021

Elizabeth Landau At a sleep research symposium in January 2020, Janna Lendner presented findings that hint at a way to look at people’s brain activity for signs of the boundary between wakefulness and unconsciousness. For patients who are comatose or under anesthesia, it can be all-important that physicians make that distinction correctly. Doing so is trickier than it might sound, however, because when someone is in the dreaming state of rapid-eye movement (REM) sleep, their brain produces the same familiar, smoothly oscillating brain waves as when they are awake. Lendner argued, though, that the answer isn’t in the regular brain waves, but rather in an aspect of neural activity that scientists might normally ignore: the erratic background noise. Some researchers seemed incredulous. “They said, ‘So, you’re telling me that there’s, like, information in the noise?’” said Lendner, an anesthesiology resident at the University Medical Center in Tübingen, Germany, who recently completed a postdoc at the University of California, Berkeley. “I said, ‘Yes. Someone’s noise is another one’s signal.’” Lendner is one of a growing number of neuroscientists energized by the idea that noise in the brain’s electrical activity could hold new clues to its inner workings. What was once seen as the neurological equivalent of annoying television static may have profound implications for how scientists study the brain. All Rights Reserved © 2021

Related chapters from BN: Chapter 18: Attention and Higher Cognition; Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 14: Attention and Higher Cognition; Chapter 10: Biological Rhythms and Sleep
Link ID: 27684 - Posted: 02.13.2021

Allyson Chiu Sleep and circadian rhythms have long been associated with the powerful effects of the sun cycle. But in recent years, a growing number of studies have suggested that another familiar celestial body might also be impacting your ability to get a restful night’s sleep: the moon. A paper published this week in the journal Science Advances found that people tend to have a harder time sleeping in the days leading up to a full moon. Researchers reported that sleep patterns among the study’s 98 participants appeared to fluctuate over the course of the 29½ -day lunar cycle, with the latest bedtimes and least amount of rest occurring on nights three to five days before the moon reaches its brightest phase. They found a similar pattern in sleep data from another group of more than 460 people. Ahead of the full moon, it took people, on average, 30 minutes longer to fall asleep and they slept for 50 minutes less, said Leandro Casiraghi, the study’s lead author and a postdoctoral researcher in the Department of Biology at the University of Washington. “What we did is we came up with a set of data that shockingly proves that this is real, that there’s an actual effect of the moon on our sleep,” Casiraghi said. Previous studies examining the moon’s effect on sleep have produced contradictory results. Some research has found minimal or no association between the lunar cycle and sleep, while other studies have demonstrated correlations in controlled settings. The findings of the Jan. 27 paper support existing observations that there is a link, Casiraghi said. But, he noted that the work he and his fellow scientists did is distinct from past research by a critical difference in methodology. © 1996-2021 The Washington Post

Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 27668 - Posted: 01.30.2021