By Jake Currie Ever wonder why jet lag is such a horribly uncomfortable experience? It’s because your biological clock doesn’t just regulate your sleep cycle, it affects a whole host of other bodily functions, like hormone levels, metabolism, your immune activity, and more. That means when your circadian rhythms get disrupted, it can throw a wrench into a variety of systems. It also means that time of day can be an important factor when considering medical treatments. For example, aortic valve replacements performed in the afternoon are associated with fewer adverse side effects. Unfortunately determining what “time” your internal clock reads is a little more difficult than glancing at a watch, in part because everyone’s biological clock ticks at a slightly different pace. Right now, the single most accurate test involves repeatedly measuring the levels of melatonin in the saliva during the hours leading up to bedtime, which is difficult to do outside of a laboratory or hospital environment. Now, according to new research published in the Proceedings of the National Academy of Sciences, chronobiologists have developed a way to get an accurate read of your biological clock from a simple hair sample. By measuring the transcriptional activity of clock genes in hair follicle cells and performing an analysis using artificial intelligence, they’ve been able to accurately pinpoint the biological clock’s time. “In these cells, we measure the activity of 17 genes that are part of the molecular clock or are controlled by it,” study author Achim Kramer of Charité—Universitätsmedizin Berlin explained in a statement. “Using machine learning, this pattern can be used to calculate at what point in the daily rhythm the person is currently at. A single sample is sufficient for this.”

Keyword: Biological Rhythms; Genes & Behavior
Link ID: 30187 - Posted: 04.04.2026

Sleeping for 11 minutes more each night, doing 4.5 additional minutes of brisk walking and eating an extra 50g or so of vegetables each day can significantly reduce a person’s risk of heart attack, a study has found. Academics found these small changes could help people avoid major cardiovascular events, including heart attacks and strokes, by about 10%. Small behaviour changes were more “achievable and sustainable”, the research team said. The study, published in the European Journal of Preventive Cardiology, was conducted by experts from Australia, Chile and Brazil who examined data on more than 53,000 middle-aged UK adults taking part in the Biobank study. Researchers looked at sleep habits and levels of exercise through data from wearable technology such as smartwatches. People also self-reported on their dietary habits. The researchers found that 2,034 major cardiovascular events occurred during an eight-year follow-up period. They were able to identify the “optimal” way people could avoid these incidents, including a good diet, eight to nine hours sleep each night and a minimum of 42 minutes of moderate-to-vigorous physical activity each day. Combining these measures leads to a 57% lower risk of heart attacks and strokes. They also found the “clinically relevant” combination of behaviours that could reduce people’s risk, including more sleep, better diet and more moderate-to-vigorous activity. According to the NHS website, moderate activity can include brisk walking, dancing, pushing a lawn mower, water aerobics and riding a bike. Vigorous activity includes running, swimming, skipping and aerobics. Dr Nicholas Koemel, the study’s lead author and a research fellow at the University of Sydney, said: “We show that combining small changes in a few areas of our lives can have a surprisingly large positive impact on our cardiovascular health. “This is very encouraging news because making a few small, combined changes is likely more achievable and sustainable for most people when compared with attempting major changes in a single behaviour. © 2026 Guardian News & Media Limited

Keyword: Sleep
Link ID: 30172 - Posted: 03.25.2026

By Marlowe Starling The passage of the sun across the sky — dawn, day, dusk, night — drives the clock of life. Some species wake with the sun and sleep with the moon. Others do the opposite, and a few keep odd hours. These naturally driven, 24-hour biological cycles are known as circadian rhythms, and they do more than cue bedtime: They regulate hormones, metabolism, DNA repair, and more. When life falls out of sync, there can be dire consequences for health, reproduction, and survival. Lacking watches, many species keep time using an internal system — a set of interacting genes and their protein products that effectively keeps track of a 24-hour period — that is calibrated by sunlight. This kind of circadian clock is widespread, found even in single-celled algae, which suggests that biological timekeeping evolved billions of years ago. Across animals, most species have the same genetic system, using genes known as CLOCK, BMAL1, and CRY, or recognizable homologues. This form of biological clock mechanism appears even in ancient lineages, including sponges and some jellyfish. But is this the only way to do it? In a pea-size jelly off the coast of Japan, biologists are examining a different kind of timekeeping. Somewhere over the course of their evolution, the class of hydrozoans — which includes certain kinds of jellyfish, hydras, and colonial siphonophores such as the Portuguese man-of-war — lost the genes that operate circadian clocks in the rest of the animal kingdom. Yet a newly discovered hydrozoan jellyfish species has a mysterious circadian clock that regularly tracks 20-hour periods, suggesting that its mechanism evolved independently. The findings, published (opens a new tab) in PLOS Biology in January 2026, push the limits of what chronobiologists consider “circadian.” © 2026 Simons Foundation

Keyword: Biological Rhythms; Evolution
Link ID: 30169 - Posted: 03.21.2026

By Bethany Brookshire When solving a puzzle, the answer could lie in your dreams. In a study of lucid dreamers, playing soundtracks linked with unsolved puzzles helped the sleepers solve the problems the next day, researchers report February 5 in Neuroscience of Consciousness. Stories of brilliant insights after a nap or daydream abound, but scientists have struggled to successfully influence people’s dreams and rigorously test the idea. “This study provides one of the first experimentally grounded demonstrations of such a link,” says Giulio Bernardi, a cognitive neuroscientist at IMT School for Advanced Studies Lucca, in Italy, who was not involved with the work. Whether we remember our dreams or not, we have countless dreams in our sleep, according to Karen Konkoly, a cognitive neuroscientist who performed the study at Northwestern University in Evanston, Ill. “Your dreams are such a big part of your inner life,” she says. And in the right circumstances, manipulating those dreams could help people think of problems in new ways. While some scientists have shown that sleeping on a problem increases the odds of solving it the next day, others have shown no benefit. Of course, it might help only if you actually think about the problem in your sleep. Konkoly and her colleagues were especially interested in helping sleepers think about specific topics using targeted memory reactivation, or TMR. “It’s this research technique where you have a sensory stimuli that’s associated with a memory,” Konkoly says. “It could be a very soft sound or a smell that’s presented to a sleeper, and it functions to remind the sleeping brain of the full memory.” While people dream in every stage of sleep, the effects of TMR have been strongest in deep, slow-wave sleep, she says. Konkoly wanted to look at the effects of TMR at a different sleep stage — rapid eye movement sleep, which could be helpful for creative thinking. © Society for Science & the Public 2000–2026.

Keyword: Sleep; Learning & Memory
Link ID: 30145 - Posted: 03.04.2026

By Holly Barker Synaptic proteins degrade more slowly in aged mice than in younger mice, a new study finds. Microglia appear to unburden the neurons of the excess proteins, but that accumulation may turn toxic, the findings suggest. To function properly, cells need to clear out old and damaged proteins periodically, but that process stalls with age: Protein turnover is about 20 percent slower in the brains of older rodents than in youthful ones, according to an analysis of whole-brain samples. The new study is the first to probe protein clearance specifically in neurons in living animals. “Neurons face unique challenges to protein turnover,” says study investigator Ian Guldner, a postdoctoral fellow in Tony Wyss-Coray’s lab at Stanford University. For instance, their longevity prevents them from distributing old proteins among daughter cells. And unlike other proteins on the path to degradation, neuronal components must first navigate the axon—sometimes traveling as far as 1 meter, Guldner says. In the new study, Guldner and his colleagues engineered mice to express a modified version of aminoacyl-tRNA synthetase—a component of the protein synthesis machinery—in excitatory neurons. Every day for one week, mice of different ages received injections of chemically altered amino acids compatible only with that mutant enzyme. Neurons used the labeled amino acids to replenish proteins, enabling the group to track how quickly those proteins degraded over the subsequent two weeks. “The achievement lies in the technical advance, namely by being able to look at protein degradation and aggregation specifically in neuronal cells,” says F. Ulrich Hartl, director of the Max Planck Institute of Biochemistry, who was not involved in the study. © 2026 Simons Foundation

Keyword: Development of the Brain; Glia
Link ID: 30114 - Posted: 02.11.2026

By Marla Vacek Broadfoot Nearly 1 in 8 dementia cases — about half a million nationwide — may be linked to insomnia. The new findings, reported December 27 in the Journals of Gerontology: Series A, add weight to growing evidence that sleep is a modifiable risk factor for dementia, akin to hearing loss and hypertension. The study does not establish a direct cause-and-effect relationship between insomnia and dementia for individuals, says Yuqian Lin, a data analyst at Massachusetts General Hospital in Boston. Rather, she says, it looks at the overall extent to which insomnia may contribute to dementia across the population. Lin and her colleagues analyzed data from the National Health and Aging Trends Study, or NHATS, a long-running survey of 5,900 U.S. adults ages 65 and older. Participants reported whether they had difficulty falling asleep, staying asleep or both. Dementia was identified using standard research tools that rely on cognitive testing and reports from family members or caregivers. To estimate the impact of insomnia on the population, Lin and her team calculated the proportion of dementia cases that could theoretically be prevented if insomnia-related sleep disturbances were eliminated. The calculation combined the prevalence of insomnia and dementia in the NHATS population with relative risk estimates drawn from recent large meta-analyses linking insomnia to dementia later in life. © Society for Science & the Public 2000–2026.

Keyword: Sleep; Alzheimers
Link ID: 30105 - Posted: 02.04.2026

Andee Tagle He couldn't stop fixating on it. "I started getting into the frame of mind most people get sucked into. I worried, 'What's going on? Is there something wrong with me?'" he says. That fear of not being able to sleep is a phenomenon called "sleep anxiety," says Orma, who went on to become a specialist in insomnia treatment. Left untreated, that anxiety can prevent people from actually falling asleep. "The more you focus on it, the less chance you'll sleep, which then makes you more anxious. That's the cycle that spins," he says. One of the most powerful ways to overcome sleep anxiety is cognitive behavioral therapy for insomnia (CBT-I). It's well studied, doesn't rely on sleep drugs and has been shown to be effective for clinical insomnia. Orma used this treatment to heal his sleep, and it's now the main focus of his therapy practice. Typically, a CBT-I program lasts about six to eight weeks, and each week, you and a provider work on a strategy to reset sleep behaviors and restructure your thinking around rest. But you don't have to be in an official program to benefit from CBT-I. Whether you're dealing with some sleep stress or just the occasional off-night, these CBT-I practices can help. Wake up at the same time every day Having a consistent wake-up time helps your body know when it's time to get sleepy, says Aric Prather, a sleep scientist and the author of The Sleep Prescription: 7 Days to Unlocking Your Best Rest. The sleepy cues are managed by your circadian rhythm, or your body's internal clock. A set wake-up time keeps your internal clock ticking on time. © 2026 npr

Keyword: Sleep
Link ID: 30082 - Posted: 01.17.2026

By Jack Tamisiea You don’t need a brain to benefit from a good night of sleep. Despite lacking a central nervous system, jellyfish and sea anemones have sleep patterns remarkably similar to those of humans, researchers report today in Nature Communications. The work supports the idea that sleep arose early in animal evolution to help the first neurons repair themselves, says Cheryl Van Buskirk, a geneticist at California State University, Northridge who was not involved with the research. “This study is another nail in the coffin of the idea that sleep evolved to manage complex, powerful brains.” In nature, sleep is risky: Snoozing organisms are vulnerable to predators. Yet species across the animal kingdom spend multiple hours a day dozing off—even ancient groups including cnidarians, which include jellyfish, anemones, and corals—all among the earliest animals to develop neurons. Researchers have recorded sleeplike behavior in upside-down jellyfish in the genus Cassiopea and small freshwater relatives of jellyfish known as hydra. To learn more about why these simple animals sleep, researchers in Israel studied the starlet sea anemone (Nematostella vectensis) and an upside-down jellyfish (Cassiopea andromeda). Both species reside along the bottoms of shallow lagoons with their tentacles hovering in the water to snag prey. In the lab, the team housed several jellyfish in an aquarium and exposed them to 12 hours of light and 12 hours of darkness over multiple days. They used infrared cameras to monitor how often the critters pulsed their umbrellalike bells, a sign of wakefulness. © 2026 American Association for the Advancement of Science.

Keyword: Sleep; Evolution
Link ID: 30070 - Posted: 01.07.2026

By Lauren Schenkman In pursuit of the brain’s secrets, neuroscientist Paul-Antoine Libourel has traveled to the ends of the earth. But during the COVID-19 lockdown in 2020, he worked closer to home—in his own darkened garage in Lyon, filming a sleeping chameleon. Libourel, a researcher at the Center for Functional and Evolutionary Ecology in Montpelier, had heard that chameleons lose their ability to camouflage during sleep. But as the hours passed in his garage, he observed something extraordinary: The chameleon’s skin fluctuated from bright to dark to bright again every few minutes. This strobing skin display, Libourel and his colleagues have since discovered, reflects an inner rhythm. The chameleon’s brain activity alternates between waves of higher and lower amplitude, synchronized with increased and decreased eye movements, plus changes in the animal’s heart rate and breathing rate. Six other species of lizard, including bearded dragons—along with rats, mice, pigeons and humans—show the same “infraslow fluctuations” in EEG activity during non-REM sleep, according to a study Libourel’s team published today in Nature Neuroscience. Because reptiles and mammals diverged about 320 million years ago, the findings mean these cycles “are a central thing, maybe a core building block of sleep,” says study investigator Antoine Bergel, research director at the Centre National de la Recherche Scientifique. They also raise the question of why these rhythms are so conserved, Bergel and Libourel say, and hint at how sleep has evolved. The sleep field, which tends to focus on mice and humans, needed this type of comparative study, says Philippe Mourrain, associate professor of psychiatry and behavioral sciences at Stanford University, who studies sleep in zebrafish but was not involved in the new work. “It’s a tour de force to do science on nonconventional species.” © 2025 Simons Foundation

Keyword: Sleep
Link ID: 30062 - Posted: 12.31.2025

By Jan Hoffman To treat their pain, anxiety and sleep problems, millions of Americans turn to cannabis, which is now legal in 40 states for medical use. But a new review of 15 years of research concludes that the evidence of its benefits is often weak or inconclusive, and that nearly 30 percent of medical cannabis patients meet criteria for cannabis use disorder. “The evidence does not support the use of cannabis or cannabinoids at this point for most of the indications that folks are using it for,” said Dr. Michael Hsu, an addiction psychiatrist and clinical instructor at the University of California, Los Angeles, and the lead author of the review, which was published last month in the medical journal JAMA. (Cannabis refers to the entire plant; cannabinoids are its many compounds.) The analysis arrives amid a surging acceptance and normalization of cannabis products, a $32 billion industry. For the review, addiction experts at academic medical centers across the country studied more than 2,500 clinical trials, guidelines and surveys conducted mostly in the United States and Canada. They found a wide gulf between the health purposes for which the public seeks out cannabis and what gold-standard science shows about its effectiveness. The researchers distinguished between medical cannabis, sold at dispensaries, and pharmaceutical-grade cannabinoids — the handful of medicines approved by the Food and Drug Administration with formulations containing either low-grade THC, a psychoactive compound, or CBD, a nonintoxicating compound. Those medicines, including Marinol, Syndros and Cesamet, are available by prescription at conventional pharmacies and have had good results in easing chemotherapy-related nausea, stimulating the appetite of patients with debilitating illnesses like H.I.V./AIDS, and easing some pediatric seizure disorders. © 2025 The New York Times Company

Keyword: Drug Abuse; Pain & Touch
Link ID: 30045 - Posted: 12.13.2025

By Emily Cataneo Imagine having a dream that you are trapped in a room with five rabid tigers. No matter how hard you try, you can’t escape. The tigers are screeching and thrashing and you’re terrified. Now imagine repurposing this dream. Imagine it from the perspective of one of the tigers. Now, you realize that the animals are panicking only because they want to escape. You open the door, inviting them to freedom, and they lie down, docile. Suddenly, the dream has become peaceful and calm, not terrifying and chaotic. BOOK REVIEW — “Nightmare Obscura: A Dream Engineer’s Guide Through the Sleeping Mind,” by Michelle Carr (Henry Holt and Co., 272 pages). Freud might have had a field day with this dream, but thanks in part to psychoanalysis’ fall from grace over the last century, medical professionals no longer put much stock in our minds’ nighttime wanderings as markers of either physical or mental health. That’s what dream scientist Michelle Carr aims to change. Carr, who serves as director of the Dream Engineering Laboratory in the Center for Advanced Research in Sleep Medicine in Montreal, has spent two decades gathering data on people like the tiger dreamer: She’s spent countless nights in labs watching people sleep, probing why we dream, why we have bad dreams, and how studying and even manipulating dreams can improve mental and physical health. In “Nightmare Obscura: A Dream Engineer’s Guide Through the Sleeping Mind,” Carr makes a passionate case for why the answers to these questions matter, deeply, especially for sufferers of trauma and suicidal ideation. What emerges is a passionate case for why dreams and nightmares are not just “random electrophysiological noise produced by the brain during sleep,” as scientists believed for many years, but rather a nightly exercise in “revising the shape of our autobiography.” In other words, Carr argues, our dreamscapes are essential pillars of who we are.

Keyword: Sleep
Link ID: 30040 - Posted: 12.06.2025

Sara Protasi I love napping. I love napping in the summer, when rhythms are more relaxed and the guilt of taking a break less intense (if only slightly). But I also love napping in the winter, when it’s cold outside, and burying myself under a warm blanket makes me feel like I’m hibernating. No matter the season, when lying in bed, I luxuriate in the feeling of my body relaxing, waiting for the moment when odd images start forming somewhere in that space between my closed lids and my corneas – or, most likely, somewhere in my mind. I love drifting into unconsciousness without worrying about the next item on my to-do list. I’m not a sound sleeper or someone who falls asleep easily at night, but napping comes easily and sweetly. I treasure the days in which I can nap. And I treasure even more the nights in which I sleep long and well. Yet our culture prizes efficiency and productivity, often seeing sleep as a waste of time. ‘Tech bros’ boast about regularly working more than 70 hours a week, and aim to reduce their sleep time as much as possible. Elon Musk suggested even more intense work schedules for government workers during his time at the US Department of Government Efficiency (DOGE). His approach resonated with many adherents of the Silicon Valley grind culture, which has sought to ‘hack’ sleep for a long time. As one CEO of a cost-cutting firm told the news site Business Insider this year: ‘While a 120-hour workweek isn’t a practical or sustainable solution for most, the principle behind it resonates. Companies that prioritise efficiency, automation and proactive cost management will always outperform those weighed down by bureaucracy.’ This approach is mirrored in a seemingly contradictory trend in the tech industry: a number of years ago, tech companies such as Apple and Google started introducing nap time for their workers. However, this approach was less a gesture of care than a response to exhaustion and sleep deprivation induced by their grind mentality, providing ‘recharging time’ to boost creativity and sustain the long hours required for work. Workers in less high-paying careers, who need to work multiple jobs, rarely have time to nap, and often have to resort to drugs such as modafinil, a stimulant prescribed for narcolepsy and used, often illegally, by students cramming for exams. This substance has gained the attention of the military. The US defence research agency DARPA has funded pharmaceutical companies and researchers to reduce sleep deprivation, with the long-term ambitious goal of operating without any need for sleep in the field. And the US isn’t alone: militaries worldwide are exploring how to keep their soldiers awake and functioning when sleep is in short supply. © Aeon Media Group Ltd. 2012-2025.

Keyword: Sleep
Link ID: 30039 - Posted: 12.06.2025

By Jennie Erin Smith More than a decade ago, when researchers discovered a ghostly network of microscopic channels that push fluid through the brain, they began to wonder whether the brain’s plumbing, as they sometimes refer to it, might be implicated in neurodegenerative diseases such as Alzheimer’s. Now, they are testing a host of ways to improve it. At the Society for Neuroscience (SfN) meeting last month in San Diego, several teams reported early promise for drugs and other measures that improve fluid flow, showing they can remove toxic proteins from animal or human brains and reverse symptoms in mouse models of neurological disease. Plastic surgeons in China, meanwhile, have gone further, conducting experimental surgeries that they say help flush out disease-related proteins in people with Alzheimer’s. The trials have generated excitement but also concern over their bold claims of success. A group of academic surgeons in the United States is planning what they say will be a more rigorous clinical trial, also in Alzheimer’s patients, that could begin recruiting as early as next year. The surgical approach “sounds unbelievable,” says neuroscientist Jeffrey Iliff of the University of Washington. “But I’m not going to say I know it can’t work. Remember, 13 years ago we didn’t know any of this existed.” In 2012, Iliff, with pioneering Danish neuroscientist Maiken Nedergaard and colleagues, described a previously unrecognized set of fluid channels in the brain that they dubbed the glymphatic system. Three years later, other groups revealed a second, related system of fluid transport: a matrix of tiny lymphatic vessels in the meninges, or membranes covering the brain. © 2025 American Association for the Advancement of Science.

Keyword: Alzheimers
Link ID: 30037 - Posted: 12.03.2025

By Caroline Hopkins Legaspi In a study published Monday in JAMA Neurology, researchers linked obstructive sleep apnea, a condition that causes temporary pauses in breathing during sleep, with Parkinson’s disease. Parkinson’s disease is a progressive nervous system disorder that causes tremors, stiffness, and difficulty speaking, moving and swallowing. It is the second-most common neurodegenerative disease in the United States, after Alzheimer’s disease, with 90,000 people diagnosed each year. There is no cure for Parkinson’s disease, said Dr. Lee Neilson, a neurologist at Oregon Health & Science University who led the study. But the researchers did find that treating sleep apnea with a continuous positive airway pressure (or CPAP) machine was associated with a reduced likelihood of developing Parkinson’s. So identifying those at highest risk for the neurological condition — and intervening early, Dr. Neilson said, “might make the biggest impact.” The researchers analyzed medical records from more than 11 million U.S. veterans treated through the Department of Veterans Affairs between 1999 and 2022. The group was predominantly male with an average age of 60, representing those at highest risk for sleep apnea, experts said. The researchers found that about 14 percent of the participants had been diagnosed with sleep apnea between 1999 and 2022, according to their medical records. When the researchers looked at their health six years after those diagnoses, they found that the veterans with sleep apnea were nearly twice as likely to have developed Parkinson’s disease compared with those who had not been diagnosed with sleep apnea. This held even after controlling for other factors that could influence the development of sleep apnea or Parkinson’s disease, including high body mass index and conditions like diabetes, high blood pressure, traumatic brain injuries and depression. © 2025 The New York Times Company

Keyword: Sleep; Parkinsons
Link ID: 30029 - Posted: 11.26.2025

Ian Sample Science editor It’s never a great look. The morning meeting is in full swing but thanks to a late night out your brain switches off at the precise moment a question comes your way. Such momentary lapses in attention are a common problem for the sleep deprived, but what happens in the brain in these spells of mental shutdown has proved hard to pin down. Now scientists have shed light on the process and found there is more to zoning out than meets the eye. The brief loss of focus coincides with a wave of fluid flowing out of the brain, which returns once attention recovers. “The moment somebody’s attention fails is the moment this wave of fluid starts to pulse,” said Dr Laura Lewis, a senior author on the study at MIT in Boston. “It’s not just that your neurons aren’t paying attention to the world, there’s this big change in fluid in the brain at the same time.” Lewis and her colleague Dr Zinong Yang investigated the sleep-deprived brain to understand the kinds of attention failures that lead drowsy drivers to crash and tired animals to become a predator’s lunch. In the study, 26 volunteers took turns to wear an EEG cap while lying in an fMRI scanner. This enabled the scientists to monitor the brain’s electrical activity and physiological changes during tests in which people had to respond as quickly as possible to hearing a tone or seeing crosshairs on a screen turn into a square. Each volunteer was scanned after a restful night’s sleep at home and after a night of total sleep deprivation supervised by scientists at the laboratory. Unsurprisingly, people performed far worse when sleep deprived, responding more slowly or not at all. © 2025 Guardian News & Media Limited

Keyword: Sleep; Attention
Link ID: 29993 - Posted: 11.01.2025

Imma Perfetto Anyone who has ever struggled through the day following a poor night’s sleep has had to wrench their attention back to the task at hand after their mind drifted off unexpectedly. Now, researchers have pinpointed exactly what causes these momentary failures of attention. The new study in Nature Neuroscience found that the brains of sleep-deprived people initiate waves of cerebrospinal fluid (CSF), the liquid which cushions the brain, which dramatically impaired attention. This process usually happens during sleep. The rhythmic flow of CSF into and out of the brain carries away protein waste which has built up over the course of the day. When this is maintenance interrupted due to lack of sleep, it seems the brain attempts to play catch up during its waking hours. “If you don’t sleep, the CSF waves start to intrude into wakefulness where normally you wouldn’t see them,” says study senior author Laura Lewis of Massachusetts Institute of Technology’s (MIT) Institute for Medical Engineering and Science. “However, they come with an attentional trade off, where attention fails during the moments that you have this wave of fluid flow. “The results are suggesting that at the moment that attention fails, this fluid is actually being expelled outward away from the brain. And when attention recovers, it’s drawn back in.” © Copyright CSIRO

Keyword: Sleep; Attention
Link ID: 29992 - Posted: 11.01.2025

Joel Snape All vertebrates yawn, or indulge in a behaviour that’s at least recognisable as yawn-adjacent. Sociable baboons yawn, but so do semi-solitary orangutans. Parakeets, penguins and crocodiles yawn – and so, probably, did the first ever jawed fish. Until relatively recently, the purpose of yawning wasn’t clear, and it’s still contested by researchers and scientists. But this commonality provides a clue to what it’s really all about – and it’s probably not what you’re expecting. “When I poll audiences and ask: ‘Why do you think we yawn?’, most people suggest that it has to do with breathing or respiration and might somehow increase oxygen in the blood,” says Andrew Gallup, a professor in behavioural biology at Johns Hopkins University. “And that’s intuitive because most yawns do have this clear respiratory component, this deep inhalation of air. However, what most people don’t realise is that that hypothesis has been explicitly tested and shown to be false.” To test the idea that we yawn to bring in more oxygen or expel excess carbon dioxide, studies published in the 1980s manipulated the levels of both gases in air inhaled by volunteers – and they found that while changes did significantly affect other respiratory processes, they didn’t influence the regularity of yawns. There also doesn’t seem to be any systematically measurable difference in the yawning behaviour of people suffering from illnesses associated with breathing and lung function – which is what you would expect if yawns were respiration-related. This, more or less, was where Gallup came to the subject. “When I was pursuing my honours thesis, my adviser at the time said, well, why not study yawning, because nobody knows why we do it?” he says. “That was intriguing – we knew it had to serve some underlying physiological function. So I started to examine the motor action pattern it involves – this extended gaping of the jaw that’s accompanied by this deep inhalation of air, followed by a rapid closure of the jaw and a quicker exhalation. And it occurred to me that this likely has important circulatory consequences that are localised to the skull.” © 2025 Guardian News & Media Limited

Keyword: Emotions; Sleep
Link ID: 29990 - Posted: 10.29.2025

Rachel Fieldhouse Slow, sleep-like brain waves persist in part of the brain that has been surgically disconnected from the rest of the organ even though the person is awake. The findings1, published in PLoS Biology, add to researchers’ understanding of what conscious and unconscious brain states look like. Children with severe epilepsy who do not respond to medication can undergo a surgical procedure called a hemispherotomy. During surgery, clinicians disconnect the part of the brain in which seizures originate from the rest of the brain, stopping them from spreading. The disconnected tissue is left in the skull and has an intact blood supply. The team wanted to find out whether the disconnected part has some form of awareness — or was capable of exhibiting consciousness, says co-author Marcello Massimini, a neurophysiology researcher at the University of Milan in Italy. “The question arises because we have no access” to the disconnected region, he says, adding that it was unclear what happens once part of the brain is isolated. Studies investigating consciousness are difficult because there is no consensus on what conscious and unconscious states in the brain look like, says Ariel Zeleznikow-Johnston, a neuroscientist at Monash University in Melbourne, Australia. “There’s no generally accepted definitive signatures of consciousness in terms of electrical readings or brain activity,” he adds. Even defining unconsciousness is challenging, because activities associated with consciousness, such as remembering dreams, can occur during states associated with unconsciousness, such as sleep or anaesthesia, Massimini says. © 2025 Springer Nature Limited

Keyword: Sleep
Link ID: 29980 - Posted: 10.22.2025

By Yasemin Saplakoglu The pillow is cold against your cheek. Your upstairs neighbor creaks across the ceiling. You close your eyes; shadows and light dance across your vision. A cat sniffs at a piece of cheese. Dots fall into a lake. All this feels very normal and fine, even though you don’t own a cat and you’re nowhere near a lake. You’ve started your journey into sleep, the cryptic state that you and most other animals need in some form to survive. Sleep refreshes the brain and body in ways we don’t fully understand: repairing tissues, clearing out toxins and solidifying memories. But as anyone who has experienced insomnia can attest, entering that state isn’t physiologically or psychologically simple. To fall asleep, “everything has to change,” said Adam Horowitz (opens a new tab), a research affiliate in sleep science at the Massachusetts Institute of Technology. The flow of blood to the brain slows down, and the circulation of cerebrospinal fluid speeds up. Neurons release neurotransmitters that shift the brain’s chemistry, and they start to behave differently, firing more in sync with one another. Mental images float in and out. Thoughts begin to warp. “Our brains can really rapidly transform us from being aware of our environments to being unconscious, or even experiencing things that aren’t there,” said Laura Lewis (opens a new tab), a sleep researcher at MIT. “This raises deeply fascinating questions about our human experience.” It’s still largely mysterious how the brain manages to move between these states safely and efficiently. But studies targeting transitions both into and out of sleep are starting to unravel the neurobiological underpinnings of these in-between states, yielding an understanding that could explain how sleep disorders, such as insomnia or sleep paralysis, can result when things go awry. Sleep has been traditionally thought of as an all-or-nothing phenomenon, Lewis said. You’re either awake or asleep. But the new findings are showing that it’s “much more of a spectrum than it is a category.” © 2025 Simons Foundation

Keyword: Sleep
Link ID: 29974 - Posted: 10.18.2025

Vladyslav Vyazovskiy After decades of research, there is still no clearly articulated scientific consensus on what sleep is or why it exists. Yet whenever sleep comes up as a topic of discussion, it is quickly reduced to its necessity and importance. Popular media remind us of what can, and will, go wrong if we do not sleep enough, and serve up some handy tips on how to overcome insomnia. Discussed exclusively in utilitarian terms, we are force-fed the idea that sleep exists solely for our immediate benefit. Is this really all we ever want to know about a third of our existence? Sleep is perhaps the biggest blind spot, or the longest blind stretch, if you will, of our life. Naturally, the health and societal implications of sleep are huge: from technogenic disasters caused by tiredness, to sleep deprivation as a form of torture or weapon of war, and to sleep disorders, some of which inflict so much suffering that they compete with chronic pain. However, in my opinion, to say sleep is important is to miss the point entirely. Sleep is the single most bizarre experience that happens to all of us, against our will, every day. The disconnect between old questions about sleep that have remained open for centuries and new, increasingly sophisticated technologies applied to solve them is ever growing. The predominant view is that sleep provides some sort of restoration for the brain or the body: what goes awry – out of balance – in waking is almost magically recalibrated by sleep. At the centre of this narrative is the individual-who-sleeps, a lone castaway, locked in a permanent, inexorable cycle of sleeping and waking, without hope of breaking free (except in death). From the moment of opening one’s eyes, the clock starts ticking, and there is a price to pay for every minute of wakeful time, measured precisely in proportion to the transgression of staying awake. Like a snake eating its own tail, waking and sleep consume each other in an endless cycle, without beginning or end. There is no mercy, and lack of sleep can be paid back only by sleep. The image of burning a candle at both ends endures. Despite vast technological advances in recent years, exponential growth in our understanding of nature and the cosmos, and major breakthroughs in biology and medicine, there is still no unified theory of sleep. I find myself pondering whether it is time to step back and seek a different angle. Medieval manuscript illustration depicting people sleeping in three beds, with two standing figures in dialogue beside them, and an ornate floral border. © Aeon Media Group Ltd. 2012-2025.

Keyword: Sleep
Link ID: 29971 - Posted: 10.15.2025