Chapter 10. Biological Rhythms and Sleep
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By Virat Markandeya It’s evening at the northern tip of the Red Sea, in the Gulf of Aqaba, and Tom Shlesinger readies to take a dive. During the day, the seafloor is full of life and color; at night it looks much more alien. Shlesinger is waiting for a phenomenon that occurs once a year for a plethora of coral species, often several nights after the full moon. Guided by a flashlight, he spots it: coral releasing a colorful bundle of eggs and sperm, tightly packed together. “You’re looking at it and it starts to flow to the surface,” Shlesinger says. “Then you raise your head, and you turn around, and you realize: All the colonies from the same species are doing it just now.” Some coral species release bundles of a pinkish- purplish color, others release ones that are yellow, green, white or various other hues. “It’s quite a nice, aesthetic sensation,” says Shlesinger, a marine ecologist at Tel Aviv University and the Interuniversity Institute for Marine Sciences in Eilat, Israel, who has witnessed the show during many years of diving. Corals usually spawn in the evening and night within a tight time window of 10 minutes to half an hour. “The timing is so precise, you can set your clock by the time it happens,” Shlesinger says. Moon-controlled rhythms in marine critters have been observed for centuries. There is calculated guesswork, for example, that in 1492 Christopher Columbus encountered a kind of glowing marine worm engaged in a lunar-timed mating dance, like the “flame of a small candle alternately raised and lowered.” Diverse animals such as sea mussels, corals, polychaete worms and certain fishes are thought to synchronize their reproductive behavior by the moon. The crucial reason is that such animals — for example, over a hundred coral species at the Great Barrier Reef — release their eggs before fertilization takes place, and synchronization maximizes the probability of an encounter between eggs and sperm. © 2023 Annual Reviews
Keyword: Biological Rhythms; Sexual Behavior
Link ID: 28681 - Posted: 02.25.2023
Kevin Rawlinson It is no mystery that a good night’s sleep and a lie-in can improve your day. But researchers are suggesting that, far from just being enjoyable, quality sleep may even add years to people’s lives. Men who regularly sleep well could live almost five years longer than those who do not, while women could benefit by two years, research suggests. And they could also enjoy better health during their lives. Researchers found that young people who had better sleep habits were less likely to die early. But the researchers said their findings indicated quantity of sleep was not in itself enough to achieve the possible health benefits – quality of sleep is also important. Good sleep was based on five different factors: ideal sleep duration of seven to eight hours a night; difficulty falling asleep no more than two times a week; trouble staying asleep no more than two times a week; not using any sleep medication; and feeling well rested after waking up at least five days a week. The findings suggested that about 8% of deaths from any cause could be attributed to poor sleep patterns. Dr Frank Qian, an internal medicine resident physician at Beth Israel Deaconess Medical Center in Boston, America, said: “We saw a clear dose-response relationship, so the more beneficial factors someone has in terms of having higher quality of sleep, they also have a stepwise lowering of all cause and cardiovascular mortality.” © 2023 Guardian News & Media Limited
Keyword: Sleep
Link ID: 28679 - Posted: 02.25.2023
By Dani Blum There are a few tried and true pieces of advice that sleep doctors always give for battling insomnia: Watch those alcoholic drinks at dinner, cut the afternoon coffee, stop scrolling before bed. And please, they beg: Keep your sleep schedule consistent. Flip-flopping between wake-up times — jolting awake at 7:30 on a Friday morning and then dozing until the afternoon on Saturday — wreaks havoc on our internal body clocks. Sleep experts refer to this as “social jet lag,” said Dr. Sabra Abbott, a sleep medicine specialist at the Northwestern Feinberg School of Medicine. Similar to changing time zones, heading to bed at vastly different times from night to night may throw off your circadian rhythm. And still, as anyone who’s worked a night shift, taken care of a toddler or fumbled back home after a party might tell you: Going to bed and waking up at the same times is easier said than done. “It’s a luxury, right?” said Kelsie Full, a behavioral epidemiologist and an assistant professor at Vanderbilt University Medical Center. Dr. Full is the lead author of a new study that tied irregular sleep to an early marker of cardiovascular disease. Researchers examined a week’s worth of sleep data from 2,000 adults over 45 and found that those who slept varying amounts each night and went to bed at different times were more likely to have hardened arteries than those with more regular sleep patterns. People whose overall sleep amounts varied by two or more hours from night to night throughout the week — getting five hours of sleep on Tuesday, say, and then eight hours on Wednesday — were particularly likely to have high levels of calcified fatty plaque built up in their arteries, compared with those who slept the same number of hours each night. The study could not confirm that inconsistent sleep patterns definitively caused the heart issues, Dr. Full said. And the findings don’t necessarily mean that the occasional late night or very early morning should be off the table. © 2023 The New York Times Company
Keyword: Sleep
Link ID: 28676 - Posted: 02.22.2023
Jane Clinton For those of us who struggle to leave our beds in the winter, taunts of “lazy” could well be misplaced. New research suggests that while humans do not hibernate, we may need more sleep during the colder months. Analysis of people undergoing sleep studies found that people get more REM (rapid eye movement) sleep in the winter. While total sleep time appeared to be about an hour longer in the winter than the summer, this result was not considered statistically significant. However, REM sleep – known to be directly linked to the circadian clock, which is affected by changing light – was 30 minutes longer in the winter than in summer. The research suggests that even in an urban population experiencing disrupted sleep, humans experience longer REM sleep in winter than summer and less deep sleep in autumn. Researchers say if the study’s findings can be replicated in people with healthy sleep, this would provide the first evidence for a need to adjust sleep habits to season – perhaps by going to sleep earlier in the darker and colder months. Dr Dieter Kunz, corresponding author of the study, based at the Clinic for Sleep & Chronomedicine at the St Hedwig hospital, Germany, said: “Seasonality is ubiquitous in any living being on this planet. “Even though we still perform unchanged over the winter, human physiology is down-regulated, with a sensation of ‘running-on-empty’ in February or March. “In general, societies need to adjust sleep habits including length and timing to season, or adjust school and working schedules to seasonal sleep needs.”
Keyword: Biological Rhythms; Sleep
Link ID: 28672 - Posted: 02.18.2023
By Kristen French George Church looks like he needs a nap. I’m talking to him on Zoom, and his eyelids have grown heavy, inclining toward slumber. Or maybe my mind is playing tricks on me. He assures me he is wide awake. But sleeping and waking life are often blurred for Church. One of the world’s most imaginative scientists, Church is a narcoleptic. A rare disorder, narcolepsy causes sudden attacks of sleep, and Church has fallen asleep in some unfortunate circumstances—at The World Economic Forum, just a few feet away from Microsoft founder Bill Gates, for instance. He also had to give up driving due to the risk that a bout of sleepiness will strike while he is behind the wheel. But Church, a Harvard geneticist known for his pathbreaking contributions to numerous fields—from genetics to astrobiology to biomedicine—says the benefits of his condition outweigh the inconveniences. Many of his wildest and most prescient ideas come from his narcoleptic naps. “The fact is, I fall asleep several times a day, and so almost everything comes from there,” Church says. His idea for a quick and simple way to “read” DNA—which resulted in the first commercial genome sequence, of the human pathogen H. pylori—came from a narcoleptic nap. He also conceived of editing genomes with CRISPR and building new genomes with off-the-shelf molecules during narcoleptic naps. More recently, in December, a wild idea for a space probe that could reach distant stars within just 20 years, at one-fifth the speed of light, came to him after a narcoleptic nap. He proposed that these lightning-speed interstellar missions could be launched by microbes and powered by laser sails. The ideas that come to him are often the result of collisions of unexpected images in his head. “I try to turn science fiction into science fact,” Church tells me. © 2023 NautilusNext Inc.,
Keyword: Sleep; Attention
Link ID: 28648 - Posted: 02.01.2023
By Diana Kwon Alan Alda was running for his life. The actor, best known for his role on the television series M*A*S*H, wasn’t on a set. This threat was real—or at least it felt that way. So when he saw a bag of potatoes in front of him, he grabbed it and threw it at his attacker. Suddenly, the scene shifted. He was in his bedroom, having lurched out of sleep, and the sack of potatoes was a pillow he’d just chucked at his wife. Acting out dreams marks a disorder that occurs during the rapid eye movement (REM) phase of sleep. Called RBD, for REM sleep behavior disorder, it affects an estimated 0.5 to 1.25 percent of the general population and is more commonly reported in older adults, particularly men. Apart from being hazardous to dreamers and their partners, RBD may foreshadow neurodegenerative disease, primarily synucleinopathies—conditions in which the protein α-synuclein (or alpha-synuclein) forms toxic clumps in the brain. Not all nocturnal behaviors are RBD. Sleepwalking and sleep talking, which occur more often during childhood and adolescence, take place during non-REM sleep. This difference is clearly distinguishable in a sleep laboratory, where clinicians can monitor stages of sleep to see when a person moves. Nor is RBD always associated with a synucleinopathy: it can also be triggered by certain drugs such as antidepressants or caused by other underlying conditions such as narcolepsy or a brain stem tumor. When RBD occurs in the absence of these alternative explanations, the chance of future disease is high. Some epidemiological studies suggest that enacted dreaming predicts a more than 80 percent chance of developing a neurodegenerative disease within the patient’s lifetime. It may also be the first sign of neurodegenerative disease, which on average shows up within 10 to 15 years after onset of the dream disorder. One of the most common RBD-linked ailments is Parkinson’s disease, characterized mainly by progressive loss of motor control. Another is Lewy body dementia, in which small clusters of α-synuclein called Lewy bodies build up in the brain, disrupting movement and cognition. A third type of synucleinopathy, multiple system atrophy, interferes with both movement and involuntary functions such as digestion. RBD is one of the strongest harbingers of future synucleinopathy, more predictive than other early markers such as chronic constipation and a diminished sense of smell.
Keyword: Parkinsons; Sleep
Link ID: 28642 - Posted: 01.25.2023
Will Stone Maybe this happens to you sometimes, too: You go to bed with some morning obligation on your mind, maybe a flight to catch or an important meeting. The next morning, you wake up on your own and discover you've beat your alarm clock by just a minute or two. What's going on here? Is it pure luck? Or perhaps you possess some uncanny ability to wake up precisely on time without help? It turns out many people have come to Dr. Robert Stickgold over the years wondering about this phenomenon. "This is one of those questions in the study of sleep where everybody in the field seems to agree that's what's obviously true couldn't be," says Stickgold who's a cognitive neuroscientist at Harvard Medical School and Beth Israel Deaconess Medical Center. Stickgold even remembers bringing it up to his mentor when he was just starting out in the field — only to be greeted with a dubious look and a far from satisfactory explanation. "I can assure you that all of us sleep researchers say 'balderdash, that's impossible,' " he says. And yet Stickgold still believes there is something to it. "This kind of precision waking is reported by hundreds and thousands of people,'" he says, including himself. "I can wake up at 7:59 and turn off the alarm clock before my wife wakes up." At least, sometimes. Of course, it's well known that humans have an elegant and intricate system of internal processes that help our bodies keep time. Somewhat shaped by our exposure to sunlight, caffeine, meals, exercise and other factors, these processes regulate our circadian rhythms throughout the roughly 24-hour cycle of day and night, and this affects when we go to bed and wake up. © 2022 npr
Keyword: Biological Rhythms
Link ID: 28614 - Posted: 12.28.2022
By Susan Milius As tiny glass frogs fall asleep for the day, they take almost 90 percent of their red blood cells out of circulation. The colorful cells cram into hideaway pockets inside the frog liver, which disguises the cells behind a mirrorlike surface, a new study finds. Biologists have known that glass frogs have translucent skin, but temporarily hiding bold red blood brings a new twist to vertebrate camouflage (SN: 6/23/17). “The heart stopped pumping red, which is the normal color of blood, and only pumped a bluish liquid,” says evolutionary biochemist Carlos Taboada of Duke University, one of the discoverers of the hidden blood. What may be even more amazing to humans — prone to circulatory sludge and clogs — is that the frogs hold almost all their red blood cells packed together for hours with no blood clots, says co-discoverer Jesse Delia, now at the American Museum of Natural History in New York City. Wake the frog up, and cells just unpack themselves and get circulating again. Hiding those red blood cells can double or triple the transparency of glass frogs, Taboada, Delia and colleagues report in the Dec. 23 Science. That greenish transparency can matter a lot for the snack-sized frogs, which spend the day hiding like little shadows on the undersides of the leaves high in the forest canopy. A photo on the left showing a sleeping female glass frog with most of her red blood cells tucked into her liver. While the photo on the right shows the frog while awake with blood circulating and less transparent. What got Delia wondering about transparency was a photo emergency. He had studied glass frog behavior, but had never even seen them asleep. “They go to bed, I go to bed — that was my life for years,” he says. When he needed some charismatic portraits, however, he put some frogs in lab dishes and at last saw how the animals sleep the day away. © Society for Science & the Public 2000–2022.
Keyword: Sleep; Aggression
Link ID: 28610 - Posted: 12.24.2022
Ari Daniel Fred Crittenden, 73, lost his sight to retinitis pigmentosa when he was 35 years old. Today he has no visual perception of light. "It's total darkness," he says. Still, he has cells in his eyes that use light to keep his internal clock ticking along nicely. Marta Iwanek for NPR Every baseball season, 73-year-old Fred Crittenden plants himself in front of his television in his small one-bedroom apartment an hour north of Toronto. "Oh, I love my sports — I love my Blue Jays," says Crittenden. "They need me to coach 'em — they'd be winning, I'll tell ya." He listens to the games in his apartment. He doesn't watch them, because he can't see. "I went blind," Crittenden recalls, when "I was 35 years young." Crittenden has retinitis pigmentosa, an inherited condition that led to the deterioration of his retinas. He lost all his rods (the cells that help us see in dim light) and all his cones (the cells that let us see color in brighter light). Within a single year, in 1985, Crittenden says he went from perfect vision to total blindness. Certain cells within Crittenden's retinas that contain melanopsin help his brain to detect light, even if what he sees is darkness. Among other things, these light-detecting cells help his body regulate his sleep cycles. Marta Iwanek for NPR "The last thing I saw clearly," he says, thinking back, "it was my daughter, Sarah. She was 5 years old then. I used to go in at night and just look at her when she was in the crib. And I could just barely still make her out — her little eyes or her nose or her lips or her chin, that kind of stuff. Even to this day it's hard." © 2022 npr
Keyword: Biological Rhythms; Vision
Link ID: 28598 - Posted: 12.17.2022
By Dino Grandoni The shrew scampered across the sand, zipping its tiny, velvety body right, left, right, left. In just a few seconds it found the prize concealed in the sandbox: a tasty mixture of earthworms, mealworms and other meat. To quickly solve the puzzle in Dina Dechmann’s lab, the shrew didn’t just need to learn where its meal was hidden. Something else astounding happened in its head. It had to regrow its own brain. “It’s a crazy animal,” said Dechmann, a behavioral ecologist at the Max Planck Institute of Animal Behavior in Germany. “We can learn a lot from the shrews.” To prepare for the depths of winter when food is scarce, many animals slow down, sleep through the cold or migrate to warmer locales. Not the common shrew. To survive the colder months, the animal eats away at its own brain, reducing the organ by as much as a fourth, only to regrow much of brain matter in the spring. The process of shrinking and expanding the brain and other organs with seasons — dubbed Dehnel’s phenomenon — allows animals to reduce calorie-consuming tissue when temperatures drop. Researchers have discovered seasonal shrinkage in the skulls of other small, high-metabolism mammals, including weasels and, most recently, moles. The shrew’s incredible shrinking brain is more than just a biological curiosity. Understanding how these animals are able to restore their brain power may help doctors treat Alzheimer’s, multiple sclerosis and other neurodegenerative diseases in humans. “In the beginning, I couldn’t quite grasp it,” said John Dirk Nieland, an associate professor of health science and technology who is now researching drugs designed to mimic shrews’ brain-altering chemistry in humans.
Keyword: Biological Rhythms; Multiple Sclerosis
Link ID: 28580 - Posted: 12.03.2022
By Dino Grandoni The shrew scampered across the sand, zipping its tiny, velvety body right, left, right, left. In just a few seconds it found the prize concealed in the sandbox: a tasty mixture of earthworms, mealworms and other meat. To quickly solve the puzzle in Dina Dechmann’s lab, the shrew didn’t just need to learn where its meal was hidden. Something else astounding happened in its head. It had to regrow its own brain. “It’s a crazy animal,” said Dechmann, a behavioral ecologist at the Max Planck Institute of Animal Behavior in Germany. “We can learn a lot from the shrews.” To prepare for the depths of winter when food is scarce, many animals slow down, sleep through the cold or migrate to warmer locales. Not the common shrew. To survive the colder months, the animal eats away at its own brain, reducing the organ by as much as a fourth, only to regrow much of brain matter in the spring. The process of shrinking and expanding the brain and other organs with seasons — dubbed Dehnel’s phenomenon — allows animals to reduce calorie-consuming tissue when temperatures drop. Researchers have discovered seasonal shrinkage in the skulls of other small, high-metabolism mammals, including weasels and, most recently, moles. The shrew’s incredible shrinking brain is more than just a biological curiosity. Understanding how these animals are able to restore their brain power may help doctors treat Alzheimer’s, multiple sclerosis and other neurodegenerative diseases in humans. “In the beginning, I couldn’t quite grasp it,” said John Dirk Nieland, an associate professor of health science and technology who is now researching drugs designed to mimic shrews’ brain-altering chemistry in humans.
Keyword: Biological Rhythms; Multiple Sclerosis
Link ID: 28579 - Posted: 12.03.2022
Max Barnhart In 2004, when physician Dr. Wilfried Mutombo began treating patients diagnosed with sleeping sickness, the available treatments were themselves horrific and sometimes deadly. "The widely available treatment then was an arsenic-based drug, and it was toxic. It could kill up to 5% of patients," he says. "I lost two of my patients. They were young, and that was a very bad experience. Sleeping sickness is an often fatal disease caused by a parasite where infected people become prone to sleeping all day and night as the disease progresses. It's endemic to 36 countries in Africa, but most cases occur in the Democratic Republic of the Congo. Now, a new oral drug has emerged that is 95% effective at curing sleeping sickness with just one dose. The results of clinical trials for this new drug, acoziborole, were published in The Lancet Infectious Diseases on Nov. 29. It has the potential to drastically change the way sleeping sickness is treated and help the World Health Organization (WHO) reach its goal of eliminating sleeping sickness by 2030. There are two kinds of sleeping sicknesses, both caused by Trypanosoma parasites. The most common form of the disease, and the one treated by this new drug, is caused by Trypanosoma brucei gambiense. Humans are the primary reservoir for the parasite, and it is spread to others by tsetse flies. WHO estimates there were roughly 300,000 cases per year in the late '90s, but the number of cases has now dropped to fewer than 1,000 cases per year. © 2022 npr
Keyword: Sleep
Link ID: 28577 - Posted: 12.03.2022
By Sandra G. Boodman The first time it happened, Erin Bousquet was a high school freshman who had been diagnosed with strep throat, a common infection in her family. After three days on an antibiotic, she wasn’t getting better, so the 14-year-old was prescribed a second drug. A day or two later, Kristen Bousquet noticed worrisome changes in her oldest child. Erin seemed “lethargic and out of it,” her mother recalled. She was irritable, her pupils looked dilated, and much of what she said made no sense. Most alarming was Erin’s newfound ability to sleep for up to 20 hours at a time. “It was quite scary,” Kristen recalled. “At first we thought she was joking.” That bizarre episode, which occurred in September 2017, has been followed by 11 more, each lasting an average of 10 days. Between episodes, Erin’s behavior is normal. For 2 1/2 years she and her parents, who live in Lincoln, Neb., consulted pediatric neurologists, a neurosurgeon, an obstetrician-gynecologist and other specialists in a largely fruitless search to identify the condition that drastically alters her personality and temporarily shuts down her life two or three times a year. The diagnosis, made in March 2020, was an enormous relief. But it has required the Bousquets to cope with continued uncertainty because so little is known about Erin’s disorder. “The hardest thing for me are the things I’ve missed out on,” said Erin, a 19-year-old sophomore at the University of Nebraska at Lincoln. They include a high school basketball championship, her 18th birthday, a family Christmas trip to Colorado and the start of her sophomore year of college. Erin slept through them all. Because her symptoms — disorientation and prolonged sleep — can be signs of a serious, even life-threatening, illness, the staff at the urgent care clinic where Erin had been treated for strep told her mother to take her to an emergency room. A test for infectious mononucleosis, a contagious virus common among adolescents and young adults that causes profound fatigue was negative and a quick neurological exam was normal. Erin was sent home.
Keyword: Sleep
Link ID: 28567 - Posted: 11.23.2022
By Christina Jewett By 2015, Philips Respironics knew its breathing devices had a problem: Foam inside the CPAP machines, which help people with sleep apnea breathe at night, was breaking off into black flecks and blowing into the mouths and noses of users. The company did nothing at the time. Years went by as complaints mounted, and the company made cursory efforts to examine the problem, according to an investigation conducted later by the Food and Drug Administration. But it was not until April of last year, the company has claimed, that it realized the flaking foam contained potentially cancer-causing particles, setting off the largest and most disruptive medical device recall in more than a decade. Nearly a year and a half after the recall that involved more than five million devices worldwide, millions of American have endured a long wait for a device. Many have been forced to find alternative methods to ensure they can breathe at night without becoming deprived of oxygen or risking a heart attack. Others have been outraged by unexpected illness, suspicious that a device meant to help them actually caused harm. The U.S. Justice Department is now negotiating the terms of a consent decree with Philips, underscoring the deep concern about what the company knew — or should have known — before millions of people received devices that many believe caused devastating illnesses. A decree would likely require the company to document the steps it would take to prevent such a failure in the future. Doug Shiffler, a retired tech executive in Utah, is one of hundreds of people suing the company. His wife began using the device in 2018, when there were no public warnings of possible problems with the machines, and developed a persistent cough. By mid-2020, Joleen Shiffler was diagnosed with an aggressive lung cancer that baffled her doctors, although a direct link between her disease and the Philips device had not been established. Ms. Shiffler, 60, died within the year. “Why weren’t we informed that there was an issue?” Mr. Shiffler asked. If they had known, “I might be standing right beside Joleen instead of mourning her loss.” © 2022 The New York Times Company
Keyword: Sleep
Link ID: 28551 - Posted: 11.16.2022
By Jackie Rocheleau For people haunted by recurring nightmares, untroubled sleep would be a dream come true. Now in a small experiment, neuroscientists have demonstrated a technique that, for some, may chase the bad dreams away. Enhancing the standard treatment for nightmare disorder with a memory-boosting technique cut down average weekly nightmares among a few dozen people from three to near zero, researchers report online October 27 in Current Biology. “The fact that they could actually make a big difference in the frequency of those nightmares is huge,” says Gina Poe, a neuroscientist at UCLA who wasn’t involved in the study. People with nightmare disorder fear the night not for the monsters under the bed, but the monsters in their dreams. Frequent, terrifying dreams disturb sleep and even affect well-being in waking life. The go-to nightmare disorder treatment is imagery rehearsal therapy, or IRT. In this treatment, patients reimagine nightmares with a positive spin, mentally rehearsing the new story line while awake. It reduces nightmares for most but fails for nearly a third of people. To boost IRT’s power, neuroscientist Sophie Schwartz of the University of Geneva and her colleagues leveraged a learning technique called targeted memory reactivation, or TMR. In this technique, a person focuses on learning something while a sound plays, and that same cue plays again during sleep. Experiencing the cue during sleep, which is important for memory storage, may reactivate and strengthen the associated memory (SN: 10/3/19). In the new study, the researchers gave 36 people with nightmare disorder training in IRT, randomly assigning half of them to rehearse their revised nightmares in silence. The other half rehearsed while a short piano chord, the TMR cue, played every 10 seconds for five minutes. © Society for Science & the Public 2000–2022.
Keyword: Sleep
Link ID: 28532 - Posted: 10.28.2022
WASHINGTON — A massive recall of millions of sleep apnea machines has stoked anger and frustration among patients, and U.S. officials are weighing unprecedented legal action to speed a replacement effort that is set to drag into next year. Sound-dampening foam in the pressurized breathing machines can break down over time, leading users to potentially inhale tiny black particles or hazardous chemicals while they sleep, manufacturer Philips warned in June 2021. Philips initially estimated it could repair or replace the units within a year. But with the recall expanding to more than 5 million devices worldwide, the Dutch company now says the effort will stretch into 2023. That's left many patients to choose between using a potentially harmful device or trying risky remedies, including removing the foam themselves, buying second-hand machines online or simply going without the therapy. The devices are called continuous positive airway pressure, or CPAP, machines. They force air through a mask to keep passageways open during sleep. Untreated sleep apnea can cause people to stop breathing hundreds of times per night, leading to dangerous drowsiness and increased heart attack risk. The problem is more common in men than women, with estimates ranging from 10% to 30% of adults affected. Most patients are better off using a recalled device because the risks of untreated sleep apnea still outweigh the potential harms of the disintegrating foam, physicians say. But doctors have been hard pressed to help patients find new machines, which generally cost between $500 and $1,000, and were already in short supply due to supply chain problems. © 2022 npr
Keyword: Sleep
Link ID: 28523 - Posted: 10.26.2022
Nicola Davis Science correspondent Playing sounds while you slumber might help to strengthen some memories while weakening others, research suggests, with experts noting the approach might one day help people living with traumatic recollections. Previous work has shown that when a sound is played as a person learns an association between two words, the memory of that word association is boosted if the same sound is played while the individual sleeps. Now researchers have found fresh evidence the approach could also be used to weaken such memories. “We can an actually induce forgetting of specific material whilst people are asleep,” said Dr Aidan Horner, co-author of the study from the University of York. Advertisement Writing in the journal Learning & Memory, Horner and colleagues report how 29 participants were shown pairs of words on a computer screen, one of which was an object word, such as bicycle, while the other was either a place word, such as office, or a person, such as David Beckham. The process was repeated for 60 different object words, and in the course of the process both possible pairings were shown, resulting in 120 associations. As the pairs flashed up, participants heard the object word being spoken out loud. The team tested the participants on a subset of the associations, presenting them with one of the words and asking them to select a paired word from a list of six options. Participants then spent a night in the team’s sleep laboratory. Once they had entered a particular sleep state – as judged by electrodes placed on their heads – they were played audio of 30 of the object words. The team tested participants on the word associations the next day. The results reveal participants’ ability to recall the first word they had learned to pair with an object word was boosted if audio of the latter was played as they slept, compared with if it was not played. However, their ability to recall the second word they learned to associate with the same object decreased relative to the audio-free scenario. © 2022 Guardian News & Media Limited
Keyword: Sleep; Learning & Memory
Link ID: 28516 - Posted: 10.19.2022
By Erin Blakemore Empathy and generosity are two traits that arguably make the world go ‘round. But a study suggests that the willingness to help collapses when people get too little — or poor — sleep. To see how sleep affects how much humans help one another, researchers conducted three experiments designed to examine the issue from the individual to the societal scale. Their results are published in PLOS Biology. In the first experiment, researchers performed functional magnetic resonance imaging scans of the brain and asked questions to 24 adults after eight hours of sleep and after a night with no sleep. When they were well rested, the participants scored well on a helping behavior test. But after sleep deprivation, 78 percent had less of a desire to help others, even when it came to friends and family. The scans showed that areas of the brain associated with social cognition — our thought processes related to other people — were less active with sleep deprivation. The second experiment tracked 136 healthy adults over four nights and asked them questions about helping the following day. The effect held for them, too, and those who reported worse sleep quality scored worse on the tests. Just one hour of extra sleep each night can lead to better eating habits To test the effects on a societal level, the researchers then looked at a database of 3 million charitable donations given between 2001 and 2016. They found that immediately following the beginning of daylight saving time — a notorious sleep disrupter — donations dropped 10 percent. The effect wasn’t found in data from Hawaii or Arizona, however; neither observe DST. Nor did the shift back to standard time have such an association with donations.
By Deborah Balthazar It’s a frustration many parents know all too well: You’ve finally lulled your crying baby to sleep, so you put them down in their crib … and the wailing begins again. Science may have a trick for you. Carrying a crying infant for about five minutes, then sitting for at least another five to eight minutes can calm and lull the baby to sleep long enough to allow a parent to put the child down without waking them, researchers report September 13 in Current Biology. Some of those same researchers previously showed that carrying a crying baby soothes the child and calms a racing heart rate (SN: 4/18/13). For the new study, the team looked at what it takes to get that crying baby to nod off and stay asleep. The researchers put heart rate monitors on 21 crying babies, ranging in age from newborns to 7 months old. The team also took videos of the infants, monitoring their moods as their mothers carried them around a room, sat holding them and laid them in a crib. That allowed the team to observe how the babies responded to different environments, whether they were crying, fussy, alert or drowsy, heartbeat by heartbeat. “We tested the physiology behind these things that tend to be kind of common knowledge, though it’s not really well understood why they work,” says Gianluca Esposito, a developmental psychologist at the University of Trento in Italy. The babies’ heart rates slowed and they stopped crying when their mothers picked them up and carried them around for five minutes. Some infants even fell asleep. But the researchers also noticed that the babies tended to respond to the movement of the parent, whether they were in deep sleep or not. For instance, a baby’s heart rate quickened if a parent turned quickly while walking or tried to put the baby down. © Society for Science & the Public 2000–2022.
Keyword: Sleep; Development of the Brain
Link ID: 28494 - Posted: 10.01.2022
By Jim Robbins Tens of thousands of bar-tailed godwits are taking advantage of favorable winds this month and next for their annual migration from the mud flats and muskeg of southern Alaska, south across the vast expanse of the Pacific Ocean, to the beaches of New Zealand and eastern Australia. They are making their journey of more than 7,000 miles by flapping night and day, without stopping to eat, drink or rest. “The more I learn, the more amazing I find them,” said Theunis Piersma, a professor of global flyway ecology at the University of Groningen in the Netherlands and an expert in the endurance physiology of migratory birds. “They are a total evolutionary success.” The godwit’s epic flight — the longest nonstop migration of a land bird in the world — lasts from eight to 10 days and nights through pounding rain, high winds and other perils. It is so extreme, and so far beyond what researchers knew about long-distance bird migration, that it has required new investigations. In a recent paper, a group of researchers said the arduous journeys challenge “underlying assumptions of bird physiology, orientation, and behavior,” and listed 11 questions posed by such migrations. Dr. Piersma called the pursuit of answers to these questions “the new ornithology.” The extraordinary nature of what bar-tailed and other migrating birds accomplish has been revealed in the last 15 years or so with improvements to tracking technology, which has given researchers the ability to follow individual birds in real time and in a detailed way along the full length of their journey. “You know where a bird is almost to the meter, you know how high it is, you know what it’s doing, you know its wing-beat frequency,” Dr. Piersma said. “It’s opened a whole new world.” The known distance record for a godwit migration is 13,000 kilometers, or nearly 8,080 miles. © 2022 The New York Times Company
Keyword: Animal Migration; Sleep
Link ID: 28484 - Posted: 09.21.2022