Chapter 14. Biological Rhythms, Sleep, and Dreaming

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Diana Kwon As Earth rotates around its axis, the organisms that inhabit its surface are exposed to daily cycles of darkness and light. In animals, light has a powerful influence on sleep, hormone release, and metabolism. Work by Takaomi Sakai, a neuroscientist at Tokyo Metropolitan University, and his team suggests that light may also be crucial for forming and maintaining long-term memories. The puzzle of how memories persist in the brain has long been of interest to Sakai. Researchers had previously demonstrated, in both rodents and flies, that the production of new proteins is necessary for maintaining long-term memories, but Sakai wondered how this process persisted over several days given cells’ molecular turnover. Maybe, he thought, an environmental stimulus, such as the light-dark cycles, periodically triggered protein production to enable memory formation and storage. Sakai and his colleagues conducted a series of experiments to see how constant darkness would affect the ability of Drosophila melanogaster to form long-term memories. Male flies exposed to light after interacting with an unreceptive female showed reduced courtship behaviors toward new female mates several days later, indicating they had remembered the initial rejection. Flies kept in constant darkness, however, continued their attempts to copulate. The team then probed the molecular mechanisms of these behaviors and discovered a pathway by which light activates cAMP response element-binding protein (CREB)—a transcription factor previously identified as important for forming long-term memories—within certain neurons found in the mushroom bodies, the memory center in fly brains. © 1986–2020 The Scientist.

Keyword: Learning & Memory; Biological Rhythms
Link ID: 27248 - Posted: 05.16.2020

By Alexandra Jacobs THE SHAPELESS UNEASE A Year of Not Sleeping By Samantha Harvey As if in unwitting aid of the malady they address, books about insomnia tend to be very dull indeed. Many are stuffed with statistics and unhelpful suggestions, like one of those oversize polyester-plumped sham pillows you see on the fancier beds — and just as likely to be flung in frustration to the floor. Samantha Harvey’s memoir of sleeplessness is more like a small and well-worn eiderdown quilt: It might not cover everything, but it both cools and warms, lofts and lulls, settling gradually on its inhabitant with an ethereal solidity. Harvey is a well-regarded novelist in the United Kingdom, and perhaps the only part of this book that feels a little lumpy and uncomfortable is her working out in its pages an O. Henry-like short story about a husband who loses his wedding ring while robbing an A.T.M. More compelled by her predicament, namely stretch after stretch of not only little sleep (or “petite nuit,” as the French more melodiously put it) but no sleep at all, I found it difficult to care about this fictional character, or figure out if his crime and punishment represented anything larger about what disenchanted millennials have taken to describing as “late-stage capitalism.” Not for nothing does the author’s own experience take place in 2016, that epoch of political shock during which a majority of her compatriots voted to leave the European Union, a.k.a. Brexit (“Why isn’t it called Ukexit,” Harvey wonders with the petty irritability of the sleep-deprived), and Donald J. Trump was elected over the pond. That these events have since been outdone by arrival of the coronavirus pandemic, with its attendant sleep disorders, only amplifies this small volume’s relevance and power. © 2020 The New York Times Company

Keyword: Sleep
Link ID: 27242 - Posted: 05.12.2020

A small study funded by the National Institutes of Health suggests that sleep problems among children who have a sibling with autism spectrum disorder (ASD) may further raise the likelihood of an ASD diagnosis, compared to at-risk children who do not have difficulty sleeping. Previous research has shown that young children who have a sibling with ASD are at a higher risk for also being diagnosed with the condition. The study appears in The American Journal of Psychiatry. If confirmed by other studies, the findings may give clinicians a tool to identify sleep problems early and provide interventions to reduce their effects on the health and development of children with autism. The findings may also provide insights into the potential role of sleep problems in the development of ASD. The study was conducted by Annette M. Estes, Ph.D., of the University of Washington Autism Center in Seattle, and colleagues in the NIH Autism Centers of Excellence Infant Brain Imaging Study Network. NIH funding was provided by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) and the National Institute of Mental Health. “The results are a promising lead,” said Alice Kau, Ph.D., of NICHD’s Intellectual and Developmental Disabilities Branch. “If confirmed by more in-depth studies, patterns of sleep disturbance in early life might be used to pinpoint increased risk for ASD among young children already at risk because they have a sibling with ASD.” The researchers analyzed data from a long-term study of children who do and do not have siblings with ASD. When the children were 6 and 12 months of age, parents were asked to respond to an infant temperament questionnaire that asks how much difficulty their child has falling asleep at bedtime and falling back to sleep after waking up during the night. At these time intervals, the children also received MRI scans to track their brain development. At 24 months, the children were assessed for ASD.

Keyword: Autism; Sleep
Link ID: 27238 - Posted: 05.08.2020

African Americans with severe sleep apnea and other adverse sleep patterns are much more likely to have high blood glucose levels — a risk factor for diabetes — than those without these patterns, according to a new study funded in part by the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health. The findings suggest that better sleep habits may lead to better blood glucose control and prove beneficial for type 2 diabetes prevention and diabetes management in African Americans, who are at higher risk for type 2 diabetes than other groups. They also point to the importance of screening for sleep apnea to help fight the potential for uncontrolled blood sugar in this high-risk group, the researchers said. Previous studies have linked disturbed sleep patterns, including sleep apnea, to increased blood glucose levels in white and Asian populations. But this new study is one of the few to use objective measurements to link these disturbed sleep patterns to increased blood glucose levels in black men and women, the researchers said. Their findings appear online on April 28 in the Journal of the American Heart Association. “The study underscores the importance of developing interventions to promote regular sleep schedules, particularly in those with diabetes,” said Yuichiro Yano, M.D., Ph.D., the lead study author and a researcher in the Department of Family Medicine and Community Health at Duke University. “It also reaffirms the need to improve the screening and diagnosis of sleep apnea, both in African Americans and other groups.”

Keyword: Sleep
Link ID: 27219 - Posted: 04.29.2020

by Peter Hess Early sleep problems predict repetitive behaviors later in childhood1. And toddlers who overreact or underreact to sensory stimuli have more repetitive behaviors and other autism traits later on2. Together, the findings from two independent studies suggest that early behavioral differences may set the stage for restricted and repetitive behaviors, a core characteristic of autism also associated with other conditions of brain development. The studies also highlight areas for early intervention, particularly if further research identifies causal links between these traits. “Addressing sleep problems might be able to improve trajectories,” says Annette Estes, director of the University of Washington Autism Center in Seattle, who led the sleep study. Autistic children are twice as likely to have trouble sleeping as typical children. Their poor sleep has been linked to severe traits including severe repetitive and restricted behaviors. The new study is unusual in that it links sleep problems with a subset of ‘higher-order’ restrictive and repetitive behaviors that include restricted interests, rituals or routines and an insistence on sameness. The study involved 38 autistic children aged 2 to 6 years and 19 children with developmental delay aged 2 to 4. Parents completed a standardized questionnaire about their children’s sleep problems at age 4 — including difficulty falling asleep, short sleep duration and parasomnias such as sleepwalking and night terrors. Clinicians assessed autism traits, including repetitive behaviors, around age 2 and at two or three later points in time. © 2020 Simons Foundation

Keyword: Autism; Sleep
Link ID: 27208 - Posted: 04.22.2020

Brandie Weikle · CBC News The strains of worry and upended routine during the COVID-19 crisis aren't exactly helping people sleep well at night. You or someone you love may be battling the novel coronavirus, or your employment may have been blown up by business shutdowns and stay-home directives. You're juggling health care with child care and cabin fever. Even if you're healthy and gainfully employed, pandemic living isn't easy. "Everyone's routine is being disrupted. It's a severely stressful event," said Dr. Atul Khullar, an Edmonton psychiatrist and senior consultant for MedSleep, a group of sleep clinics. This provokes anxiety and stress, exacerbating any pre-existing mental health and insomnia problems, or causing new ones, he said. "And for some people it can be very traumatizing. They're facing losing their livelihoods. They're faced with losing their way of life. Notwithstanding that your kids are home. It's just stressor after stressor after stressor." This isn't the stuff of which sweet dreams are made. If you're a parent wondering how to talk to your kids about the coronavirus, here's a video that'll help start the conversation. 1:27 Whether or not you're occupied at any given moment with the task or activity in front of you, below the surface remains the psychological weight of being in unprecedented and life-altering times, said Khullar. "It's kind of this dull ache for a lot of people, and you can only ignore it so much." ©2020 CBC/Radio-Canada

Keyword: Sleep
Link ID: 27171 - Posted: 04.06.2020

By Adam Popescu Many people spend their nights now tossing and turning, struggling to unglue from the constant scroll of coronavirus news updates. But, while there is no body or life hack to make you impervious to the touch of disease, we do know that sleep is key to helping our bodies stay healthy. “Sleep is an essential part of protection from and response to any infection,” said Douglas B. Kirsch, a neurologist and former president of the American Academy of Sleep Medicine. But still, he hears you: “Sleep is hard when anxiety levels are high, such as in the case of a pandemic.” There are some answers as to what you can do now. You may not like them. Create and maintain a very consistent sleep practice and schedule that works for you. The more consistent your wake-up time, the more consistent your body functions. The National Sleep Foundation recommends sticking to a sleep schedule, and here’s a simple way to do it: Set a regular bedtime. Pair it with a set time to wake. (As many people aren’t currently commuting, this might be easier than normal.) Set yourself up for success by doing the little things: use blackout curtains if you’re sleeping while it’s bright, ditto to earplugs or a sleep mask (Wirecutter, a company owned by The New York Times that judges products, recommends this sleep mask, but even a light pillow or T-shirt works in a pinch). No matter what you do, make your bedroom very comfortable and very dark. Are you easily awakened? Use a fan or a repeated track on Spotify for white noise. Still, if you’re tired, get sleep while you can. “If you’re tired during the day, get your rest then,” said Janet Mullington, a professor in the department of neurology at Harvard Medical School. © 2020 The New York Times Company

Keyword: Sleep
Link ID: 27144 - Posted: 03.27.2020

By Allison Hirschlag Everyone likes a good nap now and then, right? Whether you nod off during a boring movie, or rest your head on your desk at work for 20 minutes or so to fight the afternoon slump, naps can revitalize you in a major way. One study even showed they can boost performance and memory regulation better than caffeine. This all sounds great in theory, but many people — myself included — find naps do the opposite. I wake up from naps feeling like I’m in the throes of a New Year’s Day-strength hangover. It takes me at least 20 minutes to recover from them, and I never end up seeing any of the benefits. Even when I timed my nap to be no more than 30 minutes — the nap length sleep experts claim is the most beneficial — I came out of it certain I was experiencing the early stages of the flu (I wasn’t). Naturally, I’ve always been a little jealous of the people who take naps and wake up feeling like a million bucks. I’m a healthy, youngish, childless woman who regularly sleeps seven to eight hours a night — why don’t naps work for me? The short answer is that some adults are genetically predisposed to need more hours of continuous sleep than others (I’m leaving children out of this because, as growing bodies, they naturally need more sleep). According to a study by the National Heart, Lung and Blood Institute, at least 80 genes appear to be involved in sleep regulation, which “suggests that sleep duration in natural populations can be influenced by a wide variety of biological processes.” Simply put, sleep duration needs vary considerably because they’re based on a broad spectrum of genetic differences.

Keyword: Sleep; Genes & Behavior
Link ID: 27105 - Posted: 03.09.2020

By Laura Sanders Here’s something neat about sleeping sheep: Their brains have fast zags of neural activity, similar to those found in sleeping people. Here’s something even neater: These bursts zip inside awake sheep’s brains, too. These spindles haven’t been spotted in healthy, awake people’s brains. But the sheep findings, published March 2 in eNeuro, raise that possibility. The purpose of sleep spindles, which look like jagged bursts of electrical activity on an electroencephalogram, isn’t settled. One idea is that these bursts help lock new memories into the brain during sleep. Daytime ripples, if they exist in people, might be doing something similar during periods of wakefulness, the researchers speculate. Jenny Morton, a neurobiologist at the University of Cambridge, and her colleagues studied six female merino sheep with implanted electrodes that spanned their brains. The team collected electrical patterns that emerged over two nights and a day. As the sheep slept, sleep spindles raced across their brains. These spindles are akin to those in people during non-REM sleep, which accounts for the bulk of an adult’s sleeping night (SN: 8/10/10). But the electrodes also caught spindles during the day, when the sheep were clearly awake. These “wake” spindles “looked different from those we saw at night,” Morton says, with different densities, for instance. Overall, these spindles were also less abundant and more localized, captured at single, unpredictable spots in the sheep’s brains. © Society for Science & the Public 2000–2020.

Keyword: Sleep; Evolution
Link ID: 27089 - Posted: 03.03.2020

By Rachel Cericola A year ago, I was diagnosed with nasal polyps and regularly snored like a wild boar. I’ve had the polyps removed, but the snoring continues. I’m not alone. According to Principles and Practice of Sleep Medicine (Fifth Edition), “about 40 percent of the adult population” snores. Sometimes my snoring wakes up my husband (and vice versa), so I decided to try out six popular over-the-counter anti-snoring contraptions. To get a baseline measurement of how much I was snoring without any intervention, I used SnoreLab, a highly rated app that listens for snoring sounds, records clips, and analyzes your resting audio. After calculating an average of four nights’ intervention-free snoring readings to get a starting “sleep score,” I then slept with each anti-snoring device for several nights and tracked my SnoreLab results against that baseline. (Note that some of these devices may work for you and not me — and none of them should be used to treat sleep apnea. If you’re having restless sleep, gasping awake, or even feeling tired and foggy in the daytime, see a doctor.) While longer-term testing is needed before we could confidently recommend any of these, a few devices showed promise in our preliminary — and far from scientific — trials. Here’s how they did, in order of how much I found they helped: Smart Nora, $329 at the time of publication This system will slightly move your head when it catches you snoring. It includes a wireless, mic-equipped device that can sit bedside or be wall-mounted to detect snoring. Once it does that, it communicates with an under-bed base station that pumps air through a tube to an insert that lives inside your pillow. That motion gently adjusts your head position to reduce snoring (in my case, it effectively did so without waking me up). It sounds bizarre, but this was actually the most effective device I tried, cutting my total snoring in half, according to my SnoreLab sleep scores. It is also the most expensive. There are many options for personalization, which we will continue to test. © 2020 The New York Times Company

Keyword: Sleep
Link ID: 27052 - Posted: 02.20.2020

Shannon Bond If you're having a hard time falling asleep, that sleep tracker on your wrist might be to blame. And there's a name for this new kind of insomnia of the digital age: orthosomnia. It's "when you just really become fixated on having this perfect sleep via tracker," said Seema Khosla, medical director at the North Dakota Center for Sleep. "And then you start worrying about it, and you wind up giving yourself insomnia." Sleep trackers have become increasingly popular. They come in the form of watches, wristbands, rings and even mattresses. The gadgets measure how you breathe, how fast your heart is beating, how much you're tossing and turning. They crunch that data to produce a sleep score, usually through a smartphone app. But in an irony of our digital lifestyles, for some people, perfecting that sleep score becomes an end unto itself — so much so that they can lose sleep over it. Khosla sees this is her own practice as a sleep doctor. Stressed-out patients complain they are aiming for a sleep score of 100 but are getting only 80. It keeps them up at night. She has a simple solution. "I'll ask them just to put their tracker away for a couple of weeks. And honestly, sometimes you can just see the relief on their faces," she said. Kathrin Hamm experienced this problem firsthand. She was traveling around the world as an economist for the World Bank, and getting good sleep was a priority. © 2020 npr

Keyword: Sleep
Link ID: 27043 - Posted: 02.18.2020

By Elizabeth Pennisi Scientists seeking the origins of sleep may have uncovered important clues in the Australian bearded dragon. By tracing sleep-related neural signals to a specific region of the lizard’s brain—and linking that region to a mysterious part of the mammalian brain—a new study suggests complex sleep evolved even earlier in vertebrate evolution than researchers thought. The work could ultimately shed light on the mechanisms behind sleep—and pave the way for studies that may help humans get a better night’s rest. “Answers to the questions raised and reframed by this research seem extremely likely to be significant in many ways, including clinically,” says Stephen Smith, a neuroscientist at the Allen Institute who was not involved with the new study. Mammals and birds have two kinds of sleep. During rapid eye movement (REM) sleep, eyes flutter, electrical activity moves through the brain, and, in humans, dreaming occurs. In between REM episodes is “slow wave” sleep, when brain activity ebbs and electrical activity synchronizes. This less intense brain state may help form and store memories, a few studies have suggested. In 2016, Gilles Laurent, a neuroscientist at the Max Planck Institute for Brain Research, discovered that reptiles, too, have both kinds of sleep. Every 40 seconds, central bearded dragons (Pogona vitticeps) switch between the two sleep states, he and his colleagues reported. © 2019 American Association for the Advancement of Science

Keyword: Sleep; Evolution
Link ID: 27037 - Posted: 02.13.2020

By Shola Lawal These are tough times for fireflies. Like a lot of other insects, they face increasing threats from habitat loss, pesticides and pollution. But they also have a problem that’s unique to luminous bugs: It’s getting harder for them to reproduce because light pollution is outshining their mating signals. Fireflies, it turns out, use their special glowing powers in courtship: Males light up to signal availability and females respond with patterned flashes to show that they’re in the mood. But bright light from billboards, streetlights and houses is interfering and blocking potential firefly couples from pairing up. The problem can reach far from big cities: Bright light gets diffused in the atmosphere and can be reflected into the wilderness. In addition to messing with mating signals, it also disrupts the feeding patterns of the females of some species that glow to attract and eat males. The finding was part of a study published Monday in the journal BioScience. The study, by researchers at Tufts University and the International Union for Conservation of Nature, warned that fireflies could eventually face extinction globally because of multiple threats, including light pollution and habitat loss and habitat degradation from insecticides and chemical pollution. Many insects are affected by habitat loss, but fireflies have it particularly bad, said Sara M. Lewis, a biology professor at Tufts and the lead researcher on the study. “Some fireflies get hit especially hard when their habitat disappears because they need special conditions to complete their life cycle,” she said. Fireflies are a type of beetle. There are more than 2,000 species of them, found mainly in wetlands. But mangrove forests and marshes around the world are increasingly vanishing to make way for cash crops like palm oil, according to the new study. © 2020 The New York Times Company

Keyword: Sexual Behavior; Biological Rhythms
Link ID: 27018 - Posted: 02.04.2020

By Jade Wu Savvy Psychologist This week, let’s ask the million-dollar question: How much sleep do you really need? We all know sleep is important. Shakespeare called it the “sore labor’s bath, balm of hurt minds, great nature’s second course, chief nourisher in life’s feast.” Less poetically, headlines these days seem to be shouting: “Sleep deprivation will make you slower and dumber!” “It will give you Alzheimer's disease and heart attacks!” One mattress advertisement I saw simply said, “You can only live seven days without sleep.” Yikes. Talk about pressure to perform! Fear-mongering aside, there is good evidence that sleep is important for health, well-being, and performance. A recent meta-analysis including over 1600 participants confirmed that sleep restriction is associated with poorer attention and thinking. We’ve known for decades that sleep deprivation disrupts mood. For example, it can trigger manic episodes in those with bipolar disorder. And we’re learning now, from researchers in Sweden and Germany, that insufficient sleep can even affect the microbiota in your gut. But how much sleep is enough? Is there such a thing as too much sleep? If you ask Dr. Google, you’ll get over a billion answers. (That’s right; “billion” with a “b.”) The most common answer seems to be “eight hours.” That seems pretty straightforward. But where does this number come from? And if you’re thinking, “Dr. Google hasn’t examined me; how would she know how much sleep I need,” then you’re asking exactly the right question. © 2020 Scientific American

Keyword: Sleep
Link ID: 26977 - Posted: 01.22.2020

By Harry Guinness The world isn’t made for night owls. You struggle into work in the dark hours before 10 a.m. — or your morning coffee — and you’re greeted by some chipper person who has already been to the gym and is six items into his to-do list. I used to fantasize about fitting punishments for such morning people, but in the last two years I’ve seen the (morning) light, and I’ve become one of them. If you love staying up late but hate crawling through your mornings in a haze, here’s how you can do it too. After a long, draining day you finally get home, settle down in front of the TV and throw on whatever season you’re currently bingeing. Heaven. But then, when a reasonable bedtime rolls around, you don’t want to stop. It has been a hard day, aren’t you entitled to just one more episode? So you push play, trade a bit of sleep for more Netflix time and continue the cycle that keeps you tired all the time. Dr. Alex Dimitriu, founder of the Menlo Park Psychiatry and Sleep Medicine clinic, explained it like this: “Long days leave us tired and exhausted, but the reality is, our days would be less hard, and less exhausting, if we weren’t so tired through them. The trouble with being a night owl is that your sleep gets clipped in the morning hours, where most of the precious REM or dream sleep occurs. Instead of sleeping seven or eight hours per night, most night owls get forced to sleep five or six — with a hard start time in the morning.” Dr. Dimitriu can’t stress enough just how important REM sleep is. It’s “the key to our emotional and creative energy” and comparable to “self-therapy,” he said, adding that it “balances us out in more ways than I can describe” and that without enough of it, our memory and moods take a hit. If you have the freedom to wake up when you like, then things are different, but if that extra Netflix episode is forcing you to cut your sleep short, then you should try to do something about it. © 2020 The New York Times Company

Keyword: Biological Rhythms; Sleep
Link ID: 26973 - Posted: 01.21.2020

By Tom Siegfried Long before Apple watches, grandfather clocks or even sundials, nature provided living things with a way to tell time. Life evolved on a rotating world that delivered alternating light and darkness on a 24-hour cycle. Over time, cellular chemistry tuned itself to that rhythm. Today, circadian rhythms — governed by a master timekeeper in the brain — guide sleeping schedules and mealtimes and influence everything from diet to depression to the risk of cancer. While an Apple watch can monitor a few vital functions such as your heart rate, your body’s natural clock controls or affects nearly all of them. Lately, research by Takahashi and others has suggested strategies for manipulating the body’s clock to correct circadian-controlled chemistry when it goes awry. Such circadian interventions could lead to relief for shift workers, antidotes for jet lag, and novel treatments for mood disorders and obesity, not to mention the prospect of counteracting aging. Prime weapons for the assault on clock-related maladies, Takahashi believes, can be recruited from an arsenal of small molecules, including some existing medical drugs. “Researchers are increasingly interested in developing small molecules to target the circadian system directly for therapeutic gains,” Takahashi and coauthors Zheng Chen and Seung-Hee Yoo wrote in the 2018 Annual Review of Pharmacology and Toxicology. In sophisticated life-forms (such as mammals), central control of the body’s clock resides in a small cluster of nerve cells within the brain’s hypothalamus. That cluster, called the suprachiasmatic nucleus — SCN for short — is tuned to the day-night signal by light transmitted via the eyes and the optic nerve. But the SCN does not do the job alone. It’s the master clock, for sure, but satellite timekeepers operate in all kinds of cells and body tissues. © 2020 Annual Reviews, Inc

Keyword: Biological Rhythms
Link ID: 26962 - Posted: 01.15.2020

By Philippa Roxby Health reporter A sleep disorder that can leave people gasping for breath at night could be linked to the amount of fat on their tongues, a study suggests. When sleep apnoea patients lost weight, it was the reduction in tongue fat that lay behind the resulting improvements, researchers said. Larger and fattier tongues are more common among obese patients. But the Pennsylvania team said other people with fatty tongues may also be at risk of the sleep disorder. The researchers now plan to work out which low-fat diets are particularly good at slimming down the tongue. Tongue tied "You talk, eat and breathe with your tongue - so why is fat deposited there?" said study author Dr Richard Schwab, of Perelman School of Medicine, Philadelphia. "It's not clear why - it could be genetic or environmental - but the less fat there is, the less likely the tongue is to collapse during sleep." Sleep apnoea is a common disorder that can cause loud snoring, noisy breathing and jerky movements when asleep. It can also cause sleepiness during the day, which can affect quality of life. The most common type is obstructive sleep apnoea, in which the upper airway gets partly or completely blocked during sleep. Those who are overweight or who have a large neck or tonsils are more likely to have the condition. Researchers at the Perelman School of Medicine, University of Pennsylvania, scanned 67 people with obstructive sleep apnoea who were obese and had lost 10% of their body weight, improving their symptoms improved by 30%. © 2020 BBC.

Keyword: Sleep; Obesity
Link ID: 26946 - Posted: 01.10.2020

By Matthew Hutson When you are stuck on a problem, sometimes it is best to stop thinking about it—consciously, anyway. Research has shown that taking a break or a nap can help the brain create pathways to a solution. Now a new study expands on the effect of this so-called incubation by using sound cues to focus the sleeping mind on a targeted problem. When humans sleep, parts of the brain replay certain memories, strengthening and transforming them. About a decade ago researchers developed a technique, called targeted memory reactivation (TMR), aimed at further reinforcing selected memories: when a sound becomes associated with a memory and is later played during sleep, that memory gets reactivated. In a study published last November in Psychological Science, scientists tested whether revisiting the memory of a puzzle during sleep might also improve problem-solving. About 60 participants visited the laboratory before and after a night of sleep. In an evening session, they attempted spatial, verbal and conceptual puzzles, with a distinct music clip repeating in the background for each, until they had worked on six puzzles they could not solve. Overnight they wore electrodes to detect slow-wave sleep—slumber's deepest phase, which may be important for memory consolidation—and a device played the sounds assigned to three of the six unsolved puzzles. The next day, back at the lab, the participants attempted the six puzzles again. (Each repeated the experiment with a different set of puzzles the following night.) All told, the subjects solved 32 percent of the sound-prompted puzzles versus 21 percent of the untargeted puzzles—a boost of more than 50 percent. © 2020 Scientific American

Keyword: Sleep; Learning & Memory
Link ID: 26938 - Posted: 01.07.2020

Getting a Good Night’s Sleep Without Drugs By Jane E. Brody As many as 20 percent to 30 percent of people in the general population sleep poorly. They may have difficulty falling asleep or staying asleep, some awaken much too early, while others do not feel rested despite spending a full night seemingly asleep in bed. For one person in 10, insomnia is a chronic problem that repeats itself night after night. Little wonder that so many resort to sleeping pills to cope with it. But experts report that there are better, safer and more long-lasting alternatives than prescription drugs to treat this common problem. The alternatives are especially valuable for older people who metabolize drugs more slowly, are more likely to have treatable underlying causes of their insomnia and are more susceptible to adverse side effects of medications. Is Your Sleep Cycle Out of Sync? It May Be Genetic By Jane E. Brody Early to bed, early to rise — a fine plan for a dairy farmer who has to get up long before dawn to milk the cows. But if you’re someone who works all day with stocks and clients and may want to enjoy an evening out now and then, it would be better not to be getting up at 2 a.m. and have to struggle to stay awake through dinner or a show. Such is the challenge faced by a friend who has what sleep specialists call an advanced sleep phase. Her biological sleep-wake cycle, or circadian rhythm, is out of sync with the demands of the modern world. Read more>>> By Perri Klass, M.D. The biology of adolescent sleep reflects a natural and normal delay in melatonin secretion that leads to a later sleep onset time, which unfortunately coincides with early high school start times, creating a high-stress set up. Pediatricians often see adolescents with insomnia, who have trouble falling asleep or staying asleep, waking up too early or finding sleep not restful or refreshing. © 2019 The New York Times Company

Keyword: Sleep
Link ID: 26919 - Posted: 12.27.2019

Alejandra Manjarrez When he was a postdoc at KU Leuven in Belgium, Daniel Vigo helped analyze results from an experiment that simulated a spaceflight to Mars. Six crew members were secluded in an artificially lit, spacecraft-like facility for 520 days starting in June 2010. Part of an international project known as the Mars500 mission, the experiment aimed to assess the psychological, social, and biological effects of prolonged confinement and isolation, along with the absence of normal day and night rhythms. That isolation, of course, was just an illusion, manufactured by the Institute for Biomedical Problems of the Russian Academy of Sciences and the European Space Agency. The simulation took place in central Moscow, where any sudden medical problems could have received immediate attention—as Vigo, now a researcher at the Catholic University of Argentina and a member of the National Scientific and Technical Research Council (CONICET), tells The Scientist in Spanish. He began wondering what would happen in a less artificial scenario. One of the key findings from the study, for example, was that confinement—in this case in an artificially lit building—disrupted normal sleep patterns: the crew members in the Mars500 experiment had suffered from sleep problems and rapidly fell into sleep-wake routines that were out of sync with one another. But what would the story be like for people experiencing a similarly extreme living environment, Vigo wondered, without the safety net provided by a carefully controlled simulation? © 1986–2019 The Scientist

Keyword: Sleep; Biological Rhythms
Link ID: 26918 - Posted: 12.27.2019