Chapter 14. Biological Rhythms, Sleep, and Dreaming

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Meredith Fore A long-standing controversy in neuroscience centers on a simple question: How do neurons in the brain share information? Sure, it’s well-known that neurons are wired together by synapses and that when one of them fires, it sends an electrical signal to other neurons connected to it. But that simple model leaves a lot of unanswered questions—for example, where exactly in neurons’ firing is information stored? Resolving these questions could help us understand the physical nature of a thought. Two theories attempt to explain how neurons encode information: the rate code model and the temporal code model. In the rate code model, the rate at which neurons fire is the key feature. Count the number of spikes in a certain time interval, and that number gives you the information. In the temporal code model, the relative timing between firings matters more—information is stored in the specific pattern of intervals between spikes, vaguely like Morse code. But the temporal code model faces a difficult question: If a gap is "longer" or "shorter," it has to be longer or shorter relative to something. For the temporal code model to work, the brain needs to have a kind of metronome, a steady beat to allow the gaps between firings to hold meaning. Every computer has an internal clock to synchronize its activities across different chips. If the temporal code model is right, the brain should have something similar. Some neuroscientists posit that the clock is in the gamma rhythm, a semiregular oscillation of brain waves. But it doesn’t stay consistent. It can speed up or slow down depending on what a person experiences, such as a bright light. Such a fickle clock didn't seem like the full story for how neurons synchronize their signals, leading to ardent disagreements in the field about whether the gamma rhythm meant anything at all. © 2018 Condé Nast.

Keyword: Consciousness; Biological Rhythms
Link ID: 26494 - Posted: 08.13.2019

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. My friend, who asked to remain anonymous, has always been an early riser, even as a teenager. Getting up at 5 was an advantage in high school — she never had to worry about being late. But as she aged, her nights kept getting shorter. Now at age 63 she’s ready to go to sleep before 9 p.m., but that rarely fits with the demands of her life. No matter how delayed her bedtime, she gets up by 4 in the morning — and sometimes as early as 1:30 — and can’t get back to sleep. She said that given her stimulating job as an investment products specialist, she’s not sleepy during the day, nor does she nap. Still, she’s concerned about her short nights, partly because she’s read that insufficient sleep — especially not enough REM sleep, when dreams occur — has been linked to a possible increased risk of Alzheimer’s disease. She knows that late dinners, especially with wine, contribute to her sleep problem. But it’s also likely that her lifelong dairy-farmer sleep pattern is programmed by her genes, not the result of unavoidable disruptions or unwise living habits. And, it seems, her early-to-sleep, early-to-wake rhythm may not be as extremely rare as has long been believed. In a new study in the journal Sleep by researchers in San Francisco, Salt Lake City and Madison, Wis., of more than 2,400 patients who visited a sleep clinic for complaints like sleep apnea or insomnia, a small number of them were found to have a previously unrecognized familial form of advanced sleep phase, a kind of permanent jet lag that the study showed often runs in families. © 2019 The New York Times Company

Keyword: Biological Rhythms; Genes & Behavior
Link ID: 26488 - Posted: 08.12.2019

Nicola Davis Forget counting sheep and drinking warm milk, an effective way to tackle chronic insomnia is cognitive behavioural therapy, researchers have confirmed. The authors of a new study say that although the therapy is effective, it is not being used widely enough, with doctors having limited knowledge about it and patients lacking access. “There is a very effective treatment that doesn’t involve medication that should be available through your primary care service. If it’s not, it should be,” said Dr Judith Davidson, co-author of a new study on CBT for insomnia from Queen’s University in Ontario, Canada. Chronic insomnia, in which individuals have difficulties dropping off or staying asleep at least three nights a week for three months or more, is thought to affect about 10-15% of adults. The condition is linked to health problems including depression, as well as difficulties in functioning and sometimes resulting in accidents. Sleeping pills are not recommended for long-term use and can have side-effects, as well as posing a risk of addiction. Instead, the main treatment for chronic insomnia is CBT – a programme of changes to the way an individual approaches and thinks about sleep. These include staying away from the bed when awake, challenging attitudes about sleep loss and restricting the number of hours spent in bed. Writing in the British Journal of General Practice, Davidson and colleagues report how they examined the results from 13 previously conducted studies on the provision of CBT for insomnia through primary care. In some studies, participants were also taking medication to help them sleep. © 2019 Guardian News & Media Limited

Keyword: Sleep
Link ID: 26465 - Posted: 07.30.2019

Tickling the ear with a small electric current could rebalance the nervous system in over-55s and help them age more healthily, research suggests. Stimulation of the vagus nerve, which connects to the heart, lungs and gut, led to improvements in body, sleep and mood, a small study found. The University of Leeds team said the procedure could make a big difference to people's lives. But more research is needed to work out the long-term health effects. Why the ear? The ear acts as a gateway to the body's nervous system. One small branch of the vagus nerve can be stimulated via the skin in specific bits of the outer ear. To some people, the therapy feels ticklish. To others, it's painless. What's the vagus nerve? Also called the "wandering nerve", because it's long and well-connected, the vagus nerve transmits information from the brain to organs around the body, such as the heart and lungs. It is also fundamental to the body's autonomic nervous system. This system, which has branches known as sympathetic and parasympathetic, controls many of the body's functions, such as breathing, digestion, heart rate and blood pressure. Does the nervous system change as we age? Yes. As we get older, the balance of the body's nervous system goes awry. The sympathetic branch, which helps the body prepare for high intensity "fight or flight" activity, begins to dominate. And the parasympathetic branch, which is important for "rest and digest" activity, becomes less active. This makes people more prone to diseases, such as heart problems and hypertension, as well as depression and anxiety. © 2019 BBC

Keyword: Sleep; Depression
Link ID: 26464 - Posted: 07.30.2019

By Megan Schmidt | Soaring with the birds. Teeth falling out. A crazy psychopath is chasing you. For many of us, our dreams transport us to a surreal world where logic and reason have no reign. Some of us may even look forward to sleep – and the adventures we’ll go on in our dreams. But does everyone take a nightly trip to dreamland? While most of us remember somewhere around one or two dreams a week, some people report a subconscious experience that’s more like a blank tape. Among us are people who say they never, ever dream. A small subset of the population – around one in every 250 people – report never remembering a single dream in their lives, as a 2015 study found. What is it about people who don’t remember their dreams that sets them apart from the people that do? Is it possible for the brain to stop producing dreams? And could something be wrong in the brains of people who report never dreaming? Raphael Vallat, a neuroscientist specializing in sleep and dream research at the University of California, Berkeley Sleep and Neuroimaging Lab, offered insights to a number of these questions. Vallat says dreaming “is one of the last frontiers in our understanding of the human mind.” And learning about dream recall – the why and how of remembering one’s dreams – may help scientists solve some of the mysteries of the dreaming mind. Work by Vallat and others in the field has uncovered a number of interesting tidbits that seem to separate the dreamers from the so-called nondreamers, or the people seldom or never remember their dreams.

Keyword: Sleep
Link ID: 26448 - Posted: 07.25.2019

Dave Davies We tend to think of being asleep or awake as an either-or prospect: If you're not asleep, then you must be awake. But sleep disorder specialist and neurologist Guy Leschziner says it's not that simple. "If one looks at the brain during sleep, we now know that actually sleep is not a static state," Leschziner says. "There are a number of different brain states that occur while we sleep." As head of the sleep disorders center at Guy's Hospital in London, Leschziner has treated patients with a host of nocturnal problems, including insomnia, night terrors, narcolepsy, sleep walking, sleep eating and sexsomnia, a condition in which a person pursues sexual acts while asleep. He writes about his experiences in his book The Nocturnal Brain. Leschziner notes that the different parts of the brain aren't always in the same stage of sleep at the same time. When this happens, an individual might order a pizza or go out for a drive — while technically still being fast asleep. "Sometimes these conditions sound very funny," Leschziner says. "But on other occasions they can be really life changing, resulting in major injury or, as one of the cases that I described in the book, in a criminal conviction." On what we know about recall after a sleepwalking episode We used to think that people don't really remember anything that occurs in this stage. That seems to relate to the fact that the brain in parts is in very deep sleep whilst in other parts is awake. What we have learned over the last few years is that actually quite a lot of people have some sort of limited recall. They don't necessarily remember the details of all the events or indeed the entirety of the event, but sometimes they do experience little snippets. © 2019 npr

Keyword: Sleep
Link ID: 26445 - Posted: 07.24.2019

By Diana Kwon Your brain is a bit like a concert hall. To drive our cognitive processes, several groups of neurons need to become active—and, like the various sections of an orchestra, work in harmony to produce the symphony of computations that allow us to perceive and interact with our surroundings. As with an orchestra, the brain likely requires a conductor to keep all its active parts in sync. There are neuroscientists who think that gamma rhythms, fast brain waves that fluctuate at a frequency of approximately 40 cycles per second, play this role. By ticking at regular intervals, these oscillations are thought to act like a clock that coordinates information transfer from one group of neurons to another. There is ample evidence suggesting that gamma waves are important for the brain's computations: decades of studies in humans and other animals have found these patterns in many parts of brain and have associated them with a range of cognitive processes, such as attention and the mental scratchpad of working memory. Some studies have even linked disturbances in these oscillations to various neurological diseases, including schizophrenia and Alzheimer's. But a consensus does not exist. Some neuroscientists think that these gamma waves may not do much at all. Rather than a relevant physiological signal, one camp believes that these rhythms are simply “an exhaust fume of computation,” says Chris Moore, a neuroscientist at the Carney Institute for Brain Science at Brown University. In the same way your car releases emissions each time you drive it—the gamma signal could be perfectly correlated with brain activity, but not provide any meaningful contribution to the actual function of the car, he explains. © 2019 Scientific American

Keyword: Biological Rhythms; Attention
Link ID: 26429 - Posted: 07.19.2019

By Brian X. Chen For the last two weeks, I’ve added an extra step to my bedtime routine: strapping a computer around my wrist. The new nightly move was prompted by a cascade of wearable gadgets from companies like Fitbit and Apple, which claim that their sensor-laden bracelets and watches can improve our lives by helping us detect health problems so that we can come up with solutions. For many years, fitness gadgets have measured basic data, like footsteps or calories burned, to motivate us to stay active or shed pounds. Sleep tracking is still a nascent area that tech companies are experimenting with — one that I’ve watched with interest as someone who has been sleep deprived for many years. In the past, I’ve tried several gadgets with sleep tech, including Fitbit watches and Bose’s sleep-aid earbuds. But I hadn’t consistently tracked my sleep habits and patterns before. Would it really make a difference, I wondered, to have this data? Would it help me to sleep better? I decided to test it out. I wore an Apple Watch, since it is one of the most popular health-tracking devices. I also downloaded a top-rated app called AutoSleep, which uses the Apple Watch’s sensors to follow my movements and determine when I fell asleep and woke up. (The Apple Watch lacks a built-in sleep tracker.) Here’s what AutoSleep gathered on my sleep habits. But the excitement ended there. Ultimately, the technology did not help me sleep more. It didn’t reveal anything that I didn’t already know, which is that I average about five and a half hours of slumber a night. And the data did not help me answer what I should do about my particular sleep problems. In fact, I’ve felt grumpier since I started these tests. © 2019 The New York Times Company

Keyword: Sleep
Link ID: 26426 - Posted: 07.18.2019

Katarina Zimmer About two years ago, 29 people visited a neuroscience lab in the Netherlands to sing karaoke. Wearing muffled headphones so they could hear the music but not their own voices, it was almost inevitable that they would sing “Silent Night” or the Dutch national anthem out of tune. Dutch researchers recorded each individual sing, then played the recording back to him or her. Listening to themselves sing solo evoked feelings of shame and embarrassment and sparked higher-than-normal activity in the subjects’ amygdalae. Fortunately for some study participants, a good night’s sleep was enough to lessen the amygdala’s response when they listened to the recording again the next day. But others who had experienced restless sleep—specifically poor-quality REM, or rapid eye movement, sleep—experienced the opposite: their amygdalae were just as sensitive, if not more, to the recording the next day. The findings suggest that poor-quality REM sleep can interfere with the amygdala’s ability to process emotional memories overnight, the scientists who conducted the study say. They posit that this has implications for people with psychological disorders linked to disturbed REM sleep patterns, such as depression, anxiety, and post-traumatic stress disorder (PTSD). The research appears today (July 11) in Current Biology. © 1986–2019 The Scientist.

Keyword: Sleep; Learning & Memory
Link ID: 26414 - Posted: 07.13.2019

Tina Hesman Saey No one should have to sleep with the fishes, but new research on zebrafish suggests that we sleep like them. Sleeping zebrafish have brain activity similar to both deep slow-wave sleep and rapid eye movement, or REM, sleep that’s found in mammals, researchers report July 10 in Nature. And the team may have tracked down the cells that kick off REM sleep. The findings suggest that the basics of sleep evolved at least 450 million years ago in zebrafish ancestors, before the evolution of animals that give birth to live young instead of laying eggs. That’s 150 million years earlier than scientists thought when they discovered that lizards sleep like mammals and birds (SN: 5/28/16, p. 9). What’s more, sleep may have evolved underwater, says Louis C. Leung, a neuroscientist at Stanford University School of Medicine. “These signatures [of sleep] really have important functions — even though we may not know what they are — that have survived hundreds of millions of years of evolution.” In mammals, birds and lizards, sleep has several stages characterized by specific electrical signals. During slow-wave sleep, the brain is mostly quiet except for synchronized waves of electrical activity. The heart rate decreases and muscles relax. During REM or paradoxical sleep, the brain lights up with activity almost like it’s awake. But the muscles are paralyzed (except for rapid twitching of the eyes) and the heart beats erratically. |© Society for Science & the Public 2000 - 2019

Keyword: Sleep
Link ID: 26410 - Posted: 07.11.2019

By Kelly Mayes Your fancy sleep tracker is no match for a dedicated sleep lab. But who wants to spend 8 hours in a strange hospital room wired with electrodes while someone video records you all night? Now, several companies say they may have a compromise: high-tech sleep-monitoring headbands that combine brain wave–reading electrodes with sophisticated artificial intelligence. And best of all, they can be worn in your own bed. The technology could make it easier to get accurate readings of someone’s sleep patterns at home, says Tristan Bekinschtein, a neuroscientist at the University of Cambridge in the United Kingdom who was not involved with designing any of the devices. A prime benefit, he says, is that they get rid of the wires that inhibit movement during sleep and they can be used over multiple nights. Still, he says, the technology needs more testing before it becomes widely used in clinical research. One of the leading devices in sleep monitoring is the Dreem headband, developed by a company of the same name based in Paris. The headband is made of a slim, breathable piece of fabric designed to wrap around the head, with a separate arch extending over the top. Seven electrodes line the inner portion, making contact with the scalp. The device monitors the electrical activity of the brain with the traditional electroencephalogram readings taken in a sleep lab. And, as in sleep lab studies, the headband also tracks head movement, heart rate, and respiration, relying on sound recordings and a miniature accelerometer like those found in smartphones. Built-in artificial intelligence analyzes the data on the fly, identifying whether a person is, for example, in rapid eye movement sleep or other known stages like non–rapid eye movement sleep, which are not as deep. © 2019 American Association for the Advancement of Science.

Keyword: Sleep
Link ID: 26409 - Posted: 07.11.2019

Erin Wayman Crowds of people gather to watch an evening spectacle on beaches in Southern California: Twice a month, typically from March through August, the sand becomes carpeted with hundreds or thousands of California grunion. Writhing, flopping, silvery sardine look-alikes lunge as far onto shore as possible. As the female fish dig their tails into the sand and release eggs, males wrap around females and release sperm to fertilize those eggs. About 10 days later, the eggs hatch and the little grunion get washed out to sea. This mating ritual is set to the tides, with hatching timed to the arrival of the peak high tide every two weeks. But the ultimate force choreographing this dance is the moon. Many people know that the moon’s gravitational tug on the Earth drives the tides, and with them, the life cycles of coastal creatures. Yet the moon also influences life with its light. This story is part of a special report celebrating humans’ enduring fascination with the moon and exploring the many ways it affects life on Earth. More articles will be published in the coming weeks. See all the articles, plus our 1969 coverage of Apollo 11, here. For people living in cities ablaze with artificial lights, it can be hard to imagine how dramatically moonlight can change the nocturnal landscape. Out in the wild, far from any artificial light, the difference between a full moon and a new moon (when the moon appears invisible to us) can be the difference between being able to walk outside without a flashlight and not being able to see the hand in front of your face. |© Society for Science & the Public 2000 - 2019.

Keyword: Biological Rhythms
Link ID: 26398 - Posted: 07.08.2019

Even if you know that looking at a phone, tablet or computer screen at night is bad for your sleep, it’s hard to stop. That’s one reason there has been a growing interest in glasses or apps that can block the blue parts of the light spectrum that experts say are especially bad for sleep. This light doesn’t necessarily appear blue; it’s part of any bright white light, says Charles Czeisler, chief of the Division of Sleep and Circadian Disorders at Brigham and Women’s Hospital in Boston. “Our light exposure between when the sun sets and the sun rises is probably the primary driver of sleep deficiency in our society,” Czeisler says. While that includes artificial light of all kinds, light from electronic devices that emit blue light — such as the LED displays in smartphones, tablets, and modern computer and TV screens — is particularly troublesome for sleep, he says. A number of studies indicate that using blue-blocking glasses and apps like f.lux or Apple’s Night Shift mode may improve sleep in certain cases, but they won’t cure insomnia on their own. Experts say much more research is needed on how well they work, who can benefit the most and how to best use them. Still, they may help, though thinking about light exposure throughout the day may be even more useful. “It just depends on how many problems a person is having with their sleep,” says Lisa Ostrin, an assistant professor at the University of Houston College of Optometry who has conducted research into ways that blocking blue light affects sleep. To understand how glasses or apps affect sleep, it helps to understand light’s role in the first place. © 1996-2019 The Washington Post

Keyword: Sleep; Vision
Link ID: 26353 - Posted: 06.25.2019

By Megan Schmidt Have you ever spaced out during a meeting, but been jolted back to reality by the sound of your boss calling your name a few times? If you’ve ever been in this awkward situation, you might have experienced “microsleep.” This weird state of consciousness is characterized by brief bursts of sleep that happen while a person is awake — often while their eyes are open and they’re either sitting upright, or even performing a task. During microsleep, parts of the brain go offline for a few seconds while the rest of the brain stays awake. It’s sort of like being a zombie for a few brief moments — sans the whole “eating human flesh” part. And usually, people don’t realize it’s happening to them. Researchers don’t fully understand why certain parts of our brain switch off throughout the day. But they have found the states of sleep and wakefulness aren’t as cut and dry as we might assume. And although fatigue does seem to prime the brain for microsleep, even well-rested people do it — a lot. In an experiment published in 2012, participants who got a good night’s sleep played what may be the world’s most boring computer game — tracking a moving target on a monitor with a joystick. During the 50-minute test, researchers monitored people’s brain and eye activity. They found that people’s brains really liked sneaking in microsleep during the humdrum computer game. On average, game players experienced a whopping 79 episodes of microsleep in just under an hour, lasting up to six seconds each time.

Keyword: Sleep
Link ID: 26343 - Posted: 06.20.2019

By Jane E. Brody Shakespeare wisely recognized that sleep “knits up the ravell’d sleave of care” and relieves life’s physical and emotional pains. Alas, this “chief nourisher in life’s feast,” as he called it, often eludes millions of people who suffer from insomnia. Desperate to fall asleep or fall back to sleep, many resort to Ambien or another of the so-called “Z drugs” to get elusive shut-eye. But except for people with short-term sleep-disrupting issues, like post-surgical pain or bereavement, these sedative-hypnotics have a time-limited benefit and can sometimes cause more serious problems than they might prevent. They should not be used for more than four or five weeks. In April, the Food and Drug Administration added a boxed warning to the prescription insomnia drugs zolpidem (Ambien, Edluar, Intermezzo and Zolpimist), zaleplon (Sonata) and eszopiclone (Lunesta) following reports of injury and death from sleepwalking, sleep-driving and engaging in other hazardous activities while not fully awake. Last July, a Georgia woman was arrested when she drove the wrong way on a highway the day after using Ambien, as prescribed, to help her sleep. Although she had consumed no alcohol, she flunked a standard sobriety test and told police she was unaware of how she ended up going the wrong way. Although extreme reactions to these sleep drugs are thought to be uncommon, they are unpredictable and can be disastrous when they occur. Some have resulted in vehicular fatalities. 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. © 2019 The New York Times Company

Keyword: Sleep
Link ID: 26334 - Posted: 06.18.2019

By Karen Zraick and Sarah Mervosh Are you sabotaging your sleep in your quest to improve it? Many new tools are becoming available to monitor your sleep or help you achieve better sleep: wearable watches and bands; “nearable” devices that you can place on your bed or nightstand; and apps that work by monitoring biometric data, noise and movement. They can remind you to start winding down, or generate a report on your night’s slumber. But some sleep specialists caution that these apps and devices may provide inaccurate data and can even exacerbate symptoms of insomnia. Fiddling with your phone in bed, after all, is bad sleep hygiene. And for some, worrying about sleep goals can make bedtime anxiety even worse. There’s a name for an unhealthy obsession with achieving perfect sleep: orthosomnia. It was coined by researchers from Rush University Medical School and Northwestern University’s Feinberg School of Medicine in a 2017 case study published in the Journal of Clinical Sleep Medicine. Dr. Kelly Baron, one of the paper’s authors and the director of the University of Utah’s behavioral sleep medicine program, said that sleep trackers can be helpful in identifying patterns. She herself tracks her bedtime with a Fitbit. But she said she had noticed a trend of patients complaining based on unverified scores, even for things like the amount of deep sleep, which varies by individual. “People were putting a lot of stock in what it was telling them,” she said. “Like, ‘I’m afraid I’m not getting enough deep sleep. There’s something wrong with me.’” As gadgets proliferate, so do concerns The flood of data and buzzwords can easily become confusing: sleep debt percentages, heart rate dips, sleep rhythms, graphs of sleep disruption and comparisons to other users. © 2019 The New York Times Company

Keyword: Sleep
Link ID: 26327 - Posted: 06.14.2019

By Jane E. Brody How did you sleep last night? If you’re over 65, I hope it was better than many others your age. In a study by the National Institute on Aging of over 9,000 Americans aged 65 and older, more than half said they had difficulty falling asleep or staying asleep. Many others who believe they spend an adequate number of hours asleep nonetheless complain of not feeling rested when they get up. Chronic insomnia, which affects 5 percent to 10 percent of older adults, is more than just exhausting. It’s also linked to an increased risk of developing hypertension, Type 2 diabetes, heart attack, depression, anxiety and premature death. It may also be a risk factor for dementia, especially Alzheimer’s disease. Studies based on more than 1,700 men and women followed over many years by researchers at Pennsylvania State University College of Medicine found that the risk of developing hypertension was five times greater among those who slept less than five hours a night and three and a half times greater for those who slept between five and six hours. But there was no increased risk among those who regularly slept six or more hours. Likewise, the risk of developing diabetes was three times greater for the shortest sleepers and twice as great for those who slept between five and six hours. People with insomnia often complain that they can’t concentrate or focus and have memory problems. While the evidence for this is inconsistent, the Penn State studies showed that people with insomnia are more likely to perform poorly on tests of processing speed, switching attention and visual memory. And most studies have shown that insomnia impairs cognitive performance, a possible risk factor for mild cognitive impairment and dementia. © 2019 The New York Times Company

Keyword: Sleep; Alzheimers
Link ID: 26315 - Posted: 06.10.2019

Hannah Devlin Science correspondent Smartphone sleep-tracking apps are making people so anxious and obsessed about their sleep that they are developing insomnia, a leading neurologist has said. Speaking at the Cheltenham science festival, Dr Guy Leschziner, a sleep disorder specialist and consultant at Guy’s hospital in London, said a growing preoccupation with getting enough sleep was backfiring. “We’ve seen a lot of people who have developed significant insomnia as a result of either sleep trackers or reading certain things about how devastating sleep deprivation is for you,” Leschziner said before his talk. A high proportion of patients seeking treatment for insomnia turn up at his clinic with data about their sleep patterns and are often reluctant to delete the app, he said. “It’s rather difficult to dissuade them from using it.” Most apps have not been clinically validated and only track movement, so do not provide insight into the quality of sleep, he added. “My view of sleep trackers is fairly cynical. If you wake up feeling tired and you’ve had an unrefreshing night’s sleep then you know you’ve got a problem,” he said. “If you wake up every day and feel refreshed, are awake throughout the day and are ready to sleep at the same time every night then you’re probably getting enough sleep for you and you don’t need an app to tell you that.” Similar concerns were highlighted in a series of case studies published last year by a team in Chicago that described patients whose micromanagement of sleep using apps had led to a disorder called orthosomnia. © 2019 Guardian News & Media Limited

Keyword: Sleep
Link ID: 26314 - Posted: 06.10.2019

Laura Sanders In a nighttime experiment called the Dream Catcher, people’s dreams slipped right through the net. Looking at only the brain wave activity of sleeping people, scientists weren’t able to reliably spot a dreaming brain. The details of that leaky net, described May 27 at, haven’t yet been reviewed by other scientists. And the results are bound to be heavily scrutinized, as they run counter to earlier work that described signs of dreams in neural data. The experimental design matters, because scientists suspect that dreams hold clues about the deepest mystery of the mind — consciousness itself. The brain can create rich tapestries of awareness even in the complete absence of incoming information. Studying these instances of brain-created consciousness, which include dreaming, mind-wandering and daydreaming, “is a powerful way to understand the relationship between the brain and the mind,” says study coauthor Naotsugu Tsuchiya of Monash University in Clayton, a town near Melbourne, Australia. Tsuchiya and his colleagues analyzed data generated from nine people who slept overnight in a laboratory while wearing an electrode cap that measured brain waves. The researchers focused on a stage of sleep called non-REM sleep. (Dreams are so abundant during REM sleep that researchers would have been hard-pressed to find enough instances of nondream sleep to use as a comparison.) To identify dreams, researchers employed an irritating method: They would wake up a person once he or she had entered non-REM sleep, and ask whether the person had been dreaming. To keep the experiment free from unintentional biases, the project relied on two teams of researchers: data collectors and data analyzers. Once the collectors had gathered brain wave data on both dreams and nondreams, the data was handed over to Tsuchiya and other data analyzers without any clues about the subjects, including whether they were dreaming. |© Society for Science & the Public 2000 - 2019.

Keyword: Sleep
Link ID: 26298 - Posted: 06.04.2019

By Amitha Kalaichandran, M.D. It was 11 p.m. and my 5-year-old patient was sleeping peacefully in her hospital bed, snuggled up with her mother and several stuffed animals. Her breathing was quiet and soft. Her bedside heart rate monitor, which glowed a faint yellow in the dark hospital room, was turned to “silent.” “Sorry, I have to take a listen to her heart,” I whispered to her mother, tapping her shoulder lightly. Her mother and I had a good relationship: I had served as an advocate for her daughter several times during her seven-week stay in the ward. She had a rare disease that had been a medical mystery for many months, but she would be transferred to a more specialized center soon. I hated to wake her, but recently, when I had offered to wait to examine a child until after a nap, my attending physician had scolded: “You can’t care about that. If you do, you’ll never examine them. They have to get used to it — they’re in the hospital, after all.” But the poor girl was tired. She was poked three times a day for blood and taken to the M.R.I. or CT scanner at various times. I completed my exam: her vital signs, her heart, perfusion (how well her heart was pumping blood to her body), and palpated her abdomen to check her liver and spleen (which were enlarged, but no more than they had been). She seemed stable. I backed out slowly. The next morning, the girl’s mother mentioned that it had taken another hour for her to fall asleep again. Was there anything that we could do to allow her to sleep through the night? Wouldn’t a good night’s sleep help with her condition? She had a point. © 2019 The New York Times Company

Keyword: Sleep
Link ID: 26297 - Posted: 06.04.2019