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By Tanya Lewis The human brain may wind down when asleep, but it doesn’t lose all responsiveness. Researchers from the École Normale Supérieure in Paris and their colleagues recently used electroencephalography (EEG) to monitor the brains of volunteers listening to recordings of spoken words, which they were asked to classify as either objects or animals. Participants were able to classify words during light non-REM (NREM) sleep, but not during either deep NREM sleep or REM sleep, according to a study published today (June 14) in The Journal of Neuroscience. “With an elegant experimental design and sophisticated analyses of neural activity, [the authors] demonstrate the extent to which the sleeping brain is able to process sensory information, depending on sleep depth [or] stage,” Thomas Schreiner of the University of Fribourg in Switzerland, who was not involved in the study, wrote in an email to The Scientist. During sleep, the brain is thought to block out external stimuli through a gating mechanism at the level of the thalamus. But experiments dating back to the 1960s have shown that certain types of stimuli, such as hearing one’s name, can filter through and trigger awakening. However, the mechanisms that allow the brain to selectively take in information during sleep remain unknown. “When we fall asleep, it’s pretty similar to a coma because we lose consciousness of our self and of the [outside] world,” study coauthor Thomas Andrillon, a neuroscientist at the École Normale Supérieure, told The Scientist. The question was “whether the brain could still monitor what was going on around, just to be sure the environment was still safe,” he added. © 1986-2016 The Scientist

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 14: Attention and Consciousness
Link ID: 22334 - Posted: 06.18.2016

By Karen Weintraub Many people think they can teach themselves to need less sleep, but they’re wrong, said Dr. Sigrid Veasey, a professor at the Center for Sleep and Circadian Neurobiology at the University of Pennsylvania’s Perelman School of Medicine. We might feel that we’re getting by fine on less sleep, but we’re deluding ourselves, Dr. Veasey said, largely because lack of sleep skews our self-awareness. “The more you deprive yourself of sleep over long periods of time, the less accurate you are of judging your own sleep perception,” she said. Multiple studies have shown that people don’t functionally adapt to less sleep than their bodies need. There is a range of normal sleep times, with most healthy adults naturally needing seven to nine hours of sleep per night, according to the National Sleep Foundation. Those over 65 need about seven to eight hours, on average, while teenagers need eight to 10 hours, and school-age children nine to 11 hours. People’s performance continues to be poor while they are sleep deprived, Dr. Veasey said. Extended vacations are the best times to assess how much sleep you truly need. Once you catch up on lost sleep and are not sleep deprived, the amount you end up sleeping is a good measure how much you need every night. You can ask yourself the questions, “Do you feel that your brain is much sharper, your temper is better, you’re paying attention more effectively? If those answers are yes, than definitely get the sleep,” said Dr. Veasey, who realized -- to her chagrin -- that she needs nine hours of sleep a night to function effectively. Health issues like pain, sleep apnea or autoimmune disease can increase people's need for sleep, said Andrea Meredith, a neuroscientist at the University of Maryland School of Medicine. © 2016 The New York Times Company

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 22333 - Posted: 06.18.2016

By Ashley P. Taylor Sleep is known to aid memory and learning. For example, people who learn something, sleep on it, and are tested on the material after they wake up tend to perform better than those who remain awake in the interim. Within that general phenomenon, however, there’s a lot of unexplained variation. University of California, Riverside, sleep researcher Sara Mednick wondered “what else might be going during that sleep period that helps people’s memories,” she told The Scientist. As it turns out, activity of the autonomic nervous system (ANS) explains a large part of this variation, Mednick and colleagues show in a paper published today (June 13) in PNAS. The researchers measured not only the electrical activity of the brain during sleep, but also that of the heart, providing an indicator of ANS activity. They found that the beat-to-beat variation in heart rate accounted for much of the previously unexplained variation in how well people performed on memory and creativity tests following a nap. “There is a good possibility that this additional measure [heart-rate variability] may help account for discrepant findings in the sleep-dependent memory consolidation literature,” sleep and cognition researcher Rebecca Spencer of the University of Massachusetts, Amherst, who was not involved in the work, wrote in an email. “Perhaps we put too large of a focus on sleep physiology from the CNS [central nervous system] and ignore a significant role of the ANS.” © 1986-2016 The Scientist

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 13: Memory, Learning, and Development
Link ID: 22323 - Posted: 06.15.2016

By Ian Randall As if you needed another reason to hate the gym, it now turns out that exercise can exhaust not only your muscles, but also your eyes. Fear not, however, for coffee can perk them right up again. During strenuous exercise, our muscles tire as they run out of fuel and build up waste products. Muscle performance can also be affected by a phenomenon called “central fatigue,” in which an imbalance in the body’s chemical messengers prevents the central nervous system from directing muscle movements effectively. It was not known, however, whether central fatigue might also affect motor systems not directly involved in the exercise itself—such as those that move the eyes. To find out, researchers gave 11 volunteers a carbohydrate solution either with a moderate dose of caffeine—which is known to stimulate the central nervous system—or as a placebo without, during 3 hours of vigorous cycling. After exercising, the scientists tested the cyclists with eye-tracking cameras to see how well their brains could still control their visual system. The team found that exercise reduced the speed of rapid eye movements by about 8%, impeding their ability to capture new visual information. The caffeine—the equivalent of two strong cups of coffee—was sufficient to counteract this effect, with some cyclists even displaying increased eye movement speeds, the team reports today in Scientific Reports. So it might be a good idea to get someone else to drive you home after that marathon. © 2016 American Association for the Advancement of Science.

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 5: The Sensorimotor System
Link ID: 22243 - Posted: 05.25.2016

Bret Stetka We've all been caught in that hazy tug of war between wakefulness and sleep. But the biology behind how our brains drive us to sleep when we're sleep-deprived hasn't been entirely clear. For the first time scientists have identified the neurons in the brain that appear to control sleep drive, or the growing pressure we feel to sleep after being up for an extended period of time. The findings, published online Thursday by the journal Cell, could lead to better understanding of sleep disorders in humans. And perhaps, one day, if the work all pans out, better treatments for chronic insomnia could be developed. To explore which brain areas might be involved in sleep drive, Johns Hopkins neuroscientist Dr. Mark Wu and his colleagues turned to fruit flies, that long tinkered-with subject of scientific inquiry. Despite our rather obvious physical distinctions, humans and fruit flies – or Drosophila – have a good deal in common when it comes to genes, brain architecture and even behaviors. Included in the study were over 500 strains of fly, each with unique brain activation profiles (meaning certain circuits are more active in certain flies). By employing a genetic engineering technique in which specific groups of neurons can be activated with heat, the researchers were able to monitor the firing of nearly all the major circuits in the fruit fly brain and monitor the resulting effects on sleep. Moreover, the neurons of interest were engineered to glow green when activated allowing specific cells to be identified with fluorescent microscopy. Wu found that activating a group of cells called R2 neurons, which are found in a brain region known as the ellipsoid body, put fruit flies to sleep, even for hours after the neurons were "turned off." © 2016 npr

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 22233 - Posted: 05.21.2016

By Karen Weintraub There are case reports of people with no previously known risks having a heart attack after a nightmare, though they appear to be quite rare. No studies have been done to determine just how rare nightmare-induced heart attacks might be, and experts do not know whether they may result from the pulse-racing effects of the frightening dream itself. Nightmares are more commonly seen in the rapid eye movement, or REM, phase of sleep, which gets longer as the night progresses. Therefore, nightmares are more likely to occur in the early morning hours. Heart attacks, too, are most common in the early morning hours, when internal body clocks start secreting stress hormones and blood pressure tends to rise, said Dr. Mary Ann McLaughlin, a cardiologist at the Icahn School of Medicine at Mount Sinai in New York. If someone is at risk for a heart attack — because of high blood pressure, diabetes, sleep apnea, smoking or other factors — that attack is more likely to occur in the early morning. But “it’s rare for an otherwise healthy person to have a nightmare that causes a heart attack,” said Dr. McLaughlin. Nightmares can be triggered by alcohol, lack of sleep and medications, including some antidepressants and blood pressure medications, she said. Anxiety and depression have also been linked to increased risk of nightmares. On the flip side, patients with heart disease often have sleep apnea, a form of disordered breathing that can lead to fragmented sleep, and potentially more nightmares, said Dr. Neomi Shah, a sleep specialist, also at Mount Sinai. One 2013 study found that apnea patients with regular nightmares woke up more often than those who didn’t. Nightmares disappeared in more than 90 percent of the patients who used a continuous positive airway pressure, or CPAP, machine to treat their apnea. © 2016 The New York Times Company

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 11: Emotions, Aggression, and Stress
Link ID: 22232 - Posted: 05.21.2016

Laura Sanders Brain waves during REM sleep solidify memories in mice, scientists report in the May 13 Science. Scientists suspected that the eye-twitchy, dream-packed slumber known as rapid eye movement sleep was important for memory. But REM sleep’s influence on memory has been hard to study, in part because scientists often resorted to waking people or animals up — a stressful experience that might influence memory in different ways. Richard Boyce of McGill University in Montreal and colleagues interrupted REM sleep in mice in a more delicate way. Using a technique called optogenetics, the researchers blocked a brain oscillation called theta waves in the hippocampus, a brain structure involved in memory, during REM sleep. This light touch meant that the mice stayed asleep but had fewer REM-related theta waves in their hippocampi. Usually, post-learning sleep helps strengthen memories. But mice with disturbed REM sleep had memory trouble, the researchers found. Curious mice will spend more time checking out an object that’s been moved to a new spot than an unmoved object. But after the sleep treatment, the mice seemed to not remember objects’ earlier positions, spending equal time exploring an unmoved object as one in a new place. These mice also showed fewer signs of fear in a place where they had previously suffered shocks. Interfering with theta waves during other stages of sleep didn’t seem to cause memory trouble, suggesting that something special happens during REM sleep. R. Boyce et al. Causal evidence for the role of REM sleep theta rhythm in contextual memory consolidation. Science. Vol. 352, p. 812, May 13, 2016. doi: 10.1126/science.aad5252. © Society for Science & the Public 2000 - 2016.

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 13: Memory, Learning, and Development
Link ID: 22211 - Posted: 05.14.2016

By David Shultz Did you sleep well? The answer may depend on your age, location and gender. A survey of 5000 sleepers from across the world has revealed that women get the most sleep, particularly those under the age of 25. Daniel Forger at the University of Michigan in Ann Arbor and his team were able to get their huge dataset thanks to Entrain, a smartphone app that people use to track their sleep. With their consent, Forger’s team accessed users’ data on their wake time, bed time, time zone and how much light they were exposed to during the day. Analysing this information, they found that middle-aged men sleep the least, while women under the age of 25 sleep the most. As a whole, women appear to sleep on average for 30 minutes longer than men, thanks to going to bed slightly earlier and waking up slightly later. For an individual, the time they woke up had the strongest link to how much sleep they got, suggesting that having a job that starts early every day can mean that you get less sleep than someone who starts work at a later hour. There were also differences between countries. People in Singapore, for example, sleep for an average of 7.5 hours a night, while Australians get 8.1 hours. Late bedtimes seem to be to blame – people in Singapore tended to stay up until after 11.45 pm each night, while people in Australia were likely to hit the hay closer to 10.45 pm. The team found that, in general, national wake-up times were linked more to daylight hours than bedtimes. This could be because bedtimes are more affected by social factors. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 8: Hormones and Sex
Link ID: 22190 - Posted: 05.07.2016

By ERICA GOODE Horses snooze in their stalls. Fish take their 40 winks floating in place. Dogs can doze anywhere, anytime. And even the lowly worm nods off now and then. All animals, most scientists agree, engage in some form of sleep. But the stages of sleep that characterize human slumber had until now been documented only in mammals and birds. A team of researchers in Germany announced in a report published on Thursday, however, that they had found evidence of similar sleep stages in a lizard: specifically, the bearded dragon, or Pogona vitticeps, a reptile native to Australia and popular with pet owners. Recordings from electrodes implanted in the lizards’ brains showed patterns of electrical activity that resembled what is known as slow-wave sleep and another pattern resembling rapid eye movement, or REM, sleep, a stage of deep slumber associated with brain activity similar to that of waking. Some researchers had argued that these stages were of relatively recent origin in evolutionary terms because they had not been found in more primitive animals like amphibians, fish, reptiles other than birds, and other creatures with backbones. But the new finding, said Gilles Laurent, director of the department of neural systems at the Max Planck Institute for Brain Research and the principal author of the study, “increases the probability that sleep evolved in all these animals from a common ancestor.” He added that it also raised the possibility that staged sleep evolved even earlier and that some version of it might exist in animals like amphibians or fish. The report appeared in Thursday’s issue of the journal Science. Other researchers said the study could help scientists understand more about the purpose and mechanisms of sleep. But the finding, they added, is bound to generate more controversy about whether the resting state of primitive animals is really the same as sleep, and whether the brain activity seen in a lizard can be compared to that in mammals. © 2016 The New York Times Company

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 22164 - Posted: 04.30.2016

Tina Hesman Saey To rewrite an Alanis Morissette song, the brain has a funny way of waking you up (and putting you to sleep). Isn’t it ionic? Some scientists think so. Changes in ion concentrations, not nerve cell activity, switch the brain from asleep to awake and back again, researchers report in the April 29 Science. Scientists knew that levels of potassium, calcium and magnesium ions bathing brain cells changed during sleep and wakefulness. But they thought neurons — electrically active cells responsible for most of the brain’s processing power — drove those changes. Instead, the study suggests, neurons aren’t the only sandmen or roosters in the brain. “Neuromodulator” brain chemicals, which pace neuron activity, can bypass neurons altogether to directly wake the brain or lull it to sleep by changing ion concentrations. Scientists hadn’t found this direct connection between ions and sleep and wake before because they were mostly focused on what neurons were doing, says neuroscientist Maiken Nedergaard, who led the study. She got interested in sleep after her lab at the University of Rochester in New York found a drainage system that washes the brain during sleep (SN: 11/16/13, p. 7).When measuring changes in the fluid between brain cells, Nedergaard and colleagues realized that ion changes followed predictable patterns: Potassium ion levels are high when mice (and presumably people) are awake, and drop during sleep. Calcium and magnesium ions follow the opposite pattern; they are higher during sleep and lower when mice are awake. © Society for Science & the Public 2000 - 2016

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 22163 - Posted: 04.30.2016

Yuki Noguchi Hey! Wake up! Need another cup of coffee? Join the club. Apparently about a third of Americans are sleep-deprived. And their employers are probably paying for it, too, in the form of mistakes, productivity loss, accidents and increased health insurance costs. A recent Robert Wood Johnson Foundation report found a third of Americans get less sleep than the recommended seven hours. Another survey by Accountemps, an accounting services firm, put that number at nearly 75 percent in March. Bill Driscoll, Accountemps' regional president in the greater Boston area, says some sleepy accountants even admitted it caused them to make costly mistakes. "One person deleted a project that took 1,000 hours to put together," Driscoll says. "Another person missed a decimal point on an estimated payment and the client overpaid by $1 million. Oops. William David Brown, a sleep psychologist at the University of Texas Southwestern Medical School and author of Sleeping Your Way To The Top, says Americans are sacrificing more and more sleep every year. Fatigue is cumulative, he says, and missing the equivalent of one night's sleep is like having a blood alcohol concentration of about .1 — above the legal limit to drive. "About a third of your employees in any big company are coming to work with an equivalent impairment level of being intoxicated," Brown says. © 2016 npr

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 14: Attention and Consciousness
Link ID: 22144 - Posted: 04.26.2016

Laura Sanders Away from home, people sleep with one ear open. In unfamiliar surroundings, part of the left hemisphere keeps watch while the rest of the brain is deeply asleep, scientists report April 21 in Current Biology. The results help explain why the first night in a hotel isn’t always restful. Some aquatic mammals and birds sleep with half a brain at a time, a trick called unihemispheric sleep. Scientists have believed that humans, however, did not show any such asymmetry in their slumber. Study coauthor Yuka Sasaki of Brown University in Providence, R.I., and colleagues looked for signs of asymmetry on the first night that young, healthy people came into their sleep lab. Usually, scientists toss the data from the inaugural night because the sleep is so disturbed, Sasaki says. But she and her team thought that some interesting sleep patterns might lurk within that fitful sleep. “It was a little bit of a crazy hunch,” she says, “but we did it anyway.” On the first night in a sleep lab, people with more “awake” left hemispheres took longer to fall asleep. This asymmetry was largely gone on the second night, and people fell asleep more quickly. During a deep sleep stage known as slow-wave sleep, a network of nerve cells in the left side of the brain showed less sleep-related activity than the corresponding network on the right side. Those results suggest that the left side of the brain is a lighter sleeper. “It looked like the left hemisphere and the right hemisphere did not show the same degree of sleep,” Sasaki says. This imbalance disappeared on the second night of sleep. © Society for Science & the Public 2000 - 2016

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 15: Brain Asymmetry, Spatial Cognition, and Language
Link ID: 22134 - Posted: 04.23.2016

By Kj Dell’Antonia If you tell your child’s pediatrician that your child is having trouble sleeping, she might respond by asking you how well you sleep yourself. A team of Finnish researchers found that parents with poor sleep quality tended to report more sleep-related difficulties in their children than parents who slept well. But when the researchers looked at an objective monitor of the children’s sleep, using a bracelet similar to a commercial fitness tracker that monitored movement acceleration, a measure of sleep quality, they found that the parents were often reporting sleep problems in their children that didn’t seem to be there. “The only thing that was associated with sleeping problems, as reported by the parents, was their own reported sleeping problems,” said Marko Elovainio, a professor of psychology at the University of Helsinki and one of the authors of the study, which was published this month in the journal Pediatrics. The study was relatively small, involving 100 families with children aged 2 to 6. But the findings suggest that parents’ report of sleep problems in their children are influenced by their own attitudes and behaviors surrounding sleep. The researchers were inspired to do their study, in part, by research showing that mothers with depression over-report behavioral problems in their children, seeing issues that teachers do not see. In pediatrics, the researchers noted, doctors rely heavily on parental reports for information — and if that information is biased by a parent’s own experience, diagnosis becomes more difficult. “Sleep is a good measure of stress,” said Dr. Elovaino, and it is one tool doctors use to evaluate how much stress a child is experiencing. But when making a diagnosis involving a child’s sleeping patterns, “we can’t rely on reports of parents. We need to use more objective measures.” One reason to look at sleep in this context, he said, is that unlike other possible markers of stress, it can be measured objectively. © 2016 The New York Times Company

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 22073 - Posted: 04.06.2016

Feel like you haven’t slept in ages? If you’re one of the 5 per cent of the population who has severe insomnia – trouble sleeping for more than a month – then your brain’s white matter might be to blame. The cell bodies and synapses of our brain cells make up our brain’s grey matter, while bundles of their tails that connect one brain region to another make up the white matter. These nerve cell tails – axons – are cloaked in a fatty myelin sheath that helps transmit signals. Radiologist Shumei Li from Guangdong No. 2 Provincial People’s Hospital in Guangzhou, China, and her team, scanned the brains of 30 healthy sleepers and 23 people with severe insomnia using diffusion tensor imaging MRI. This imaging technique lights up the white matter circuitry. Axons unsheathed They found that in the brains of the people with severe insomnia, the regions in the right hemisphere that support learning, memory, smell and emotion were less well connected compared with healthy sleepers. They attribute this break down in circuitry to the loss of the myelin sheath in the white matter. A study in November suggested that smoking could be one cause for myelin loss. The team also found that the insomniacs had poorer connections in the white matter of the thalamus, a brain region that regulates consciousness, alertness and sleep. The study proposes a potential mechanism for insomnia but there could be other factors, says Max Wintermark, a radiologist at Stanford. He says it’s not possible to say whether the poor connections are the cause of result of insomnia. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 22069 - Posted: 04.05.2016

By Jerome Siegel To say whether an animal sleeps requires that we define sleep. A generally accepted definition is that sleep is a state of greatly reduced responsiveness and movement that is homeostatically regulated, meaning that when it is prevented for a period of time, the lost time is made up—an effect known as sleep rebound. Unfortunately, the application of this definition is sometimes difficult. Can an animal sleep while it is moving and responsive? How unresponsive does an animal have to be? How much of the lost sleep has to be made up for it to be considered homeostatically regulated? Is the brain activity that characterizes sleep in humans necessary and sufficient to define sleep in other animals? Apart from mammals, birds are the only other animals known to engage in both slow-wave and rapid eye movement (REM) sleep. Slow-wave sleep, also called non-REM sleep, is characterized by slow, high-amplitude waves of electrical activity in the cortex and by slow, regular respiration and heart rate. During REM sleep, animals exhibit a waking-like pattern of cortical activity, as well as physiological changes including jerky eye twitches and increased variability of heart rate and respiration. (See “The A, B, Zzzzs.”) But many more animals, including some insects and fish, engage in behaviors that might be called sleep, such as resting with slow but regular respiration and heart rates and a desensitization to environmental stimuli. In addition to diversity in the neural and physiological correlates of sleep, species vary tremendously in the intensity, frequency, and duration of sleep. Some animals tend to nap intermittently throughout the day, while others, including humans, tend to consolidate their sleep into a single, long slumber. The big brown bat is the current sleep champion, registering 20 hours per day; giraffes and elephants doze less than four hours daily. © 1986-2016 The Scientist

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 21974 - Posted: 03.10.2016

By Kerry Grens On a closed-circuit television I watch Marie settle into her room, unpacking her toiletries in the bathroom and arranging her clothes for the next day. Her digs at the University of Chicago sleep lab look like an ordinary hotel room, with a bed, TV, desk, nightstand. Ordinary, except for the camera keeping watch from across the bed and the small metal door in the wall next to the headboard. The door, about one foot square, is used when researchers want to sample the study participants’ blood during the night without disturbing them; an IV line passes from the person’s arm through the door and into the master control room where I’m watching Marie on the screen. She’s come to the lab on a weekday evening to be screened for possible inclusion in a study on insomnia. Marie says her sleep problems started almost 20 years ago, on the first day of her job as a flight attendant. “The phone rang in the middle of the night,” she recalls. It was work, scheduling her for a flight. “Something was triggered in my mind. It was the first time in my life I experienced a night with no sleep. Something clicked. Then the second night I couldn’t sleep. It just went on. I lost my ability to sleep.” After a few years, Marie (not her real name—she asked to remain anonymous for privacy) stopped working. Most nights she’ll sleep for a short stretch—maybe a few hours—then wake up and lie awake for hours as pain in her neck consumes her and makes her uneasy and restless. “I’ve seen psychologists, physical therapists, doctors. I’ve been prescribed medications for depression. But it didn’t work,” she says. “Every single day it’s a struggle . . . I feel like when Job was attacked by the devil. Someone is trying to take my vitality away.” © 1986-2016 The Scientist

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 21959 - Posted: 03.07.2016

Ian Sample Science editor Too little sleep may bring on a form of the marijuana “munchies”, say scientists who found that sleep-deprived people craved crisps, sweets and biscuits far more than healthier foods. The US researchers believe that skimping on sleep alters brain chemicals in much the same way as the hunger-boosting ingredient in cannabis, which has long propped up snack sales at 24-hour convenience stores. After several nights of poor sleep, healthy volunteers who took part in the study reached for snacks containing more calories - and nearly twice as much fat - than ones they favoured after sleeping well for the same period, the scientists say. When sleepy, the participants had terrible trouble resisting the snacks, even when they were full, said Erin Hanlon, who led the study at the University of Chicago. Research has shown time and again that sleep loss raises the risk of obesity, but the reasons are complex and unclear. Insufficient sleep disrupts hormones that govern appetite and satiety. But those who sleep less have more time to eat, and may be too tired to exercise. To muddy the waters further, obesity can lead to breathing problems that themselves disrupt sleep patterns. In a small study published in the journal Sleep, Hanlon invited 14 men and women in their twenties to spend two four-day sessions at the university’s clinical research centre. The volunteers’ time in bed was controlled, so that on one visit they averaged 7.5 hours of sleep a night, but on the other only 4 hours 11 minutes a night. During their stays, the volunteers ate identical meals, dished out at 9am, 2pm and 7pm.

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 21943 - Posted: 03.01.2016

By Claire Asher A poor night's sleep is enough to put anyone in a bad mood, and although scientists have long suspected a link between mood and sleep, the molecular basis of this connection remained a mystery. Now, new research has found several rare genetic mutations on the same gene that definitively connect the two. Sleep goes hand-in-hand with mood. People suffering from depression and mania, for example, frequently have altered sleeping patterns, as do those with seasonal affective disorder (SAD). And although no one knows exactly how these changes come about, in SAD sufferers they are influenced by changes in light exposure, the brain’s time-keeping cue. But is mood affecting sleep, is sleep affecting mood, or is there a third factor influencing both? Although a number of tantalizing leads have linked the circadian clock to mood, there is “no definitive factor that proves causality or indicates the direction of the relationship,” says Michael McCarthy, a neurobiologist at the San Diego Veterans’ Affairs Medical Center and the University of California (UC), San Diego. To see whether they could establish a link between the circadian clock, sleep, and mood, scientists in the new study looked at the genetics of a family that suffers from abnormal sleep patterns and mood disorders, including SAD and something called advanced sleep phase, a condition in which people wake earlier and sleep earlier than normal. The scientists screened the family for mutations in key genes involved in the circadian clock, and identified two rare variants of the PERIOD3 (PER3) gene in members suffering from SAD and advanced sleep phase. “We found a genetic change in people who have both seasonal affective disorder and the morning lark trait” says lead researcher Ying-Hui Fu, a neuroscientist at UC San Francisco. When the team tested for these mutations in DNA samples from the general population, they found that they were extremely rare, appearing in less than 1% of samples. © 2016 American Association for the Advancement of Science.

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 21926 - Posted: 02.23.2016

By Ariana Eunjung Cha The Centers for Disease Control and Prevention just published their first national survey of sleep for all 50 states and the District of Columbia. In many respects, it's consistent with our image of ourselves as bleary-eyed insomniacs downing triple espresso shots and melatonin pills as we stare at our iPhones like zombies. The CDC found that more than a third of American adults are not getting the recommended amount of seven-plus hours of sleep on a regular basis. Here's a look at what sleep looks like across the United States, as broken down by marital status, geography, race/ethnicity and employment. The results aren't always what you might expect. 1. First, here's a breakdown of how much sleep Americans are getting overall. This is based on a random telephone survey of 444,306 respondents. Overall, about 65 percent reported a "healthy sleep duration" (seven or more hours of sleep on a regular basis) and about 35 percent reported they were getting less than that. 2. Being unable to work or being unemployed appears to affect sleep in a negative way. That's consistent with previous research on sleep quality and mental health issues like depression that can be related to unemployment. 3. People with college degrees or higher were more likely to get enough sleep. Maybe it's because they are more likely to know how important good sleep is to your health or maybe because they have jobs or income that allow them to get more sleep?

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 11: Emotions, Aggression, and Stress
Link ID: 21917 - Posted: 02.20.2016

By John Bohannon Didn't get your 40 winks last night? Better not get yourself arrested, or you may admit to a crime you didn't commit. False confessions are surprisingly easy to extract from people simply by keeping them awake, according to a new study of sleep deprivation. It puts hard numbers to a problem that criminal law reformers have worried about for decades. The “crime” in question took place in a sleep lab run by Kimberly Fenn at Michigan State University in East Lansing. Together, she and Elizabeth Loftus, a psychologist at the University of California (UC), Irvine, and two of their former Ph.D. students recruited 88 Michigan State students to take part in an experiment. During two separate visits, the students worked at computers solving problems and filling out questionnaires. They were all given a stern warning: Do not press the escape key, because it will erase important study data. After their second session, the subjects were split into two groups. Half of them were forced to stay awake all night under the watch of the researchers. Scrabble, TV shows, and a card game called euchre seemed to do the trick. The rest were allowed to get a full night's sleep. But that also required policing. "We actually had a student leave the study because he wanted to stay awake all night to study for an exam the next day," Fenn says, adding that "I certainly do not advocate this!" The next morning, everyone received a typed statement describing their performance. The statement accused them of hitting the escape key on the first day, even though none of them actually did so—the computers recorded all keystrokes. © 2016 American Association for the Advancement of Science

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 14: Attention and Consciousness
Link ID: 21877 - Posted: 02.09.2016