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By Brady Dennis, Insomniacs of the world: If you think taking a long run today will make you sleep better tonight, think again. While exercise has long been a prescription for insomnia, new research suggests that exercise doesn’t immediately translate into a better night’s sleep — unless you stick with it for months. A study published Thursday in the Journal of Clinical Sleep Medicine found that aerobic exercise can lead to more rest at night for people who suffer from existing sleep problems, but only if they maintain an exercise regimen for roughly four months. “Exercise isn’t a quick fix. . . . It takes some time and effort,” the study’s lead author, Kelly Glazer Baron, a clinical psychologist and director of the behavioral sleep program at Northwestern University’s Feinberg School of Medicine, said in an interview. “It’s a long-term relationship.” Studies have long suggested that aerobic exercise can contribute to better sleeping habits. But much of the research on the daily effects of exercise on sleep was conducted with healthy sleepers. Tuesday’s study, by contrast, looked at the long-term effects of exercise in people already suffering from sleep disorders. © 1996-2013 The Washington Post

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 18526 - Posted: 08.19.2013

By KATIE THOMAS The first test for a new sleep drug is — unsurprisingly — how safely it puts people to sleep. Now comes a second test: how safely it lets people wake up. The Food and Drug Administration is taking heightened interest in the issue, as new evidence suggests what many people have long suspected: the effects of common prescription sleep aids like Ambien can persist well into the next day. Of particular concern is whether people who take the drugs before bed can drive safely the next morning. Consumer advocates have warned for years about possible links between sleep drugs and car accidents. In one prominent example, Kerry Kennedy, the former wife of Gov. Andrew M. Cuomo, was arrested last year after tests showed she had taken a sleep aid before swerving her car into a tractor-trailer. The F.D.A.’s actions are part of a robust national conversation about how to cope with the throngs of drivers who take to roads every day under the influence of prescription drugs. Law enforcement authorities have struggled with how to prosecute those who are impaired, especially when they have a prescription. A government survey in 2007 found that nearly 5 percent of daytime drivers tested positive for prescription or over-the-counter medications. Doctors wrote close to 60 million prescriptions for sleep aids in the United States last year, according to the research firm IMS Health, but experts say testing how these drugs affect driving is not easy. Nonetheless, the F.D.A. has been unusually active. Last month, it rejected an application by Merck to approve a new sleep drug, suvorexant, in part because tests showed that some people had trouble driving the next day. In May, the agency warned patients taking common allergy drugs like Benadryl against driving, noting that the sedating effects can sometimes last into the following day. In January, citing similar concerns, the F.D.A. took the unusual step of requiring that all manufacturers of zolpidem, the generic name of Ambien, cut in half the dosage for women. © 2013 The New York Times Company

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: 18508 - Posted: 08.14.2013

By ANAHAD O'CONNOR Losing sleep tends to make people eat more and gain weight, and now a new study suggests that one reason may be the impact that sleep deprivation has on the brain. The research showed that depriving people of sleep for one night created pronounced changes in the way their brains responded to high-calorie junk foods. On days when the subjects had not had proper sleep, fattening foods like potato chips and sweets stimulated stronger responses in a part of the brain that helps govern the motivation to eat. But at the same time, the subjects experienced a sharp reduction in activity in the frontal cortex, a higher-level part of the brain where consequences are weighed and rational decisions are made. The findings suggested that one unfortunate result of sleep loss is this “double hit” in brain activity, said Matthew P. Walker, an author of the study and a professor of psychology and neuroscience at the University of California, Berkeley. A sleepy brain appears to not only respond more strongly to junk food, but also has less ability to rein that impulse in. Some experts have theorized that in a sleep-deprived state, people eat more food simply to make up for all the calories they expend as they burn the midnight oil. But the new study showed that the changes in brain activity were evident even when the subjects were fed extra food and not experiencing any increased sensations in hunger. “Their hunger was no different when they were sleep deprived and when they had a normal night of sleep,” Dr. Walker said. “That’s important because it suggests that the changes we’re seeing are caused by sleep deprivation itself, rather than simply being perhaps more metabolically impaired when you’re sleep deprived.” Copyright 2013 The New York Times Company

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: 18471 - Posted: 08.07.2013

Sleepless night, the moon is bright. People sleep less soundly when there's a full moon, researchers discovered when they analyzed data from a past sleep study. If you were tossing and turning and howling at your pillow this week, you’re not necessarily a lunatic, at least in the strictest sense of the word. The recent full moon might be to blame for your poor sleep. In the days close to a full moon, people take longer to doze off, sleep less deeply, and sleep for a shorter time, even if the moon isn’t shining in their window, a new study has found. “A lot of people are going to say, ‘Yeah, I knew this already. I never sleep well during a full moon.’ But this is the first data that really confirms it,” says biologist Christian Cajochen of the University of Basel in Switzerland, lead author of the new work. “There had been numerous studies before, but many were very inconclusive.” Anecdotal evidence has long suggested that people’s sleep patterns, moods, and even aggression is linked to moon cycles. But past studies of potential lunar effects have been tainted by statistical weaknesses, biases, or inconsistent methods, Cajochen says. Between 2000 and 2003, he and his colleagues had collected detailed data on the sleep patterns of 33 healthy volunteers for an unrelated study on the effects of aging on sleep. Using electroencephalograms (EEG) that measure brain activity, they recorded how deep and how long each participant’s nightly sleep was in a controlled, laboratory setting. Years after the initial experiment, the scientists were drinking in a pub—during a full moon—and came up with the idea of going back to the data to test for correlations with moon cycles. © 2012 American Association for the Advancement of Science.

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 7: Vision: From Eye to Brain
Link ID: 18415 - Posted: 07.27.2013

By Scicurious We all know we should get more sleep, we’re just not very good at it. In fact, we’re so BAD at it that 28.3% of us (as of 2007, anyway) got less than 6 hours of sleep per night. Really, are we surprised? After all, there are kids that wake up in the night, stress that keeps us awake, always more things to do, multiple jobs, and only so many hours in the day. But that lack of sleep can have some not so great effects on our bodies. It decreases things like cognitive performance, increases anxiety, and…it’s not good for our waistlines. Sleep loss is associated with higher caloric intake, when you can’t sleep you eat. But does this increased caloric intake translate to weight gain? The biggest positive point of this study on sleep restriction was how LARGE it was. When doing human studies that are not large scale surveys (which usually involve phone calls or mail in or online and therefore are less expensive) it costs a LOT of money to bring some people in to the lab to do nothing but hang out and sleep for a week, especially if you are watching for things like food intake (and controlling what they eat). I’m very pleased that they got these numbers, 225 people! The authors took these 225 people, and brought them into the lab. They got two baseline nights (to see how much they naturally slept), 5 sleep restriction nights, and then another 2 recovery nights. But unfortunately, they did not balance the control and sleep restriction, where they were restricted down to FOUR HOURS a night of sleep (ick). They only had 27 controls out of all of these (people allowed to sleep fully all the nights of the study), the rest were sleep restriction. I have to wonder why they did it this way. While the two original nights and the two recovery nights could in theory serve as a partial control, I don’t think that those would work. After all, if most people are slightly sleep restricted, the original two nights will be recovery as well, and both sets of recovery nights may not be representative of optimal sleep. © 2013 Scientific American

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: 18402 - Posted: 07.23.2013

By Scicurious It seems like the worst sort of cycle. The less sleep you get, the less effective you are. Then you have more to do, get more stressed, and stay up trying to get it all done (or lie awake stressing about it). The next day, less sleep, and even more anxiety. The ironic part is that you might not be quite so anxious…if you could just get some SLEEP. The authors of this study wanted to look at anxiety responses in people, and how they were affected by lack of sleep. To do this, you need 19 healthy participants, an fMRI machine, a test of anxiety…and way to keep people up all night. How do you assess anxiety responses? Start with cues, and then give outcomes. You can see the layout of the studies above. The participants were placed in an fMRI scanner. During the recording, they were shown signs, followed by stimuli. If they got a negative sign, they would always get a negative stimuli (a man with a gun, which is plenty good enough to provoke an anxiety response). If they got a zero sign, they got a normal stimuli (a doorknob. Nothing scary there). If they got a question mark, they have a 50% chance of getting the negative stimulus. This question mark gives you an ambiguous stimulus, you don’t know what to expect. They had the participants go through the series of stimuli in two conditions: rested and sleep deprived. And when they sleep deprived them, BOY did they. Many sleep deprivation studies will restrict sleep to, say, 4 hours the night before the study, or 5. Not these guys. No, they had the participants pull an all-nighter! © 2013 Scientific American

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: 18379 - Posted: 07.16.2013

By Michelle Roberts Health editor, BBC News online Late nights and lax bedtime routines can blunt young children's minds, research suggests. The findings on sleep patterns and brain power come from a UK study of more than 11,000 seven-year-olds. Youngsters who had no regular bedtime or who went to bed later than 21:00 had lower scores for reading and maths. Lack of sleep may disrupt natural body rhythms and impair how well the brain learns new information say the study authors. They gathered data on the children at the ages of three, five and then seven to find out how well they were doing with their learning and whether this might be related to their sleeping habits. Erratic bedtimes were most common at the age of three, when around one in five of the children went to bed at varying times. By the age of seven, more than half the children had a regular bedtime of between 19:30 and 20:30. Overall, children who had never had regular bedtimes tended to fare worse than their peers in terms of test scores for reading, maths and spatial awareness. The impact was more obvious throughout early childhood in girls than in boys and appeared to be cumulative. BBC © 2013

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: 18362 - Posted: 07.09.2013

Melatonin is marketed as a natural sleep aid but it's potentially risky for healthy children to use long term, Canadian pediatricians say. Difficulties settling, falling asleep and staying asleep affect up to 25 per cent of children generally and up to half of those with physical and mental health problems, according to the Canadian Sleep Society. Melatonin is a hormone of darkness that is part of the sleep cycle. People can buy melatonin supplements at pharmacies and health food stores to overcome jet lag or occasional insomnia. But long-term use by healthy, developing children isn't advised, said Dr. Shelly Weiss, a neurologist at the Hospital for Sick Children in Toronto, who is studying the use of melatonin supplements for improving sleep in children with epilepsy. "It's being touted as this magic pill," said Weiss. "There's definitely concern that people are going to use it more widely and not appreciate that their child can learn to sleep better without a hormone being given." Melatonin supplements contain between 25 to 50 times as much melatonin as the body makes at night, Weiss noted. "There's definitely potential risk, mostly to delayed puberty or delayed development in children who have taken it for a long time," said Weiss, who is also president of the Canadian Sleep Society and an associate professor at the University of Toronto. © CBC 2013

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 5: Hormones and the Brain
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 8: Hormones and Sex
Link ID: 18354 - Posted: 07.08.2013

A UC Berkeley study suggests that sleep deprivation triggers anxiety by inducing hyperactivity in brain regions that control emotions. The study, published in the Journal of Neuroscience, suggests that sleep therapy can help patients with anxiety disorders. Stress and anticipation bring anxiety that can sometimes be good; if under control, anxiety might help a person focus and be more efficient. But a patient with anxiety disorders, such as post-traumatic stress disorder (PTSD), generalized anxiety disorder (GAD), obsessive-compulsive disorder (OCD) or other disorders and phobias, cannot control it. The feeling of anxiety and nervousness is constant and has major negative impact on their everyday life. The socioeconomic impact is huge as about one in five adults in the U.S. are affected by such mental illnesses. What are the drivers of anxiety disorders? Why can some people control anxiety while others cannot? Research studies have shown over the years that causes can be genetics, personality, social environment and brain chemistry. Scientists have found a network of neurons in the brain that supports affective anticipation and anxiety. More precisely, those with anxiety disorders have hyperactivity in certain regions of the brain that process emotions, including the amygdala and anterior insula cortex. On top of that, sleep deprivation amplifies the symptoms, a setback for patients because it is very common for them to suffer from sleep abnormalities. Looking for more clues about the connection between sleep and anxiety management, Matthew P. Walker, professor of psychology and neuroscience at UC Berkeley, led a study that looked for differences in the activity of the amygdala and anterior insula cortex in the brains of healthy adults after sleep deprivation and after a good night’s 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: 18345 - Posted: 07.04.2013

Till Roenneberg Sleep is essential for health, performance and wellbeing. Yet in many countries, people are getting one to two hours less of it each night than their ancestors did 50–100 years ago. Even when people have the opportunity to sleep, many cannot. Sleep pathologies are approaching epidemic levels, affecting an estimated 70 million people in the United States alone (see go.nature.com/6dgqhg). And in some countries, direct and indirect costs of sleep-related problems are thought to approach 1% of gross domestic product1. Despite these alarming numbers, sleep research ranks only 91st in the 235 categories on this year's funding list of the US National Institutes of Health — below, for instance, studies of tobacco (see go.nature.com/ces1rf). Researchers have made great advances in understanding which neurotransmitters and brain regions are involved in sleep2, and how the timings of sleep and wakefulness are controlled by an internal (circadian) clock3, among other things. Yet we still do not have answers to the most basic questions. It is not really understood, for instance, what sleep is for, how much is optimal, how sleep quality can be measured and predicted, or the role of genetic and environmental factors in determining ideal sleeping patterns. One reason for this lack of understanding is that most of what is known about sleep comes from laboratory studies. Subjects in these studies tend to be mice or hamsters that are kept in artificial light–dark cycles, or people who have been instructed to sleep at certain times in beds that are not their own, with electrodes fastened to their heads. Assessments of sleep are also often based on subjective responses to questions about how 'well' people feel after they have slept, or whether they think they experienced a good night's sleep. To learn about sleep in the real world, and to establish how to manage sleep to improve productivity, health and quality of life, we need a multidisciplinary 'human sleep project'. © 2013 Nature Publishing Group

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 18325 - Posted: 06.29.2013

by Sue Langthorp Losing sleep doesn't just make us hazy and irritable. It can also lead to cardiovascular disease, type 2 diabetes, and a host of other conditions. But catching up on some shuteye may help combat these problems. According to a new study, sleep-deprived men who dozed an extra 2 to 3 hours on the weekend may reduce their risk of developing type 2 diabetes. Researchers led by Peter Liu, an endocrinologist at the Los Angeles Biomedical Research Institute at the Harbor-University of California, Los Angeles, Medical Center, recruited 19 men in good health who, due to their workload, were poor sleepers. The subjects, age 29 on average, had been clocking about 6 hours of shuteye on weeknights for just over 5 years. However, they made the most of their weekends and slept an extra 2.3 hours a night on Friday and Saturday. When selecting the candidates for the trial, the scientists verified their reported schedules using sleep actigraphs, devices worn like wrist watches that record sleep patterns. The men slept in the lab for three nights. Some were allowed to sleep 10 hours without interruption, catching up on the sleep that they had lost earlier in the week. Others slept 10 hours with frequent interruption, and still others slept 6 hours without interruption. All the subjects ate the same diet, so the researchers could normalize their insulin and sugar levels. © 2010 American Association for the Advancement of Science

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: 18288 - Posted: 06.20.2013

By JANE E. BRODY Think you do just fine on five or six hours of shut-eye? Chances are, you are among the many millions who unwittingly shortchange themselves on sleep. Research shows that most people require seven or eight hours of sleep to function optimally. Failing to get enough sleep night after night can compromise your health and may even shorten your life. From infancy to old age, the effects of inadequate sleep can profoundly affect memory, learning, creativity, productivity and emotional stability, as well as your physical health. According to sleep specialists at the University of Pittsburgh School of Medicine and Western Psychiatric Institute and Clinic, among others, a number of bodily systems are negatively affected by inadequate sleep: the heart, lungs and kidneys; appetite, metabolism and weight control; immune function and disease resistance; sensitivity to pain; reaction time; mood; and brain function. Poor sleep is also a risk factor for depression and substance abuse, especially among people with post-traumatic stress disorder, according to Anne Germain, associate professor of psychiatry at the University of Pittsburgh. People with PTSD tend to relive their trauma when they try to sleep, which keeps their brains in a heightened state of alertness. Dr. Germain is studying what happens in the brains of sleeping veterans with PTSD in hopes of developing more effective treatments for them and for people with lesser degrees of stress that interfere with a good night’s sleep. Copyright 2013 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: 18280 - Posted: 06.17.2013

Posted by Dr. Claire McCarthy Thumbnail image for sleep.jpgAccording to a study just released, the number of hours kids sleep at night is more affected by genetics than by bedtime or how quiet or dark it is. While daytime naps can be affected and changed by messing with the environment, nighttime sleep is a more wired thing. This doesn’t surprise me at all, actually. For years I’ve been hearing from parents about how much their children sleep, and there is remarkable variation. Some kids sleep a lot at night and a lot during the day too, while others truly barely sleep at all—and yet, for the most part, they seem to get the sleep they need. It’s hard to explain this variation to parents, who understandably think that all kids of a certain age must need roughly the same amount of sleep. That’s just one of the conversations I seem to have again and again about sleep. When I read the study I thought: this would be a great opportunity to write a blog about the things I wish all parents knew about sleep. So here they are: Every child needs a different amount of sleep, as the study points out. It depends on age, to some extent, but it also depends on genetics, what they do during the day and all sorts of factors we don’t understand yet. So instead of counting hours, look at your kid. Are they generally tired or cranky during the day? If so, they may need more sleep. If they are healthy, act rested, have enough energy, get along with others (and are doing okay in school if they go to school), they are probably getting enough sleep. © 2013 NY Times Co.

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 18216 - Posted: 06.01.2013

How long a toddler sleeps at night depends in part on genes but environmental factors seem to make more of a difference for naps, a study of nearly 1,000 Canadian twins suggests. Researchers asked parents of 405 identical and 586 fraternal infants born in the Montreal area to answer questions about daytime and nighttime sleep habits at ages six months, 18 months, 30 months and 48 months. Twin girls sleep. Canadian researchers studied the sleep habits of twins, with the results being published this week.Twin girls sleep. Canadian researchers studied the sleep habits of twins, with the results being published this week. (iStock) "This study is the first to show that daytime sleep duration in early childhood is strongly influenced by environmental factors," Dr. Jacques Montplaisir from the University of Montreal and his colleagues concluded in Monday's issue of the journal Pediatrics. At most ages, genetics accounted for between 47 and 58 per cent of nighttime sleep duration. The majority of children slept 10 or 11 continuous hours at night. The exception was nighttime sleep at 18 months, which the researchers called "a critical environmental time-window" for establishing sleep patterns. On the other hand, genes never explained more than about one-third of daytime nap time. Environmental factors like family routines accounted for between 33 and 79 per cent of whether or not twins napped and for how long. © CBC 2013

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 13: Memory, Learning, and Development
Link ID: 18198 - Posted: 05.28.2013

By Michelle Roberts Health editor, BBC News online Sharing a bed with a newborn increases the risk of sudden infant death syndrome fivefold, research claims. The risk applies even if parents avoid tobacco, alcohol and drugs - other factors firmly linked to cot deaths. The BMJ Open research compared nearly 1,500 cot deaths with a control group of more than 4,500 parents. Current guidance in the UK is that parents should decide where their baby sleeps, but says the safest option is in a crib or cot in the same room. No consensus Many other countries, such as the US and the Netherlands, go further and say parents should not share a bed with their baby for the first three months of his or her life. Prof Bob Carpenter, from the London School of Hygiene & Tropical Medicine, carried out the analysis and says the UK should now follow suit and "take a more definitive stance against bed-sharing for babies under three months". The government said it had asked the public health watchdog NICE to urgently examine its guidance on co-sleeping in light of this new study. BBC © 2013

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 18179 - Posted: 05.21.2013

By VATSAL G. THAKKAR IN the spring of 2010, a new patient came to see me to find out if he had attention-deficit hyperactivity disorder. He had all the classic symptoms: procrastination, forgetfulness, a propensity to lose things and, of course, the inability to pay attention consistently. But one thing was unusual. His symptoms had started only two years earlier, when he was 31. Though I treat a lot of adults for attention-deficit hyperactivity disorder, the presentation of this case was a violation of an important diagnostic criterion: symptoms must date back to childhood. It turned out he first started having these problems the month he began his most recent job, one that required him to rise at 5 a.m., despite the fact that he was a night owl. The patient didn’t have A.D.H.D., I realized, but a chronic sleep deficit. I suggested some techniques to help him fall asleep at night, like relaxing for 90 minutes before getting in bed at 10 p.m. If necessary, he could take a small amount of melatonin. When he returned to see me two weeks later, his symptoms were almost gone. I suggested he call if they recurred. I never heard from him again. Many theories are thrown around to explain the rise in the diagnosis and treatment of A.D.H.D. in children and adults. According to the Centers for Disease Control and Prevention, 11 percent of school-age children have now received a diagnosis of the condition. I don’t doubt that many people do, in fact, have A.D.H.D.; I regularly diagnose and treat it in adults. But what if a substantial proportion of cases are really sleep disorders in disguise? © 2013 The New York Times Company

Related chapters from BP7e: Chapter 17: Learning and Memory; Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 10: Biological Rhythms and Sleep
Link ID: 18086 - Posted: 04.28.2013

By Russell Foster "Making teens start school in the morning is ‘cruel,’ brain doctor claims." So declared a British newspaper headline in 2007 after a talk I gave at an academic conference. One disbelieving reader responded: "This man sounds brain-dead." That was a typical reaction to work I was reporting at the time on teenage sleep patterns and their effect on performance at school. Six years on, there is growing acceptance that the structure of the academic day needs to take account of adolescent sleep patterns. The latest school to adopt a later start time is the UCL Academy in London; others are considering following suit. So what are the facts about teenage slumber, and how should society adjust to these needs? The biology of human sleep timing, like that of other mammals, changes as we age. This has been shown in many studies. As puberty begins, bedtimes and waking times get later. This trend continues until 19.5 years in women and 21 in men. Then it reverses. At 55 we wake at about the time we woke prior to puberty. On average this is two hours earlier than adolescents. This means that for a teenager, a 7 a.m. alarm call is the equivalent of a 5 a.m. start for people in their 50s. Precisely why this is so is unclear, but the shifts correlate with hormonal changes at puberty and the decline in those hormones as we age. However, biology is only part of the problem. Additional factors include a more relaxed attitude to bedtimes by parents, a general disregard for the importance of sleep, and access to TVs, DVDs, PCs, gaming devices, cellphones, and so on, all of which promote alertness and eat into time available for sleep. © 2013 The Slate Group, LLC.

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 13: Memory, Learning, and Development
Link ID: 18084 - Posted: 04.27.2013

Published by scicurious under Behavioral Neuro It's late. I've got a lot on my plate. A lot to do. And most of us do. So here I am, burning the midnight oil along with many of my neighbors. I usually count myself lucky to get 7 hours a night, and I AM lucky. For many parents or other caregivers, for example, 7 hours is unheard-of luxury. Is it just me? Probably not. Most of us don't get enough sleep, and those who don't sleep? Snack. But why? And what does this mean for issues like obesity? We know that there has been an increase in obesity in this country. And many people are asking why. There are probably lots of reasons involved: too much sugar, too little exercise, genetics, too much fat. But what about sleep? It turns out that getting less sleep is a risk factor for obesity, but...how are sleep and weight gain related? It turns out that sleep, or lack thereof, can have a lot of influence on how much we need to eat and how much we feel like eating. For example, sleep deprivation changes hunger hormone levels, which can change food intake, and some scientists hypothesize that decreased sleep can change energy expenditure as well. But in order to understand just how lack of sleep influences weight gain, well you need to sleep deprive some people. The authors took 8 men and 8 women who reported getting an average of 8 hours of sleep per night into an inpatient facility. They were taken off caffeine one week before the study and were told to stick to 9 hours of sleep opportunity (stay in bed 9 hours) per night for the first week. They also were put on a diet that was calibrated exactly to maintain their current weight. Copyright © 2013

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: 18074 - Posted: 04.25.2013

By Stephani Sutherland Scientists have long known that once we nod off, certain memories grow stronger. One recent theory suggests that forgetting, too, is an essential function of sleep [see “Sleep's Secret Repairs,” by Jason Castro; Scientific American Mind, May/June 2012]. Researchers now suspect that post-traumatic stress disorder (PTSD) may emerge from flaws in sleep's forgetting process. Two studies presented at the 2012 meeting of the Society for Neuroscience in New Orleans indicate that sleep might offer a window of opportunity for weakening memories and providing relief from lingering reminders of trauma. Neuroscientists believe that during sleep, a memory-elimination routine cleans out obsolete information by physically weakening synapses, the junctions between communicating neurons. Gina Poe, a neuroscientist at the University of Michigan, found in mice that for synapses to lose strength, levels of the neurotransmitter noradrenaline must drop. Noradrenaline levels typically fall during REM sleep in rodents and humans, but in people with PTSD the amount stays high throughout sleep. Normalizing noradrenaline with pharmaceuticals, Poe says, “could absolutely be a key target to actually cure PTSD through normal sleep.” In a separate experiment, researcher Asya Rolls of Stanford University hijacked memory remodeling in sleeping mice to make a traumatic association less scary. Rolls and her colleagues conditioned mice to fear the scent of jasmine flowers by pairing the smell with a foot shock. When the mice slept, they released a puff of jasmine. Under normal circumstances, the smell would reactivate and bolster the memory, a process that requires newly made structural proteins. The researchers gave some mice a drug that prevented the manufacture of these building blocks in a key fear-memory area. When these mice woke up, they no longer responded to the odor with fearful behavior, indicating that the memory had been successfully disrupted. The findings might someday translate to a new kind of sleep-based therapy in people whose traumatic experiences are tied to specific sounds and smells—such as the noise of a bomb going off—that can be presented to their sleeping brain. © 2013 Scientific American

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: 18006 - Posted: 04.09.2013

Barry Gordon, professor of neurology and cognitive science at the Johns Hopkins University School of Medicine, replies: We are aware of a tiny fraction of the thinking that goes on in our minds, and we can control only a tiny part of our conscious thoughts. The vast majority of our thinking efforts goes on subconsciously. Only one or two of these thoughts are likely to breach into consciousness at a time. Slips of the tongue and accidental actions offer glimpses of our unfiltered subconscious mental life. The intrusive thoughts you may experience throughout the day or before bed illustrate the disconcerting fact that many of the functions of the mind are outside of conscious control. Whether we maintain true control over any mental functions is the central debate about free will. Perhaps this lack of autonomy is to be expected as the foundations for almost all the mind's labors were laid long before our ancestors evolved consciousness. Even deliberate decisions are not completely under our power. Our awareness only sets the start and the end of a goal but leaves the implementation to unconscious mental processes. Thus, a batter can decide to swing at a ball that comes into the strike zone and can delineate the boundaries of that zone. But when the ball comes sailing through, unconscious mental functions take over. The actions required to send him to first base are too complex and unfold too quickly for our comparatively slow conscious control to handle. © 2013 Scientific American

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: 18000 - Posted: 04.08.2013