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by Elizabeth Norton The ability to recognize faces is so important in humans that the brain appears to have an area solely devoted to the task: the fusiform gyrus. Brain imaging studies consistently find that this region of the temporal lobe becomes active when people look at faces. Skeptics have countered, however, that these studies show only a correlation, but not proof, that activity in this area is essential for face recognition. Now, thanks to the willingness of an intrepid patient, a new study provides the first cause-and-effect evidence that neurons in this area help humans recognize faces—and only faces, not other body parts or objects. An unusual collaboration between researchers and an epilepsy patient led to the discovery. Ron Blackwell, an engineer in Santa Clara, California, came to Stanford University in Palo Alto, California, in 2011 seeking better treatment for his epilepsy. He had suffered seizures since he was a teenager, and at age 47, his medication was becoming less effective. Stanford neurologist Josef Parvizi suggested some tests to locate the source of the seizures—and also suggested that it might be possible to eliminate the seizures by surgically destroying a tiny area of brain tissue where they occurred. Parvizi used electrodes placed on Blackwell's scalp to trace the seizures to the temporal lobe, about an inch above Blackwell's right ear. Then, surgeons placed more electrodes on the surface of Blackwell's brain, near the suspect point of origin in the temporal lobe. Parvizi stimulated each electrode in turn with a mild current, trying to trigger Blackwell's seizure symptoms under safe conditions. "If we get those symptoms, we know that we are tickling the seizure node," he explains. © 2010 American Association for the Advancement of Science.
Keyword: Attention
Link ID: 17414 - Posted: 10.24.2012
by Shaoni Bhattacharya Talk about having your cake and eating it. Fasting might not be the only route to a longer life – a hormone seems to work just as well, for mice at least. We know that some animals can extend their lifespan by consuming fewer calories. Engineered mice can get the same effect by simply pumping out high levels of a hormone normally produced during a fast, according to Steven Kliewer and David Mangelsdorf at the University of Texas Southwestern Medical Center in Dallas. Their team found that mice engineered to make higher levels of the hormone, FGF21, increased their lifespan on average by over a third. "What we are seeing is the benefit of caloric restriction without having to diet," he says. Humans have the hormone too, and Kliewer believes FGF21 has the potential to extend the human "health-span" – the time we live healthy lives. The researchers believe FGF21 may act to prolong life by affecting pathways such as the insulin-like growth factor-1 (IGF-1) pathway implicated in ageing. "It blocks growth hormones promoting pathways which are associated with diseases, including cancers and metabolic diseases, and as a consequence these animals live longer," says Kliewer. © Copyright Reed Business Information Ltd.
Keyword: Obesity; Hormones & Behavior
Link ID: 17413 - Posted: 10.24.2012
By Maggie Fox and Linda Carroll Does this sound like you? Two cups of coffee in the morning, a coffee break at 11 or so, another cup in the afternoon and a cup after dinner? That might be enough to interfere with sleep or even give some people the jitters, but it’s nowhere near an overdose. It may also be nothing compared to what some teenagers are consuming to deal with schoolwork or job pressures. James Stone, a 19-year-old from Wallingford, Conn., died in 2006 after he took nearly two dozen NoDoz tablets. Each tablet has about 200 mg of caffeine – about twice that found in a cup of coffee. But while it would be near impossible to down 48 cups of coffee in a few hours, it’s relatively easy to pop a handful of small tablets. Now the question is whether guzzling energy drinks might be as dangerous as popping No-Doz. The Food and Drug Administration is investigating reports that five people died and one survived a heart attack after consuming energy drinks. It is not yet clear whether the drinks actually caused – or even contributed to - those adverse events, said FDA spokeswoman Shelly Burgess. “So far there’s been no causal link,” Burgess said. “There could have been other products involved. We don’t know that yet and that’s why we’re taking this seriously and looking into it.” © 2012 NBCNews.com
Keyword: Drug Abuse
Link ID: 17412 - Posted: 10.24.2012
By Scicurious Picture this: the prince has won his way past the dragon, past the huge walls of briars. He paces slowly through the sleeping castle, toward the tower where the princess lies, in a deep, deep sleep. Finally he sees her, leans over her lovely form… …and gently inserts a probe into her brain, letting a yellow light activate her locus coeruleus. Within moments, the princess awakes. Now THAT’S a kiss. I’ll admit, this post isn’t about sleeping beauty. Instead, it’s about sleep-wake transitions, and how they might work. And the answer involves an up and coming molecule, hypocretin (aka orexin), and an area of the brain called the locus coeruleus (LC). And it involves mice, who are little sleeping beauties in their own way. We’ll start with hypocretin (or orexin*). Hypocretin is a small peptide released from the hypothalamus of the brain. It’s a very recently discovered molecule (published in 1998), and has been enjoying a recent explosion in popularity, due to its interesting involvement in drug addiction and feeding behavior, and its very clear role in sleep. You see, hypocretin controls sleep/wake cycles by mediating what we call “arousal” (which is not that, though it’s that, too). Neurons that produce hypocretin are silent while you are asleep, but burst of firing and the release of hypocretin from these neurons comes immediately before wakefulness. And hypocretin is such a strong mediator of sleep/wake transitions that loss of hypocretin produces some very striking narcolepsy. © 2012 Scientific American
Keyword: Sleep
Link ID: 17411 - Posted: 10.23.2012
By Michelle Roberts Health editor, BBC News online Exercising in your 70s may stop your brain from shrinking and showing the signs of ageing linked to dementia, say experts from Edinburgh University. Brain scans of 638 people past the age of retirement showed those who were most physically active had less brain shrinkage over a three-year period. Exercise did not have to be strenuous - going for a walk several times a week sufficed, the journal Neurology says. But giving the mind a workout by doing a tricky crossword had little impact. The study found no real brain-size benefit from mentally challenging activities, such as reading a book, or other pastimes such as socialising with friends and family. When the researchers examined the brain's white matter - the wiring that transmits messages round the brain - they found that the people over the age of 70 who were more physically active had fewer damaged areas than those who did little exercise. And they had more grey matter - the parts of the brain where the messages originate. Experts already know that our brains tend to shrink as we age and that this shrinkage is linked to poorer memory and thinking. BBC © 2012
Keyword: Alzheimers
Link ID: 17410 - Posted: 10.23.2012
By Maria Konnikova I don’t remember if I had any problems paying attention to Jane Austen’s Mansfield Park when I first read it. I doubt it, though. I devoured all of my Austen in one big gulp, book after book, line after line, sometime around the eighth grade. My mom had given a huge, bright blue hardcover, with text as small as the book was weighty, that contained the Jane Austen oeuvre from start to finish. And from start to finish I went. I’ve since revisited most of the novels—there’s only so much you retain, absorb, and process on a thirteen-year-old’s reading binge—but Mansfield Park hasn’t fared quite as well as some of the others. I’m not sure why. I’ve just never gone back. Until a few weeks ago, that is, when I saw that this somewhat neglected (and often frowned upon) novel had been made the center of an intriguing new study of reading and attention. “This is your brain on Jane Austen,” rang the headline. Oh, no, not another one, went my head. It seems like every day, we get another “your brain on…” announcement, and at this point, an allergic reaction seems in order. This one, however, proved to be different. It’s not about your brain on Jane Austen. Not really. It’s about a far more interesting question: can our brains pay close attention in different ways? The neural correlates of attention are a hot research topic—and with good reason. After all, with the explosion of new media streams, new ways of digesting material, new ways of interacting with the world, it would make sense for us to be curious about how it all affects us at the most basic level of the brain. Usually, though, the research deals with the differences between paying attention, like really paying attention, and not paying attention all that much, be it because of increased cognitive load or other forms of multitasking or divided attention. © 2012 Scientific American
Keyword: Attention
Link ID: 17409 - Posted: 10.23.2012
by Ann Gibbons Eating a raw food diet is a recipe for disaster if you're trying to boost your species' brainpower. That's because humans would have to spend more than 9 hours a day eating to get enough energy from unprocessed raw food alone to support our large brains, according to a new study that calculates the energetic costs of growing a bigger brain or body in primates. But our ancestors managed to get enough energy to grow brains that have three times as many neurons as those in apes such as gorillas, chimpanzees, and orangutans. How did they do it? They got cooking, according to a study published online today in the Proceedings of the National Academy of Sciences. "If you eat only raw food, there are not enough hours in the day to get enough calories to build such a large brain," says Suzana Herculano-Houzel, a neuroscientist at the Federal University of Rio de Janeiro in Brazil who is co-author of the report. "We can afford more neurons, thanks to cooking." Humans have more brain neurons than any other primate—about 86 billion, on average, compared with about 33 billion neurons in gorillas and 28 billion in chimpanzees. While these extra neurons endow us with many benefits, they come at a price—our brains consume 20% of our body's energy when resting, compared with 9% in other primates. So a long-standing riddle has been where did our ancestors get that extra energy to expand their minds as they evolved from animals with brains and bodies the size of chimpanzees? © 2010 American Association for the Advancement of Science.
Keyword: Development of the Brain; Evolution
Link ID: 17408 - Posted: 10.23.2012
Ewen Callaway “Who told me to get out?” asked a diver, surfacing from a tank in which a whale named NOC lived. The beluga’s caretakers had heard what sounded like garbled phrases emanating from the enclosure before, and it suddenly dawned on them that the whale might be imitating the voices of his human handlers. The outbursts — described today in Current Biology1 and originally at a 1985 conference — began in 1984 and lasted for about four years, until NOC hit sexual maturity, says Sam Ridgway, a marine biologist at National Marine Mammal Foundation in San Diego, California. He believes that NOC learned to imitate humans by listening to them speak underwater and on the surface. A few animals, including various marine mammals, songbirds and humans, routinely learn and imitate the songs and sounds of others. And Ridgway’s wasn’t the first observation of vocal mimicry in whales. In the 1940s, scientists heard wild belugas (Delphinapterus leucas) making calls that sounded like “children shouting in the distance”2. Decades later, keepers at the Vancouver Aquarium in Canada described a beluga that seemed to utter his name, Lagosi. Ridgway’s team recorded NOC, who is named after the tiny midges colloquially known as no-see-ums found near where he was legally caught by Inuit hunters in Manitoba, Canada, in the late 1970s. His human-like calls are several octaves lower than normal whale calls, a similar pitch to human speech. After training NOC to 'speak' on command, Ridgway’s team determined that he makes the sounds by increasing the pressure of the air that courses through his naval cavities. They think that he then modified the sounds by manipulating the shape of his phonic lips, small vibrating structures that sit above each nasal cavity. © 2012 Nature Publishing Group
Keyword: Language; Evolution
Link ID: 17407 - Posted: 10.23.2012
By SINDYA N. BHANOO Most people have a moment or two they would rather not remember. The brain has two opposite ways of dealing with those memories, researchers report in a new study. The first is to simply block out the memory. The second is to recall a substitute memory. Take the case of a fight with a loved one, said Roland Benoit, a cognitive neuroscientist at the Medical Research Council Cognition and Brain Sciences Unit in Cambridge, England. “You don’t want to think about it because you want to just go on with life,” Dr. Benoit said. “You can somehow push it out, or you could try to think of something else, like maybe that nice vacation to France you had together.” Dr. Benoit and his colleagues asked study participants to associate the words “beach” and “Africa.” Then one group was told to avoid thinking about the associated words altogether. Another group was told to start thinking about the word “snorkel” in association with “beach,” rather than “Africa.” The participants were put under a functional M.R.I. scanner, and the researchers found that in the case of memory substitution, the left prefrontal cortex works in conjunction with the hippocampus, an area of the brain connecting to conscious remembering. But when an unwanted memory is simply suppressed or blocked out, the prefrontal cortex actually inhibits the functioning of the hippocampus. © 2012 The New York Times Company
Keyword: Learning & Memory
Link ID: 17406 - Posted: 10.23.2012
by Sara Reardon We talk to ourselves all day, whether it's convincing ourselves to get out of bed, or avoid that second piece of cake. But this internal voice uses a lot of brainpower. People who have to concentrate on resisting an addiction appear to sacrifice this ability in order to conserve brainpower for other tasks. The average person can juggle about four mental tasks at any time, says Monica Faulkner of Johns Hopkins University in Baltimore. How much you can multitask is related to working memory. With the assumption that recovering addicts must think constantly about their addiction, Faulkner and her colleagues wondered whether this comes at the cost of using up one of those four "slots", possibly impairing their overall working memory. Faulkner and Cherie Marvel, also of Johns Hopkins, recruited six people who had never used drugs and six recovering from a heroin addiction who were taking methadone to help. They showed the volunteers an image, either of a word, a Chinese character, or a pattern. They then waited six seconds, and showed the volunteers a second image. During those six seconds, the researchers recorded the volunteers' brain activity using functional magnetic resonance imaging (fMRI). The volunteers' task was to press a button if the second image matched the first. The people recovering from addiction took a few hundred milliseconds longer than the controls to determine whether they had seen the images previously. But the more interesting result came from the pattern of activity in their brains throughout the 6 second window. © Copyright Reed Business Information Ltd.
Keyword: Drug Abuse; Attention
Link ID: 17405 - Posted: 10.23.2012
By Christina Agapakis Smell is notoriously subjective and hard to define. Odors can be perceived differently by different people depending on genetics, culture, past experience, the environment, and whether they’ve had a really bad sinus infection or not. Even worse, the same person can perceive the same smell differently at different times, depending on how the smell is described and other sensory fluctuations. Leslie Vosshall’s Laboratory of Neurogenetics and Behavior at Rockefeller University studies how complex behaviors are influenced by the chemical senses in organisms ranging from mosquitoes to humans. In order to better understand how human odor perception varies, both within individuals at different times and between different people, the lab asked nearly 400 New Yorkers to describe and rate the intensity and pleasantness of 66 different smells, at the same time collecting demographic data (significantly more diverse than the typical study of undergraduate psychology students) as well as data about their eating habits and perfume usage, finding many instances of variability in how people perceive smells. The lab recently published their extensive survey titled “An olfactory demography of a diverse metropolitan population” in the open-access journal BMC Neuroscience. They’ve also made their data freely available (you can download the huge excel file here) for further analysis or data-mining. This study has been ongoing for several years, and two years ago inspired Nicola Twilley’s wonderful Scratch-and-Sniff Map of New York’s olfactory psychogeography. Rather than mapping what people smell, the odors that they would encounter in different neighborhoods, she mapped how they smell, mapping odor preferences by neighborhood using homemade scratch-and-sniff stickers, sampling some of the variation in our smell universe. © 2012 Scientific American
Keyword: Chemical Senses (Smell & Taste)
Link ID: 17404 - Posted: 10.22.2012
By ERIC NAGOURNEY There are any number of reasons you might be up at 2 in the morning instead of snuggled asleep in bed. Maybe you are finishing some work — an article, say, that you owe the editor of that new Booming blog. Maybe you are one of those people who decided to have a baby at an age when parents would once have been making their last tuition payments. Or maybe the condo you bought over that all-night bowling alley was so cheap for a reason. But there could be another explanation. Maybe you are not asleep because you can’t sleep. As baby boomers age, many may find that a basic act they once took for granted (or intentionally neglected) has become a lot more complicated. They are finding it harder to get to sleep or stay asleep, and they may feel the consequences during the day. “The older we get, the more likely we are to develop sleep problems,” said Dr. William C. Kohler, a Florida sleep specialist and a past official of the American Academy of Sleep Medicine. This is not to say that trouble sleeping is inevitable. “Healthy aging is not necessarily associated with poor sleep,” said Dr. Nathaniel F. Watson, a director of the University of Washington Medicine Sleep Center. “Some people have this sense that ‘Oh, I’m just going to sleep badly when I get older, because that’s what happens to everybody.'” That said (and you knew this was coming), even in the absence of illness, as people age, the “sleep architecture,” as Dr. Watson put it, tends to change. They spend less time in deep non-REM sleep. And all the while, their old circadian rhythm is shifting ever earlier for reasons no one really understands. © 2012 The New York Times Company
Keyword: Sleep; Development of the Brain
Link ID: 17403 - Posted: 10.22.2012
By Caroline Parkinson Health editor, BBC News website The brains of teenage girls with behavioural disorders are different to those of their peers, UK researchers have found. The Journal of Child Psychology and Psychiatry study of 40 girls revealed differences in the structure of areas linked to empathy and emotions. Previous work has found similar results in boys. Experts suggest it may be possible to use scans to spot problems early, then offer social or psychological help. An estimated five in every 100 teenagers in the UK are classed as having a conduct disorder. It is a psychiatric condition which leads people to behave in aggressive and anti-social ways, and which can increase the risk of mental and physical health problems in adulthood. Rates have risen significantly among adolescent girls in recent years, while levels in males have remained about the same. In this study, funded by the Wellcome Trust and Medical Research Council, UK and Italian researchers conducted brain scans of 22 teenage girls who had conduct disorder and compared them with scans of 20 who did not. BBC © 2012
Keyword: Aggression; Sexual Behavior
Link ID: 17402 - Posted: 10.22.2012
Researchers in the U.S. have found signs of puberty in American boys up to two years earlier than previously reported — age nine on average for blacks, 10 for whites and Hispanics. Other studies have suggested that girls, too, are entering puberty younger. Why is this happening? Theories range from higher levels of obesity and inactivity to chemicals in food and water, all of which might interfere with normal hormone production. But those are just theories, and they remain unproven. Doctors say earlier puberty is not necessarily cause for concern. And some experts question whether the trend is even real. Boys are more likely than girls to have an underlying physical cause for early puberty.Boys are more likely than girls to have an underlying physical cause for early puberty. (Jennifer DeMonte/Associated Press) Dr. William Adelman, an adolescent medicine specialist in the Baltimore area, says the new research is the first to find early, strong physical evidence that boys are maturing earlier. But he added that the study still isn't proof and said it raises a lot of questions. Earlier research based on 20-year-old national data also suggested a trend toward early puberty in boys, but it was based on less rigorous information. The new study involved testes measurements in more than 4,000 boys. Enlargement of testes is generally the earliest sign of puberty in boys. The study was published online Saturday in Pediatrics to coincide with the American Academy of Pediatrics' national conference in New Orleans. © CBC 2012
Keyword: Development of the Brain; Hormones & Behavior
Link ID: 17401 - Posted: 10.22.2012
By JANE E. BRODY I recently met a slender, health-conscious young woman who insisted that the size of sugar-sweetened drinks should not be legislated. “Getting people to drink less of them should be done through education,” she said. It is an opinion shared by many others. Some may be unaware of the role that these beverages are playing in the nation’s burgeoning epidemics of obesity and Type 2 diabetes. Few know the disappointing history of efforts to change human behavior solely through education. The young woman was reacting to a New York City regulation, to take effect on March 12, limiting to 16 ounces the size of sugar-sweetened soft drinks available for purchase at restaurants, street carts, movie theaters and sporting events. The Barclays Center in Brooklyn, the new home of the Nets, has already imposed this limit. Convenience stores, vending machines and some newsstands are exempted from the regulation. Several new studies underscore the public health potential of the restriction. If it succeeds in curbing the consumption of sweet liquid calories, it is likely to be copied elsewhere, because the nation’s love affair with super-size sugary soft drinks is costing cities and states billions of dollars annually in medical care. We are all born with a natural preference for sweetness, which through evolution enabled us to know when fruits and berries were ripe and ready to eat. But as Gary K. Beauchamp, a biopsychologist and director of the Monell Chemical Senses Center in Philadelphia, has put it, “We’ve separated the good taste from the good food.” Our sweet tooth is no longer working to our advantage. Copyright 2012 The New York Times Company
Keyword: Obesity
Link ID: 17400 - Posted: 10.22.2012
By Gary Stix Oliver Sacks, HBO and others have chronicled the life of autistic savant Temple Grandin. The unique patterns of thought produced by Grandin’s brain enabled her to design now-ubiquitous methods to treat cattle more humanely, and she has served as inspiration to others diagnosed with the condition. Until now, no one has tried to assess the actual brain physiology of the professor of animal sciences at Colorado State University. Grandin herself wanted to know more about the biological basis of her cognitive strengths and deficits. So she entered into a collaboration with the University of Utah, which performed a battery of imaging tests—MRI, DTI and fMRI—to determine brain volume, cortical thickness and the structure of the insulating white matter that surrounds the long, wire-like axons that connect one brain cell with another. Supplemented with neuropsychological testing, researchers compared these results with those from three other “neurotypical” female subjects of about the same age. It turns out that Grandin’s brain appears to be similar to that of other autistic savants. She has greater volume in the right hemisphere, which might account for her superior visuospatial abilities. She also has increased thickness of the entorhinal cortex, an area involved with memory As with others with autism, she has an overall larger brain size. And the enlarged amygdala and the smaller cortical thickness in the fusiform gyrus may relate to the deficits autistic individuals experience in dealing with emotion and reading faces. “There’s this idea in the savant literature that left hemisphere damage occurs during development and the right hemisphere compensates in some way,” says Jason Cooperrider, a graduate student at the University of Utah who presented the findings at the conference. “All of the savant skills are right hemisphere-dominant abilities, which would include Dr. Grandin’s exceptional visual and spatial ability which would be considered savant level.” © 2012 Scientific American
Keyword: Autism; Chemical Senses (Smell & Taste)
Link ID: 17399 - Posted: 10.22.2012
Young people who sustain brain injuries are more likely to commit crimes and end up in prison, research suggests. The University of Exeter study says such injuries can lead maturing brains to "misfire", affecting judgement and the ability to control impulses. It calls for greater monitoring and treatment to prevent later problems. The findings echo a separate report by the Children's Commissioner for England on the impact of injuries on maturing brains and the social consequences. In the report, Repairing Shattered Lives, Professor Huw Williams from the University of Exeter's Centre for Clinical Neuropsychology Research, describes traumatic brain injury as a "silent epidemic". It is said to occur most frequently among children and young people who have fallen over or been playing sport, as well as those involved in fights or road accidents. The consequences can include loss of memory, with the report citing international research which indicates the level of brain injuries among offenders is much higher than in the general population. A survey of 200 adult male prisoners in Britain found 60% claimed to have suffered a head injury, it notes. The report acknowledges there may be underlying risk factors for brain injury and offending behaviour but says improving treatment and introducing screening for young offenders would deliver significant benefits in terms of reducing crime and saving public money. BBC © 2012
Keyword: Aggression; Brain Injury/Concussion
Link ID: 17398 - Posted: 10.20.2012
Results of a new study presented at Neuroscience 2012, the annual meeting of the Society of Neuroscience, has suggested the right hemisphere of the brain performs important tasks during its resting state, implying different end results for left-handed people and right-handed people, who use the right and left sides of their brains differently. Findings showed that when resting, the right hemisphere of the brain communicates more with itself and the left side of the brain, than when the left hemisphere talks to itself and communicates to the right side of the brain, regardless of participants' dominant hand. Neuroscientists did note that right-handed people used their left hemisphere at a higher rate, and vice versa. The authors of this study say that during rest, the right hemisphere is "doing important things, we don't yet understand." The activities that are being processed by the right hemisphere could be storing and processing acquired information, daydreaming, or similar creative tasks. Andrei Medvedev, Ph.D., an assistant professor in the Center for Functional and Molecular Imaging at Georgetown explains: The researchers had 15 participants connect to near-infrared spectroscopy (NIRS) equipment. This inexpensive and moveable technology uses light to calculate changes in oxygenated hemoglobin inside the body. Participants wore a hat that contained optical fibers delivering infrared light to the outermost layers of the brain and then assessed the light that bounced back. Through this method, the device could see which parts of the brain are active and communicate at the highest rate, based on heightened use of oxygen in the blood and elevated simultaneous occurrence of their activities.
Keyword: Sleep; Laterality
Link ID: 17397 - Posted: 10.20.2012
Mo Costandi Scientists have learned how to discover what you are dreaming about while you sleep. A team of researchers led by Yukiyasu Kamitani of the ATR Computational Neuroscience Laboratories in Kyoto, Japan, used functional neuroimaging to scan the brains of three people as they slept, simultaneously recording their brain waves using electroencephalography (EEG). The researchers woke the participants whenever they detected the pattern of brain waves associated with sleep onset, asked them what they had just dreamed about, and then asked them to go back to sleep. This was done in three-hour blocks, and repeated between seven and ten times, on different days, for each participant. During each block, participants were woken up ten times per hour. Each volunteer reported having visual dreams six or seven times every hour, giving the researchers a total of around 200 dream reports. Most of the dreams reflected everyday experiences, but some contained unusual content, such as talking to a famous actor. The researchers extracted key words from the participants’ verbal reports, and picked 20 categories — such as 'car', 'male', 'female', and 'computer' — that appeared most frequently in their dream reports. Kamitani and his colleagues then selected photos representing each category, scanned the participants’ brains again while they viewed the images, and compared brain activity patterns with those recorded just before the participants were woken up. © 2012 Nature Publishing Group
Keyword: Sleep; Brain imaging
Link ID: 17396 - Posted: 10.20.2012
Mo Costandi A disturbed night's sleep might signal a future diagnosis of Alzheimer’s disease, according to findings presented this week at the annual meeting of the Society for Neuroscience in New Orleans, Louisiana. Patients with Alzheimer’s often complain of changes in their sleep patterns during the early stages of the disease. In healthy people, for example, daytime naps usually last around 20 minutes, but they can be to 3 hours long in patients with Alzheimer’s disease. Roxanne Sterniczuk, a neurophysiologist at Dalhousie University in Halifax, Canada, and her colleagues wanted to determine how early these changes occur and if they could predict a person’s future risk of developing the disease. Sterniczuk and her colleagues analysed data from around 14,600 healthy people, collected as part of the Survey of Health, Ageing and Retirement in Europe (SHARE), a long-term observational study of people aged 50 and over from 12 European countries. They looked at various measures of sleep quality, and used them to produce a ‘sleep disturbance index’. The researchers found that participants who reported sleeping restlessly, feeling tired during the day and taking sleep medication were more likely to be diagnosed with Alzheimer’s within the next 2 years, and that the greater the extent of these problems, the more severe were the symptoms of the subsequent disease. “Increased daytime sleepiness was the biggest predictor,” says Sterniczuk. “It would appear that subtle changes in the sleep–wake cycle are taking place before any disease pathology.” © 2012 Nature Publishing Group
Keyword: Alzheimers; Sleep
Link ID: 17395 - Posted: 10.20.2012