By C. CLAIBORNE RAY A. A widely discussed 2006 study of transit noise in New York City, measuring noise on buses as well as in subway cars and on platforms, was described at the time as the first such formal study published since the 1930s. Done by scientists at the Mailman School of Public Health at Columbia University and published in The Journal of Urban Health, the study concluded that noise levels at subway and bus stops could easily exceed recognized public health recommendations and had the potential to damage hearing, given sufficient exposure. For example, guidelines from the Environmental Protection Agency and the World Health Organization set a limit of 45 minutes’ exposure to 85 decibels, the mean noise level measured on subway platforms. And nearly 60 percent of the platform measurements exceeded that level. The maximum noise levels inside subway cars were even higher than those on the platforms, with one-fifth exceeding 100 decibels and more than two-thirds exceeding 90 decibels. The study recommended properly fitted earplugs and earmuff-type protectors in loud transit environments, saying they could cut noise levels significantly at the eardrum. And it warned that personal listening devices only increased the total noise and risk. © 2013 The New York Times Company

Keyword: Hearing
Link ID: 18495 - Posted: 08.13.2013

By Melinda Wenner Moyer Our world is determined by the limits of our five senses. We can't hear pitches that are too high or low, nor can we see ultraviolet or infrared light—even though these phenomena are not fundamentally different from the sounds and sights that our ears and eyes can detect. But what if it were possible to widen our sensory boundaries beyond the physical limitations of our anatomy? In a study published recently in Nature Communications, scientists used brain implants to teach rats to “see” infrared light, which they usually find invisible. The implications are tremendous: if the brain is so flexible it can learn to process novel sensory signals, people could one day feel touch through prosthetic limbs, see heat via infrared light or even develop a sixth sense for magnetic north. Miguel Nicolelis, a neurobiologist at Duke University, and his colleagues trained six rats to poke their nose inside a port when the LED light above it lit up. Then the researchers surgically attached infrared cameras to the rats' head and wired the cameras to electrodes they implanted into the rats' primary somatosensory cortex, a brain region responsible for sensory processing. When the camera detected infrared light, it stimulated the animals' whisker neurons. The stimulation became stronger the closer the rats got to the infrared light or the more they turned their head toward it, just as brain activation responds to light seen by the eyes. Then the scientists let the animals loose in their chambers, this time using infrared light instead of LEDs to signal the ports the rats should visit. At first, none of the rats used the infrared signals. But after about 26 days of practice, all six had learned how to use the once invisible light to find the right ports. © 2013 Scientific American

Keyword: Vision; Robotics
Link ID: 18494 - Posted: 08.13.2013

By GINA KOLATA Researchers studying two seemingly unrelated conditions — autism and cancer — have unexpectedly converged on a surprising discovery. Some people with autism have mutated cancer or tumor genes that apparently caused their brain disorder. Ten percent of children with mutations in a gene called PTEN, which causes cancers of the breast, colon, thyroid and other organs, have autism. So do about half of children with gene mutations that can lead to some kinds of brain and kidney cancer and large tumors in several organs, including the brain. That is many times the rate of autism in the general population. “It’s eerie,” Evan Eichler, a professor of genome science at the University of Washington, said about the convergence. He and others caution that the findings apply to only a small proportion of people with autism; in most cases, the cause remains a mystery. And as with nearly all genetic disorders, not everyone with the mutations develops autism or cancer, or other disorders associated with the genes, like epilepsy, enlarged brains and benign brain tumors. But researchers say the findings are intriguing, given that there are no animals that naturally get autism, no way of analyzing what might cause autism in developing brains and no cure. The newly discovered link has enabled scientists to genetically engineer mice with many symptoms of the human disorder. And it has led to the first clinical trial of a treatment for children with autism, using the drug that treats tumors that share the same genetic basis. Richard Ewing of Nashville, a 10-year-old who has a form of autism caused by a tumor-causing gene, is among those in the new study. His parents, Alexandra and Rick Ewing, know he is at risk for tumors in the brain, heart, kidney, skin and eyes. But that bad news was tempered by his eligibility for the clinical trial, which has only just started. © 2013 The New York Times Company

Keyword: Autism; Genes & Behavior
Link ID: 18493 - Posted: 08.12.2013

By Neuroskeptic Thanks to newly-developed “super-resolution” microscopy techniques, a group of French neuroscientists have discovered a remarkable world of complexity on a tiny scale. Writing in the Journal of Neuroscience, Deepak Nair colleagues report that: Super-Resolution Imaging Reveals That AMPA Receptors Inside Synapses Are Dynamically Organized in Nanodomains Regulated by PSD95 Neurons communicate with each other via chemical synapses. Here, two cells almost touch each other, and one of them can release a messenger molecule (neurotransmitter) which activates proteins (receptors) on the receiving (postsynaptic) neuron, thus conveying information. Here’s part of a single cell: the synapses are where the little ‘spines’ or ‘bulbs’ meet those present on another cell (not pictured).Until now, it’s been believed that within a synapse, receptors are just randomly distributed over the postsynaptic cell membrane. However, Nair et al’s work reveals an unsuspected level of organization. It turns out that receptors – or at least AMPA receptors, the only kind they looked at – are in fact clustered together into structures the authors dub nanodomains. Each nanodomain contains about 20 receptors, and is about 70 nanometers across. This is small. It’s roughly the size of a virus, and about 1/1000th the width of a human hair. When I saw this picture, it didn’t call to mind anything else I’d ever seen in neuroscience. Rather, it reminded me of the Hubble Deep Field images of distant galaxies… and funnily enough, one of the proteins that plays a secondary role in this paper is called stargazin.

Keyword: Brain imaging
Link ID: 18492 - Posted: 08.12.2013

By CATHERINE SAINT LOUIS Children with chronic stomach pains are at high risk for anxiety disorders in adolescence and young adulthood, a new study has found, suggesting that parents may wish to have their children evaluated at some point for anxiety. Researchers at Vanderbilt University tracked 332 children with recurring stomachaches that could not be traced to a physical cause — so-called functional abdominal pain — comparing them as they reached young adulthood with 147 children who had never had such stomachaches. About half the teenagers and young adults who had had functional abdominal pain as children developed an anxiety disorder at some point, compared with 20 percent of the control group, the researchers found. The vulnerability to anxiety persisted into adulthood even if the pain had disappeared, although the risk was highest if the pain continued. Forty percent of the children with functional abdominal pain went on to experience depression, compared with 16 percent of those who had never had these stomachaches. The study was published on Monday in the journal Pediatrics. “What this study shows is a strong connection between functional abdominal pain and anxiety persists into adulthood, and it drives home the point that this isn’t by chance,” said Dr. John V. Campo, chairman of the department of psychiatry at Ohio State University, who was not involved in the new study. In 2001, Dr. Campo published a smaller study that found that 28 young adults who had suffered functional abdominal pain as children were far more likely to have an anxiety disorder than 28 similar adults who had experienced another childhood illness. Copyright 2013 The New York Times Company

Keyword: Stress; Development of the Brain
Link ID: 18491 - Posted: 08.12.2013

by Douglas Heaven It's a cognitive leap forward. IBM can now program an experimental chip they unveiled two years ago. The chips, designed to mimic how our brains work, are set to power computers that handle many streams of input data at once – much like the sensory input we deal with all the time. IBM's TrueNorth computer chips contain memory, processors and communication channels wired up like the synapses, neurons and axons of a brain. A key idea is that the chips can be hooked up into vast grids with many thousands working together in parallel. For certain types of task, such as quickly responding to large amounts of input data from sensors, they are much faster and less power-hungry than standard chips. They could one day replace human reflexes in self-driving cars or power the sensory systems of a robot, for example. But because the chips rewrite the rulebook for how computers are normally put together, they are not easy to program. Dharmendra Modha and his colleagues at IBM Research in San Jose, California, learned this the hard way. The team's first attempts were full of errors: "The programs were very unintuitive and extremely difficult to debug," says Modha. "Things looked hopeless." So they designed a new way of programming. This involves telling the computer how to yoke together the many individual chips in play at once. The IBM team came up with a way to package the functionality of each chip inside blocks of code they call "corelets". © Copyright Reed Business Information Ltd.

Keyword: Robotics
Link ID: 18490 - Posted: 08.12.2013

By D. D. GUTTENPLAN LONDON — With its battered desks, fluorescent lights and interactive whiteboard showing an odd creature that, depending on how you look at it, could be either a duck or a rabbit, this could be a class in any university philosophy department. But this is a class with a difference. It is the Maudsley Philosophy Group, a seminar that meets regularly on the grounds of the Maudsley Hospital, Britain’s largest mental health teaching hospital, which is affiliated with the Institute of Psychiatry at King’s College London. Participants at the last session included psychiatrists, psychologists, philosophers and an actor who had just finished working as a chaplain in a locked men’s ward at the hospital and who was about to organize a storytelling group there. “We started out as a reading group for trainee psychiatrists,” said Gareth S. Owen, a researcher at the Institute of Psychiatry who co-founded the group in 2002. “Then, gradually, we developed and started inviting philosophers — at first it was quite low key. We would talk about our clinical experiences and then they would relate those experiences to their way of thinking.” Robert Harland, another co-founder of the group, said he had known Dr. Owen since they “cut up a corpse together at medical school.” “The analytic philosophers brought a real clarity to our discussions,” Dr. Harland said. “We were looking at various models to help us understand what we were doing as psychiatrists. “There is lots of applied science now in psychiatry: neuroimaging, genetics, epidemiology. But they don’t have much to say about sitting with a patient and trying to understand that person’s experiences.” © 2013 The New York Times Company

Keyword: Depression; Schizophrenia
Link ID: 18489 - Posted: 08.12.2013

Roger Dobson Older male nightingales have perfected an art that would be the envy of men having a mid-life crisis: a trick that makes them more attractive to females than their younger male competitors. Their mastery of successful courtship is achieved with a dazzling array of up to 100 trills a second, far more than their younger competitors can manage, and more than any other investigated bird, according to new research. That ability, backed up by a sophisticated playlist of about 200 songs, means that they are probably seen as better mates by young trill-seeking females. Singing so many trills at peak frequency requires a lot of physical effort and, as a result, it has evolved as a sign on fitness, say the researchers. "Females could assess the age of the male singer by the trill rate, and mate preferably with older ones," says the zoologist Dr Valentin Amrhein, who led the study at the University of Basel, Switzerland. "This makes sense for the females because older males have more experience with defending their territory or with raising young, and therefore have a better reproductive performance." The research, being published in the Journal of Avian Biology, shows that older birds can come up with 100 trills a second, making them the fastest singers. They also performed about 200 different song types, but the researchers think it is the immediate impact of the trills that is attracting the females. It would take more than an hour for the male to go through his whole song list. "Since the performance of these sounds is very demanding, the rate at which they can be repeated is limited. Trying to sing rapidly increasing sounds in fast repetition is very hard for us humans as well," says Dr Amrhein. "Singing rapid broadband trills comes at a certain price for the male nightingale, so trilling is a good indicator for mate quality." © independent.co.uk

Keyword: Sexual Behavior; Language
Link ID: 18488 - Posted: 08.12.2013

By Neuroskeptic Back in April a paper came out in Nature Reviews Neuroscience that shocked many: Katherine Button et al’s Power failure: why small sample size undermines the reliability of neuroscience It didn’t shock me, though, skeptic that I am: I had long suspected that much of neuroscience (and science in general) is underpowered – that is, that our sample sizes are too small to give us an acceptable chance of detecting the signals that we claim to be able to isolate out of the noise. In fact, I was so unsurprised by Button et al that I didn’t even read it, let alone write about it, even though the authors list included such neuro-blog favorites as John Ionaddis, Marcus Munafo and Brian Nosek (I try to avoid obvious favouritism, you see). However this week I took a belated look at the paper, and I noticed something interesting. Button et al took 49 meta-analyses and calculated the median observed statistical power of the studies in each analysis. The headline finding was that average power is small. I was curious to know why it was small. So I correlated the study characteristics (sample size and observed effect size) with the median power of the studies. I found that median power in a given meta-analysis was not correlated with the median sample size of those studies (d on the left, RR on the right):

Keyword: Miscellaneous
Link ID: 18487 - Posted: 08.12.2013

By Nathan Seppa The late rock and roll singer Jim Morrison was not a poster boy for public safety — and was no authority on safe driving. After all, later in “Roadhouse Blues,” he has beer for breakfast. But the opening line of that Doors’ song still resonates as sound guidance. If only such good advice could stand the test of time. “Roadhouse Blues” hit the airwaves in 1970, long before the unlikely marriage of driving and talking on a cell phone. Millions of people now routinely conduct remote conversations while driving, despite research showing that it’s dangerous — even with two eyes on the road and both hands upon the wheel. It turns out that hands don’t matter. It’s the conversation that can be lethal. Cell phone conversations impede what a driver sees and processes, a number of studies have shown. That, in turn, slows reactions and other faculties. This distracted state should be familiar to everyone. “That’s why you can drive home and not remember having driven home,” says Daniel Simons, a psychologist at the University of Illinois at Urbana-Champaign. “Just because you look at something doesn’t mean you see it.” Simons has shown that people assigned to observe certain activities in a lab setting can totally miss other events occurring in the very same space. The on-road versions of such blind spots show up when drivers engaged in a cell phone conversation fail to look at side streets or watch for pedestrians. This distraction may seem subtle and even fleeting, but it takes a toll: The risk of an accident quadruples when the driver is on the phone, studies have suggested. © Society for Science & the Public 2000 - 2013

Keyword: Attention
Link ID: 18486 - Posted: 08.10.2013

Keith Barry, skilled magician that he is, doesn't give away his tricks but he does give the audience a clue when he says "magic is all about directing attention." Neuroscientists have long known that attention plays a key role in perception, and yet, we still don't fully understand the details of how attention works and what neural mechanisms are involved. Only a small fraction of the information that comes in through our eyes is actually perceived by our conscious brains. Attention is the filter that directs what is most salient in our environment to our conscious awareness. Almost all magic tricks somehow take advantage of loopholes in attention. For instance, a key strategy for magicians taps into something which cognitive neuroscientists call "inattentional or perceptual blindness", our inability to notice an object or feature in a visual scene because attention is directed elsewhere. You have experienced this phenomenon yourself. Your brain is constantly bombarded with stimuli, and it is impossible to pay attention to them all. While your attention is focused on one thing -- neuroscientists call this the "attentional spotlight"-- your ability to perceive objects outside this focus area is compromised. Indeed, if we could record the activity of the neurons in your brain that track to the visual scene, the neural responses for those areas outside the attentional spotlight would be dampened. The magician takes advantage of this phenomenon. By distracting your attention with sly hand movements, lively banter, humor, or skillful shifts of gaze, he can move your "attentional spotlight," while manipulating the action elsewhere, all without your knowing it and indeed while you think you are paying close attention! So, there you have it -- the neuroscientific answer to "how did he do that?" But, the fact that there is a logical, brain-based explanation behind the magician's tricks is not so surprising. The more interesting question is, if neuroscience can explain magic, can magic teach us anything about neuroscience? © 2013 TheHuffingtonPost.com, Inc.

Keyword: Attention
Link ID: 18485 - Posted: 08.10.2013

Here's what the Swedish artist Oscar Reutersvard did. In 1934, he got himself a pen and paper and drew cubes, like this. He called this final version "Impossible Triangle of Opus 1 No. 293aa." I don't know what the "293aa" is about, but he was right about "impossible." An arrangement like this cannot take place in the physical universe as we know it. You follow the bottom row along with your eyes, then add another row, but when the third row pops in, where are you? Nowhere you have ever been before. At some step in the process you've been tricked, but it's very, very hard to say where the trick is, because what's happening is your brain wants to see all these boxes as units of a single triangle and while the parts simply won't gel, your brain insists on seeing them as a whole. It's YOU who's playing the trick, and you can't un-be you. So you are your own prisoner. At first, this feels like a neurological trap, like a lie you can't not believe. But when you think about for a bit, it's the opposite, it's a release. Twenty years later, the mathematician/physicist Roger Penrose (and his dad, psychologist Lionel Penrose) did it again. They hadn't seen Reutersvard's triangle. Theirs was drawn in perspective, which makes it even more challenging. Here's my version of their Penrose Triangle. What's cool about this? I'm going to paraphrase science writer John D. Barrow, in several places: We know that these drawings can't exist in the physical world. Even as we look at them, particularly when we look at them, we know they are impossible. And yet, we can imagine them anyway. Our brains, it turns out, are not prisoners of the world we live in; we can fly free! We can, any time we like, create the impossible. ©2013 NPR

Keyword: Vision; Attention
Link ID: 18484 - Posted: 08.10.2013

Some colors humans are exposed to late at night could cause symptoms of clinical depression. That is the conclusion of a study that builds on previous findings that individuals exposed to dim levels of light overnight, such as from a glowing television set, can develop signs of clinical depression. Investigators, curious as to whether the color of light contributed to depressive symptoms in humans, designed an experiment that exposed hamsters to different colors. They chose hamsters because they are nocturnal, meaning they sleep during the day and are active at night. One group of hamsters was kept in the dark during their nighttime period. Another group of rodents was exposed to blue light and a third group slept in the presence of white light. A fourth group of hamsters was exposed to glowing red light. After four weeks, researchers noted how much sugary water the hamsters drank. The more depressed rodents consumed the least amount of water. Randy Nelson, chair of Ohio State University’s Department of Neuroscience and co-author of the study, said animals that slept in blue and white light appeared to be the most depressed. “What we saw is these animals didn’t show any sleep disruptions at all but they did have mucked up circadian clock genes and they did show depressive phenotypes whereas if they were in the dim red light, they did not,” Nelson said. Nelson explained that photosensitive cells in the retina, which don’t have much to do with vision, detect light and transmit signals to the master circadian clock in the brain that controls the natural sleep-wake cycle.

Keyword: Biological Rhythms; Depression
Link ID: 18483 - Posted: 08.10.2013

Autism affects male and female brains differently, a study has suggested. UK experts studied brain scans of 120 men and women, with half of those studied having autism. The differences found in the research, published in journal Brain, show more work is needed to understand how autism affects girls, the scientists say. Experts said girls with the condition could be more stigmatised than boys - and it could be harder for them to be diagnosed at all. Autism affects 1% of the population and is more prevalent in boys, so most research has focused on them. In this study, scientists from the Autism Research Centre at the University of Cambridge used magnetic resonance imaging (MRI) to examine how autism affects the brain of males and females. The study looked at the difference between the brains of typical males and those with autism - and then females with and without autism. They found the brains of females with autism "look" more like - but still not the same as - healthy males, when compared with healthy females. But the same kind of difference was not seen in males with autism - so their brains did not show "extreme" male characteristics. Dr Meng-Chuan Lai, who worked on the study said: "What we have known about autism to date is mainly male-biased. BBC © 2013

Keyword: Autism; Sexual Behavior
Link ID: 18482 - Posted: 08.10.2013

By Fred Guterl Myths can be more harmful than lies, Nobel laureate Harry Kroto has said, because they are more difficult to recognize and often go unexamined. For many years, a diagnosis of schizophrenia was like a prison sentence, because many people (some of them in the medical profession) held to the notion that a schizophrenic could not recover from the illness and was condemned to an inexorable decline into madness. Like any myth, this one had some truth to it. Many people with severe symptoms do not recover. But some can, as Eleanor Longden discovered for herself. Longden began hearing voices when she was an undergraduate. At first they were somewhat benign, making mostly neutral, factual comments, but they grew more troublesome as she struggled to adjust to college life. Longden was diagnosed as schizophrenic and underwent conventional treatment. By her own account, in “Listening to Voices” in the September/October 2013 issue of Scientific American MIND, the label of schizophrenic and the attitudes of those around her to that label exacerbated her own internal struggles. The voices grew more menacing. Longden began her own slide into madness. But then something odd happened: she began to recover. She did so in part, she says, by accepting the voices in her head as an aspect of her own personality. She listened to them, and tried to understand them. In this way she was able to tame them, and she got enough control over her life to attend school and pursue her graduate studies. © 2013 Scientific American

Keyword: Schizophrenia
Link ID: 18481 - Posted: 08.10.2013

“OUR primary goal is for our users to see us as a gym, where they can work out and keep mentally fit,” says Michael Scanlon, the co-founder and chief scientist of Lumos Labs. For $14.95 a month, subscribers to the firm’s Lumosity website get to play a selection of online games designed to improve their cognitive performance. There are around 40 exercises available, including “speed match”, in which players click if an image matches a previous one; “memory matrix”, which requires remembering which squares on a matrix were shaded; and “raindrops”, which involves solving arithmetic problems before the raindrops containing them hit the ground. The puzzles are varied, according to how well users perform, to ensure they are given a suitably challenging brain-training session each day. The popularity of Lumosity since its launch in 2007 has been, well, mind-blowing. Its smartphone app has been the top education app in the iTunes store at some point in 38 countries. On August 1st it launched an iPad version, which it expects to boost its existing 45m registered users in 180-plus countries. Lumos Labs has already raised almost $70m in venture capital, and is one of two firms vying to become the first public company serving the new “digital brain health” market, says Alvaro Fernandez of SharpBrains, a research firm. (The firm hoping to beat it to the punch is NeuroSky, which makes “brainwave sensors”—including some shaped like cats’ ears that will apparently wiggle if you are enjoying yourself and droop if you are relaxed.) The metaphor of workouts for the mind will set alarm bells ringing for anyone familiar with Brain Gym, a series of physical exercises for children, adopted unquestioningly by many British schools, whose supposed cognitive benefits were debunked in “Bad Science”, a 2008 book by Ben Goldacre. However, Mr Scanlon, who quit his neuroscience PhD at Stanford University to co-found Lumos Labs, says he was inspired to do so by the mounting academic evidence of the plasticity of the brain and of the ability to improve cognitive function through simple exercises. © The Economist Newspaper Limited 2013

Keyword: Learning & Memory
Link ID: 18480 - Posted: 08.10.2013

Richard Johnston Scientists have mapped the dense interconnections and neuronal activity of mouse and fruitfly visual networks. The research teams, whose work is published in three separate studies today in Nature1–3, also created three-dimensional (3D) reconstructions, shown in the video above. All three studies interrogate parts of the central nervous system located in the eyes. In one, Moritz Helmstaedter, a neurobiologist at the Max Planck Institute of Neurobiology in Martinsried, Germany, and his collaborators created a complete 3D map of a 950-cell section of a mouse retina, including the interconnections among those neuronal cells. To do so, the team tapped into the help of more than 200 students, who collectively spent more than 20,000 hours processing the images1. The two other studies investigated how the retinas of the fruitfly (Drosophila melanogaster) detect motion. Shin-ya Takemura, a neuroscientist at the Howard Hughes Medical Institute in Ashburn, Virginia, and his collaborators mapped four neuronal circuits associated with motion perception and found that each is wired for detecting motion in a particular direction — up, down, left or right2. In the third study, Matthew Maisak, a computational biologist at the Max Planck Institute of Neurobiology, and his colleagues mapped the same four cellular networks and tagged the cells of each with protein markers that fluoresce in red, green, blue or yellow in response to stimulation with light3. © 2013 Nature Publishing Group,

Keyword: Vision
Link ID: 18479 - Posted: 08.08.2013

By Laura Sanders Pregnant mice buzzed on caffeine gave birth to pups with brain changes and lasting memory deficits, a new study shows. The results, published Aug. 7 in Science Translational Medicine, leave unclear whether caffeine causes a similar effect in people. The study convincingly shows that caffeine changes the brains of exposed pups, says child neurologist Barry Kosofsky of Weill Cornell Medical College in New York. But he cautions that mouse and human brains develop very differently, so direct comparisons are impossible. The study has no immediate message for pregnant women, Kosofsky says. “We are totally at a loss about what to say for caffeine.” For a mouse mother, though, the experiment’s story is clearer: Moderate caffeine intake during pregnancy changes baby brains, and not for the better. While pregnant and later lactating, mice drank water laced with caffeine — an amount comparable to that in three to four cups of coffee a day. In offspring, cells in a memory center in the brain called the hippocampus fired off too many messages, an abnormal behavior that could lead to seizures, Carla Silva, of the French National Institute of Health and Medical Research and the University of Coimbra in Portugal, and colleagues found. As adults, the caffeine-exposed mice performed worse than nonexposed mice on memory tests. Usually, mice ignore familiar objects and spend lots of time investigating something new. But mice exposed to caffeine while developing weren’t keen on exploring new objects, suggesting that they couldn’t remember which object was new. What’s more, these mice had fewer neurons in parts of the hippocampus than normal mice. © Society for Science & the Public 2000 - 2013

Keyword: Development of the Brain; Drug Abuse
Link ID: 18478 - Posted: 08.08.2013

Drinking cocoa every day may help older people keep their brains healthy, research suggests. A study of 60 elderly people with no dementia found two cups of cocoa a day improved blood flow to the brain in those who had problems to start with. Those participants whose blood flow improved also did better on memory tests at the end of the study, the journal Neurology reported. Experts said more research was needed before conclusions could be drawn. It is not the first time cocoa has been linked with vascular health and researchers believe that this is in part due to it being rich in flavanols, which are thought to have an important role. In the latest study, researchers asked 60 people with an average age of 73 to drink two cups of cocoa a day - one group given high-flavanol cocoa and another a low-flavanol cocoa - and consume no other chocolate. Ultrasound tests at the start of the study showed 17 of them had impaired blood flow to the brain. There was no difference between those who drank flavanol-rich cocoa and those who had flavanol-poor cocoa. But whichever drink they were given, 88% of those with impaired blood flow at the start of the study saw improvements in blood flow and some cognitive tests, compared with 37% of people whose blood flow was normal at the beginning of the study. BBC © 2013

Keyword: Alzheimers; Learning & Memory
Link ID: 18477 - Posted: 08.08.2013

By Nathan Seppa High blood glucose levels appear to be associated with an increased risk of dementia in older people, a new study finds. Paul Crane at the University of Washington in Seattle and his colleagues recorded blood glucose levels in 2,067 people an average of 76 years old who initially had no signs of dementia. After five years, roughly one-fourth of the participants developed some form of dementia. Among people without diabetes, the risk of developing dementia was 18 percent greater in those with high blood glucose levels than in those with low levels. In people with diabetes, the risk of dementia was 40 percent higher in the high-glucose group, the scientists report in the Aug. 8 New England Journal of Medicine. The researchers took into account differences in age, gender, education, heart disease, blood pressure, smoking history and exercise level. While the study doesn’t establish a biological link between high blood glucose and dementia, the researchers speculate that the association could be explained by either glucose-related damage to tiny blood vessels in the central nervous system or insulin resistance – in which cells lose the ability to efficiently process sugar. © Society for Science & the Public 2000 - 2013

Keyword: Alzheimers
Link ID: 18476 - Posted: 08.08.2013