By Eric Kandel Our attraction to faces, and particularly to eyes, appears to be innately determined. Infants as well as adults prefer to look at eyes rather than other features of a person’s face, and both infants and adults are sensitive to gaze. The direction of a person’s gaze is very important in our processing of the emotions displayed by that person’s face, because the brain combines information from gaze with information from facial expressions. Reginald Adams from Pennsylvania State University and Robert Kleck from Dartmouth College have found that a direct gaze and an expression of happy emotion facilitate the communication and processing of joy, friendliness, and approach-oriented emotions presumably because, as Uta Frith has found, only direct gaze recruits the dopaminergic reward system. In contrast, an averted, sad, or fearful gaze communicates the avoidance-oriented emotions of fear and sadness. Although gaze and facial expression are processed together, other aspects of beauty, such as gender and age, are processed independently. In a biological experiment designed to examine the neural correlates of beauty—that is, the mechanisms in our brain that account for our sense of beauty—John O’Doherty and his colleagues explored the role of the smile. They found that the orbitofrontal (ventrolateral) region of the prefrontal cortex, the region that is activated by reward and thought to be the apex of the representation of pleasure in the brain, is also activated by attractive faces. Moreover, the response of this region is enhanced by the presence of a smile. © 2012 Scientific American,

Keyword: Emotions; Vision
Link ID: 17151 - Posted: 08.13.2012

by Sara Reardon Freedom of information requests have revealed that pregnant women may not have been given all the facts before taking an experimental treatment to prevent female fetuses from being masculinised as a result of a rare genetic disorder. Research has provided some evidence that dexamethasone, a drug normally prescribed to relieve inflammation, can prevent girls with a rare hormonal disease from developing male genitalia and same-sex attraction if they are treated as fetuses. But as yet, no clinical studies show that this treatment is safe, says Alice Dreger of Northwestern University in Evanston, Illinois. She claims that researchers have misled an unknown number of pregnant women into taking the experimental treatment without properly informing them of its risks. Since the 1980s, Maria New of Mount Sinai School of Medicine in New York has studied and popularised the idea of prescribing dexamethasone "off-label" to women at risk of having foetuses with congenital adrenal hyperplasia (CAH). The treatment is now taught as standard practice in medical schools. But because the drug must be given very early in pregnancy before the fetus' gender or CAH status is known, many fetuses are treated unnecessarily. A child with two carrier parents has a one-in-four chance of having the disease, and the treatment only works for girls. There is little research available on the effects of dexamethasone, which mimics a steroid hormone. And because dexamethasone doesn't cure CAH but only prevents masculinisation of girls, it can be difficult to distinguish possible effects of the drug from other treatments the children receive after birth. © Copyright Reed Business Information Ltd.

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 17150 - Posted: 08.11.2012

By Tina Hesman Saey If variety lends life flavor, then humans are kicking things up to a previously unrecognized notch on the spice-o-meter. New efforts to decipher the genetic blueprints of thousands of people have turned up more than half a million tweaks in human DNA, many more than scientists expected. Most of these tweaks are new to science, and a majority fall into a class called “rare variants,” found in 0.5 percent of the population or less. Some of the variety recently uncovered is so uncommon that it shows up in people living in a single geographic region, or even in only one person. Despite their limited spread, the newly discovered rare variants could profoundly affect susceptibility to disease or how well drugs work. They may also help researchers reconstruct recent human migrations around the world. For years, scientists have been examining the chemical units of DNA called nucleotides that act as letters in the human genetic instruction book. So researchers thought they had a good handle on how often to expect single-letter changes in the A’s, G’s, T’s and C’s in that book. Such changes stem from errors in copying and are spotted via comparison with some majority-rule blueprint. They can go by terms like “single nucleotide polymorphisms” or “mutations” depending on where and when they show up. When looking at 202 genes predicted to be important in diseases from 14,002 people, John Novembre of the University of California, Los Angeles and colleagues unearthed five times as many rare genetic variants as expected. © Society for Science & the Public 2000 - 2012

Keyword: Genes & Behavior
Link ID: 17149 - Posted: 08.11.2012

Duncan Graham-Rowe A skull implant that can detect an epileptic seizure and deliver therapeutic electrical impulses can reduce the length of these events by 60% in rats. The device, tested on nine rats with a ‘petit mal’ form of epilepsy, is described today in Science1. Most electrical stimulation devices, such as those that deliver deep-brain stimulation (DBS) to treat Parkinson’s disease and depression, operate continuously, delivering impulses regardless of the patient’s brain activity. But this can cause a range of undesirable side effects, such as headaches. Seizure-responsive versions of DBS devices are coming to market, such as the Responsive Neurostimulator System developed by NeuroPace, based in Mountain View, California. The system is awaiting approval by the US Food and Drug Administration and will be aimed at adults with certain types of partial-onset seizures, which tend to be localized to certain regions of the brain. But as the name implies, DBS uses electrodes that penetrate the brain, which can also carry certain risks, such as a worsening of epilepsy symptoms. In the latest study, György Buzsáki, a neuroscientist at the New York University School of Medicine, and his colleagues used a less invasive approach that involves transcranial electrical stimulation (TES) of neurons using electrodes implanted in the skull. This technique has been shown to be effective at modifying the brain's cortical (outermost) neurons, which become abnormally excited during epileptic seizures. To detect the onset of a seizure, recording electrodes that detect neural activity were implanted on the brain's surface. © 2012 Nature Publishing Group,

Keyword: Epilepsy
Link ID: 17148 - Posted: 08.11.2012

By Cheryl Murphy Liliputs and little people, cartoon characters dancing on your desk, a civil war soldier in your living room, a zebra walking down the street. Typically not what we’d expect to see with our own eyes. But for some, it happens almost every day…for a year or so anyway. The “visions” aren’t always complex or bizarre. Sometimes they can “blend in” to our everyday lives a bit more. One case study was recently published in the Canadian Journal of Ophthalmology described a patient having visual hallucinations of small children popping up in her vision. She didn’t try to speak or interact with them in any way and they never spoke to her. She didn’t recognize them. She knew that they weren’t real and she wasn’t frightened of them but there they were. She saw them. Why? It turns out she had Charles Bonnet Syndrome, a condition in which visual hallucinations are caused by recent visual field loss… and, in her case, a brain tumor. People who have suffered newly acquired vision loss from eye conditions such as macular degeneration, diabetic retinopathy or cataracts (or from damage to other parts of the visual pathway in the brain) can have new visual field defects as a result and sometimes they begin to “see” things that really aren’t there. These people have no prior history of dementia or cognitive impairment, have never had any hallucinations in the past and are not taking medications known to have hallucinations as one of their side effects. Typically, no other sense (taste, touch, smell, or hearing) is affected in Charles Bonnet Syndrome other than sight. It can affect the young as well as the old in that there have been cases of Charles Bonnet Syndrome reported in young children who suffered vision loss from retinopathy of prematurity. In some cases, the vision loss is only to a part of their whole field of vision and their vision can sometimes remain as sharp as 20/40. © 2012 Scientific American,

Keyword: Vision; Attention
Link ID: 17147 - Posted: 08.11.2012

by Michael Marshall You may think you can cope without sleep, but you have nothing on male pectoral sandpipers. Some of these birds can go more than a fortnight with hardly any sleep – the most extreme case of uninduced sleep deprivation known in any animal. What's more, the males that sleep the least father the most offspring, suggesting they benefit from their lack of slumber. Pectoral sandpipers (Calidris melanotos) breed on the Arctic tundra of Asia and North America. Males don't help with childcare – instead they try to mate with as many females as possible. Bart Kempenaers of the Max Planck Institute for Ornithology in Seewiesen, Germany and colleagues fitted radio tags to 149 birds – accounting for most of a population living near Barrow in Alaska. This showed that males were highly active during periods when females were fertile. One male was active 95 per cent of the time for 19 days. The team then fitted 29 of the males with devices that recorded their brain activity, something never done before with a wild bird. This allowed them to look at the active males' sleep patterns. They found that the males that slept the least slept more deeply, but calculations show that this wouldn't make up for the sleep they missed, says team member Niels Rattenborg. © Copyright Reed Business Information Ltd

Keyword: Sleep; Sexual Behavior
Link ID: 17146 - Posted: 08.11.2012

by Chelsea Wald Some of our personality traits from childhood stick with us for the rest of our lives. An early shyness on the playground doesn't always go away in the boardroom, for example. But what if your entire body changed as you aged, transforming you into a completely unrecognizable creature? Would you retain the personality of your youth? A new study in frogs suggests that you would. In the past decade, scientists have shown that a broad range of animals—from dogs to sea anemones—display consistent personalities throughout their lives. Despite changes in their environment, individuals maintain their tendencies, such as being more or less active and exploratory, relative to other individuals of their species. But some researchers have theorized that animals that undergo metamorphosis should be exceptions. The full-body transformation, seen in everything from frogs to butterflies, dramatically alters every aspect of the animal—not only its shape, but also where it lives and what it needs to do to survive and reproduce. Why, then, shouldn't metamorphosis also change the animal's personality, so that strengths in larvae don't become flaws in adults? The relative restlessness that helps a caterpillar find food better than its peers, for instance, could get the butterfly into trouble with predators. Few researchers have attempted to study personality before and after metamorphosis, says behavioral ecologist Alexander Wilson of the Leibniz-Institute of Freshwater Ecology and Inland Fisheries in Berlin. He says his new study of frogs, to be published later this month in Behavioral Ecology, is the first to tackle the question in vertebrates. It was hard, Wilson says, to find personality tests that would work well for tadpoles and frogs, which are like two distinct animals. "[They] reach a certain stage of their life and then, bam! They change into something completely different." © 2010 American Association for the Advancement of Science

Keyword: Emotions; Evolution
Link ID: 17145 - Posted: 08.11.2012

ROBINS appear to have an eye for numbers, at least when it comes to choosing the biggest meal. "Discriminating between two large groups of objects that are close in number would be pretty exceptional for any animal or human, but that's exactly what the robins did," says Alexis Garland at Victoria University of Wellington in New Zealand. Garland let 36 wild North Island robins choose one of two wells after seeing different numbers of mealworms dropped en masse into each. Most picked the fuller well as long as the ratio was below 0.75 - correctly selecting, say, 64 over 32 worms. The mechanism at work here is called ratio-based representation and involves guessing which large group of items has the bigger bulk. The robins did even better when the worms were dropped into the wells one by one and covered so that the masses could not be compared: they managed a ratio of 0.88, albeit with a smaller number of worms. For the largest trial at this ratio - 14 versus 16 worms - most robins chose correctly (Animal Cognition, DOI: 10.1007/s10071-012-0537-3). Other animals tested like this have only managed to track about four items. Robins hide multiple food items in several places so it may be advantageous to distinguish more from less quickly, says Garland. © Copyright Reed Business Information Ltd.

Keyword: Intelligence; Evolution
Link ID: 17144 - Posted: 08.11.2012

By Rick Nauert PhD Senior News Editor Most of us take the ability to read and write for granted. For some, however, these fundamental skills are difficult to master. Sadly, factors associated with the variety of symptoms that contribute to a diagnosis of dyslexia have remained obscure. New research may change this picture as researchers announce a major advancement toward understanding the cause of dyslexia. Neuroscientist Begoña Díaz, Ph.D., and her colleagues at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany, have discovered an important neural mechanism underlying dyslexia. They believe problems arise in the part of the brain called the medial geniculate body in the thalamus. Experts believe this discovery can provide the basis for developing potential treatments for the condition. People who suffer from dyslexia have difficulties with identifying speech sounds in spoken language. For example, while most children are able to recognize whether two words rhyme even before they go to school, dyslexic children often cannot do this until late primary school age. Most people suffer from dyslexia for their whole lives although many learn to compensate. Experts say that between five and 10 percent of children suffer from dyslexia, yet very little is known about its causes. © 1992-2012 Psych Central

Keyword: Dyslexia
Link ID: 17143 - Posted: 08.11.2012

By Stephanie Pappas Senior Writer Parrots can draw conclusions about where to find a food reward not only from clues as to its location, but also from the absence of clues — an ability previously only seen in humans and other apes. In a new study, researchers tested African Grey parrots on their reasoning abilities by shaking empty boxes and boxes filled with food so that the parrots could hear the snacks rattling around. To pick the box that would win them a treat, the parrots had to figure out that the sound indicated food and that a lack of sound from one box probably meant food in the other. It's a challenge that even human children can't reason through until about age 3. "It suggests that Grey parrots have some understanding of causality and that they can use this to reason about the world," study scientist Christian Schloegl, a researcher at the University of Vienna, told LiveScience. African Grey parrots are known to be clever, as are many other birds. In earlier studies with Grey parrots, researchers have shown them two opaque boxes, one full of food and one empty. When the parrots are shown that one box has no food in it, they almost always pick the second box in search of a treat. This could be because the parrots infer that if one box is empty, the other is likely full, Schloegl said. But researchers couldn't rule out that they were simply avoiding the empty box for some unknown reason. © 2012 NBCNews.com

Keyword: Intelligence; Evolution
Link ID: 17142 - Posted: 08.08.2012

By Michael Harré As humans, we aren't born with formidable armaments or defenses, nor are we the strongest, fastest, or biggest species, yet despite this we are amazingly successful. For a long time it was thought that this success was because our enlarged brains allows each of us to be smarter than our competitors: better at abstract thinking, better with tools and better at adapting our behavior to those of our prey and predators. But are these really the most significant skills our brains provide us with? Another possibility is that we are successful because we can form long-lasting relationships with many others in diverse and flexible ways, and that this, combined with our native intelligence, explains why homo sapiens came to dominate the planet. In every way from teaching our young to the industrial division of labour we are a massively co-operative species that relies on larger and more diverse networks of relationships than any other species. In 1992 British anthropologist Robin Dunbar published an article showing that, in primates, the ratio of the size of the neo-cortex to that of the rest of the brain consistently increases with increasing social group size. For example, the Tamarin monkey has a brain size ratio of about 2.3 and an average social group of size of about 5 members. On the other hand, a Macaque monkey has a brain size ratio of around 3.8 but a very large average group size of about 40 members. From this work Dunbar put forward what is now known as the “social brain hypothesis.” The relative size of the neo-cortex rose as social groups became larger in order to maintain the complex set of relationships necessary for stable co-existence. Most famously, Dunbar suggested that given the human brain ratio we have an expected social group size of around 150 people, about the size of what Dunbar called a “clan.” © 2012 Scientific American,

Keyword: Evolution
Link ID: 17141 - Posted: 08.08.2012

By Stephanie Pappas Senior Writer For women looking to pass on their genes, it pays to be short. For men, tall is the ideal. The result? An evolutionary tug-of-war in which neither gender reaches their perfect height. Those are the results of a new study published Aug. 7 in the journal Biology Letters. The research finds that an evolutionary battle of the sexes keeps the genders in an endless feedback loop of height variations across the generations. "We should not simply assume that when a trait is beneficial for one sex, that selection or evolution will necessarily favor this trait," study researcher Gert Stulp, a scientist at the University of Groningen in the Netherlands, told LiveScience in an email. In the same way, traits that harm one sex but not the other may not be "weeded out" by natural selection, Stulp said. "This may even hold for health-related traits, such that genetic underpinnings beneficial to the health of one sex may increase the susceptibility to disease in the other sex," he said. In modern western societies, studies have found that women who are on the short side tend to have more children. In contrast, average-height men do the best, reproductively speaking, outpacing short and tall men in number of children fathered, Stulp said. © 2012 NBCNews.com

Keyword: Sexual Behavior; Evolution
Link ID: 17140 - Posted: 08.08.2012

By Julie Appleby, An increasing number of psychiatrists and hospitals — as well as entrepreneurs opening rTMS centers around the country — are betting that there are millions of people like Curtis, discouraged by depression treatments that have proved unsuccessful and willing to pony up thousands of dollars for the possibility of relief. The treatment, which has been approved by the Food and Drug Administration, is covered by Medicare in five states, but few private insurers pay for it routinely. While rTMS has ardent supporters, its effectiveness is still debated, and there is little evidence showing how long the results last. The technique has been shown to work better than a placebo, but the proportion of patients who show complete relief ranges widely, from as few as 10 percent to as many as 57 percent, according to various studies. The debate has huge implications, not just for many of the 14 million Americans who suffer from major depression every year but also for businesses eyeing a potentially lucrative market and insurers weighing whether to cover it. About half of those 14 million Americans seek relief through psychotherapy and prescription drug treatment, according to an evaluation by the federal Agency for Healthcare Research and Quality. But studies show that antidepressants provide complete cessation of symptoms only about a third of the time. Magnetic stimulation is aimed at patients with such “treatment-resistant depression.” Supporters say rTMS is worth the cost — between $6,000 and $12,000 for the four-to-six-week treatment — because it enables people such as Curtis to resume productive lives. Skeptics question the price tag in light of uncertain benefits. © 1996-2012 The Washington Post

Keyword: Depression
Link ID: 17139 - Posted: 08.08.2012

By Scicurious Our brains are made of millions of neurons. Tons. A lot. We scientists spend a lot of time studying those neurons, how they function individually, and how they respond to outside stimulation. But neurons cannot function alone. What sets a neuron apart is its ability to carry electric signals and to transfer chemical signals to other neurons. The function of neurons is not in the neurons themselves, it is in the connection between them. And this incredibly complicated network, composed of billions of connections, is called the connectome. If we knew the connectome of the human, we’d know a lot more about the brain than we do now. We are learning it, little by little, but with a series of connections that are so incredibly vast, it’s just too much right now to examine every single possible connection. Right now the only way to ensure getting every single connection in painstaking detail is to use electron microscopy to view synapses, the connections between neurons. Concentrations of the little organelles which signify a synapse (such as vesicles full of neurotransmitter), can tell you where each connection is placed. But the electron microscope can only look at a very small section at a time, making the mapping of a connectome an incredibly arduous task. C. elegans, to be exact. The nematode is a darling of basic research, and for a very good reason. C. elegans is incredibly simple, having exactly 302 neurons in the entire body. Well, 302, or 383. There are two kinds of C. elegans, hermaphrodite and male (there are no females). The males mate with the hermaphrodites. But this means that the male C. elegans is slightly different from the hermaphrodite C. elegans. While the hermaphrodite has 302 neurons, the male has 383. And most of these appear to be devoted to a complex series of behaviors characteristic of mating. © 2012 Scientific American,

Keyword: Development of the Brain; Sexual Behavior
Link ID: 17138 - Posted: 08.07.2012

By Katherine Harmon Jill, a 60-year-old woman in Milwaukee, has overcome extreme poverty. So, now that she has enough money to put food in the fridge, she fills it. She also fills her freezer, her cupboard and every other corner of her home. “I use duct tape to close the freezer door sometimes when I’ve got too many things in there,” she told A&E’s Hoarders. Film footage of her kitchen shows a cat scrambling over a rotten grapefruit; her counters—and most surfaces in her home—seemed to be covered with several inches of clutter and spoiled food. “I was horrified,” her younger sister said after visiting Jill. And the landlord threatened eviction because the living conditions became unsafe. Jill joins many others who have been outed on reality TV as a “hoarder.” We might have once called people with these tendencies “collectors” or “eccentrics.” But in recent years, psychiatrists had suggested they have a specific type of obsessive-compulsive disorder (OCD). A movement is underfoot, however, for the new edition of the psychiatric field’s diagnostic bible (the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, or DSM-5), to move hoarding disorder to its own class of illness. And findings from a new brain scan study, published online August 6 in Archives of General Psychiatry, support this new categorization. Hoarding disorder is categorized as “the excessive acquisition of and inability to discard objects, resulting in debilitating clutter,” wrote the researchers behind the new study, led by Yale University School of Medicine’s David Tolin. © 2012 Scientific American,

Keyword: OCD - Obsessive Compulsive Disorder; Brain imaging
Link ID: 17137 - Posted: 08.07.2012

By KATIE THOMAS Johnson & Johnson and Pfizer announced on Monday that they were halting development of a closely watched Alzheimer’s drug after two clinical trials failed to show that it was effective in patients with mild to moderate forms of the disease. Late last month, results of a large clinical trial of the drug, called bapineuzumab, failed to show that patients — all of whom carried a particular gene that raises the risk of getting Alzheimer’s — improved either cognition or daily functioning compared with a placebo. The companies announced Monday that the results of a second trial, which tested the drug on patients who did not carry the gene, also did not meet its goals. Because the results of the earlier trial were already known, the decision to discontinue the drug was not altogether unexpected. Bapineuzumab, like other Alzheimer’s drugs being developed, targets beta amyloid, a protein that has toxic effects on the brain and is believed to be a cause of the disease. Given the failure of the drug, some have called that theory into question. But Dr. Husseini K. Manji, the global therapeutic area head for neuroscience at Janssen Research and Development, a unit of Johnson & Johnson, said the failed trials did not mean researchers should abandon the beta amyloid theory. “While we are disappointed in the results of the two bapineuzumab IV studies, particularly in light of the urgent need for new advancements in Alzheimer’s disease, we believe that targeting and clearing beta amyloid remains a promising path to potential clinical benefits for people suffering from this disease,” he said in a news release. © 2012 The New York Times Company

Keyword: Alzheimers
Link ID: 17136 - Posted: 08.07.2012

By Lara Salahi Can one head injury lead to Alzheimer’s? New research suggests one moderate to severe head injury can disrupt the proteins that regulate an enzyme associated with Alzheimer’s disease. Researchers from Tufts University School of Medicine and Harvard Medical School first measured protein levels in the brains of mice two days after they had incurred moderate to severe head trauma. The researchers found a reduction in the levels of two proteins, GGA1 and GGA3, and an increased level of the enzyme BACE1, which has previously been associated with Alzheimer’s disease. Researchers analyzed Alzheimer’s patients’ brain tissue and found the same protein reduction and enzyme level increase the mice had experienced. The findings suggest that a single brain injury could significantly increase the risk of developing Alzheimer’s disease, according to the researchers. BOTTOM LINE: A moderate to severe head injury can disrupt the proteins that regulate an enzyme associated with Alzheimer’s. CAUTIONS: The study does not look at the long-term effects of enzyme disruption after a traumatic brain injury and whether it leads to the development of Alzheimer’s disease. WHERE TO FIND IT: Journal of Neuroscience, July issue © 2012 NY Times Co.

Keyword: Alzheimers; Brain Injury/Concussion
Link ID: 17135 - Posted: 08.07.2012

by Michael Marshall The relatively sophisticated brain of a songbird has been transplanted into the body of a distantly related, less intelligent species. The study could help us understand how brains develop, perhaps opening the way to treating some brain conditions. Since 2009, Chun-Chun Chen of Duke University in Durham, North Carolina, has performed over 100 brain transplants in birds. In her latest study she transferred the cells destined to become the forebrain of zebra finches (Taeniopygia guttata) into Japanese quail (Coturnix japonica) embryos, after removing the equivalent quail cells. After the transplants, Chen incubated the eggs for up to 16 days, before opening them to find that the transplanted cells had integrated into their hosts, forming the normal neural pathways. None of the chimeric embryos hatched, however, perhaps because their hybrid brains could not trigger breathing. Chen says she will try to crack the hatching problem by transplanting just half a zebra finch forebrain, leaving half the quail forebrain still in place. Researchers have been attempting such transplants for decades. In 1957, Petar Martinovitch of Yale University transplanted the heads of one set of chicken embryos to another (Proceedings of the National Academy of Sciences, vol 43, p 354). Few survived. © Copyright Reed Business Information Ltd.

Keyword: Development of the Brain; Evolution
Link ID: 17134 - Posted: 08.07.2012

By ANAHAD O'CONNOR THE FACTS Certain regions of the human brain are dedicated to the various senses. The visual cortex handles vision, for example, while the auditory cortex processes sound. But what happens if one of the senses is lost? Do the neurons in the auditory cortex of a deaf person atrophy and go to waste, for instance, or are they put to work processing vision and other senses? In studies, scientists have shown that when one sense is lost, the corresponding brain region can be recruited for other tasks. Researchers learned this primarily by studying the blind. Brain imaging studies have found that blind subjects can locate sounds using both the auditory cortex and the occipital lobe, the brain’s visual processing center. But recently a similar phenomenon was discovered in the deaf. In a study financed by the National Institutes of Health and published in The Journal of Neuroscience, researchers recruited 13 deaf volunteers and a dozen volunteers with normal hearing and looked at what happened in their brains when touch and vision responses were stimulated. They found that both senses were processed in Heschl’s gyrus, where the auditory cortex is situated, suggesting that this part of the brain had been dedicated to other senses. Other studies have shown that structural changes in the auditory cortex are noticeable in the brains of deaf children from a very early age. THE BOTTOM LINE Losing one sense can cause the brain to become rewired. Copyright 2012 The New York Times Company

Keyword: Pain & Touch; Hearing
Link ID: 17133 - Posted: 08.07.2012

By Alyssa A. Botelho, Melanie Brunson, who has been blind since birth, suddenly awoke and found herself standing at 15th and K streets in Northwest Washington. She had stopped at the corner on her way home from work to await a safe time to cross and had dozed off. Even on awakening, she was so groggy she couldn’t focus well enough to hear passing cars and judge when it was safe to cross. The incident was a startling reminder of the sleep problems that had plagued her since birth. “Who knows how long I had been standing there,” she said. “I realized then that my safety was in jeopardy, and I began searching for remedies with a vengeance.” But years after that 2005 traffic scare and many subsequent visits to doctors and sleep clinics, Brunson still lies awake in bed night after night and then is desperately sleepy during the day. Although doctors have not definitively identified her disorder, researchers believe she suffers from non-24-hour sleep-wake disorder, or “non-24.” The chronic and little-known sleep condition is characterized by a body clock that is not aligned with a 24-hour day. Though non-24 can affect those with normal vision, it is especially prevalent among blind people who cannot sense light, the strongest environmental signal that synchronizes the brain’s internal sleep-wake pattern to the 24-hour cycle of the Earth day. © 1996-2012 The Washington Post

Keyword: Biological Rhythms; Vision
Link ID: 17132 - Posted: 08.07.2012