Joanna Marchant Female athletes may not be eligible to compete as women if they have natural testosterone levels in the male range. That's the upshot of new guidelines on female hyperandrogenism, recommended by the International Olympic Commission (IOC) on 5 April and accepted by the International Association of Athletics Federations (IAAF) on 12 April. The rules have been welcomed by experts as a reasonable compromise, but there remain some doubts over how they would work in practice. Nature looks at the science behind the tests. The regulations cover female athletes with hyperandrogenism, a condition in which the body produces higher than normal levels of hormones called androgens, particularly testosterone. This can cause the development of bulky muscles, perhaps giving athletes an unfair competitive advantage. The issue hit the headlines in 2009, when the South African athlete Caster Semenya was asked to undergo sex testing after winning the 800-metre final at the Berlin World Championships in Athletics (see 'A question of sex'). She was unable to compete for nearly a year, but has now returned to the track. The results of her tests remain confidential. Officials deny that the new rules are a direct response to Semenya's case, however. There have been other controversial cases, and they say there has long been a need to clarify the rules and procedures involved. This week's announcement is the culmination of an 18-month review carried out by the IOC Medical Commission and the IAAF, including a meeting held last October and attended by scientists as well as athletes, bioethicists, human-rights lawyers and a representative of the intersex community. © 2011 Nature Publishing Group,

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 15219 - Posted: 04.16.2011

by Rowan Hooper BLIND people could one day have their sight restored thanks to a treatment that borrows a gene from an unlikely source - algae - and inserts it into the retina. The technique has succeeded in restoring the ability to sense light and dark to blind mice, and clinical trials in humans could begin in as little as two years. "The idea is to develop a treatment for blindness," says Alan Horsager, a neuroscientist at the Institute of Genetic Medicine at the University of Southern California, Los Angeles, who leads the research. "We introduce a gene that encodes a light-sensitive protein, and we target the expression of that gene to a subset of retinal cells." Some 15 million people worldwide have some form of blindness, such as retinitis pigmentosa (RP) or age-related macular degeneration (AMD). In people with these conditions the photoreceptors, which transform light hitting the eye into electrical impulses, are damaged, preventing the brain from receiving image information. As the global population ages, it is thought that the number of people affected will increase. There are experimental attempts to develop electronic implantsMovie Camera and to use stem cells to grow new retinal tissues to restore sight, but there is currently no commercial treatment available. Horsager hopes his work will change that. His team's approach is based on gene therapy, where a "tame" virus is harnessed to transfer a gene into target cells in the recipient. In this case the gene of interest is one that makes Channelrhodopsin-2 (ChR2), a photosensitive protein used by unicellular algae to help them move towards light. The target cells are bipolar cells in the retina. © Copyright Reed Business Information Ltd.

Keyword: Vision; Regeneration
Link ID: 15218 - Posted: 04.14.2011

by Cian O'Luanaigh THE bones of your middle ear were once part of a mammalian ancestor's jaw. Now a remarkable Cretaceous fossil provides a snapshot of how this shift took place. The lower jaws of modern mammals have just one bone: the tooth-bearing dentary. Reptiles, by contrast, also sport smaller bones where the jaw meets the skull. Biologists have long postulated that as mammals evolved, the smaller, post-dentary bones shrank to form the tiny bones of the middle ear. Fossils of ancient mammals such as Morganucodon hint at this: the post-dentary bones are still attached to the dentary, and are used for both hearing and feeding. What happened next had been left to best guesses. Now Liaoconodon hui, discovered in China by Jin Meng of the American Museum of Natural History in New York, has filled the gap. "It is the first unambiguous evidence showing that transitional stage," says Meng. The 120-million-year-old mammal, about the size of a large rat, was a close relative of early mammals. Of interest is a bridge called Meckel's cartilage, which connects the small bones to the jaw (see diagram). Living mammals, including humans, have Meckel's cartilage as embryos, but it disappears as they mature. In the L. hui fossil - an adult - it is ossified and the fossil shows how it supported some of the post-dentary bones as they shifted into the ear (Nature, DOI: 10.1038/nature09921). © Copyright Reed Business Information Ltd.

Keyword: Hearing; Evolution
Link ID: 15217 - Posted: 04.14.2011

Philip Ball Languages evolve in their own idiosyncratic ways, rather than being governed by universal rules set down in human brain patterns. That is the conclusion of a study that compares the grammar of several hundred languages by looking at their evolutionary trees. Russell Gray, a psychologist at the University of Auckland in New Zealand, and his colleagues examined the relationships between traits such as the ordering of verbs and nouns in four linguistic families, and found no sign of any persistent, universal guiding principles (See 'Universal truths'). Their work is published today by Nature1. It is already proving controversial. "There is nothing in the paper that brings into question the views that they are arguing against," says Matthew Dryer, a linguist at the State University of New York at Buffalo. Fixed patterns There are thought to be around 7,000 languages in the world today, and they show tremendous diversity in structure. Some, such as Finnish, have complex ways of making composite words, whereas others, such as Mandarin Chinese, have simple, short and invariant words. Some put verbs first in a sentence, others in the middle and yet others at the end. But many linguists suspect that there is some universal logic behind this bewildering variety — that common cognitive factors underpin grammatical structures. US linguists Noam Chomsky and Joseph Greenberg proposed two of the most prominent 'universalist' theories of language. © 2011 Nature Publishing Group,

Keyword: Language
Link ID: 15216 - Posted: 04.14.2011

Douglas Fox Last year a succession of volunteers sat down in a research lab in Albuquerque, New Mexico to play DARWARS Ambush!, a video game designed to train US soldiers bound for Iraq. Each person surveyed virtual landscapes strewn with dilapidated buildings and abandoned cars for signs of trouble — a shadow cast by a rooftop sniper, or an improvised explosive device behind a rubbish bin. With just seconds to react before a blast or shots rang out, most forgot about the wet sponge affixed to their right temple that was delivering a faint electric tickle. The volunteers received a few milliamps of current at most, and the simple gadget used to deliver it was powered by a 9-volt battery. It might sound like some wacky garage experiment, but Vincent Clark, a neuroscientist at the University of New Mexico, says that the technique, called transcranial direct-current stimulation (tDCS), could improve learning. The US Defense Advanced Research Projects Agency funded the research in the hope that it could be used to sharpen soldiers' minds on the battlefield. Yet for all its simplicity, it seems to work. Volunteers receiving 2 milliamps to the scalp (about one-five-hundredth the amount drawn by a 100-watt light bulb) showed twice as much improvement in the game after a short amount of training as those receiving one-twentieth the amount of current1. "They learn more quickly but they don't have a good intuitive or introspective sense about why," says Clark. The technique, which has roots in research done more than two centuries ago, is experiencing something of a revival. © 2011 Nature Publishing Group,

Keyword: Learning & Memory; Parkinsons
Link ID: 15215 - Posted: 04.14.2011

Ewen Callaway Before committing suicide at the age of 22, an anonymous man with schizophrenia donated a biopsy of his skin cells to research. Reborn as neurons, these cells may help neuroscientists to unpick the disease he struggled with from early childhood. Experiments on these cells, as well as those of several other patients, are reported today in Nature1. They represent the first of what are sure to be many mental illnesses 'in a dish', made by reprogramming patients' skin cells to an embryonic-like state from which they can form any tissue type. Recreating neuropsychiatric conditions such as schizophrenia and bipolar disorder using such cells represents a daunting challenge: scientists do not know the underlying biological basis of mental illnesses; symptoms vary between patients; and although psychiatric illnesses are strongly influenced by genes, it has proved devilishly hard to identify many that explain more than a fraction of a person's risk. "All of us had been contacted by patients asking 'when can I get my stem cells to solve my schizophrenia'. It's not as simple as that," says Russell Margolis, a psychiatrist and neurogeneticist at Johns Hopkins University in Baltimore, Maryland, who was not involved in the study. "It's an additional piece to the puzzle as opposed to the answer." © 2011 Nature Publishing Group,

Keyword: Schizophrenia
Link ID: 15214 - Posted: 04.14.2011

People with multiple sclerosis may show blocked neck veins as a result of the disease rather than as a cause, a large study published Wednesday suggests. The findings cast doubt on the theory that blocked or narrowed veins are a main cause of MS, study author Dr. Robert Zivadinov of the University of Buffalo said. The findings published in the journal Neurology were consistent with thinking that the condition — also known as chronic cerebrospinal venous insufficiency, or CCSVI — is more common in patients with multiple sclerosis but not to the degree first reported by the Italian doctor Paolo Zamboni. "These findings indicate that CCSVI does not have a primary role in causing MS," said Zivadinov, who has worked with Zamboni. Zamboni proposed that multiple sclerosis may be linked with vascular problems, and that using angioplasty, or ballooning, to open blocked neck veins can help treat MS symptoms by changing blood flow patterns. Patients eager for surgery For more than a year, Canadians with MS have been leaving the country to get the surgery, despite reluctance from neurologists at home. An ultrasound technician, who did not know which group the subjects were in, did the test. The team found 56 per cent of people in the MS group met the criteria for CCSVI, as did 23 per cent of the healthy controls and 46 per cent of people with other neurological diseases. © CBC 2011

Keyword: Multiple Sclerosis
Link ID: 15213 - Posted: 04.14.2011

By James Gallagher Health reporter, BBC News Brain scans may be able to indicate potential Alzheimer's patients years before symptoms appear, according to the results of a small study. Research published in Neurology showed parts of some patients' brains had shrunk up to a decade before signs of Alzheimer's would otherwise be evident. Alzheimer's Research UK said there was stong evidence that the disease began to develop in mid-life. Early diagnosis may one day prove vital in enabling effective treatment. Sixty-five patients, all of whom started with normal brain function, took part in the study at Massachusetts General Hospital and the Rush University Medical Center in the US. MRI scans were taken and the thickness of regions of the brain were measured. Brain Thinning Twenty per cent of patients with brains of average thickness went on to develop Alzheimer's. However, no patients with thicker brains developed the disease, while 55% of those with thinner ones also contracted it. Dr Brad Dickerson, lead author and neuroscientist at the Massachusetts General Hospital, said: "We used what we know about the signature brain changes seen in patients with Alzheimer's dementia, measured those areas in individuals with no symptoms and eventually determined that those who ultimately developed dementia showed subtle shrinking long before they had any symptoms." BBC © 2011

Keyword: Alzheimers; Brain imaging
Link ID: 15212 - Posted: 04.14.2011

by Michael Balter About 65 million years ago, most of the dinosaurs and many other animals and plants were wiped off Earth, probably due to an asteroid hitting our planet. Researchers have long debated how and why some species survived the so-called Cretaceous-Tertiary mass extinction, marked in ancient rocks by a transition called the K-T boundary. A new study suggests that one group of survivors, the birds, may have sniffed their way across by evolving an enhanced sense of smell. Scientists had long thought that birds have a poor sense of smell. But several recent studies show that birds use smell to help them forage for food, communicate with other birds, and even orient themselves in flight. And a 2009 study of dinosaur olfaction, led by paleontologist Darla Zelenitsky of the University of Calgary in Canada, found that dinosaur lineages thought to have given rise to today's birds some 150 million years ago had a keener sense of smell than dinosaurs that went extinct without leaving feathered progeny behind. To further explore how the sense of smell might have influenced bird evolution, Zelenitsky and her colleagues looked at the olfactory abilities of 157 species of dinosaurs, extinct birds, and living birds. As in the earlier work, the team used a parameter called the olfactory ratio as a proxy for how keen a bird's sense of smell is. In the vertebrates (animals with backbones), smell is processed in the olfactory bulb, which in birds and reptiles is found in the very front of the brain. In birds, the olfactory ratio is the relative size of the bulb compared with that of the brain's cerebral hemispheres and is usually expressed as a percentage. Numerous studies in birds have shown the olfactory ratio, which ranges from less than 10% to more than 30% in a few species, to be a reliable indicator of the sense of smell. © 2010 American Association for the Advancement of Science.

Keyword: Hearing; Genes & Behavior
Link ID: 15211 - Posted: 04.14.2011

By Michael S. Gazzaniga The world of law as practiced in the real world is far removed from that usually discussed by law professors and philosophers or shown on television and in movies. In idealized or fictional cases the law always operates formally and may seem to pursue some abstract quest for justice. In the everyday practice of law, however, things work differently—it is all about cobbling together the most compelling and convincing story possible either for or against a defendant. Attorneys will shoehorn into their arguments any information they can find that might further their ends. The legal system therefore efficiently uses every scrap of relevant data that might pertain to a case—including findings such as brain scans that might not normally be formally admissible during trials. The reality is that few criminal cases—only about 3 percent of federal ones and a bit more than 4 percent at the state level—ever go to trial. Normally, after someone is charged with a crime, the prosecution and the defense attorneys engage in confidential plea bargaining away from the courtroom. The plea negotiations are usually conducted informally (although in intense cases, such as those that might involve the death penalty, they can take on the appearance of a condensed sentencing hearing). During these plea bargaining discussions, the defense presents any available information that might reduce the severity of the charges or the potential penalty against the defendant. To save a client from the death penalty, for instance, the defense might bring up brain-imaging data that suggests the defendant has a certain neurological or psychiatric condition that should reduce his or her culpability. The defense might suggest that the brain scans would at least cast doubt on the prosecution's ability to get a jury to return a sentence of death. © 2011 Scientific American

Keyword: Brain imaging
Link ID: 15210 - Posted: 04.14.2011

(HealthDay News) -- A hormone called ghrelin enhances the nose's ability to sniff out food, researchers report. It was already known that ghrelin promotes hunger and fat storage. The new study suggests that the hormone may increase the ability to use smell to detect food and link that input with the body's natural regulation of metabolism and body weight, said University of Cincinnati scientists. Click here to find out more! The study, which included experiments with humans and rats, appears in the April 13 issue of the Journal of Neuroscience. It was led by Dr. Jenny Tong and Dr. Matthias Tschop, both of the university's endocrinology, diabetes and metabolism division. "Smell is an integral part of feeding, and mammals frequently rely on smell to locate food and discriminate among food sources. Sniffing is the first stage of the smell process and can enhance odor detection and discrimination," Tong said in a university news release. "Other studies have shown that hunger can enhance odor detection and sniffing in animals," Tschop added in the release. "Since ghrelin is a hunger-inducing stomach hormone that is secreted when the stomach is empty, this hormone pathway may also be responsible for the hunger-induced enhancement of sniffing and odor detection." The researchers plan further research to identify the exact molecular pathways through which ghrelin affects sniff behavior. © 2011 HealthDay.

Keyword: Chemical Senses (Smell & Taste); Obesity
Link ID: 15209 - Posted: 04.14.2011

By Rachael Rettner A drug frequently prescribed to treat people with mild Alzheimer's disease does not appear to be an effective therapy for many of these patients, according to a new study. The results show the drug, memantine, is no better than a dummy pill when it comes to ameliorating disease symptoms, including the decline of mental abilities, the researchers say. There is also meager evidence that the drug works for patients with moderate Alzheimer's, the researchers say. Memantine is approved by the Food and Drug Administration to treat patients with moderate and severe Alzheimer's. However, physicians often prescribe it off-label to those with mild forms of the disease. About 19 percent of U.S. patients with mild Alzheimer's disease take the drug, the researchers say. The drug is intended to improve cognitive functions and make it easier for patients to perform daily activities. Though there is no proof that the drug thwarts disease progress, some physicians may prescribe it, and some patients may take it, "under the hopes that it's better to treat with this drug now rather than it is to wait until somebody becomes severe and then treat them," said study researcher Dr. Lon Schneider, of the University of Southern California Keck School of Medicine in Los Angeles. Doctors should take into account these new findings when they consider treating mild and moderate Alzheimer's patients with memantine, Schneider said. Additional studies should be conducted looking at the effects of memantine on patients with mild disease, Schneider said. © 2011 msnbc.com

Keyword: Alzheimers
Link ID: 15208 - Posted: 04.12.2011

By PERRI KLASS, M.D. It opened on East 62nd Street in February 1921, its mission to remove the tonsils and adenoids of poor children on the East Side of Manhattan, thereby preventing sore throats and streptococcal infections and all their serious consequences in an era without antibiotics. Parents saw scarlet fever, named for its red, sandpapery rash, as a frightening and dangerous childhood illness; rheumatic fever, which sometimes followed strep, could seriously damage the heart. But times have changed. Built on studies of throat infections and tonsillectomies, new guidelines from the American Academy of Otolaryngology, issued in January, suggest tonsillectomy for recurrent sore throats only if frequent or severe. At the same time, the academy now recommends that the operation be considered for children who have trouble breathing while they sleep. The new guidelines reflect changes in clinical practice, and attempt to bring scientific evidence to bear on an operation at times popular to the point of ubiquity. In the era of the Tonsil Hospital, pretty much all children got tonsillectomies. Consider “Cheaper by the Dozen”: The 1948 memoir about two efficiency experts and their 12 children happens to contain the single funniest tonsillectomy chapter in literature (granted, competition is limited). © 2011 The New York Times Company

Keyword: Sleep
Link ID: 15207 - Posted: 04.12.2011

by Clare Wilson I'M WATCHING this revolution exploding around me," says Mark George, a neuropsychiatrist at the Medical University of South Carolina in Charleston. "I'm like a kid in a candy store." George is referring to his role as editor-in-chief of Brain Stimulation, a journal launched three years ago to cover the growing list of technologies that can alter the brain's electrical activity. The tools involved range from electrodes and optical fibres to magnetic fields and sound waves, but they all give neuroscientists the power to fine-tune the brain's activity, making them computer hackers of the mind. Fifteen years ago, only a couple of such technologies existed and they were seen as experimental techniques on the fringes of neuroscience. Today there are at least eight methods, all with their own pros and cons, and some are on the verge of becoming mainstream treatments for Parkinson's disease, epilepsy and depression. Innumerable more uses are being explored. Until recently the only treatments available for conditions affecting the brain were drugs or surgery - a "hammer over the head approach", according to William Tyler, a biomedical engineer at Virginia Tech Carilion Research Institute in Roanoke and a pioneer of the new brain stimulation techniques. © Copyright Reed Business Information Ltd.

Keyword: Miscellaneous
Link ID: 15206 - Posted: 04.12.2011

by Rebecca Kessler Most years, Spaniards encounter just one giant squid as long as a city bus along their northern shores—a fisherman might haul one up from the depths accidentally, or beachgoers might stumble across a carcass stranded on a beach. So it was surprising in 2001 when five squid littered the beaches over a 2-month period and in 2003 when four washed up or were found floating at sea near death in a single month. At the time of the strandings, ships offshore were exploring for oil and gas with air guns, which produce high-intensity, low-frequency sounds. Some researchers suspected that the loud noises were harming the squid, just as they are known to harm marine mammals. A new study supports that hunch, reporting massive damage to the sound-detecting structures of squid and other cephalopods that were exposed to loud noises. In recent years, scientists have gathered evidence that sonar and other humanmade noises may hurt everything from whales to crustaceans. But they didn't know whether this audio pollution could perturb cephalopods—the animal group that includes cuttlefish, squid, and octopuses—because researchers have only recently demonstrated their ability to hear. To find out, a team led by marine bioacoustician Michel André of the Technical University of Catalonia in Spain brought 87 wild cephalopods back to laboratory aquariums. For 2 hours, the researchers blared low-frequency sounds that were between 157 and 175 decibels at the animals. For comparison, a supertanker's engine noise might hit 190 decibels in the water 1 meter away from the ship. At intervals up to 96 hours after the sound barrage, the researchers killed the animals and preserved their statocysts—the sound-detecting structures behind their eyes—for microscopic analysis. For controls, the researchers killed and collected the statocysts of 100 wild cephalopods immediately after they were captured. © 2010 American Association for the Advancement of Science.

Keyword: Hearing
Link ID: 15205 - Posted: 04.12.2011

by Greg Miller If you've ever walked to the kitchen to get a snack, been interrupted by a phone call, and then forgotten what you wanted from the fridge, you may have seen a glimpse of your future. A wealth of studies have found that as we age we become more distracted by interruptions and less able to juggle multiple tasks at once. Now neuroscientists have identified a potential explanation: a sticky switch in the neural circuits that coordinate memory and attention. In the new study, published online today in the Proceedings of the National Academy of Sciences, Wesley Clapp and Adam Gazzaley of the University of California, San Francisco, and colleagues recruited 20 healthy adults in their 60s and 70s to play a simple memory game inside a brain scanner. An image of a scene, such as a field or a forest, flashed on a monitor inside the scanner, and volunteers had to keep it in mind for about 15 seconds before indicating whether a second image was a match. In this version of the test, the older volunteers did extremely well, getting 96% correct. But when the researchers added an interruption, the older subjects struggled. When they had to perform a second task while keeping the scene in mind—for example, judging the age and gender of a face flashed on the monitor—their performance on the memory test for the scenes dropped to 88%. A control group of mostly 20-something volunteers was less fazed by the interruption; their performance did not drop significantly. © 2010 American Association for the Advancement of Science. All Rights Reserved.

Keyword: Attention; Alzheimers
Link ID: 15204 - Posted: 04.12.2011

By ABBY GOODNOUGH and KATIE ZEZIMA BANGOR, Me. — The mother got the call in the middle of the night: her 3-day-old baby was going through opiate withdrawal in a hospital here and had to start taking methadone, a drug best known for treating heroin addiction, to ease his suffering. The mother had abused prescription painkillers like OxyContin for the first 12 weeks of her pregnancy, buying them on the street in rural northern Maine, and then tried to quit cold turkey — a dangerous course, doctors say, that could have ended in miscarriage. The baby had seizures in utero as a result, and his mother, Tonya, turned to methadone treatment, with daily doses to keep her cravings and withdrawal symptoms at bay. As prescription drug abuse ravages communities across the country, doctors are confronting an emerging challenge: newborns dependent on painkillers. While methadone may have saved Tonya’s pregnancy, her son, Matthew, needed to be painstakingly weaned from it. Infants like him may cry excessively and have stiff limbs, tremors, diarrhea and other problems that make their first days of life excruciating. Many have to stay in the hospital for weeks while they are weaned off the drugs, taxing neonatal units and driving the cost of their medical care into the tens of thousands of dollars. Like the cocaine-exposed babies of the 1980s, those born dependent on prescription opiates — narcotics that contain opium or its derivatives — are entering a world in which little is known about the long-term effects on their development. Few doctors are even willing to treat pregnant opiate addicts, and there is no universally accepted standard of care for their babies, partly because of the difficulty of conducting research on pregnant women and newborns. © 2011 The New York Times Company

Keyword: Drug Abuse; Development of the Brain
Link ID: 15203 - Posted: 04.11.2011

By Jill U. Adams, Special to the Los Angeles Times Maraschino cherries, Cheetos, Gatorade and Froot Loops. The rainbow of colors in candies and decorated birthday cakes. The colors of these foods are not from nature — and depending whom you talk to, they are harmless fun or making kids bounce off walls. Late last month, an advisory panel for the U.S. Food and Drug Administration concluded there was enough evidence to say that foods containing artificial food dyes may trigger hyperactivity in a small percentage of children with behavioral problems such as attention deficit hyperactivity disorder (ADHD) but that there was not enough to say that food dyes cause hyperactivity in the general population. Without clear evidence of harm, the panel voted against recommending warning labels for food products containing artificial colors. "There's not any convincing data that it's something we need to remove from the diet," says Dr. Wesley Burks, a pediatric allergist at Duke University in Durham, N.C., who served on the FDA panel. Still, critics of food dyes note that there's no health benefit to having artificial colors in foods, so any risk is unacceptable. "Allowing the use of artificial dyes violates the FDA's mandate to protect consumers from unsafe products," wrote two fierce proponents of an FDA ban — psychiatrist David Schab and consumer advocate Michael Jacobson of the Center for Science in the Public Interest — in a Washington Post opinion article in March. Los Angeles Times Copyright 2011

Keyword: ADHD; Neurotoxins
Link ID: 15202 - Posted: 04.11.2011

SYMPTOMS of Alzheimer's disease in mice have been eased by extra supplies of "heat shock" proteins, which re-fold or dispose of proteins implicated in the disease. Tohru Mizushima of Kumamoto University, Japan, and his colleagues used mice bred to mimic symptoms of Alzheimer's. Half the mice were also engineered to make extra supplies of heat shock protein (HSP) 70 in their brains. The HSP70-boosted mice were much better than the others at finding their way around mazes, and post-mortems showed their brains to be free of the characteristic beta-amyloid plaques that clog the brains of people with Alzheimer's. That's because the boosted mice produced normal - rather than high - levels of the amyloid precursor proteins from which plaques are made. What's more, any plaques that did form were more readily removed. Mizushima's team says that HSP70 amplifies the expression of chemicals such as insulin-degrading enzyme and transforming growth factor beta 1, linked to the destruction of the beta-amyloid proteins (Journal of Neuroscience, DOI: 10.1523/jneurosci.5478-10.2011). Elsewhere in the field, Nature Genetics carries reports of four new genes linked with Alzheimer's disease by consortia in the US (DOI: 10.1038/ng.801) and Europe (DOI: 10.1038/ng.803). These genetic discoveries reinforce earlier gene studies implicating abnormal inflammation and fat metabolism in the disease. © Copyright Reed Business Information Ltd.

Keyword: Alzheimers
Link ID: 15201 - Posted: 04.11.2011

by Greg Miller In 1688, an Irish polymath named William Molyneux wrote the English philosopher John Locke a letter in which he posed a vexing question: Could a blind person, upon suddenly gaining the ability to see, recognize an object by sight that he'd previously known by feel? The answer has potentially important implications for philosophers and neuroscientists alike. Now, researchers working with a medical charity that provides surgery to restore vision in blind children say they've found the answer to Molyneux's question. It's "no" but with a twist. Molyneux posed his question in the midst of a philosophical debate about how we comprehend the world around us. An affirmative answer to the question would support the argument that we possess innate (and presumably God-given) concepts that are independent of the senses—for example, that we possess a concept of a sphere, regardless of whether we have only seen one, only felt one, or both. A negative answer to Molyneux's question would support the alternative argument that any concept of a sphere or other object must be tied to sensory experience. In that view, a blind person would have only a tactile concept of a sphere that would be of no use in recognizing the shape by sight. For modern neuroscientists, Molyneux's question raises issues about how the brain integrates information from the different senses, says Richard Held, a professor emeritus of brain and cognitive sciences at the Massachusetts Institute of Technology (MIT) in Cambridge. In search of the elusive answer, Held teamed up with MIT colleague Pawan Sinha, who founded an organization in 2003 to help blind children in India. Called Project Prakash, after the Sanskrit word for "light," the group collaborates with Indian surgeons who operate to restore sight in children who've been blind from cataracts or other curable causes. © 2010 American Association for the Advancement of Science.

Keyword: Development of the Brain; Vision
Link ID: 15200 - Posted: 04.11.2011