Ewen Callaway Anyone who's done a bad Elvis impression knows that contorting your mouth makes talking feel wrong – never mind how ridiculous you sound. People who have lost their hearing use the same sense to retain their speech, new research suggests. When five deaf volunteers were asked to talk while a robot nudged their jaws slightly, they quickly learned to compensate for the perturbation. "One of the real mysteries of human language is that people who become deaf as adults remain capable of producing intelligible speech for years in the complete absence of any auditory input," says David Ostry, a neuroscientist at McGill University in Montreal, Canada, who led the new study along with colleague Sazzad Nasir. Most neuroscientists who study speech focus on how the brain learns from sounds to correct for errors. Yet just as a tennis player learns whether a forehand shot will land in or out just from the feel, people sense whether or not they are speaking correctly, Ostry says. To separate this ability from learning by hearing, he and Nasir enlisted the help of five deaf people with cochlear implants that allowed them to hear. © Copyright Reed Business Information Ltd.

Keyword: Language; Hearing
Link ID: 12042 - Posted: 06.24.2010

By Maggie Fox WASHINGTON - A rare genetic mutation may underlie some cases of mad cow disease in cattle and its discovery may help shed light on where the epidemic started, U.S. researchers reported on Friday. The mutation, in an Alabama cow that tested positive in 2006 for bovine spongiform encephalopathy, or BSE, is identical to one that causes a related brain-wasting disease in humans and that suggests BSE may sometimes arise spontaneously in cattle. The finding also may lend credence to a 2005 theory that the BSE epidemic in cattle could be traced to feed contaminated with either cattle or human remains scavenged from India's Ganges River, the researchers report in the Public Library of Science journal PLoS Pathogens. BSE or mad cow disease swept through British dairy herds in the 1980s, forcing the destruction of millions of animals. No one ever found where it came from but most experts thought it may have come from cattle feed that contained the remains of sheep infected with a similar disease called scrapie. Cattle were never known to develop BSE before the epidemic, but some experts had argued they may have. This report lends credence to that idea. BSE, scrapie and a human version called Creutzfeldt-Jakob disease, or CJD, are all brain-destroying illnesses called transmissible spongiform encephalopathies. In some cases, animals or people that eat brain and nervous system material from victims of these disease can develop them, too. Copyright 2008 Reuters.

Keyword: Prions
Link ID: 12041 - Posted: 09.13.2008

By Elizabeth Mitchell Scientists have uncovered evidence for an inbuilt "sat-nav" system in the brains of London taxi drivers. They used magnetic scanners to explore the brain activity of taxi drivers as they navigated their way through a virtual simulation of London's streets. Different brain regions were activated as they considered route options, spotted familiar landmarks or thought about their customers. The research was presented at this week's BA Science Festival. Earlier studies had shown that taxi drivers have a larger hippocampus - a region of the brain that plays an important role in navigation. Their brains even "grow on the job" as they build up detailed information needed to find their way around London's labyrinth of streets - information famously referred to as "The Knowledge". "We were keen to go beyond brain structure - and see what activity is going on inside the brains of taxi drivers while they are doing their job," said Dr Hugo Spiers from University College London. The scientists used functional magnetic resonance imaging (fMRI) to obtain "minute by minute" brain images from 20 taxi drivers as they delivered customers to destinations on "virtual jobs". The scientists adapted the Playstation2 game "Getaway" to bring the streets of London into the scanner. After the scan - and without prior warning - the drivers watched a replay of their performance and reported what they had been thinking at each stage. (C)BBC

Keyword: Learning & Memory
Link ID: 12040 - Posted: 09.13.2008

By Julie Steenhuysen CHICAGO - Scientists who tricked monkeys by swapping images of sailboats for teacups have figured out how the brain learns to recognize objects, a finding that could lead to robots that "see." "One of the central questions of how the brain recognizes objects and faces is that you never essentially see the same image twice," said James DiCarlo, an associate professor of neuroscience at Massachusetts Institute of Technology. He said humans have no trouble recognizing a dog, regardless of whether it is running, lying down, wagging its tail or begging for food. "The pattern of light in your eyes is never the same when you view your wife or your dog, yet you can still recognize that as the person or creature that you love," said DiCarlo, whose research appears on Thursday in the journal Science. Scientists think people do it by gathering a host of different snapshots of the same object over a short period of time. "Even though we don't see the same images twice, nearby images in time tend to be images of the same object," DiCarlo said in a telephone interview. To test this idea, DiCarlo set up an experiment on two monkeys in which the scientists tried to trick them into unlearning their assumptions about an object. Copyright 2008 Reuters

Keyword: Vision; Robotics
Link ID: 12039 - Posted: 09.13.2008

By JENNIFER EGAN When Claire, a pixie-faced 6-year-old in a school uniform, heard her older brother, James, enter the family’s Manhattan apartment, she shut her bedroom door and began barricading it so swiftly and methodically that at first I didn’t understand what she was doing. She slid a basket of toys in front of the closed door, then added a wagon and a stroller laden with dolls. She hugged a small stuffed Pegasus to her chest. “Pega always protects me,” she said softly. “Pega, guard the door.” James, then 10, had been given a diagnosis of bipolar disorder two years earlier. He was attending a therapeutic day school in another borough and riding more than an hour each way on a school bus, so he came home after Claire. Until James’s arrival that April afternoon, Claire was showing me sketches she had drawn of her Uglydolls and chatting about the Web site JibJab, where she likes to watch goofy videos. At the sound of James’s footsteps outside her bedroom door, she flattened herself behind the barricade. There was a sharp knock. After a few seconds, James’s angry, wounded voice barked, “Forget it,” and the steps retreated. “If it’s my brother, I don’t open it,” Claire said. “I don’t care if I’m being mean. . . . I never trust him. James always jumps out and scares me. He surprises me in a bad way.” Copyright 2008 The New York Times Company

Keyword: Schizophrenia; Development of the Brain
Link ID: 12038 - Posted: 06.24.2010

By David Biello More than 15 million Americans drink too much, according to the National Institute on Alcohol Abuse and Alcoholism. New research on rats may help them curb that addiction. At present, there are three approved drugs for battling alcoholism, none of which work very well. Among them: naltrexone, which is effective for some alcoholics (as well as opiate addicts) because it blocks a pain pathway in the brain associated with the pleasures of drinking. In an effort to boost its effectiveness, neuroscientist Selena Bartlett of the Ernest Gallo Clinic & Research Center at the University of California, San Francisco, and her colleagues chemically manipulated naltrexone so that it cut off a related pleasure pathway in the brain. Their findings, published in the journal Biological Psychiatry: rats (trained to crave alcohol) given the new compound, dubbed SoRI-9409, consumed half as much hooch. In addition, there were fewer side effects. Researchers say that unlike naltrexone, this drug did not diminish the animals' desire for water and other nonalcoholic beverages, such as sugar water. "It is much more selective in its effect on drinking," Bartlett says. Rats given the drug for 28 days refrained from heavy drinking for another four weeks after they were taken off the drug. "That is currently the biggest challenge in alcoholism treatment," which relies primarily on rehabilitation centers, Bartlett notes. When people return home, they typically also return to drinking. "Drinking stays down without the drug in place. It's done something to permanently change and reduce the drinking." © 1996-2008 Scientific American Inc.

Keyword: Drug Abuse
Link ID: 12037 - Posted: 06.24.2010

By Bruce Bower Depressed moms can raise their children’s risk for depression via nurture alone Some youngsters get depressed in the absence of any genetic legacy of the mood disorder, a new investigation finds. Researchers report that having a depressed mother substantially ups a teenager’s likelihood of becoming depressed, even if he or she was adopted and shares no genes with the mother. This finding provides the first direct evidence that purely environmental factors can promote depression in the children of depressed women, says a team led by psychologist Erin Tully of the University of Minnesota in Minneapolis. Having a depressed father does not increase depression susceptibility in either adopted or non-adopted teens, Tully and her colleagues report in the September American Journal of Psychiatry. Two other investigations, both published in the same journal, further emphasize nurture’s role in depression. They show that successful treatment of depressed mothers — either with medication or psychotherapy — spurs emotional gains in their depressed children. © Society for Science & the Public 2000 - 2008

Keyword: Depression; Genes & Behavior
Link ID: 12036 - Posted: 06.24.2010

by Christopher Bergendorff Everybody knows that it feels good to do good. Giving someone a gift can be just as rewarding as getting one yourself. In fact, studies using MRI scans have shown that the part of our brain that stimulates pleasure when receiving a gift also reacts when giving one. Until now, scientists believed that such emotional responses were distinctly human traits, but new research indicates monkeys have them too. Primatologist Frans de Waal, at the Yerkes National Primate Research Center in Atlanta, gave a group of capuchin monkeys a task that involved taking one of two tokens while in the presence of another monkey. "One token would give them a reward, and the other token would give them and their partner a reward. So the first token we call a selfish token, because you only work for yourself. This second token we call a pro-social token, because we reward both monkeys at the same time," says de Waal. The selfish token was colored purple, while the pro-social was green. Once the monkey had chosen, their reward would be a piece of fruit, given to them by the same researcher presenting the tokens. ©2008 ScienCentral

Keyword: Emotions
Link ID: 12035 - Posted: 06.24.2010

Ewen Callaway When picking a husband or wife, American couples seek out new immune genes, while Africans stick to the ones they've got. New research shows that American couples of European ancestry go for mates with versions of immune genes that recognise pathogens dissimilar from those their own genes recognise. These genes are part of the major histocompatibility complex, and the more MHC genes a person has, the greater variety of pathogens his or her immune system recognises. Previous work in fish, lizards and birds has suggested that animals seek out mates with different MHC genes than their own. Yet studies in humans have painted a far blurrier picture of MHC-driven mating preferences. One study concluded that Hutterites, who live communally, wed people with different versions of the genes, while another found that women prefer the scent of sweaty T-shirts worn by men with similar MHC genes. However, an additional sweaty T-shirt experiment using slightly different methods showed just the opposite trend. “It seems that body odours can reveal someone’s immune genetics, and so through the smell we could be able to distinguish the MHC genes from different potential mates,” says Raphaëlle Chaix, a human population geneticist at the National Centre for Scientific Research in Paris, France. © Copyright Reed Business Information Ltd

Keyword: Sexual Behavior; Genes & Behavior
Link ID: 12034 - Posted: 06.24.2010

By Ashley Yeager Men are dense — in the temporal neocortex anyway. An investigation of brain tissue recovered from epilepsy patients during surgery showed men had a higher density of brain cell connectors, called synapses, than their female counterparts, researchers report September 8 online in the Proceedings of the National Academy of Sciences. The find might explain why men have better spatial perception, while women better remember what they hear and can talk faster, the researchers suggest. “Or, it could mean men’s brains are just more redundant,” says Edward Jones, director of the Center for Neuroscience at the University of California, Davis, who was not involved in the study. Right now, it’s hard to know exactly what the difference means, he says. For many years, scientists have searched for structural variations between men’s and women’s brains to explain psychological studies showing that, overall, the sexes think and act differently. Past studies found differences in brain mass and neuron density, but “they were hyped and untrustworthy,” Jones says. This study is meticulously detailed, he notes. It is the first to show gender differences on such a fine scale — at the synapse, which is the juncture where an electrical signal passes from one brain cell to another. “The level of detail and meticulousness are why I have confidence in the results,” he says. © Society for Science & the Public 2000 - 2008

Keyword: Sexual Behavior
Link ID: 12033 - Posted: 06.24.2010

Some cases of cot death may be due to a bacterial infection, researchers say. The Archives of Disease in Childhood study found samples from babies who had died for no apparent reason often carried potentially-harmful bacteria. Some experts believe toxins produced by these bacteria could trigger a chemical storm, which overwhelms the baby, resulting in sudden death. There are around 250 sudden infant deaths a year in the UK. The majority are never fully explained. Scientists know that there are certain things that parents can do to cut the risk of cot death - such as not smoking during or after pregnancy, and putting babies to sleep on their backs, but the precise reasons why this helps are not completely understood. Associate professor Paul Goldwater, from The Women's and Children's Hospital and the University of Adelaide in Australia, who carried out the latest research, believes bacterial infections may contribute to some sudden infant deaths. He analysed the post mortem reports for 130 babies who had died of sudden infant death syndrome (SIDS), 32 who had died suddenly as a result of infection, and 33 who had died of non-infectious cause, such as a road traffic accident. He then analysed the bacterial isolates from "sterile" sites which are normally free of infections, such as heart blood, spleen, or cerebrospinal fluid, in the SIDS babies, and compared these with those of the other 65 babies. Infection at a sterile site was rare in those infants who had died of non-infectious causes, but this was relatively common in both the SIDS babies and the babies who had died suddenly as a result of infection. Unsurprisingly, almost one in five of the babies who had died suddenly as a result of infection had a sterile site infection. But so too did one in 10 of the SIDS babies. (C)BBC

Keyword: Sleep; Development of the Brain
Link ID: 12032 - Posted: 09.11.2008

Bob Holmes HOW do you go about finding a mate? For female barking tree frogs it appears the trick is to use complex calculations to pick out the loudest male in a chorus, even when distance makes him sound quieter than a nearer rival. To determine the females' favourite mating call, Christopher Murphy, a behavioural ecologist at James Madison University in Harrisonburg, Virginia, played captured frogs an artificial chorus of male calls from an array of loudspeakers. The females hopped towards the call they found most attractive. Females generally preferred louder calls, probably because they indicate a bigger, stronger male. Indeed, when Murphy played the louder call through a more distant speaker, so that a closer but lower-volume call sounded louder to the female, she still chose the speaker with the inherently louder call (Journal of Comparative Psychology, vol 122, p 264). This suggests that females have some way of judging a male's distance apart from how loud his call appears. "They're smarter than I realised," says Murphy. He adjusted the sound again to rule out two techniques the frogs might use: judging distance by how the sound degrades, or working out how quickly the sound gets louder as they approach. © Copyright Reed Business Information Ltd

Keyword: Hearing; Sexual Behavior
Link ID: 12031 - Posted: 06.24.2010

By Rachel Zelkowitz Standing alone in a dark alley, you whirl around at the sound of footsteps. A figure moves in the distance, its silhouette barely visible by a sliver of moonlight. Is the stranger coming toward you? If he's a man, your senses will tell you yes, according to a new study, even if he's actually walking away. How someone walks can reveal their feelings. Slumped shoulders and a labored gait, for example, indicate unhappiness. Researchers often study these kinds of signals using something called a point-light figure, a collection of dots arranged in a human form. The figure is supposed to convey minimal information, but simple manipulations--broadening the dots on the shoulder region or narrowing dots that represent the waist--can make figures seem more masculine or more feminine. Ben Schouten, a psychologist at the University of Leuven in Belgium, and colleagues tested whether giving the point-light figure a distinctive gender would affect how an observer perceives its motion. They asked five volunteers--three women and two men--to watch videos of point-light figures on a computer screen. By changing the point arrangements, the researchers made the figures seem either very masculine, very feminine, or gender-neutral. The subjects watched a 3- to 4-second clip of the figure walking and had to identify whether the figure was moving toward or away from them. The researchers then showed a second set of videos that incorporated subtle shifts of movement in the background to give more information on the walker's direction. © 2008 American Association for the Advancement of Science.

Keyword: Sexual Behavior; Emotions
Link ID: 12030 - Posted: 06.24.2010

By Pascal Belin The use of vocalizations, such as grunts, songs or barks, is extremely common throughout the animal kingdom. Nevertheless, humans are the only species in which these vocalizations have attained the sophistication and communicative effectiveness of speech. How did our ancestors become the only speaking animals, some tens of thousands of years ago? Did this change happen abruptly, involving the sudden appearance of a new cerebral region or pattern of cerebral connections? Or did it happen through a more gradual evolutionary process, in which brain structures already present to some extent in other animals were put to a different and more complex use in the human brain? A recent study in Nature Neuroscience yields critical new information, uncovering what could constitute the “missing link” between the brain of vocalizing nonhuman species and the human brain: evidence that a cerebral region specialized for processing voice, known to exist in the human brain, has a counterpart in the brain of rhesus macaques. Neuroscientist Christopher I. Petkov of the Max Planck Institute for Biological Cybernetics in Tübingen, Germany, and his colleagues used functional magnetic resonance imaging to explore the macaque brain. They measured cerebral activity of awake monkeys that were listening to different categories of natural sounds, including macaque vocalizations. The researchers found evidence for a “voice area” in the auditory cortex of these macaques: a discrete region of the anterior temporal lobe in which activity was greater for macaque vocalizations than for other sound categories. © 1996-2008 Scientific American Inc.

Keyword: Language; Evolution
Link ID: 12029 - Posted: 06.24.2010

Vigorous physical activity could blunt the effects of a common gene linked to obesity, claim US researchers. Carrying two copies of the FTO gene significantly increases the chances of becoming obese. However, a study carried out among the US Amish community found an active lifestyle appeared to remove this risk. A UK specialist said the results, reported in the Archives of Internal Medicine journal, would be interesting if repeated by larger studies. The complex relationships between our genes and lifestyles, which can mean obesity for some people and not for others, has yet to be fully understood. Several genetic variants have been linked to obesity, but none is wholly responsible for it. The most common of these is FTO, with half of all people in Europe carrying either one or two copies of it. It is not clear how it influences weight gain, although some scientists have suggested it may play a role in an individual's appetite. The study from the University of Maryland supports other research which suggests that a person's level of exercise may help determine whether their genetic makeup will contribute to obesity. The researchers looked at 704 Amish men and women, chosen because of that community's relative genetic "purity", with members generally able to trace their ancestry back for 14 generations to early settlers from Europe. Volunteers were fitted with "accelerometers", measuring their precise movements over a period of time. They found that while the expected link between the number of copies of FTO carried and increased body mass index could be seen in less active volunteers, that link was broken once in those who recorded high levels of activity - equivalent to three to four hours of moderately intensive activity. (C)BBC

Keyword: Obesity; Genes & Behavior
Link ID: 12028 - Posted: 09.09.2008

For years, researchers have known that women are twice as likely to develop depression as men and they suffer a wider range of symptoms. But when it came to prescribing effective treatments, researchers couldn't agree if gender mattered. As some small studies suggested, certain drugs worked better in women than men. Could there be significant biological differences in how each gender responded to these medications? A $35 million, federally funded study, was commissioned to answer the controversy, and its just-published results suggest that the answer to both questions is a probable yes. The STAR*D (Sequenced Treatment Alternatives to Relieve Depression) study, the largest and most rigorous depression study done to date, enrolled 2,876 men and women (ages 18 to 75) from 41 treatment centers with funding from the National Institute of Mental Health (NIMH). All participants were treated for 12 to 14 weeks with citalopram (popularly known as Celexa), a selective serotonin reuptake inhibitor (SSRI), currently the most popular class of antidepressants on the market. Even though the women in the study generally had more severe depressive symptoms than the men, they were 33 percent more likely than the male participants to achieve a full remission. "These results are very exciting because they give more confirmation that gender is a factor that should be considered when prescribing treatment for depression," said Dr. Susan Kornstein, professor of psychiatry and obstetrics/gynecology at Virginia Commonwealth University, and one of the study's lead authors. "This is one more big piece of the puzzle as we try to understand sex differences in treatment response." The results were recently published in the online version of the Journal of Psychiatric Research. © 2008 Newsweek, Inc.

Keyword: Depression; Sexual Behavior
Link ID: 12027 - Posted: 06.24.2010

A vitamin found in meat, fish and milk may help stave off memory loss in old age, a study has suggested. Older people with lower than average vitamin B12 levels were more than six times more likely to experience brain shrinkage, researchers concluded. The University of Oxford study, published in the journal Neurology, tested the 107 apparently healthy volunteers over a five-year period. Some studies suggest two out of five people are deficient in the vitamin. The problem is even more common among the elderly, and recent moves to supplement bread with folic acid caused concern that this could mask B12 deficiency symptoms in older people. The Oxford study looked at a group of people between 61 and 87, splitting it into thirds depending on the participants' vitamin B12 levels. Even the third with the lowest levels were still above a threshold used by some scientists to define vitamin B12 deficiency. However, they were still much more likely to show signs of brain shrinkage over the five-year period. Professor David Smith, who directs the Oxford Project to Investigate Memory and Ageing, said he now planned a trial of B vitamins in the elderly to see if taking them could slow brain shrinkage. He said: "This study adds another dimension to our understanding of the effects of B vitamins on the brain - the rate of shrinkage of the brain as we age may be partly influenced by what we eat." Shrinkage has been strongly linked with a higher risk of developing dementia at a later stage and Rebecca Wood, the chief executive of the Alzheimer's Research Trust, said further research was needed. "This study suggests that consuming more vitamin B12 through eating meat, fish, fortified cereals or milk as part of a balanced diet might help protect the brain. Liver and shellfish are particularly rich sources of B12. "Vitamin B12 deficiency is a common problem among elderly people in the UK and has been linked to declining memory and dementia." (C)BBC

Keyword: Alzheimers; Learning & Memory
Link ID: 12026 - Posted: 09.09.2008

By NICHOLAS BAKALAR Failure to properly absorb vitamin B12, found in meat, milk and eggs, has been implicated in various neurological disorders. Now a British study suggests that low levels of the vitamin in older people may cause the brain to shrink. The study, published Tuesday in Neurology, included 107 men and women, average age 73, who had no mental impairments. Researchers used M.R.I. scans to measure brain volume and blood tests to record vitamin B12 levels. They divided the subjects into three groups, based on their level of the vitamin, and followed them for five years with annual scans and physical and mental examinations. The group with the lowest levels of vitamin B12 lost twice as much brain volume as those with the highest levels. The difference was significant even after controlling for initial brain size, age, sex, education, cognitive test scores and various measures of blood chemistry. David Smith, an emeritus professor of pharmacology at Oxford and the lead author of the study, said the work established an association, but not a causal connection. “This doesn’t mean you should go out and buy vitamin B12 tablets tomorrow,” he said. “We need to know the results of a clinical trial in which we’re testing whether B12 does actually prevent brain shrinkage.” Copyright 2008 The New York Times Company

Keyword: Alzheimers
Link ID: 12025 - Posted: 06.24.2010

By KEVIN SACK and BRENT McDONALD DALLAS — With a friend videotaping, 27-year-old Christopher Lenzini of Dallas took a hit of Salvia divinorum, regarded as the world’s most potent hallucinogenic herb, and soon began to imagine, he said, that he was in a boat with little green men. Mr. Lenzini quickly collapsed to the floor and dissolved into convulsive laughter. Nathan K. calls his use of salvia “just a very gentle letting go, a very gentle relaxing.” When he posted the video on YouTube this summer, friends could not get enough. “It’s just funny to see a friend act like a total idiot,” he said, “so everybody loved it.” Until a decade ago, the use of salvia was largely limited to those seeking revelation under the tutelage of Mazatec shamans in its native Oaxaca, Mexico. Today, this mind-altering member of the mint family is broadly available for lawful sale online and in head shops across the United States. Though older Americans typically have never heard of salvia, the psychoactive sage has become something of a phenomenon among this country’s thrill-seeking youth. More than 5,000 YouTube videos — equal parts “Jackass” and “Up in Smoke” — document their journeys into rubber-legged incoherence. Copyright 2008 The New York Times Company

Keyword: Drug Abuse
Link ID: 12024 - Posted: 06.24.2010

Duncan Graham-Rowe It was six months after her operation that Elisabeth Bryant first started to see the effects, quite literally. Clinically blind, Bryant began to make out the swinging pendulum of her grandfather clock from across the room. Since then her vision improved to the point that she could read large print editions of Reader's Digest, send emails and continue with past activities like sewing and knitting. Bryant is one of ten patients to have received a retinal transplant as part of a phase II trial to replace diseased photoreceptors in conditions such as retinitis pigmentosa (RP) and age-related macular degeneration (AMD). Before the transplant she could see nothing but shadows. But within a year her vision had improved from 20/800 to 20/160, a remarkable recovery. Each of the patients in the trial received a small 4 millimetre square of retinal tissue, complete with retinal progenitor cells and the retinal pigment epithelium that nourishes them. The tissues were placed in the sub-retinal space beneath the fovea, the area of the retina responsible for sharp central vision. Seven of the subjects experienced an improvement in their visual acuity, says Norman Radtke, the ophthalmologist who carried out the surgery at the Retina Vitreous Resource Center in Louisville, Kentucky. The results are reported in the August issue of the American Journal of Ophthalmology1. © 2008 Nature Publishing Group

Keyword: Vision
Link ID: 12023 - Posted: 06.24.2010