Colin Barras Here's a possible explanation for why rock star Ozzy Osbourne infamously bit the head off a bat: he couldn't stand the competition. Bat calls, it turns out, can reach up to a deafening 140 dB – that's 20 dB louder than a rock concert and 15 dB above the human pain threshold. Bats use high-pitched calls to echolocate because only at those ultrasonic frequencies can they detect their small, swiftly moving insect prey. But high-frequency calls don't travel far through the air, leaving bats unable to detect prey beyond a few metres. Annemarie Surlykke at the University of Southern Denmark in Odense and Elisabeth Kalko of the University of Ulm, Germany, reasoned that bats with the highest frequency calls would compensate for the small detection distance with louder cries, because a louder call travels further. To test this they recorded the calls of 11 bat species living on Barro Colorado Island in Panama. They found that the call of one species – the lesser bulldog bat (Noctilio albiventris) – reached an ear-shattering 137 dB, an estimate they think is likely to be on the conservative side because of the high directionality of the calls. Even so, N. albiventris now holds the record as the loudest winged animal yet recorded. © Copyright Reed Business Information Ltd.

Keyword: Hearing
Link ID: 11572 - Posted: 06.24.2010

By NICHOLAS BAKALAR A new study has found that it may be possible to train people to be more intelligent, increasing the brainpower they had at birth. Until now, it had been widely assumed that the kind of mental ability that allows us to solve new problems without having any relevant previous experience — what psychologists call fluid intelligence — is innate and cannot be taught (though people can raise their grades on tests of it by practicing). But in the new study, researchers describe a method for improving this skill, along with experiments to prove it works. The key, researchers found, was carefully structured training in working memory — the kind that allows memorization of a telephone number just long enough to dial it. This type of memory is closely related to fluid intelligence, according to background information in the article, and appears to rely on the same brain circuitry. So the researchers reasoned that improving it might lead to improvements in fluid intelligence. First they measured the fluid intelligence of four groups of volunteers using standard tests. Then they trained each in a complicated memory task, an elaborate variation on Concentration, the child’s card game, in which they memorized simultaneously presented auditory and visual stimuli that they had to recall later. Copyright 2008 The New York Times Company

Keyword: Learning & Memory
Link ID: 11571 - Posted: 06.24.2010

By Nikhil Swaminathan It is well established that the brain uses more energy than any other human organ, accounting for up to 20 percent of the body's total haul. Until now, most scientists believed that it used the bulk of that energy to fuel electrical impulses that neurons employ to communicate with one another. Turns out, though, that is only part of the story. A new study in Proceedings of the National Academy of Sciences USA indicates that two thirds of the brain's energy budget is used to help neurons or nerve cells "fire'' or send signals. The remaining third, however, is used for what study co-author Wei Chen, a radiologist at the University of Minnesota Medical School, refers to as "housekeeping," or cell-health maintenance. Researchers reached their conclusions after imaging the brain with magnetic resonance spectroscopy (MRS) to measure its energy production during activity shifts. Chen says the technology, which has been around for three decades and is used to track the products of metabolism in different tissues, could prove instrumental one day in detecting brain defects or to diagnose tumors or precursors of neurodegenerative diseases (such as Alzheimer's and Parkinson's) early. © 1996-2008 Scientific American Inc.

Keyword: Brain imaging
Link ID: 11570 - Posted: 06.24.2010

Nick Bryant Australian scientists believe they may have discovered how to help people lose weight without cutting back on food. Researchers in Melbourne found that by manipulating fat cells in mice they were able to speed up metabolism. After removing a particular enzyme, scientists found the mice were able to eat the same amount as others but burn more calories and gain less weight. The breakthrough could pave the way for fat-burning drugs and also help to combat diabetes. The research found that mice in which the angiotensin converting enzyme (ACE) had been removed were, on average, 20% lighter than normal mice and had up to 60% less body fat. Because of their faster metabolisms, it also appeared they had less chance of developing diabetes because they processed sugar more quickly. Drugs which impair the action of ACE in humans already exist, and are used to combat high blood pressure. The latest research could help the development of weight loss pills. The question is whether they will have the same slimming effect on people as they have done on mice. Dr Ian Campbell, medical director of the charity Weight Concern, said the study was "interesting", but stressed the work had only been carried out in mice. (C)BBC

Keyword: Obesity
Link ID: 11569 - Posted: 04.29.2008

By ABIGAIL ZUGER, M.D. Marya Hornbacher is a virtuoso writer: humorous, articulate and self-aware. She is also, as she has now documented in two books, incurably mentally ill. Even on the best possible treatment, Ms. Hornbacher tiptoes along the same high wire as Plath, Lowell, Woolf and the rest of the unbalanced artistes. Off medication, she reliably falls into a turmoil of confused self-destruction, which, as she would be the first to acknowledge, means heartbreak and worry for her friends and relatives, challenges for her doctors, and, in the age-old contradiction, new fodder for her muse. For scientists trying to parse the mystery of brain and mind, she is one more case of the possible link between mental illness and artistic creativity. With all our scans and neurotransmitters, we are not much closer to figuring out that relationship than was Lord Byron, who announced that poets are “all crazy” and left it at that. But effective drugs make the question more urgent now: would Virginia Woolf, medicated, have survived to write her final masterpiece, or would she have spent her extra years happily shopping? Copyright 2008 The New York Times Company

Keyword: Anorexia & Bulimia; Schizophrenia
Link ID: 11568 - Posted: 06.24.2010

By Dennis Drabelle I never used to be a napper. In fact, daytime slumber was virtually beyond a congenitally wired type like me. My buddies would catch 40 winks on the long bus ride home from our high school, but for me that was out of the question. With age, however, my metabolism has changed. After the double whammy of a late-morning run and lunch, I'm pretty much a goner. I lie down and nod off in much the same way that Marlene Dietrich fell in love in that old song of hers: because I can't help it. While it lasted, though, my nap resistance put me in sync with the American way of sleep: Do it all at once and strictly at night. Traditionally, we've begrudged ourselves naps. They may be forced on toddlers, recommended for pregnant women and tolerated among senior citizens with nothing better to do, but they've been frowned upon for worker bees in their prime. Recently, however, sleep scientists have discovered advantages to napping, which they view not just as solace but also as something akin to brain food. No longer written off as a cop-out for the weak and the bored, the nap is coming into its own as an element of a healthy life. When you take a look at American history, we might seem to be a nap-friendly people. After all, some of our most productive figures napped shamelessly during the day, among them Benjamin Franklin and Thomas Edison. But they probably did so because, like Dietrich, they couldn't help it. Consider the daily schedule Franklin drew up for "The Art of Virtue," a treatise he worked on for 50 years but never finished: Over a 24-hour period, sleep gets allotted a mere five hours. Or take the contemptuous words of Edison: "Sleep is an acquired habit. Cells don't sleep. Fish swim in the water all night. Even a horse doesn't sleep. A man doesn't need any sleep." © Copyright 1996-2008 The Washington Post Company

Keyword: Sleep
Link ID: 11567 - Posted: 06.24.2010

Heidi Ledford Can training one aspect of the mind, such as memory, improve overall mental sharpness? Researchers conducting a study on healthy college students suggest that such mental cross-training does work. The notion that a few daily puzzles and quizzes sharpens the intellect and staves off cognitive decline is controversial (see Brain craze). Most research has shown that such brain games do little more than allow the participant to develop strategies for improving performance on that particular task. The improvement does not typically extend beyond the game itself. But a new study published this week in Proceedings of the National Academy of Sciences reports that a group of college students improved their performance on a pattern-recognition test — a commonly used intelligence test — after training their working memory1. Susanne Jaeggi and Martin Buschkuehl, both now at the University of Michigan in Ann Arbor, and their colleagues recruited 70 participants from the University of Bern in Switzerland, and trained them on a rigorous memory test. The test consisted of a string of events: every three seconds, a small white box would appear on the screen in varying locations while at the same time a letter of the alphabet was read aloud. © 2008 Nature Publishing Group

Keyword: Learning & Memory
Link ID: 11566 - Posted: 06.24.2010

By Pallab Ghosh A 18-year-old whose sight was failing has had his vision improved in a pioneering operation carried out by doctors at Moorfields Eye Hospital. The London researchers used gene therapy to regenerate the dying cells in Steven Howarth's right eye. As a result he can now confidently walk alone in darkened rooms and streets for the first time. Steven, from Bolton, is the third person to have the operation - doctors expect better results in future cases. Before the procedure, he could hardly see at all at night and in time he would have lost his sight completely. His condition - Lebers congenital amaurosis - was due to a faulty gene that meant that the light-detecting cells at the back of his eye were damaged and slowly degenerating further. After a few months, doctors detected some improvements. But Steven did not notice these changes until he confidently strode through a dimly-lit maze designed to test his vision. Until then he had kept walking into walls - and it would take him nearly a minute to walk a few feet. His doctors were shocked at the improvement. Professor Robin Ali, of the Institute for Ophthalmology, who led the trial, said: "To get this indication after only three patients is hugely exciting. "I find it difficult to remember being as excited as I am today about our science and what it might achieve." (C)BBC

Keyword: Vision
Link ID: 11565 - Posted: 04.28.2008

By GENE JOHNSON SEATTLE -- Timothy Garon's face and arms are hauntingly skeletal, but the fluid building up in his abdomen makes the 56-year-old musician look eight months pregnant. His liver, ravaged by hepatitis C, is failing. Without a new one, his doctors tell him, he will be dead in days. But Garon's been refused a spot on the transplant list, largely because he has used marijuana, even though it was legally approved for medical reasons. "I'm not angry, I'm not mad, I'm just confused," said Garon, lying in his hospital bed a few minutes after a doctor told him the hospital transplant committee's decision Thursday. With the scarcity of donated organs, transplant committees like the one at the University of Washington Medical Center use tough standards, including whether the candidate has other serious health problems or is likely to drink or do drugs. And with cases like Garon's, they also have to consider _ as a dozen states now have medical marijuana laws _ if using dope with a doctor's blessing should be held against a dying patient in need of a transplant. Most transplant centers struggle with the how to deal with people who have used marijuana, said Dr. Robert Sade, director of the Institute of Human Values in Health Care at the Medical University of South Carolina. © 2008 The Associated Press

Keyword: Drug Abuse
Link ID: 11564 - Posted: 06.24.2010

Kerri Smith Blind mice have been made to sense light by inserting a protein derived from algae into their eyes. A similar method could one day be used to treat certain forms of blindness in humans, the researchers hope. The light-sensitive protein, called channelrhodopsin-2 (ChR2), is used by algae to sense light for photosynthesis. Some researchers are interested in using these light-sensitive proteins to replace damaged or missing photoreceptors in animals' eyes. This happens in several human conditions, including the late stages of a relatively common form of blindness: age-related macular degeneration. At present, there are no cures for such patients, though treatments including gene therapy and laser surgery are being tested. The algae protein has been used by neuroscientists before in the lab, in order to make 'light switches' that turn neurons of interest on and off in lab animals1. But its use as a therapy against blindness is in very early stages. If the technique can be perfected, it could allow people rendered totally blind by the loss of photoreceptors able to see — albeit in black and white. © 2008 Nature Publishing Group

Keyword: Vision; Biological Rhythms
Link ID: 11563 - Posted: 06.24.2010

CHICAGO - Two of the largest and longest studies so far show a “brain pacemaker” can effectively treat depression and obsessive-compulsive disorder, researchers said on Friday. Devices implanted in the chest, with leads that send electrical impulses to parts of the brain, have already been approved to treat movement disorders, such as Parkinson’s disease, essential tremor and dystonia. Dr. Ali Rezai, head of neurosurgery at the Cleveland Clinic, who led the studies, said the technique known as deep brain stimulation helped the most severely depressed patients improve significantly. Researchers from Butler Hospital/Brown Medical School, Massachusetts General Hospital and Harvard Medical School were also involved in the depression study. Seventeen paarea of the brain and is likely to generate similar findings. He said there were no serious side effects in using the Medtronic device. The trial treating OCD included 26 patients who were followed for three years and also showed marked improvement. Copyright 2008 Reuters.

Keyword: Depression
Link ID: 11562 - Posted: 06.24.2010

By Deborah Blum Kelly Klump is a curly-haired, compact woman who is fascinated by eating disorders. Her own habits are healthy, but as a high school “peer counselor” she found herself besieged by girls struggling with the addictive starvation of anorexia nervosa and the compulsive binge-and-purge of bulimia. Now a 37-year-old associate professor at Michigan State University in East Lansing, Klump has spent the past 10 years probing the genetic influences in such illnesses and pondering a stubborn question about why biology makes women more likely targets than men for eating disorders. Lately she has revisited that frustrating question from a new angle. Working with graduate student Kristen Culbert and other colleagues, Klump published a paper in the March Archives of General Psychiatry focusing on a very specific group: females from a male-female twin pair. A few years ago this would have seemed a rather narrow approach to a widespread problem. But several recent studies now suggest that the girl twin in a mixed pair offers provocative evidence concerning the way biology shapes people before birth. Psychologists in both the United States and Europe have found that females from opposite-sex twin pairs tend to be more aggressive and adventurous, process spatial information more like men, and show more typically masculine left brain dominance during language tests. Across a range of research, these female co-twins seemed shifted toward the male end of the behavioral spectrum. © Society for Science & the Public 2000 - 2008

Keyword: Hormones & Behavior; Anorexia & Bulimia
Link ID: 11561 - Posted: 06.24.2010

WASHINGTON - Cuddling up against mother's bare skin can help tiny premature babies recover more quickly from the pain of being stuck with needles and other procedures, Canadian researchers reported on Wednesday. Babies held tightly against their mother's skin in a "kangaroo mother care" position squirmed and grimaced less than babies swaddled in blankets, the researchers found. "Skin-to-skin contact by the mother, referred to as kangaroo mother care, has been shown to be efficacious in reducing pain in three previous studies," Celeste Johnston of McGill University School of Nursing in Montreal and her colleagues wrote in the journal BioMed Central Pediatrics. But those studies involved older babies. Her team tested 61 preterm babies born between 28 and 31 weeks. Such preemies spend weeks in neonatal intensive care units and are often subjected to painful medical procedures. Parents and nurses alike find it one of the most distressing things about having an infant in the unit, the researchers said. Copyright 2008 Reuters.

Keyword: Pain & Touch
Link ID: 11560 - Posted: 04.26.2008

Although children in North America are exposed to less lead than children 30 years ago, the lead problem has not disappeared. Lead exposure in inner-city and certain minority populations remains a serious problem. Depending on the intensity of exposure and the age of the exposed person, lead can cause developmental problems, mental retardation, stunted growth, and fertility problems. Add to that a potential new effect of lead exposure: an increased risk of Alzheimer’s Disease. University of Rhode Island neurologist Nasser Zawia and colleagues have published a study in the Journal of Neuroscience, pointing to an association between lead exposure in infancy and Alzheimer’s in adulthood. “People mostly think of lead exposure as being something that only affects children, and nobody has been studying the elderly and adults to see if they’re impacted,” says Zawia. But by studying monkeys exposed to low lead levels in 1980 and 1981, Zawia and his team found evidence that childhood lead exposure could trigger growth of brain plaques associated with Alzheimer’s Disease. “What we found was simply, in the monkeys that were exposed to lead as infants, there was an increase in the expression of the genes involved in Alzheimer’s Disease and the proteins…that are part of the core of the plaques,” Zawia explains. © ScienCentral, 2000-2008.

Keyword: Alzheimers; Neurotoxins
Link ID: 11559 - Posted: 06.24.2010

Rachel Nowak Vive la difference – between men. That's the attitude of the female painted dragon lizard, which lives across the southern states of Australia. The females are polyandrous, and mate with as many males as possible. That is easy, because they only need to copulate for 10 seconds before males ejaculate. What is more, they store ejaculates inside their reproductive tracts for up to five months, forcing sperm from different males to compete to fertilise their eggs. Evolutionarily speaking, this all makes good sense. By encouraging competition the female increases her chances of getting hold of good-quality sperm. What has been a mystery is the fact that the brightly-coloured male dragons come in more than one version: some have red heads, some yellow heads, and a third version – discovered last year – have orange heads. Usually natural selection weans out inferior versions of an organism, so the fact that all versions of male painted dragons exist in the population has been hard to explain. Now a team of evolutionary ecologists believe that they have solved a major piece of the puzzle. © Copyright Reed Business Information Ltd

Keyword: Sexual Behavior; Evolution
Link ID: 11558 - Posted: 06.24.2010

By MARILYNN MARCHIONE CHICAGO -- Two years ago, scientists had high hopes for new pills that would help people quit smoking, lose weight and maybe kick other tough addictions like alcohol and cocaine. The pills worked in a novel way, by blocking pleasure centers in the brain that provide the feel-good response from smoking or eating. Now it seems the drugs may block pleasure too well, possibly raising the risk of depression and suicide. Margaret Bastian of suburban Rochester, N.Y., was among patients who reported problems with Chantix, a highly touted quit-smoking pill from Pfizer Inc. that has been linked to dozens of reports of suicides and hundreds of suicidal behaviors. "I started to get severely depressed and just going down into that hole ... the one you can't crawl out of," said Bastian, whose doctor took her off Chantix after she swallowed too many sleeping pills and other medicines one night. Side effects also plague two other drugs: _ Rimonabant, an obesity pill sold as Acomplia in Europe, was tied to higher rates of depression and a suicide in a study last month. The maker, Sanofi-Aventis SA, still hopes to win its approval in the United States. _ Taranabant, a similar pill in late-stage testing, led to higher rates of depression and other side effects in a study last month. Its maker, Merck & Co., stopped testing it at middle and high doses. © Copyright 1996-2008 The Washington Post Company

Keyword: Drug Abuse; Depression
Link ID: 11557 - Posted: 06.24.2010

Mind Matters editor Jonah Lehrer chats with Gary F. Marcus, New York University psychologist and head of the Infant Language Learning Center, about how computing, genetic biology and psychology together can help probe the wonders of human language development. JONAH LEHRER: What first made you interested in studying the development of language in children? GARY F. MARCUS: I came to language development through early exposure to computers, back in the late 1970s and early 1980s, when I was in grade school. I was one of those kids who took to programming like a fish takes to water, and very soon wanted to push the limits: What could I get a computer to do? One obvious thing was to try get a computer program to understand language; I pretty quickly figured out just how hard that was—there was no way I was going to get my Commodore 64 to talk—but along the way I developed an abiding interest in human mind and how it managed to solve difficult problems. And to this day I still find it amazing just how good human children are at learning languages. No other creature comes close, and nor does any computer program, even now, 20 years later. How come our memories are so lousy relative to computers, yet our capacities for learning language are so good? That's the kind of question I like. © 1996-2008 Scientific American Inc.

Keyword: Language; Development of the Brain
Link ID: 11556 - Posted: 06.24.2010

Ten-year-old Charles, who has autism, is happy to tell you a story by himself. But when asked to collaborate with another child on a story, he doesn't have much to say. Autism is marked by impairments in communication and social behavior; people with autism may perform repetitive behaviors and prefer an unchanging environment. Autism is a brain disorder that is typically diagnosed in children before the age of three. The effects of autism vary along a spectrum of severity, but it most often impairs both social interaction and the ability to learn in a typical classroom setting. Valeria Nanclares, child psychologist at Advocate Illinois Masonic Medical Center, explains, "The difference between typically developing peers and children with autism has to do with their ability to build and sustain a conversation. Typically developing kids can understand that they need to pick up on the other child's cues, follow the leads of what they just said, so they can build a conversation," she says. To address that deficit, Justine Cassell, director of the Center for Technology & Social Behavior at Northwestern University and her team developed a life-sized virtual pal named Sam. Sam helps autistic kids practice the back-and-forth exchange of conversation – a skill Cassell says is essential for making social connections and learning in the classroom. © ScienCentral, 2000-2008.

Keyword: Autism
Link ID: 11555 - Posted: 06.24.2010

Ewen Callaway Any hedge-fund manager will tell you that money and status go hand in hand. Now brain-scanning studies suggest that the link between profits and power takes place in the striatum – part of the brain involved in sensing rewards. "This provides the biological basis of our everyday experience that personal reputation is felt as reward," says Norihiro Sadato, a neuroscientist at the National Institute for Physiological Sciences in Aichi, Japan, who led one of the studies. Sadato's team scanned the brains of 19 volunteers while they gambled. Volunteers selected one of three cards that flashed onto a computer screen. After making a choice, the subjects learned of their winnings – between 0 and 60 yen (about $0.50) per card. Volunteers also played the game with no winnings, allowing the researches to compare how the brain responded to profit. After the game, the subjects took a personality quiz and introduced themselves in front of a video camera. Sadato's team told the volunteers they would be evaluated by others. In reality, the researchers faked the evaluations. The next day, volunteers returned to the brain scanner. Instead of money, they received praise or scorn. Photos of each volunteer were flashed across a computer screen with personal judgments like "modest," "trustworthy," and "selfish" next to their picture. © Copyright Reed Business Information Ltd.

Keyword: Emotions
Link ID: 11554 - Posted: 06.24.2010

Human imaging studies have for the first time identified brain circuitry associated with social status, according to researchers at the National Institute of Mental Health (NIMH) of the National Institutes of Health. They found that different brain areas are activated when a person moves up or down in a pecking order — or simply views perceived social superiors or inferiors. Circuitry activated by important events responded to a potential change in hierarchical status as much as it did to winning money. "Our position in social hierarchies strongly influences motivation as well as physical and mental health," said NIMH Director Thomas R Insel, M.D. "This first glimpse into how the brain processes that information advances our understanding of an important factor that can impact public health." Caroline Zink, Ph.D., Andreas Meyer-Lindenberg, M.D., Ph.D., and colleagues of the NIMH Genes Cognition and Psychosis Program, report on their functional magnetic resonance imaging (fMRI) study in the journal Neuron. Meyer-Lindenberg is now director of Germany's Central Institute of Mental Health. Prior studies have shown that social status strongly predicts health. Animals chronically stressed by their hierarchical position have high rates of cardiovascular and depression/anxiety-like syndromes. A classic study of British civil servants found that the lower one ranked, the higher the odds for developing cardiovascular disease and dying early. Lower social rank likely compromises health through psychological effects, such as by limiting control over one's life and interactions with others. However, in hierarchies that allow for more upward mobility, those at the top who stand to lose their positions can have higher risk for stress-related illness. Yet little is known about how the human brain translates such factors into health risk.

Keyword: Stress; Neuroimmunology
Link ID: 11553 - Posted: 06.24.2010