By HENRY FOUNTAIN To the long list of the unintended effects of environmental contaminants, add one — eating polluted worms affects the songs of male starlings. Researchers from Cardiff University in Wales report in the open-access online journal PLoS One that male starlings that consume estrogen and similar compounds, chemicals normally found in sewage, showed brain and behavioral changes related to singing. Shai Markman, now at the University of Haifa in Israel; Katherine L. Buchanan, now of Deakin University in Australia; and colleagues studied wild starlings foraging at sewage treatment works in southwestern Britain. The birds eat small worms found in huge quantities along filter beds. The worms accumulate natural estrogen excreted in human waste and estrogenlike compounds from plastics manufacturing. The chemicals are known to disrupt endocrine function, with anatomical and behavioral effects. Dr. Buchanan said he was not certain of the effects the chemicals might have on the birds’ songs. With some contaminants toxic to neural development, a result might be less complex songs. “But if you have estrogenic chemicals, that could affect song complexity in the opposite direction,” she said. Copyright 2008 The New York Times Company

Keyword: Sexual Behavior; Neurotoxins
Link ID: 11371 - Posted: 06.24.2010

Rex Dalton The ‘hobbit’ could be a cretin, Australian scientists say. But this latest assertion in the ongoing row over the identity of the small human skeleton found on the island of Flores in Indonesia is already being challenged — not least because the Australians used only cast images and never examined the actual skeleton. And they misinterpret a crucial skull component, according to three researchers who created casts of the remains. Peter Obendorf of RMIT University in Melbourne and his colleagues say1 that the cast shows an impression (called a fossa) of an enlarged pituitary gland at the base of the skull behind the nasal region. This, they say, is evidence that the skeleton is not from a new species (called Homo floresiensis ) but from a H. sapiens with cretinism — a condition in which a person is born with a deficient thyroid gland. Untreated, such people often have an enlarged pituitary gland as well as severely stunted growth and a small brain. The Australians call their idea “a tentative hypothesis”, although Obendorf says he thinks they “are on the right track”. They now are seeking access to the original specimen. But Dean Falk, an anthropologist at Florida State University in Tallahassee who was the lead author on the first analysis of the skull cast2, says that the pituitary fossa is small. “There is no way they can reach the conclusions they did,” she argues. And Ralph Holloway, a neuroanatomist at Columbia University in New York who has a cast created from data from the original skull, says that his model also shows a small pituitary. © 2008 Nature Publishing Group

Keyword: Evolution; Hormones & Behavior
Link ID: 11370 - Posted: 06.24.2010

Scientists believe they may have found a potential new way to treat obesity by stopping the stomach from expanding. They have identified two cell proteins that relax the gut and help accommodate a big meal. In theory, a drug which blocked this relaxation would reduce a person's ability and desire to gorge on excessive amounts of food. The University College London study appears in the Journal of Pharmacology and Experimental Therapeutics. The two proteins identified by the researchers - P2Y1 and P2Y11 - control both fast and slow relaxations of the gut. The human stomach has a "resting" internal volume of 75 millilitres, but by relaxing its muscular wall can expand to an internal volume of two litres or more. This expansion is controlled by nerves inside the stomach wall which release molecules that stimulate P2Y1 and P2Y11, which are embedded in muscle cells, also in the gut wall. Researcher Dr Brian King said: "The mechanism of slow relaxation of the stomach might represent a future drug target in the fight to control weight gain and reverse obesity. "We are looking to identify drugs that would block the P2Y11 receptor and, therefore, prevent slow relaxation of the stomach. "As a result of blocking the P2Y11-based mechanism, meal size would be smaller, offering the person a better chance of regulating their food intake." Dr King said this would represent a new approach to weight control. (C)BBC

Keyword: Obesity
Link ID: 11369 - Posted: 03.04.2008

Older men with lower levels of the male sex hormone testosterone in their blood may be more prone to depression, a study suggests. A study of about 4,000 men aged over 70 found those with lowest testosterone were three times more likely to be depressed than those with the most. Researchers suspect the hormone may affect levels of key brain chemicals. The study, by the University of Western Australia, features in Archives of General Psychiatry. Research has found that women are more likely to be depressed than men until the age of 65, when the difference between the genders almost disappears. Testosterone levels decline with age - but there is wide variation. The Australian team studied 3,987 men over the age of 70. Each gave blood samples and took part in tests to determine whether they were depressed. In total 203 of the participants were assessed as being depressed. They had significantly lower levels of both total testosterone, and free testosterone, which is not bound to proteins. The researchers then adjusted the data to take account of factors such as educational attainment and body fat levels. They found those men whose level of free testosterone was in the bottom 20% were three times more likely to be depressed than those in the top 20%. (C)BBC

Keyword: Hormones & Behavior; Depression
Link ID: 11368 - Posted: 03.04.2008

By BENEDICT CAREY “It’s indisputable that autism is on the rise among children,” Senator John McCain said while campaigning recently in Texas. “The question is, What’s causing it? And we go back and forth, and there’s strong evidence that indicates that it’s got to do with a preservative in vaccines.” With that comment, Mr. McCain marked his entry into one of the most politicized scientific issues in a generation. Mr. McCain is correct that autism diagnoses have increased in recent decades; no one disputes that. He is on much shakier ground when talking about the preservative as a cause. While some parents’ groups and lawmakers assert that the preservative, which contains mercury and is called thimerosal, has caused an epidemic of new autism cases, most mainstream researchers strongly disagree. Several large-scale studies have found no evidence of a link between thimerosal and autism, and medical groups including the Centers for Disease Control and Prevention, the Institute of Medicine and the American Academy of Pediatrics have publicly stated as much. In January, California reported an increase in autism cases, despite the removal of thimerosal from most vaccines. Copyright 2008 The New York Times Company

Keyword: Autism; Neurotoxins
Link ID: 11367 - Posted: 06.24.2010

By Jennifer Huget Are you beat? Tuckered out? Dragging, flagging or just plain pooped? Or maybe you're just tired of hearing others complain about how tired they are. In this era of burning candles at both ends (whoever works the longest hours wins), with stops only for caregiving and a few stolen winks, most everyone gets tired now and then. Sometimes all you need to recover is a solid night's sleep or an actual vacation, sans BlackBerry. But in some instances, tiredness moves to the next realm and becomes the soul-sucking, energy-draining condition called fatigue. And whereas sleepiness is generally remedied by sleep, fatigue can maintain its grip even when you sleep for hours on end. Fatigue makes you feel exhausted just thinking of paying the bills or walking the dog. It makes you want to bury your head under your pillow, even though you're sitting in your cubicle at work and there's no pillow in sight. Kevin Ferentz, director of clinical operations in the University of Maryland School of Medicine's Department of Family Medicine, cites a 1994 study showing that fatigue is the primary reason for between 1 and 7 percent of all medical office visits made by adults, and another study published in 2000 that calls fatigue the seventh most common complaint in primary care. © 2008 The Washington Post Company

Keyword: Depression
Link ID: 11366 - Posted: 06.24.2010

By ANAHAD O’CONNOR Medical experts have been saying for years that caffeine acts as a potent diuretic. Consume too many caffeinated beverages, and you end up drinking yourself into dehydration. But research has not confirmed that notion. Most studies have found that in moderate amounts, caffeine has only mild diuretic effects — much like water. One report, by a scientist at the University of Connecticut who reviewed 10 previous studies, appeared in June 2002 in The International Journal of Sport Nutrition and Exercise Metabolism. Investigations comparing caffeine with water or placebo seldom found a statistical difference in urine volume, the author wrote. “In the 10 studies reviewed, consumption of a caffeinated beverage resulted in 0 to 84 percent retention of the initial volume ingested, whereas consumption of water resulted in 0 to 81 percent retention.” Another study, in the same journal in 2005, involved scientists following 59 active adults over 11 days while controlling their caffeine intake. They were given caffeine in capsule form on some days and on other days were given a placebo. Researchers found no significant differences in levels of excreted electrolytes or urine volume. Copyright 2008 The New York Times Company

Keyword: Drug Abuse
Link ID: 11365 - Posted: 06.24.2010

By David B. Caruso NEW YORK - When Peter Braunstein was put on trial last year for a twisted Halloween torture attack, his lawyers used a visual aid to suggest that his actions were the product of mental illness. It was a scan of the defendant's brain. A doctor testified that the patterns it revealed indicated that Braunstein, accused of donning a firefighter's costume and imprisoning a woman for 13 hours, suffered from schizophrenia. The New York trial was one of a growing number of instances in which cutting-edge neuroscience has found its way into U.S. courts. Brain scans have emerged as potentially powerful tools in battles over defendants' sanity. More defense attorneys are seeking scans showing brain damage or abnormalities that might have made it difficult for their clients to control violent impulses. And experts say there is much more to come — including a few things that seem the stuff of science fiction. Within years, brain scans might be capable of serving as reliable lie detectors. Similar tests could potentially show whether a plaintiff in a personal injury case is really in pain, or faking it for sympathy, and brain images might even help jurors assess the reliability of a witness's memory. However, some question whether the legal community might be moving too fast to embrace unproven technology. © 2008 Microsoft

Keyword: Brain imaging; Aggression
Link ID: 11364 - Posted: 06.24.2010

By JANE E. BRODY When it comes to understanding, preventing and treating chronic diseases, multiple sclerosis ranks among the most challenging. The word “multiple” is apt in more ways than one. Various suggested causes include early-life exposure to certain viruses or toxic agents, geographic and dietary influences, inherent immunological defects and underlying genetic susceptibilities. MS is highly unpredictable. Rarely are any two patients alike in the presentation, duration and progression of symptoms; even the underlying cause of disability in MS is being reconsidered. And rarely do any two patients respond in the same way to a given therapy, be it medically established or alternative. Trial and error is the name of the game, experts say, because it is often not possible to know in advance what will work best for individual patients. These are the frequent underpinnings of confusion and distrust among those afflicted and their families. They sometimes give rise to claims that the organizations raising large amounts of money to support research and patient services and the scientists studying the disease have no intention of finding a cure, lest it put them out of business. It is a ridiculous notion on its face, since many of those involved in fund-raising and research have watched loved ones suffer and succumb to diseases like MS. Copyright 2008 The New York Times Company

Keyword: Multiple Sclerosis; Neuroimmunology
Link ID: 11363 - Posted: 06.24.2010

Kerri Smith Babies and adults use opposite sides of their brains to process colours. And the switch is due to the influence of language, a study suggests. It is well known that in adults, perception of colour is processed predominantly by the left hemisphere, which is also where most people process language. Studies have shown that the language one speaks can have an impact on the colour one sees. Paul Kay at the University of California, Berkeley, and his colleagues wanted to know if this left-side bias was carved out by the development of language in the left hemisphere, or whether it was present even before language is acquired. So they tested two age groups — adults and 4–6-month-old babies — with the same colour-perception task. A coloured target is shown at a randomly chosen location on a different coloured background, and the researchers watch to see how long it takes the participant to shift their attention to the target's location. Adults reacted more quickly if the target was presented in the right side of the visual field, which is processed by the left hemisphere of the brain. For babies, the pattern reversed: they were quicker if the target was in the left visual field, which is processed by the right hemisphere. The results are published in Proceedings of the National Academy of Sciences 1. © 2008 Nature Publishing Group

Keyword: Vision; Language
Link ID: 11362 - Posted: 06.24.2010

By BENEDICT CAREY The urge to binge mindlessly, though it can strike at any time, seems to stir in the collective unconscious during the last weeks of winter. Maybe it’s the television images from places like Fort Lauderdale and Cabo San Lucas, of communications majors’ face planting outside bars or on beaches. Or perhaps it’s a simple a case of seasonal affective disorder in reverse. Not SAD at all, but anticipation of warmth and eagerness for a little disorder. Either way, researchers have had a hard time understanding binge behavior. Until recently, their definition of binge drinking — five drinks or more in 24 hours — was so loose that it invited debate and ridicule from some scholars. And investigators who ventured into the field, into the spray of warm backwash and press of wet T-shirts, often returned with findings like this one from a 2006 study: “Spring break trips are a risk factor for escalated alcohol use.” Or this, from a 1998 analysis: “The men’s reported levels of alcohol consumption, binge drinking and intoxication were significantly higher than the women’s.” In fact, the dynamics of bingeing may have more to do with personal and cultural expectations than with the number of upside-down margaritas consumed. In their classic 1969 book, “Drunken Comportment,” recently out in paperback, the social scientists Craig MacAndrew and Robert B. Edgerton wrote that the disconnect between the conventional wisdom on drunken behavior and the available evidence “is even now so scandalous as to exceed the limits of reasonable toleration.” Copyright 2008 The New York Times Company

Keyword: Drug Abuse; Depression
Link ID: 11361 - Posted: 06.24.2010

Rachel Courtland Wandering albatrosses seem to have a keen sense of smell: so keen that they can follow their nose to food some 20 kilometres away from their starting point. Following scent trails on the open ocean is not easy, even for an albatross on the prowl for dead fish or squid. Although pungent odours at sea are known to be carried downwind, air turbulence chops up the trail, resulting in intermittent patches of scent. Researchers have long suspected that a sense of smell plays a role in albatross foraging, but the extent to which they used it was surprising. “We expected more birds to circle around and around” using their eyes to find food, says Gabrielle Nevitt of the University of California, Davis. Instead, Nevitt estimates, smell contributes to almost half of in-flight food finds. The results are published in the Proceedings of the National Academy of Sciences 1. To study foraging behaviour, the team tagged 19 wandering albatrosses (Diomedea exulans) during brief nesting periods on Possession Island in the southwestern Indian Ocean. The researchers outfitted the birds with small global positioning system (GPS) sensors and fed them small capsules to measure stomach temperature changes that correspond with feeding events. © 2008 Nature Publishing Group

Keyword: Chemical Senses (Smell & Taste)
Link ID: 11360 - Posted: 06.24.2010

By CARL ZIMMER For the past two decades, Kay E. Holekamp has been chronicling the lives of spotted hyenas on the savannas of southern Kenya. She has watched cubs emerge from their dens and take their place in the hyena hierarchy; she has seen alliances form and collapse. She has observed clan wars, in which dozens of hyenas have joined together to defend their hunting grounds against invaders. “It’s like following a soap opera,” said Dr. Holekamp, a professor at Michigan State University. Throughout her career, Dr. Holekamp has remained vigilant against anthropocentrism. She does not think of the hyenas as long-eared people running around on all fours. But the lives of spotted hyenas, she has concluded, share some profound similarities with our own. In both species, a complex social world has driven the evolution of a big, complex brain. Scientists have long puzzled over the enormous size of the human brain. It is seven times larger than one would predict for an average mammal of our size. Many of our extra neurons are in a region called the frontal cortex, where much of the most sophisticated thought takes place. Copyright 2008 The New York Times Company

Keyword: Sexual Behavior
Link ID: 11359 - Posted: 06.24.2010

Art Glenberg It has become commonplace in neuroscience - and even in everyday conversation - to compare human cognition to that of computers. We know that computers work by using rules to manipulate symbols composed of zeros and ones. According to this metaphor, people also use rules to manipulate abstract and arbitrary symbols. The brain, in other words, was a computer that processed data largely independently of the body. A newer theory that is gaining ground among neuroscientists, embodied cognition, departs from the "computer-as-mind" metaphor. Instead, the body is seen as playing an important role in cognitive processes. Cognition evolved to guide real bodies in the real world, argue the researchers in favor of this idea. Our thoughts are constrained and influenced by the details of our flesh. How you move your arm or leg actually shapes the way you perceive, think and remember. The latest research in embodied cognition demonstrates just how entangled the body and brain are. Holt and Beilock's research plays the embodiment card in two ways. First, they show that when trying to understand written language, people invoke perceptual and action experiences. The words we use when reading (and perhaps also when listening) point to particular shared bodily experiences, and these experiences, in turn, are used by the reader to understand sentences. In the second important advance, Holt and Beilock also show that when people have had different personal experiences they will understand the same sentences differently. © 1995-2007 Scientific American Inc.

Keyword: Attention
Link ID: 11358 - Posted: 06.24.2010

CHICAGO - Defects in working memory — the brain's temporary storage bin — may explain why one child cannot read her history book and another gets lost in algebra, new research suggests. As many as 10 percent of school age children may suffer from poor working memory, British researchers said in a report last week, yet the problem remains rarely identified. "You can think of working memory as a pure measure of your child's potential," Dr. Tracey Alloway of Britain's Durham University said in a telephone interview. "Some psychologists consider working memory to be the new IQ because we find that working memory is the single most important predictor of learning," Alloway said. Many children with poor working memory are considered lazy or dim. But Alloway said with early identification and memory training, many of these underachievers can improve. Working memory allows people to hold and manipulate a few items in their minds, such as a telephone number. Alloway compares working memory to a box. Copyright 2008 Reuters.

Keyword: ADHD; Learning & Memory
Link ID: 11357 - Posted: 06.24.2010

If the safety hazards of talking on the phone while driving weren't bad enough, researchers have now shown that motor mouths also cost other commuters significant time, money and health risks from pollution exposure. In a study presented to the Transportation Research Board of the National Academies, psychologist David Strayer and his colleagues at the University of Utah used driving simulators to approximate the experience of driving in various levels of traffic. The simulators, which are the same kind used to train police officers, create a realistic depiction of driving in city and highway environments. Using a computer connected to the simulator, researchers can measure a number of simulated variables, including crash risk, following distance, and even a driver's ability to stay in one lane. As Strayer explains, "what we have is a fairly sophisticated replication of what you'd see in a car, but we can take very good measures of how people are driving." In his past research, Strayer has used simulators like this to observe a number of different driving behaviors. But for this latest study, he was interested in one overarching question: does cell phone use while driving affect the flow of traffic? © ScienCentral, 2000-2008.

Keyword: Attention
Link ID: 11356 - Posted: 06.24.2010

Stephen L. Macknik The source of many of the world's woes might be tracked to a specific brain area responsible for identifying people that are not of our ilk. If so, a study on the neural bases of prejudice and its modulation (read abstract or download the pdf), by Jason Mitchell and Mahzarin R. Banaji, of Harvard University, and C Neil Macrae, at the University of Aberdeen in Scotland, published in Neuron in May 2006, could be as important to the burgeoning field of social cognitive neuroscience as Martin Luther King Jr.'s "I have a dream" speech was to the American civil rights movement. How does the brain differentiate those who are similar to us from those who are different? Does it analyze differences in skin color, language, religion, height, eye color, foot size? Does it discriminate cat versus dog lovers, Pepsi versus Coke drinkers, Shiite versus Sunni, Crips versus Bloods? In a way, the brain does all this and more by simply distinguishing those who don't meet various definitions of who we are. Specifically, a forebrain area called the dorsal medial prefrontal cortex (mPFC) appears to predict the behavior of members of outgroups by employing prejudices about their presumed background -- assumptions we make, in other words, based on what groups their various traits and contexts seem to put them in or out of. In this sense, outsiders, or those in outgroups, include humans of dissimilar cultural or ethnic identities or any other perceived stereotyped dissimilarity from your own self-identified groups, as well as non-human agents such as cartoons and animals and even inanimate moving objects. We distinguish otherness by all sorts of indicators, from the seemingly obviously, like sex or race, to the more obviously cultural, such as whether a person is wearing, say, a Yankees cap, a Dodgers cap, or a tee-shirt that says Baseball Sucks. © 1995-2007 Scientific American Inc

Keyword: Emotions
Link ID: 11355 - Posted: 06.24.2010

A small striped fish is helping scientists understand what makes people susceptible to a common form of hearing loss, although, in this case, it's not the fish's ears that are of interest. In a study published in the Feb. 29 issue of the journal PLoS Genetics, researchers at the University of Washington have developed a research method that relies on a zebrafish's lateral line — the faint line running down each side of a fish that enables it to sense its surroundings — to quickly screen for genes and chemical compounds that protect against hearing loss from some medications. The study was funded in part by the National Institute on Deafness and Other Communication Disorders (NIDCD), one of the National Institutes of Health. "The fish's lateral line contains sensory cells that are functionally similar to those found in the inner ear, except these are on the surface of the fish's body, making them more easily accessible," said James F. Battey, Jr., M.D., Ph.D., director of the NIDCD. "This means that scientists can very efficiently analyze the sensory structures under different conditions to find out what is likely to cause damage to these structures and, conversely, what can protect them from damage." When people are exposed to some antibiotics and chemotherapy agents, the sensory structures in the inner ear, called hair cells, can be irreversibly damaged, resulting in hearing loss and balance problems. Such medications are called ototoxic. People vary widely in their susceptibility to these agents as well as to damage caused by other chemical agents, loud sounds and aging.

Keyword: Hearing; Genes & Behavior
Link ID: 11354 - Posted: 06.24.2010

After seeing 27-year-old Amanda Baggs, featured in this month’s Wired magazine, you may rethink your views of the so-called “normal” world. Ms. Baggs, who lives in Burlington, Vt., is autistic and doesn’t speak. But she has become an Internet sensation as a result of an unusual video she created called “In My Language.'’ For the first three minutes of the video, she rocks, flaps her hands, waves a piece of paper, buries her face in a book and runs her fingers repeatedly across a computer keyboard, all while humming a haunting two-note tune. Then, the words “A Translation” appear on the screen. Although Ms. Baggs doesn’t speak, she types 120 words a minute. Using a synthesized voice generated by a software application, Ms. Baggs types out what is going on inside her head. The movement, the noise, the repetitive behaviors are all part of Ms. Baggs’ own “native” language, she says via her computerized voice. It’s a language that allows her to have a “constant conversation” with her surroundings. My language is not about designing words or even visual symbols for people to interpret. It is about being in a constant conversation with every aspect of my environment, reacting physically to all parts of my surroundings. Far from being purposeless, the way that I move is an ongoing response to what is around me….The way I naturally think and respond to things looks and feels so different from standard concepts or even visualization that some people do not consider it thought at all. But it is a way of thinking in its own right. Copyright 2007 The New York Times Company

Keyword: Autism; Language
Link ID: 11353 - Posted: 06.24.2010

By Sarah E. Richards Deep brain stimulation might help severely depressed patients Doctors long have struggled over what to do with severely depressed patients who don't respond to treatment. Give them more medications that haven't worked so far? Recommend more talk therapy or another round of shock treatment? Here's a new idea: open up a depressed head, find the brain parts that aren't working, and fix them with electricity. It's not all that far-fetched. Earlier this month, the Food and Drug Administration gave a medical device manufacturer the green light to recruit patients for a large-scale clinical trial of an electrode implanted deep inside the brain to alleviate severe depression. As invasive and Frankenstein-ish as it may seem, deep brain stimulation, as the method is called, may offer real hope for the 20 percent of depressed Americans whom Prozac can't help. Anti-depressant drugs carpet-bomb the entire body. Electroconvulsive therapy jolts the whole brain. Deep brain stimulation aims to pinpoint the malady. Neurosurgeons drill through a patient's skull, place the DBS electrode's eight contact points directly on the trouble spots and connect them to an electrical current from a pacemaker embedded in the chest. This allows doctors to rev up sluggish areas or calm overactive regions. 2008 Washington Post.Newsweek Interactive Co

Keyword: Depression
Link ID: 11352 - Posted: 02.29.2008