Most Recent Links
Follow us on Facebook or subscribe to our mailing list, to receive news updates. Learn more.
Jennifer Viegas -- Human parents may worry about the effects of TV violence on their kids, but among male crayfish, watching a fight appears to actually chill aggression. That finding adds to the growing body of evidence that individuals, particularly males, of many species watch competitive encounters. Viewing such events either seems to stimulate further aggression, or lessen it. "Think about the problems some countries have during soccer matches," said Paul Moore, who co-authored the crayfish study. "Observing the competition, especially if there are a lot of fouls, tends to [intensify] the aggression in the audience." "The concept of watching fights and having this experience change the potential outcome of the next encounter is something that matches with both studies and anecdotal evidence," added Moore, who is a professor in the Department of Biological Sciences at Bowling Green State University. Moore and colleagues Thomas Zuland and Rebecca Zuland-Schneider chose to study crayfish because the aggressive shellfish form dominance hierarchies and engage in ritualized fighting. © 2008 Discovery Communications
Keyword: Aggression
Link ID: 11377 - Posted: 06.24.2010
Jim Giles JUST as the dispute over whether vaccines cause autism was dying down at last, a US government decision has added fresh fuel to the fire. Last week it emerged that the federal government is to compensate a couple who say that the regular childhood vaccines, given to their baby daughter in 2000, caused her to develop autism. Damages have not yet been set, but could exceed $1 million. Significantly, the government's decision says nothing about whether vaccines cause autism. Instead, government lawyers concluded only that vaccines aggravated a pre-existing cellular disorder in the child, causing brain damage that included features of autism. Nonetheless, anti-vaccination campaigners are claiming vindication. "It's official," wrote one autism blogger. "The sky has fallen. The fat lady has sung. Pigs are flying." Autism experts say it is unclear why compensation is being paid. Almost 5000 other families have lodged similar claims which are being considered by the court, but decades of research have failed to find any link between vaccines and autism and few experts thought that the government would pay up. “It's unclear why compensation is being paid. Decades of research have failed to find any link between vaccines and autism”Scientists say there is nothing in the medical history of the child in question to change that thinking. "I'm stunned that they decided to settle," says Jay Gargus, a paediatrician at the University of California, Irvine. Exactly why the US government did so is still being debated, as details of the decision have been sealed and the Department of Health and Human Services won't comment. © Copyright Reed Business Information Ltd
Keyword: Autism; Neurotoxins
Link ID: 11376 - Posted: 06.24.2010
Kerri Smith Scientists have developed a way of ‘decoding’ someone’s brain activity to determine what they are looking at. “The problem is analogous to the classic ‘pick a card, any card’ magic trick,” says Jack Gallant, a neuroscientist at the University of California in Berkeley, who led the study. But while a magician uses a ploy to pretend to ‘read the mind’ of the subject staring at a card, now researchers can do it for real using brain-scanning instruments. “When the deck of cards, or photographs, has about 120 images, we can do better than 90% correct,” says Gallant. The technique is a step towards being able to see the contents of someone’s visual experiences. “You can imagine using this for dream analysis, or psychotherapy,” says Gallant. Already the results are helping to provide neuroscientists with a more accurate model of how the human visual system works. If the work can be broadened to developing more general models of how the brain responds to things beyond visual stimuli, such brain scans could help to diagnose disease or monitor the effects of therapy. © 2008 Nature Publishing Group
Keyword: Brain imaging; Vision
Link ID: 11375 - Posted: 06.24.2010
By JULIA MOSKIN IN 1968 a Chinese-American physician wrote a rather lighthearted letter to The New England Journal of Medicine. He had experienced numbness, palpitations and weakness after eating in Chinese restaurants in the United States, and wondered whether the monosodium glutamate used by cooks here (and then rarely used by cooks in China) might be to blame. The consequences for the restaurant business, the food industry and American consumers were immediate and enormous. MSG, a common flavor enhancer and preservative used since the 1950s, was tagged as a toxin, removed from commercial baby food and generally driven underground by a new movement toward natural, whole foods. “It was a nightmare for my family,” said Jennifer Hsu, a graphic designer whose parents owned several Chinese restaurants in New York City in the 1970s. “Not because we used that much MSG — although of course we used some — but because it meant that Americans came into the restaurant with these suspicious, hostile feelings.” Even now, after “Chinese restaurant syndrome” has been thoroughly debunked (virtually all studies since then confirm that monosodium glutamate in normal concentrations has no effect on the overwhelming majority of people), the ingredient has a stigma that will not go away. But then, neither will MSG. Copyright 2008 The New York Times Company
Keyword: Chemical Senses (Smell & Taste)
Link ID: 11374 - Posted: 06.24.2010
By BENEDICT CAREY In marketing as in medicine, perception can be everything. A higher price can create the impression of higher value, just as a placebo pill can reduce pain. Now researchers have combined the two effects. A $2.50 placebo, they have found, works better one that costs 10 cents. The finding may explain the popularity of some high-cost drugs over cheaper alternatives, the authors conclude. It may also help account for patients’ reports that generic drugs are less effective than brand-name ones, though their active ingredients are identical. The research is being published on Wednesday in The Journal of the American Medical Association. The investigators had 82 men and women rate the pain caused by electric shocks applied to their wrist, before and after taking a pill. Half the participants had read that the pill, described as a newly approved prescription pain reliever, was regularly priced at $2.50 per dose. The other half read that it had been discounted to 10 cents. In fact, both were dummy pills. The pills had a strong placebo effect in both groups. But 85 percent of those using the expensive pills reported significant pain relief, compared with 61 percent on the cheaper pills. The investigators corrected for each person’s individual level of pain tolerance. Copyright 2008 The New York Times Company
Keyword: Pain & Touch
Link ID: 11373 - Posted: 06.24.2010
JERUSALEM - When Moses brought the Ten Commandments down from Mount Sinai, he may have been high on a hallucinogenic plant, according to a new study by an Israeli psychology professor. Writing in the British philosophy journal Time and Mind, Benny Shanon of Jerusalem’s Hebrew University said two plants in the Sinai desert contain the same psychoactive molecules as those found in plants from which the powerful Amazonian hallucinogenic brew ayahuasca is prepared. The thunder, lightning and blaring of a trumpet which the Book of Exodus says emanated from Mount Sinai could just have been the imaginings of a people in an “altered state of awareness,” Shanon hypothesized. “In advanced forms of ayahuasca inebriation, the seeing of light is accompanied by profound religious and spiritual feelings,” Shanon wrote. “On such occasions, one often feels that in seeing the light, one is encountering the ground of all Being ... many identify this power as God.” © 2008 Microsoft
Keyword: Drug Abuse
Link ID: 11372 - Posted: 06.24.2010
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


.gif)

