By Rob Stein Being overweight boosts the risk of dying from diabetes and kidney disease but not cancer or heart disease, and carrying some extra pounds actually appears to protect against a host of other causes of death, federal researchers reported yesterday. The counterintuitive findings, based on a detailed analysis of decades of government data about more than 39,000 Americans, supports the conclusions of a study the same group did two years ago that suggested the dangers of being overweight may be less dire than experts thought. "The take-home message is that the relationship between fat and mortality is more complicated than we tend to think," said Katherine M. Flegal, a senior research scientist at the Centers for Disease Control and Prevention in Atlanta, who led the study. "It's not a cookie-cutter, one-size-fits-all situation, where excess weight just increases your mortality risk for any and all causes of death." The study, published today in the Journal of the American Medical Association, was greeted with sharply mixed reactions. Some praised it for providing persuasive evidence that the dangers of fat have been overblown. "What this tells us is the hazards have been very much exaggerated," said Steven N. Blair, a professor of exercise science, epidemiology and biostatistics at the University of South Carolina. "It's just not as big a problem as people have said." © 2007 The Washington Post Company

Keyword: Obesity
Link ID: 10942 - Posted: 06.24.2010

Jennifer Viegas -- Sharks, rays and skates use a gel-like substance on their heads to pick up electrical current signals from their water environments, and possibly to follow a bloody trail, according to a new study. Since the process, known as electroreception, can override the animals' other senses, such as taste and smell, the discovery may help to explain why sharks pursue bloody victims, even when other "easy target" prey is around and the gushing blood obscures the shark's vision and smell. "The gel contains various proteins and salts, so it's similar to mucus, only with a jello-like consistency. Basically, it's shark snot," said lead author R. Douglas Fields. There are several reports of swimmers towing wounded buddies to shore, with the shark still going after the injured person instead of the rescuer, said Fields, who is chief of the Nervous System Development and Plasticity Section of the National Institutes of Health. "Bloody salts produce a strong electrical field that sharks can detect" with the gel, he explained. The findings, which have been accepted for publication in the journal Neuroscience Letters, negate a prior study that claimed shark gel serves as a semiconductor, meaning that it generates electricity in response to temperature changes. The author of that paper, B.R. Brown, agreed to issue a correction. © 2007 Discovery Communications

Keyword: Chemical Senses (Smell & Taste)
Link ID: 10941 - Posted: 06.24.2010

Debora MacKenzie It's official: you are more likely to think other people are attractive if they are looking straight at you and smiling. The finding helps to explain long-standing questions over the subtle ways in which evolution can determine human preferences. An important question in biology is whether a particular function or ability is the result of evolution or an accidental byproduct of it. Some biologists believe that human perception falls into this second category because there has been little evidence that how we perceive things like faces affects our biological success in ways that are selected for or against. But the evidence is mounting that evolution has conditioned our perception in subtle ways. Claire Conway and colleagues at the University of Aberdeen in Scotland, UK, paired nearly identical photos of computer-generated faces, with smiling or disgusted expressions. The pair differed only in where the irises were pointed: straight at the viewer, or off to the side (see image top right). Several hundred Aberdeen undergraduates, in the lab and online, rated the faces for sexual attractiveness, and for likeability, a sexually neutral quality. Both men and women found faces looking straight at them to be more attractive and more likeable, even if the faces looked disgusted though unsurprisingly, there was a greater preference for smiles. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Emotions
Link ID: 10940 - Posted: 06.24.2010

Heidi Ledford It’s a common situation: you’re embroiled in an argument over a fact and you know for certain that you have the right answer. But when someone rushes to their laptop to google the correct answer, you discover that you were wrong. Whether in a fight with a spouse or giving testimony on the witness stand, it is clear that our memories are not always trustworthy. Now, researchers have found that although those vivid false memories may seem indistinguishable from true memories to you, but they are sometimes processed by different parts of the brain1. The results could one day be used to devise an early test for Alzheimer’s disease, or to assess the accuracy of witness testimony, says study author Roberto Cabeza, a neuroscientist at Duke University in Durham, North Carolina. Cabeza and Hongkeun Kim of Daegu University in South Korea asked 11 people to read lists of words that fall into a certain category, such as ‘farm animals’. The subjects were later asked whether specific words had occurred on the original lists, while functional magnetic resonance imaging was used to measure the changes in blood flow to different areas of their brains. The participants were also asked to say how confident they were in their answers. © 2007 Nature Publishing Group

Keyword: Learning & Memory
Link ID: 10939 - Posted: 06.24.2010

By Gretchen Vogel A burger, fries, and a double fudge sundae for dessert is probably not the best recipe for a good night's sleep. Indeed, a new study shows that in mice, high-fat diets seem to disrupt the body's natural day and night rhythms. The work may help scientists understand why obesity, diabetes, and sleep disruption are often intertwined in human patients. The body's daily rhythms are governed by the so-called circadian clock. The clock influences not only when we sleep but also when we get hungry and how efficiently our bodies process food. Several studies have shown that mutations in circadian clock genes can cause mice to gain weight (ScienceNOW, 21 April 2005). And humans deprived of sleep soon begin to overeat. But neurobiologist Joseph Bass and colleagues at Northwestern University in Evanston, Illinois, wondered if the connection worked the other way--whether diet could influence the clock. The researchers put mice on a high-fat diet and measured their activity and eating behavior throughout the day and the night, comparing the rodents to mice on regular rations. After a week of noshing on high-fat chow, the mice were more restless during daylight hours, when most mice are sleeping. And they seemed to have the mouse equivalent of midnight munchies: Mice on high-fat diets consumed nearly a third of their food during the daytime hours, whereas the control mice consumed only about 20% of their calories during the day, the team reports in the 7 November issue of Cell Metabolism. © 2007 American Association for the Advancement of Science.

Keyword: Biological Rhythms; Obesity
Link ID: 10938 - Posted: 06.24.2010

Alison Abbott Researchers have found a drug that can reduce aggressive behaviour in feral rats that have been trained to be violent. Although the find may not lead directly to a cure for pathological violence in humans, it does unpick a mechanism behind such violence, the researchers say, which could open the door to future treatments. Sietse de Boer and his colleagues from the University of Groningen in the Netherlands, who have developed the first animal model of pathological aggression, reported these findings at the Society for Neuroscience meeting in San Diego yesterday. Although violence is a serious societal problem, until now scientists have only been able to study 'normal' or 'appropriate' aggression in animals — such as fighting over limited resources of food or mates. Such studies are usually done using normal laboratory rodents, which have been bred over the decades to be docile and easier for researchers to handle. So the researchers decided to work with feral rats instead. Although a male rat will fight other males, it won’t attack females, preferring instead to court their sexual favours. It will also not fight with an anaesthetised 'intruder', recognising that it poses no threat. But de Boer was able to change this, training the rats to be gratuitously violent. © 2007 Nature Publishing Group

Keyword: Aggression
Link ID: 10937 - Posted: 06.24.2010

By JOHN TIERNEY For half a century, social psychologists have been trying to figure out the human gift for rationalizing irrational behavior. Why did we evolve with brains that salute our shrewdness for buying the neon yellow car with bad gas mileage? The brain keeps sending one message — Yesss! Genius! — while our friends and family are saying, “Well... ” This self-delusion, the result of what’s called cognitive dissonance, has been demonstrated over and over by researchers who have come up with increasingly elaborate explanations for it. Psychologists have suggested we hone our skills of rationalization in order to impress others, reaffirm our “moral integrity” and protect our “self-concept” and feeling of “global self-worth.” If so, capuchin monkeys are a lot more complicated than we thought. Or, we’re less complicated. In a paper in Psychological Science, researchers at Yale report finding the first evidence of cognitive dissonance in monkeys and in a group in some ways even less sophisticated, 4-year-old humans. The Yale experiment was a variation of the classic one that first demonstrated cognitive dissonance, a term coined by the social psychologist Leon Festinger. In 1956 one of his students, Jack Brehm, carted some of his own wedding gifts into the lab (it was a low-budget experiment) and asked people to rate the desirability of things like an electric sandwich press, a desk lamp, a stopwatch and a transistor radio. Copyright 2007 The New York Times Company

Keyword: Attention; Emotions
Link ID: 10936 - Posted: 06.24.2010

High blood pressure may be more difficult to control in winter, US research suggests. A five-year study found people treated in the summer were on average 8% more likely to see their blood pressure come down to healthy levels. The US Department of Veterans Affairs team analysed data on 443,632 veterans treated for hypertension. The study, reported to the American Heart Association, suggests a more active summer lifestyle may be the key. Lead researcher Dr Ross Fletcher said: "People gain weight in the winter and lose weight in the summer. People tend to exercise more in the summer and less in the winter." The researchers said it was also possible that people might eat more salty foods in winter. Salt is strongly linked to raised blood pressure. The study analysed electronic health records from 15 VA hospitals in cities throughout the US. People with a blood pressure reading of more than 140 mm Hg systolic or more than 90 mm Hg diastolic on three separate days were identified as hypertensive. The researchers found the same pattern emerged from each hospital they studied, regardless of whether it was based in a warm or cold climate. Locations ranged from Anchorage, Alaska to San Juan, Puerto Rico. Dr Fletcher, chief of staff at the VA Medical Center in Washington, said people should be aware of the possibility their blood pressure may be harder to control in the winter - and be more vigilant at this time. Professor Bryan Williams, a trustee of the Blood Pressure Association, said blood pressure was very variable - even on a minute by minute basis. However, he said blood pressure levels - and rates of stroke and heart attack - tended to be higher in winter. (C)BBC

Keyword: Biological Rhythms
Link ID: 10935 - Posted: 11.06.2007

By Christopher Lane If anyone in my parents' generation had argued that shyness and other run-of-the-mill behaviors might one day be called mental disorders, most people would probably have laughed or stared in disbelief. At the time, wallflowers were often admired as modest and geeks considered bookish. Those who were shy might sometimes have been thought awkward -- my musically gifted mother certainly was -- but their reticence fell within the range of normal behavior. When their discomfort was pronounced, the American Psychiatric Association called it "anxiety neurosis," a psychoanalytic term that encouraged talk-related treatment. All that changed in February 1980, when the APA classified the broadly defined "avoidant personality disorder" and "social phobia" (later dubbed "social anxiety disorder") as diseases. The professional group also listed 110 other new disorders in its revised diagnostic manual, with the result that the total number of mental illnesses on the books almost doubled overnight. It was a dramatic example of the modern medicalization of behavior. Bashfulness, once prized as a virtue, became a sign for medical concern. According to the 1994 National Comorbidity Survey, as much as 12.1 percent of the U.S. population might have social anxiety disorder and a staggering 28.8 percent suffer from some kind of anxiety disorder. © Copyright 1996-20072007 The Washington Post Company

Keyword: Autism; Depression
Link ID: 10934 - Posted: 06.24.2010

By BENEDICT CAREY For an organ that has been scanned millions of times by experts using high-end imaging technology, the brain remains in large part a shrouded landscape, as lost in darkness as the ocean floor. One reason has less to with the brain’s complexity than its uniformity: it contains billions of identical-looking cells, most sprouting multiple identical-looking branches to other cells, near and far. A needle in a haystack at least looks different from the strands around it; finding and mapping large numbers of neurons is more like working out the root system beneath a tropical rain forest. But last week, researchers at Harvard published pictures in which all those anonymous gray cells glowed in distinctive colors, like a bougainvillea bush gone haywire. The scientists bred mice so their brain cells had genetic inserts containing genes for three colors of fluorescent protein, red, green and blue. They prompted each insert to randomly express one color, using a genetic trigger. Because there were multiple copies of the three-gene insert in each cell, the cell itself expressed a random mixture of the three colors, some 90 shades in all. What emerged was a kind of beaded rainbow belt of neurons, with the fluorescent glow radiating out through each cell’s neural branches. The researchers called the technique “Brainbow.” Copyright 2007 The New York Times Company

Keyword: Development of the Brain
Link ID: 10933 - Posted: 06.24.2010

by Jonah Lehrer In 1974 Oliver Sacks was climbing a mountain in Norway by himself. It was early afternoon, and he had just begun his descent when a slight misstep sent him careening over a rocky cliff. His left leg was "twisted grotesquely" beneath his body, his limp knee wracked with pain. "My knee could not support any weight at all, but just buckled beneath me," he wrote in A Leg to Stand On. Sacks began to "row" himself down the mountain, sliding on his back and pushing with his hands, so that his leg, which he'd splinted with his umbrella, was "hanging nervelessly" in front of him. After a few hours, Sacks was exhausted, but he knew that if he stopped he would not survive the cold night. What kept Sacks going was music. As he painstakingly descended the mountain, he began to make a melody out of his movements. "I fell into a rhythm," Sacks writes, "guided by a sort of marching or rowing song, sometimes the Volga Boatman's Song, sometimes a monotonous chant of my own. I found myself perfectly coordinated by this rhythm—or perhaps subordinated would be a better term: The musical beat was generated within me, and all my muscles responded obediently...I was musicked along." Sacks reached the village at the bottom of the mountain just before nightfall. A long convalescence followed, as he tried to regain the use of his injured leg, but the nerves in his limb had been severely damaged. When Sacks tried to walk, he was forced to consciously calculate his movements, to think before each step. © Copyright 2005-2007 Seed Media Group, LLC.

Keyword: Hearing
Link ID: 10932 - Posted: 06.24.2010

By Greg Miller SAN DIEGO, CALIFORNIA--Paris Hilton: Actress, author, ... analgesic? Neuroscientists have found that a cardboard cutout of the ubiquitous Hilton Hotel heiress has a painkilling effect on mice. But don't expect clinical trials to begin anytime soon: Paris works only for males, and it may be only because she stresses them out. The idea for the unconventional experiment arose when Jeffrey Mogil of McGill University in Montreal, Canada, and his colleagues noticed that male mice spent less time licking the site of a painful injection--indicating that they had less pain--when a scientist was present. To investigate whether it was the sight or smell of a human that caused the effect, the researchers acquired a promotional cardboard cutout of Hilton from her television show The Simple Life ("A special order," says Mogil's collaborator Leigh MacIntyre). As in humans, Paris's effect appears to be gender-specific. Male mice spent less time licking their wounds when fake Paris was in sight, but females showed no such effect, the researchers reported here Saturday at the annual meeting of the Society for Neuroscience. When the team put up a screen to block the rodents' view, the effect went away. Following a Paris Hilton encounter, male mice--but not females--also had lower-than-usual expression of a gene called c-fos in a part of the spinal cord that transmits pain signals to the brain, suggesting reduced neural activity in this pain pathway. © 2007 American Association for the Advancement of Science.

Keyword: Pain & Touch; Stress
Link ID: 10931 - Posted: 06.24.2010

Preschoolers who are diagnosed with ADHD are not likely to respond to treatment with the stimulant methylphenidate, regardless of dosage, if they also have three or more coexisting disorders, according to a recent analysis of data from the Preschoolers with ADHD Treatment Study (PATS). PATS was funded by the National Institutes of Health’s National Institute of Mental Health (NIMH). Previously reported PATS results showed that overall, low doses of methylphenidate were safe and effective in treating 3-5-year-olds diagnosed with ADHD. This most recent study, one of seven new PATS articles published November 5, 2007, in the Journal of Child and Adolescent Psychopharmacology, sought to identify individual characteristics that may affect how a child would respond to treatment. The other articles examine topics such as the effectiveness of methylphenidate over a follow-up phase, the effects of the medication on functional outcomes for the preschoolers, and others. "This new data is an important step forward in bridging the gap between research results and clinical practice, bringing potentially valuable information to clinicians about ways to better customize treatments for their patients," said NIMH Director Thomas R. Insel, M.D. "It also identifies a group of young children who have significant and multiple problems, and for whom more research is needed to identify effective treatments."

Keyword: ADHD
Link ID: 10930 - Posted: 06.24.2010

Candidates are out there every day, shaking hands, giving speeches, meeting people and debating the issues. Positions on the issues are painstakingly laid out, and enormous sums of money are spent by candidates to get voters to select their names on Election Day. But, research now suggests that a factor in our decision making about people, including candidates for office, happens in just one-tenth of a second. Alexander Todorov, assistant professor of psychology and public affairs at Princeton University, has studied how people react to the faces of candidates. In a study published in the journal Science in 2005, he asked people to view similar side-by-side photos of candidates for the U.S. Senate and House of Representatives. They asked the volunteers to use the photos to judge who was more competent. Todorov says, "If you ask people what is the most important attribute for a politician, they say competence. And, in fact judgment of competence based on facial appearance predicts election outcomes." In that study, the volunteers' decisions on who was more competent matched up about 70% of the time with the outcome of the races. Todorov argued that these decisions happened very quickly, but the 2005 research didn't measure that. Writing in the Proceedings of the National Academy of Sciences, he explained how they repeated the study, giving the volunteers only a brief glimpse of the faces. In one experiment they saw the candidates' faces for only one-tenth of a second. A second series of experiments extended the glimpse to a quarter of a second while a third series gave them two seconds to view the candidates' photos. If the volunteers recognized someone, those results were excluded. The results showed that, on average, the volunteers correctly predicted 64 percent of the races. © ScienCentral, 2000-2007.

Keyword: Emotions
Link ID: 10929 - Posted: 06.24.2010

Matt Kaplan Does breast-feeding a child boost its brain development and raise its intelligence? Only if the child carries a version of a gene that can harness the goodness of breast-milk, say researchers. The results add to the ‘nature versus nurture’ debate over intelligence, by showing how the two effects can interact. The question of whether people are born intelligent or made intelligent by their environment has been debated for decades. Research with identical twins separated at birth has shown that both genetics and rearing conditions are important in determining intelligence. One of the important environmental effects seems to be breast-feeding. Children who are breast-fed generally perform better in IQ tests than do those fed on other types of milk. Researchers think that this might be because specific fatty acids found in human milk, but not in cow’s milk or infant formulas, improve brain development. Avshalom Caspi and Terrie Moffitt, psychologists at King’s College, London, and their colleagues looked at the relationship between breast-feeding and intelligence to explore the possibility that in this case nature and nurture might be intimately linked. © 2007 Nature Publishing Group

Keyword: Development of the Brain; Genes & Behavior
Link ID: 10928 - Posted: 06.24.2010

Our brains can turn down our ability to see to help them listen even harder to music and complex sounds, say experts. A US study of 20 non-musicians and 20 musical conductors found both groups diverted brain activity away from visual areas during listening tasks. Scans showed activity fell in these areas as it rose in auditory ones. But during harder tasks the changes were less marked for conductors than for non-musicians, researchers told a Society for Neuroscience conference. The researchers, from Wake Forest University Baptist Medical Center and the University of North Carolina, used functional Magnetic Resonance Imaging, which can measure real-time changes in brain activity based on the blood flow to different areas of the brain. Previous research has identified various parts of the brain involved in vision and hearing. The experiment involved 20 professional orchestral conductors or band leaders and 20 musically untrained students, all aged between 28 and 40. While lying in the scanner, they were asked to listen to two different musical tones played a few thousandths of a second apart and identify which was played first. The task was made harder for the professional musicians than for the non-musicians, to allow for the differences in their background. What the scientists found was that while activity rose, as expected, in the auditory part of the brain, it correspondingly fell in the visual part. As the task was made harder and harder, the non-musicians carried on diverting more and more activity away from the visual parts of the brain to the auditory side, as they struggled to concentrate. However, after a certain point, the conductors did not suppress their brains, suggesting that their years of training had provided a distinct advantage in the way their brains were organised. (C)BBC

Keyword: Hearing; Vision
Link ID: 10927 - Posted: 11.05.2007

Carrying two genes linked to epilepsy may actually make you less likely to have a seizure, say US researchers. People who have more than one gene defect might be expected to be more prone to illness - but experts found the reverse. The Baylor College of Medicine team, which carried out its research on mice, reported its findings in the Nature Neuroscience journal. More than 450,000 people in the UK suffer from some form of epilepsy. There are many different types of epilepsy and the degrees of severity vary widely from patient to patient. Scientists have long suspected that some cases are partly due to a genetic problem and are searching for the particular genes involved so that new treatments can be devised. The two defects highlighted by this research involve the Kcna1 gene, which is involved in the transport of the chemical potassium in and out of the body's cells, and the Cacna1a gene, which plays a role in calcium levels. The first of these has been linked to severe seizures in "temporal lobe" epilepsy, which affects the part of the brain involved in speech, sight, sound and memory. Mice with defective Kcna1 genes can die suddenly as a result. The second gene is linked to so-called "absence" epilepsy, in which patients do not jerk or move in the way most people associate with an epileptic fit but stare into space instead. When mice were bred with both gene defects, far from worsening their symptoms, they suffered dramatically reduced seizures and did not die suddenly. The researchers, led by Dr Jeffrey Noebels, said that this could help point towards new ways of treating certain types of epilepsy. (C)BBC

Keyword: Epilepsy; Genes & Behavior
Link ID: 10926 - Posted: 11.05.2007

By MIKE STOBBE ATLANTA - A few decades ago, people probably would have said kids like Ryan Massey and Eddie Scheuplein were just odd. Or difficult. Both boys are bright. But Ryan, 11, is hyper and prone to angry outbursts, sometimes trying to strangle another kid in his class who annoys him. Eddie, 7, has a strange habit of sticking his shirt in his mouth and sucking on it. Both were diagnosed with a form of autism. And it's partly because of children like them that autism appears to be skyrocketing: In the latest estimate, as many as one in 150 children have some form of this disorder. Groups advocating more research money call autism "the fastest-growing developmental disability in the United States." Indeed, doctors are concerned there are even more cases out there, unrecognized: The American Academy of Pediatrics last week stressed the importance of screening every kid — twice — for autism by age 2. But many experts believe these unsociable behaviors were just about as common 30 or 40 years ago. The recent explosion of cases appears to be mostly caused by a surge in special education services for autistic children, and by a corresponding shift in what doctors call autism. Autism has always been diagnosed by making judgments about a child's behavior; there are no blood or biologic tests. For decades, the diagnosis was given only to kids with severe language and social impairments and unusual, repetitious behaviors. © 2007 MSNBC.com © 2007 Microsoft

Keyword: Autism
Link ID: 10925 - Posted: 06.24.2010

EAST LANSING, Mich. — A mouse created by Michigan State University scientists studying a disease thought to be a neurological disorder that weakens men has exposed two surprises: Testosterone appears to be the culprit and it’s attacking muscles, not nerves. The muscles of male mice genetically engineered in the laboratory of Cynthia Jordan, professor of neuroscience and psychology, have extra receptors that latch onto testosterone – a trick that left researchers anticipating mouse versions of bulked up body builders. Instead, these mice developed into shrunken weaklings. More significantly, their condition precisely imitated a rare human condition called Kennedy’s Disease. The results, reported in the Oct. 29 online issue of the Proceedings of the National Academy of Sciences, not only directly contradict conventional wisdom about the root of Kennedy’s Disease, but also offer significant hope. Researchers say these new results make a strong case that Kennedy’s Disease is a muscular disease rather than a neurological disease, and put testosterone in the category of cause, not cure. “When we started studying this little wimp mouse, we were surprised to find that we inadvertently created a model for Kennedy’s Disease,” Jordan said. “Our story provides some hope, because it’s an easier problem to target muscles therapeutically than the motor neurons in the spinal cord. Our sick mice get well when we take testosterone away from them.”

Keyword: Movement Disorders; Hormones & Behavior
Link ID: 10924 - Posted: 06.24.2010

Jennifer Viegas -- "Personality" would seem to be an exclusive attribute of humans, since the very word reflects back on us, but several recent studies examining a wide range of species, from squid to horses and even insects, suggest we share the planet with a lot of unique characters. Noted psychologist Lawrence Pervin has defined personality as "those characteristics of a person that account for consistent patterns of feeling, thinking and behaving." Non-humans are left out of the picture. Applied animal behaviorist Adele Lloyd of England's Bishop Burton College admits there are limits to applying such people-centric definitions to animals, especially since it's difficult to measure how animals think and feel. Lloyd and her colleagues, however, believe it is possible to assess observed behavior "in order to demonstrate individual differences" in animals. It could even be that humans are the limiting factor, given the way we process information and self-compare. Nevertheless, Lloyd told Discovery News that anthropomorphism -- the use of human terms to describe animal behavior -- is much easier for us to deal with than statistical data quantifying animal behaviors. The popular 1960s television show "Mister Ed," about a talking horse, took anthropomorphism to an improbable level, but Lloyd's recent work on horses indicates that at least particular types possess their own behavioral characteristics. © Discovery Communications

Keyword: Emotions; Evolution
Link ID: 10923 - Posted: 06.24.2010