by Jessica Hamzelou Never underestimate the value of a good night's sleep. Not only does a lack of shut-eye leave you irritable, it has been linked to diabetes and weight gain, though no one understood why. To investigate, Matthew Brady at the University of Chicago and his colleagues tested fat cells taken from the bellies of seven adults after four nights of sleeping up to 8 and a half hours, and then again after four nights on a measly 4 and a half hours. The team found that after sleep deprivation fat cells from the same person were on average 30 per cent less responsive to insulin – a hormone that makes muscle, liver and fat cells take up glucose after a meal. High blood glucose levels are linked to diabetes. Fat cells also normally release the appetite-regulating hormone leptin. Brady suggests that if sleep-deprived cells are generally malfunctioning, this mechanism may also be disrupted, affecting weight gain. "We were surprised at how robust the response was," says Brady. "Four nights of sleep curtailment represents a real-world situation, such as sitting for final exams or having a newborn in the house." Journal reference: Annals of Internal Medicine, DOI: 10.7326/0003-4819-157-8-201210160-00005 © Copyright Reed Business Information Ltd.

Keyword: Obesity; Sleep
Link ID: 17370 - Posted: 10.16.2012

By Megan Gannon Something "uncanny" seems familiar yet alien at the same time, often stirring a feeling of fear or revulsion. For example, we tend to feel creeped out around lifelike robots and animatronics that fall in the "uncanny valley," the divide between the fully human and the not-exactly-human. New research suggests this type of reaction might start in infancy. Scientists in Japan studied how 57 babies reacted to pictures of faces. The infants were shown real photographs — either of the child's mother or a complete stranger — and natural-looking morphed images that combined either the mother's face and a stranger's face or two strangers' faces. In previous studies, researchers showed that infants tend to stare at pictures of both mothers and strangers for about the same amount of time, but measures of their neural responses suggest they process the two faces differently. "Infants like both familiarity and novelty in objects," Yoshi-Taka Matsuda of Tokyo's Riken Brain Science Institute said in a statement. "We wondered how their preference might change when they encountered objects that are intermediate between familiarity and novelty." Using an eye-tracking system, the researchers found the infants looked at the photos of their mothers longer than the "half-mother" hybrid faces. This effect strengthened with the infant's age, the team said. There was no significant difference in the infants' preference between the real and morphed photos of strangers. © 2012 NBCNews.com

Keyword: Emotions; Development of the Brain
Link ID: 17369 - Posted: 10.15.2012

By LAURA GEGGEL For years, young people — often girls and young women — have frequented Web sites promoting anorexia and bulimia as a source of inspiration and tips on staying thin, even as online companies have worked to ban such content. Now, groups and Web sites focused on recovery from eating disorders are fighting back. “We need to be looking at these communities and see what we can learn from them, and what we can provide as a positive alternative,” said Claire Mysko, manager of Proud2Bme.org, a Web site and online community focused on healthy recovery that is financed by the nonprofit National Eating Disorders Association. “That’s what we’re trying to do here.” This Saturday, the group is taking its message to the University of South Florida in Tampa for its free annual Proud2Bme Summit. Attendees will be encouraged to engage in activities like taking a stand on Twitter against “body snarking,” a bullying tactic that draws attention to a person’s body or weight gain, and hear from speakers including Julia Bluhm, a 14-year-old who collected more than 86,000 signatures to petition Seventeen magazine to print one unaltered photo spread a month. “Our goal here is to make it a space where people can connect,” Ms. Mysko said. The site began in 2011 after the success of its Dutch counterpart, Proud2Bme.nl, whose co-founder Scarlet Hemkes struggled with anorexia and bulimia as a teenager and young adult and was horrified to find countless sites where girls competed to lose weight or shared tips on how to lie to parents about weight loss. Inspired by France’s move in 2008 to ban such sites — commonly called pro-ana (for pro-anorexia) sites — Ms. Hemkes collected 10,000 signatures with the hopes of inspiring similar Dutch legislation. When that didn’t work, she created a community on Hyves, a Facebook-like social network for girls with eating disorders, before founding Proud2Bme with a psychologist, Eric van Furth, in 2009. Copyright 2012 The New York Times Company

Keyword: Anorexia & Bulimia
Link ID: 17368 - Posted: 10.13.2012

Sitting exams and tests is often a nerve-racking experience, but being anxious beforehand may boost a candidate's grades, researchers say. A study published in the British Journal of Psychology finds being anxious only has a negative impact on results if a child's memory is poor. But if a young person has a good memory, a tendency to feel anxious is linked with getting better marks. The research assessed 96 children aged 12 to 14 in memory and anxiety tests. A questionnaire established how anxious the children usually felt, and the results were measured against their ability to perform computerised tests involving "complex" or working-memory skills. "We found that for individuals with low working-memory capacity, increases in [a tendency towards] anxiety were related to decreases in cognitive test performance," the study says. "For those with high working-memory capacity, however, the pattern of results was reversed. An increase in [a tendency towards] anxiety was linearly associated with higher test scores. "These effects were not better accounted for by gender, age, or time of testing." Poor memory The researchers say the results of the study should encourage education professionals to target help at anxious children with poor complex memory skills. BBC © 2012

Keyword: Stress; Learning & Memory
Link ID: 17367 - Posted: 10.13.2012

By ARTHUR A. STONE DESPITE the beating that Mondays have taken in pop songs — Fats Domino crooned “Blue Monday, how I hate blue Monday” — the day does not deserve its gloomy reputation. Two colleagues and I recently published an analysis of a remarkable yearlong survey by the Gallup Organization, which conducted 1,000 live interviews a day, asking people across the United States to recall their mood in the prior day. We scoured the data for evidence that Monday was bluer than Tuesday or Wednesday. We couldn’t find any. Mood was evaluated with several adjectives measuring positive or negative feelings. Spanish-only speakers were queried in Spanish. Interviewers spoke to people in every state on cellphones and land lines. The data unequivocally showed that Mondays are as pleasant to Americans as the three days that follow, and only a trifle less joyful than Fridays. Perhaps no surprise, people generally felt good on the weekend — though for retirees, the distinction between weekend and weekdays was only modest. Likewise, day-of-the-week mood was gender-blind. Over all, women assessed their daily moods more negatively than men did, but relative changes from day to day were similar for both sexes. And yet still, the belief in blue Mondays persists. Several years ago, in another study, I examined expectations about mood and day of the week: two-thirds of the sample nominated Monday as the “worst” day of the week. Other research has confirmed that this sentiment is widespread, despite the fact that, well, we don’t really feel any gloomier on that day. © 2012 The New York Times Company

Keyword: Depression; Emotions
Link ID: 17366 - Posted: 10.13.2012

by Douglas Heaven I spy, with my mechanical eye. It seems a simple mechanical change plays a role in sensory perception in fruit flies, and possibly in many other animals, including humans. The eyes of the common fruit fly (Drosophila melanogaster) contain clusters of light-sensitive cells organised into rods. When light strikes one of these cells, it triggers a series of chemical reactions. These cause a protein called a transient receptor potential (TRP) ion channel to open. When it's open, the TRP allows charged particles to flow into the cell, causing the cell to send a signal to the fly's brain. TRP channels play a part in sensory perception in many animals, from nematodes to humans. But nobody knew how the chemical signals make the TRP channel open. Shrinking rods "Everyone's been looking for years and years at the chemical messengers," says Roger Hardie of the University of Cambridge, UK. A mechanical trigger was never considered. "No one thought to look," he says. With Kristian Franze, Hardie found that the chemical signals change the surface area of the cell's outer membrane by destroying some of its constituent molecules. When several cells shrink like this, the entire rod contracts by up to 400 nanometres, a margin big enough to be seen with a microscope. "The whole membrane shrinks," says Hardie. "It's like a little muscle twitching." © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 17365 - Posted: 10.13.2012

When you hear the sound of a nail scratching a blackboard, the emotional and auditory part of your brain are interacting with one another, a new study reveals. The heightened activity and interaction between the amygdala, which is active in processing negative emotions, and the auditory parts of the brain explain why some sounds are so unpleasant to hear, scientists at Newcastle University have found. "It appears there is something very primitive kicking in," said Dr. Sukhbinder Kumar, the paper’s author. "It’s a possible distress signal from the amygdala to the auditory cortex." Researchers at the Wellcome Trust Centre for Neuroimaging at UCL and Newcastle University used functional magnetic resonance imaging (fMRI) to examine how the brains of 13 volunteers responded to a range of sounds. Listening to the noises inside the scanner, the volunteers rated them from the most unpleasant, like the sound of knife on a bottle, to the most pleasing, like bubbling water. Researchers were then able to study the brain response to each type of sound. "At the end of every sound, the volunteers told us by pressing a button how unpleasant they thought the sound was," Dr. Kumar said. Researchers found that the activity of the amygdala and the auditory cortex were directly proportional to the ratings of perceived unpleasantness. They concluded that the emotional part of the brain, the amygdala, in effect takes charge and modulates the activity of the auditory part of the brain, provoking our negative reaction. © CBC 2012

Keyword: Hearing; Emotions
Link ID: 17364 - Posted: 10.13.2012

By Nathan Seppa Men with high blood levels of lycopene — the compound that makes tomatoes red — are about half as likely to have a stroke as those low on lycopene, researchers in Finland report October 9 in Neurology. Some evidence suggests that lycopene quells inflammation, limits cholesterol production and inhibits blood clotting. But first and foremost, lycopene is a carotenoid, an antioxidant that sops up unstable molecules in the body called free radicals —agents that can induce DNA damage, kill cells, attack proteins and contribute to blood vessel disease. Lycopene’s direct effect on stroke risk is less clear. Studies have found that a diet rich in fruits and vegetables, meaning plenty of carotenoids, seems to reduce the risk of heart disease and stroke. But few studies have analyzed lycopene’s effect specifically on stroke risk over time, the researchers note. Jouni Karppi and colleagues at the University of Eastern Finland in Kuopio used blood tests to determine the lycopene levels of 1,031 men ages 46 to 65. Afterward, the men were monitored for a median of 12 years. The researchers tallied 67 strokes in the men over that span. Men with the lowest lycopene levels at the outset were more than twice as likely to have a stroke later as were those with the highest. “This is a very good study, and I’m really surprised they were able to find this relationship with only 67 strokes,” says Lyn Steffen, a nutritional epidemiologist at the University of Minnesota. © Society for Science & the Public 2000 - 2012

Keyword: Stroke
Link ID: 17363 - Posted: 10.13.2012

Cort Pedersen at the University of North Carolina at Chapel Hill and his team gave 11 alcohol-dependent volunteers two daily doses of an oxytocin nasal spray or a placebo, during the first three days of a detox programme. The volunteers also received lorazepam - a detox drug - when their withdrawal symptoms reached a specific level. The oxytocin group had fewer alcohol cravings and milder withdrawal symptoms than the placebo group, and used just one-fifth of the lorazepam (Alcoholism: Clinical and Experimental Research, doi.org/jgp). "Four [oxytocin] volunteers didn't need any lorazepam at all," says Pedersen. This is good news because lorazepam is highly addictive. While it reduces anxiety and seizures during alcohol withdrawal, users can experience insomnia and cravings when they come off the drug. Although it is unclear how oxytocin - famed for its role in social bondingMovie Camera - helps to aid withdrawal, it has no known side effects. Pedersen hopes that alcoholics who take the hormone will therefore be less likely to experience the unpleasant symptoms that can lead to relapse. © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse; Hormones & Behavior
Link ID: 17362 - Posted: 10.13.2012

By John McCarthy Humans can focus on one thing amidst many. “Searchlight of attention” is the metaphor. You recall a childhood friend’s face one moment, then perhaps the dog you loved back then, and then…what you will. Your son’s face on stage rivets your attention; the rest of the cast is unseen. No “ghost” in the brain aims that searchlight. What does? Neurons do, somehow, but how is a mystery that new research actually deepened. The experiment used monkeys. They can focus attention like people do. They can zero in on a red square on a screen full of distractions, for instance. When the square moves, a trained monkey will press a button. Electrodes inserted in a monkey neuron will reveal “firing” (minuscule electrical ripples) simultaneous with attention. This may locate brain areas by which the monkey watched that red square. It’s not only the explosive firing in neurons that instruments detect. They also spot the milder priming to fire, when the monkey expects (from training) that neurons are about to be stimulated. Neurons in a one area of the cortex fire when an object moves (but not, for instance, if it gets brighter but stays still.) If a monkey learns that an onscreen cue (a blip of light) signals that the red square is about to move, the cue alone primes the motion-sensing neurons. They also synchronize more tightly (i.e. reduce random noise among them.) Cues cock neurons, like a gun. It’s like Pavlov’s dogs salivating at the bell that preceded feeding. © 2012 Scientific American

Keyword: Attention
Link ID: 17361 - Posted: 10.11.2012

Virginia Hughes On a chilly, January night in 1986, Elizabeth Ebaugh carried a bag of groceries across the quiet car park of a shopping plaza in the suburbs of Washington DC. She got into her car and tossed the bag onto the empty passenger seat. But as she tried to close the door, she found it blocked by a slight, unkempt man with a big knife. He forced her to slide over and took her place behind the wheel. The man drove aimlessly along country roads, ranting about his girlfriend's infidelity and the time he had spent in jail. Ebaugh, a psychotherapist who was 30 years old at the time, used her training to try to calm the man and negotiate her freedom. But after several hours and a few stops, he took her to a motel, watched a pornographic film and raped her. Then he forced her back into the car. She pleaded with him to let her go, and he said that he would. So when he stopped on a bridge at around 2 a.m. and told her to get out, she thought she was free. Then he motioned for her to jump. “That's the time where my system, I think, just lost it,” Ebaugh recalls. Succumbing to the terror and exhaustion of the night, she fainted. Ebaugh awoke in freefall. The man had thrown her, limp and handcuffed, off the bridge four storeys above a river reservoir. When she hit the frigid water, she turned onto her back and started kicking. “At that point, there was no part of me that thought I wasn't going to make it,” she says. Few people will experience psychological and physical abuse as terrible as the abuse Ebaugh endured that night. But extreme stress is not unusual. In the United States, an estimated 50–60% of people will experience a traumatic event at some point in their lives, whether through military combat, assault, a serious car accident or a natural disaster. Acute stress triggers an intense physiological response and cements an association in the brain's circuits between the event and fear. If this association lingers for more than a month, as it does for about 8% of trauma victims, it is considered to be post-traumatic stress disorder (PTSD). The three main criteria for diagnosis are recurring and frightening memories, avoidance of any potential triggers for such memories and a heightened state of arousal. © 2012 Nature Publishing Group,

Keyword: Stress; Learning & Memory
Link ID: 17360 - Posted: 10.11.2012

Alison Abbott In 1965, health authorities in Camberwell, a bustling quarter of London's southward sprawl, began an unusual tally. They started to keep case records for every person in the area who was diagnosed with schizophrenia, depression, bipolar disorder or any other psychiatric condition. Decades later, when psychiatrists looked back across the data, they saw a surprising trend: the incidence of schizophrenia had more or less doubled, from around 11 per 100,000 inhabitants per year in 1965 to 23 per 100,000 in 1997 — a period when there was no such rise in the general population (J. Boydell et al. Br. J. Psychiatry 182, 45–49; 2003). The result raised a question in many researchers' minds: could the stress of city life be increasing the risk of schizophrenia and other mental-health disorders? The question is an urgent one. Back in 1950, less than one-third of the world's population lived in cities. Now, lured by the prospect of work and opportunity, more than half do. Mental illnesses already comprise the world's biggest disease burden after infectious diseases and, although global statistics do not yet show any major increase in incidence, the cost is rising. In Germany, the number of sick days taken for psychiatric ailments doubled between 2000 and 2010; in North America, up to 40% of disability claims for work absence are related to depression, according to some estimates. “It seems that cities may be making us sick,” says Jane Boydell at the Institute of Psychiatry in London, who led the Camberwell study. Anecdotally, the link between cities, stress and mental health makes sense. Psychiatrists know that stress can trigger mental disorders — and modern city life is widely perceived as stressful. City dwellers typically face more noise, more crime, more slums and more people jostling on the streets than do those outside urban areas. Those who have jobs complain of growing demands on them in the workplace, where they are expected to do much more in less time. © 2012 Nature Publishing Group

Keyword: Schizophrenia; Stress
Link ID: 17359 - Posted: 10.11.2012

Strokes are occurring at a younger age, say researchers who call the trend concerning. Researchers looked at strokes occurring in people aged 20 to 54 in the Greater Cincinnati and Northern Kentucky regions. "We found trends toward increasing stroke incidence at younger ages," study author Dr. Brett Kissela of the University of Cincinnati College of Medicine in Ohio and his co-authors concluded in Wednesday's online issue of the journal Neurology. A rise in risk factors such as obesity, Type 2 diabetes and high cholesterol are potential reasons for the trend, Kissela said. Better diagnosis from MRI could also be contributing. "Regardless, the rising trend found in our study is of great concern for public health because strokes in younger people translate to greater lifetime disability," he said in a release. In the study, researchers looked at first strokes that occurred during three, separate year-long periods between 1993 and 2005. What's behind stroke trend? The average age of people who experienced stroke fell from 71 years in 1993 and 1994 to 69 years in 2005, the researchers found. Among the young stroke patients, more coronary heart disease was found in 1999 and 2005 compared with the first year. The prevalence of heart disease among the general population didn't change. © CBC 2012

Keyword: Stroke; Development of the Brain
Link ID: 17358 - Posted: 10.11.2012

By Erin Wayman Rusty red stains on the head of a fossilized segmented creature found in southwestern China are a paleontological record-breaker: They are the remains of the oldest arthropod brain ever found. The imprint of the 520-million-year-old critter’s three-part brain indicates that complex nervous systems evolved fairly early in animal evolution, among the ancestors of insects, centipedes and crustaceans. The roughly 7-centimeter-long specimen includes the entire body of Fuxianhuia protensa. The species lived during the Cambrian period, before modern arthropod lineages evolved. The fossil shows F. protensa had a brain composed of three sections that sat in front of the animal’s gut. That’s the same setup seen today in insects, crabs, lobsters and many other arthropods, researchers report in the Oct. 11 Nature. “It was very fascinating and very exciting,” says study coauthor Nicholas Strausfeld, a neuroscientist at the University of Arizona. “It suggests that the organization we see in the modern [arthropod] brains is very ancient.” Scientists had thought early arthropods had simpler brains like those of modern water fleas, fairy shrimp and other tiny freshwater crustaceans called branchiopods. The branchiopod brain consists of two connected parts with a third mass of nervous tissue sitting behind the stomach. Sometime after the branchiopod lineage split from the other arthropods, scientists had assumed, the nervous tissue behind the gut migrated up and connected with the other parts of the brain, Strausfeld says. © Society for Science & the Public 2000 - 2012

Keyword: Evolution
Link ID: 17357 - Posted: 10.11.2012

by Emily Underwood Four young boys with a rare, fatal brain condition have made it through a dangerous ordeal. Scientists have safely transplanted human neural stem cells into their brains. Twelve months after the surgeries, the boys have more myelin—a fatty insulating protein that coats nerve fibers and speeds up electric signals between neurons—and show improved brain function, a new study in Science Translational Medicine reports. The preliminary trial paves the way for future research into potential stem cell treatments for the disorder, which overlaps with more common diseases such as Parkinson's disease and multiple sclerosis. "This is very exciting," says Douglas Fields, a neuroscientist at the National Institutes of Health in Bethesda, Maryland, who was not involved in the work. "From these early studies one sees the promise of cell transplant therapy in overcoming disease and relieving suffering." Without myelin, electrical impulses traveling along nerve fibers in the brain can't travel from neuron to neuron says Nalin Gupta, lead author of the study and a neurosurgeon at the University of California, San Francisco (UCSF). Signals in the brain become scattered and disorganized, he says, comparing them to a pile of lumber. "You wouldn't expect lumber to assemble itself into a house," he notes, yet neurons in a newborn baby's brain perform a similar feat with the help of myelin-producing cells called oligodendrocytes. Most infants are born with very little myelin and develop it over time. In children with early-onset Pelizaeus-Merzbacher disease, he says, a genetic mutation prevents oligodendrocytes from producing myelin, causing electrical signals to die out before they reach their destinations. This results in serious developmental setbacks, such as the inability to talk, walk, or breathe independently, and ultimately causes premature death. © 2010 American Association for the Advancement of Science

Keyword: Stem Cells; Glia
Link ID: 17356 - Posted: 10.11.2012

By GINA KOLATA Scientists have selected three different types of Alzheimer’s drugs to be tested in the first large-scale international attempt to prevent the disease in people who are otherwise doomed to get it. It is one of three studies with the same goal that will start early next year. This one involves 160 people from the United States, Britain and Australia with a variety of gene mutations that cause Alzheimer’s with absolute certainty. Most of the test subjects will have no symptoms yet of the degenerative disease that ravages the brain, destroying memory and thought. But they would be expected to start showing signs of problems with memory and thinking within five years unless the drugs work. The hope is that by intervening early, the disease might be headed off. Another study starting next year involves an extended family in Colombia that shares the same mutation. Anyone who inherits that mutated gene get Alzheimer’s disease. A third study will involve people in the United States age 70 and older who seem perfectly healthy and who do not have any known Alzheimer’s mutations but in whom, brain scans show, the disease is starting to manifest itself. In recent years, as studies involving people who already have Alzheimer’s have failed, researchers increasingly have called for studies in those who do not yet have the disease, arguing that the time to intervene is before the brain is irreversibly damaged. So the new study with people who are destined to get Alzheimer’s unless a drug can stop it is a way to test that idea. © 2012 The New York Times Company

Keyword: Alzheimers
Link ID: 17355 - Posted: 10.11.2012

by Robert F. Service According to George Bernard Shaw: "The most intolerable pain is produced by prolonging the keenest pleasure." Not to be picky George, but actually both sensations result from the activity of a diverse family of proteins on the surface of cells. This year's Nobel Prize in chemistry was awarded to two Americans—Robert Lefkowitz of Duke University in Durham, North Carolina, and Brian Kobilka of Stanford University School of Medicine in Palo Alto, California—who revealed the inner workings of these proteins, which also orchestrate a variety of things such as the way we see, smell, taste, feel, and fight infections. The notion that a single family of proteins was responsible for so many different physiological processes was far from evident early on. One hint came at the end of the 19th century, when scientists studying the effects of the hormone adrenaline discovered that it had different effects in various parts of the body. It made heart rate and blood pressure increase, but it decreased digestive activity and caused pupils to relax. One idea was that proteins called receptors on different cells somehow captured adrenaline molecules and either ferried the hormone into cells or transferred a message inside to trigger a response. In the 1940s, an American biologist named Raymond Ahlquist made enough progress to conclude that there must be two types of adrenaline receptors, one that caused smooth muscle cells to contract, and the other that stimulated the heart. © 2010 American Association for the Advancement of Science

Keyword: Pain & Touch; Vision
Link ID: 17354 - Posted: 10.11.2012

By Susan Milius A dollop of living yellow ooze has aced a test of navigation, showing that you don’t really need a mind to make spatial memories. The egg-yolk-colored slime mold Physarum polycephalum is a single cell without any nervous system. But this blob of a creature uses its slime trails as a form of external spatial memory, says complex systems biologist Chris R. Reid of the University of Sydney. Smears of goo left behind as a slime mold crawls act as records of past paths. Given a choice, slime molds won’t crawl over their old slime, Reid and his colleagues found. These simple external “memories” work quite well. When lured into a U-shaped dead-end in front of a sugar treat, slime molds were able to escape. Instead of just throbbing futilely against the closed end of the U or crawling around in circles, 39 out of 40 managed to ooze their way back out of the blind alley and creep to the treat by an outside route, Reid and his colleagues report October 8 in the Proceedings of the National Academy of Sciences. “It’s the first time any spatial memory system has been found in an organism without a brain,” Reid says. Ants, which Reid also studies, lay trails of scents as they scurry to food sources, and these scents can function as external memories of the whole colony. Ants do have brains though. © Society for Science & the Public 2000 - 2012

Keyword: Learning & Memory
Link ID: 17353 - Posted: 10.11.2012

By Jason G. Goldman My high school biology teacher once told me that nothing was binary in biology except for alive and dead, and pregnant and not pregnant. Any other variation, he said, existed along a continuum. Whether or not the claim is technically accurate, it serves to illustrate an important feature of biological life. That is, very little in the biological world falls neatly into categories. A new finding, published today in PLoS ONE by Gustavo Arriaga, Eric P. Zhou, and Erich D. Jarvis from Duke University adds to the list of phenomena that scientists once thought were categorical but may, in fact, not be. The consensus among researchers was that, in general, animals divide neatly into two categories: singers and non-singers. The singers include songbirds, parrots, hummingbirds, humans, dolphins, whales, bats, elephants, sea lions and seals. What these species all have in common – and what distinguishes them from the non-singers of the animal world – is that they are vocal learners. That is, these species can change the composition of their sounds that emanate from the larynx (for mammals) or syrinx (for birds), both in terms of the acoustic qualities such as pitch, and in terms of syntax (the particular ordering of the parts of the song). It is perhaps not surprising that songbirds and parrots have been extremely useful as models for understanding human speech and language acquisition. When other animals, such as monkeys or non-human apes, produce vocalizations, they are always innate, usually reflexive, and never learned. But is the vocal learner/non-learner dichotomy truly reflective of biological reality? Maybe not. It turns out that mice make things more complicated. © 2012 Scientific American

Keyword: Hearing; Sexual Behavior
Link ID: 17352 - Posted: 10.11.2012

By Janet Raloff For pregnant women, diets rich in fish can offer their babies protection against developing behaviors associated with attention-deficit/hyperactivity disorder, or ADHD, a new study finds. Yet for most Americans, fish consumption is the leading source of exposure to mercury — a potent neurotoxic pollutant that has been linked to a host of health problems, including delays in neural development. Data from the new study, published online October 8 in Archives of Pediatrics and Adolescent Medicine, demonstrate that low-mercury diets and regular fish consumption are not mutually exclusive, says epidemiologist and study leader Susan Korrick of Brigham and Women’s Hospital in Boston. “It really depends on the type of fish that you’re eating,” she says. In fact, some study participants had been eating more than two servings of fish weekly yet accumulated relatively little mercury. As part of a long-running study of children born during the 1990s in New Bedford, Mass., 515 women who had just given birth completed a dietary survey. About 420 also provided samples of their hair for mercury testing. About eight years later, Korrick’s team administered a battery of IQ and other tests to assess behaviors associated with ADHD in the children. The children spanned a continuum running from almost no ADHD-related behaviors to those with outright clinical disease. A mom’s hair-mercury level tended to be associated with where her child fell along this spectrum. © Society for Science & the Public 2000 - 2012

Keyword: ADHD; Neurotoxins
Link ID: 17351 - Posted: 10.09.2012