By Rebecca Cheung Constant low-level noise might cause hearing problems, a new study in rats finds. The discovery, published online May 15 in Nature Communications, suggests that extended exposure to noise at levels usually deemed safe for human ears could actually impair sound perception. The findings are “definitely a warning flag,” says study coauthor Michael Merzenich, an integrative neuroscientist at the University of California, San Francisco. He adds that it will be important to find out whether people employed at factories where continuous low-intensity noise is emitted throughout the workday experience similar consequences. “The big picture is that there is no safe sound,” says Jos Eggermont, an auditory neuroscientist at the University of Calgary in Canada. Even sounds considered safe can cause damage if delivered in a repetitive way, he says. “There might be not-so-subtle effects that accumulate and affect communication and speech understanding.” It’s common knowledge that sustained exposure to louder noises — such as that above 85 decibels — or brief exposures to very loud noises above 100 decibels can cause inner ear damage and hearing impairments. But until recently, the impact of chronic, quieter sound hasn’t been well studied. In the new study, Merzenich and his colleague Xiaoming Zhou of East China Normal University in Shanghai exposed adult mice to 65 decibel sound — roughly at the higher end of normal human speech volume — for 10 hours daily. © Society for Science & the Public 2000 - 2012

Keyword: Hearing
Link ID: 16802 - Posted: 05.16.2012

By Mariette DiChristina “I see you have a watch with a buckle.” Standing at my side, Apollo Robbins held my wrist lightly as he turned my hand over and back. I knew exactly what was coming but I fell for it anyway. “Yes,” I said, trying to keep an eye on him, “that looks pretty easy for you to take off, but my rings would be harder.” He agreed, politely, while looking down at my hands and then up into my eyes: “Which one do you think would be hardest to remove?” While I considered the answer, he had already removed my watch and put it on his own wrist behind his back, unseen. He isn’t called the “The Gentleman Thief” for nothing. Robbins had just skillfully managed my attentional spotlight—that is, the focus of awareness at any given moment. To conceal his pilfering, Robbins had employed what is generally called “misdirection”: he got me to attend to the wrong things, added to my brain’s cognitive load with his humorous patter, created a distracting internal dialogue in me by giving me a question to answer, and generally flummoxed me all the while by pressing here and there on a shoulder or wrist. Adding insult to injury, Robbins had just described what he does—and shown his techniques while swiftly lifting another watch and emptying the pockets of the amiable Flip Phillips of Skidmore College. Still, I never stood a chance. My response to being fooled so easily? I laughed out loud. © 2012 Scientific America

Keyword: Attention
Link ID: 16801 - Posted: 05.16.2012

By Mariette DiChristina Early behavioral intervention has shown some promise as a way to help children with autism. But it’s difficult to see the hallmarks of autism before two years of age with today’s diagnostic criteria. Could we find other methods? Seeking to answer that question is Jed Elison at the California Institute of Technology, who is working with Ralph Adolphs at Caltech and Joe Piven at the University of North Carolina among other colleagues around the U.S. and Canada. Elison provided some preliminary findings at the Neuromagic 2012 conference held from May 7 to 10, 2012 on San Simón, the Island of Thought, near Vigo, Spain. Today’s criteria, from the psychiatric bible called the DSM-IV, include attributes of social impairments, communication deficits, and repetitive patterns of behavior and restricted interests (either in intensity or content). “There’s a biological reality,” said Elison, “that you can’t capture perfectly with a classification system like this.” Nevertheless, there’s “no question that the classification system serves a very important role in identifying kids who require specialized clinical services” Recognizing the condition early can help. “There’s some evidence that early intervention alleviates” some of the behavioral challenges for these children, he added. Elison and collaborative partners of the Infant Brain Imaging Study Network are recruiting families who have a child with autism and an infant sibling under six months of age. © 2012 Scientific American

Keyword: Autism; Brain imaging
Link ID: 16800 - Posted: 05.16.2012

By SciCurious Before stimulant drugs such as Ritalin, Concerta and Adderall began their rise to popularity in the 1970s, treatment for attention-deficit hyperactivity disorder (ADHD) focused on behavioral therapy. But as concerns build over the mounting dosages and extended treatment periods that come with stimulant drugs, clinical researchers are revisiting behavioral therapy techniques. Whereas stimulant medications may help young patients focus and behave in the classroom, research now suggests that behaviorally based changes make more of a difference in the long-term. A new synthesis of behavioral, cognitive and pharmacological findings emerged at the recent Experimental Biology meeting, held last month in San Diego, where experts in ADHD research and treatment gathered to present their work. Their findings suggest that behavioral and cognitive therapies focused on reducing impulsivity and reinforcing positive long-term habits may be able to replace current high doses of stimulant treatment in children and young adults. Recent surveys indicate that 9 percent of all children in the U.S. have been diagnosed with ADHD. The condition's core symptoms include hyperactivity, inattention, inability to perform monotonous tasks and lack of impulse control. Children with ADHD have trouble in school and forming relationships, and 60 percent will continue to suffer from the disorder well into adulthood. As of 2007, 2.7 million U.S. children and adolescents with ADHD were being treated with stimulant drugs. But new research reveals that these drugs are not necessarily the panacea they have been thought to be. Psychologist Claire Advokat of Louisiana State University has been looking at the effects of stimulant medications in college students to see what improves with medication and what does not. © 2012 Scientific American

Keyword: ADHD; Attention
Link ID: 16799 - Posted: 05.16.2012

By Adam Halberstadt and Mark Geyer What would you see if you could look inside a hallucinating brain? Despite decades of scientific investigation, we still lack a clear understanding of how hallucinogenic drugs such as LSD (lysergic acid diethylamide), mescaline, and psilocybin (the main active ingredient in magic mushrooms) work in the brain. Modern science has demonstrated that hallucinogens activate receptors for serotonin, one of the brain’s key chemical messengers. Specifically, of the 15 different serotonin receptors, the 2A subtype (5-HT2A), seems to be the one that produces profound alterations of thought and perception. It is uncertain, however, why activation of the 5-HT2A receptor by hallucinogens produces psychedelic effects, but many scientists believe that the effects are linked to increases in brain activity. Although it is not known why this activation would lead to profound alterations of consciousness, one speculation is that an increase in the spontaneous firing of certain types of brain cells leads to altered sensory and perceptual processing, uncontrolled memory retrieval, and the projection of mental “noise” into the mind’s eye. The English author Aldous Huxley believed that the brain acts as a “reducing valve” that constrains conscious awareness, with mescaline and other hallucinogens inducing psychedelic effects by inhibiting this filtering mechanism. Huxley based this explanation entirely on his personal experiences with mescaline, which was given to him by Humphrey Osmond, the psychiatrist who coined the term psychedelic. Even though Huxley proposed this idea in 1954, decades before the advent of modern brain science, it turns out that he may have been correct. Although the prevailing view has been that hallucinogens work by activating the brain, rather than by inhibiting it as Huxley proposed, the results of a recent imaging study are challenging these conventional explanations. © 2012 Scientific American,

Keyword: Drug Abuse
Link ID: 16798 - Posted: 05.16.2012

Caroline Morley, online picture researcher On the edge of your vision as you read this, the water swirls but the starfish turns in the other direction, floating above the background. The image itself is, of course, still: the movement is created in your head. It uses the phenomenon of periphery drift to make us see movement where there is none. The different contrasts between the colours are the key to making us see the star and the background move in opposite directions. This image was created by Kaia Nao, an alternative identity for wildlife painter Joe Hautman. It is a finalist in the 2012 Best Illusion of the Year Contest, run by the Neural Correlate Society to encourage and publicise the work of researchers in the field of visual illusions. See the winning video in our New Scientist TV post "Best illusion of 2012: The disappearing hand trick". © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 16797 - Posted: 05.16.2012

By PAM BELLUCK In a clinical trial that could lead to treatments that prevent Alzheimer’s, people who are genetically guaranteed to develop the disease — but who do not yet have any symptoms — will for the first time be given a drug intended to stop it, federal officials announced Tuesday. Experts say the study will be one of the few ever conducted to test prevention treatments for any genetically predestined disease. For Alzheimer’s, the trial is unprecedented, “the first to focus on people who are cognitively normal but at very high risk for Alzheimer’s disease,” said Dr. Francis S. Collins, director of the National Institutes of Health. Most participants will come from the world’s largest family to experience Alzheimer’s, an extended clan of 5,000 people who live in Medellín, Colombia, and remote mountain villages outside that city. Family members with a specific genetic mutation begin showing cognitive impairment around age 45, and full dementia around age 51, debilitated in their prime working years as their memories fade and the disease quickly assaults their ability to move, eat, speak and communicate. Three hundred family members will participate in the initial trial. Those with the mutation will be years away from symptoms, some as young as 30. “Because of this study, we do not feel as alone,” said Gladys Betancur, 39, a family member. Her mother died of Alzheimer’s, three of her siblings already have symptoms, and she had a hysterectomy because of her fears that she has the mutation and would pass it on to her children. “Sometimes we think that life is ending, but now we feel that people are trying to help us.” The $100 million study will last five years, but sophisticated tests may indicate in two years whether the drug helps delay memory decline or brain changes, said Dr. Eric M. Reiman, executive director of the Banner Alzheimer’s Institute in Phoenix and a study leader. © 2012 The New York Times Company

Keyword: Alzheimers
Link ID: 16796 - Posted: 05.16.2012

By John Horgan When I teach history of science at Stevens Institute of Technology, I devote plenty of time to science’s glories, the kinds of achievements that my buddy George Johnson wrote about in The Ten Most Beautiful Experiments (Alfred A. Knopf, 2008). George helps us appreciate what Galileo did with inclined planes, Newton with prisms, Pavlov with dogs, Galvani with frogs, Millikan with oil drops, Faraday with a magnet and coil of wire. (When George demonstrated Faraday’s experiment on Comedy Central’s The Colbert Report, Stephen Colbert found the experiment so shocking that he blurted out, “Mother——!”) But I tell my students about science’s missteps, too, to remind them that scientists can be as flawed as the rest of us mortals. In that negative spirit, here are five experiments that I consider to be especially hideous, horrible, immoral—in short, ugly. Walter Freeman and Transorbital Lobotomies In 1949, the Portuguese neurologist Egas Moniz won a Nobel Prize for inventing the lobotomy, a treatment for mental illness that called for inserting a sharp instrument into holes drilled through the skull and destroying tissue in the frontal lobes. By then, physician Walter Freeman Jr., (father of neuroscientist Walter Freeman III, a leading consciousness researcher) had already begun carrying out lobotomies in the United States. In 1941 Freeman lobotomized the unruly, 23-year-old sister of John F. Kennedy; Rosemary Kennedy was so severely disabled after her lobotomy that she required care for the rest of her life. Freeman later invented the transorbital lobotomy, which involved slipping an ice pick past the eyeball, thrusting it through the rear of the eye socket and swishing it back and forth in the brain. © 2012 Scientific American

Keyword: Schizophrenia; Sexual Behavior
Link ID: 16795 - Posted: 05.15.2012

By Ferris Jabr Over the years, I have taught my copy of Microsoft Word a lot of neuroscience terminology: amygdala, corpus callosum, dendritic spines, voxel. But it always knew what neuron meant. I thought I did too. Neurons—the electrically excitable cells that make up the brain and nervous system—first fascinated me in high school. In college, like so many other students studying the brain, I dutifully memorized the structure of the archetypal neuron. I also remember learning about a few different types of neurons with different shapes and functions: motor neurons that make muscles twitch, for example, and unique sensory neurons in the eyes and nose. Only recently, however, have I begun to recognize and appreciate the extraordinary diversity of cells in the nervous system—cells that differ from one another more than the cells of any other organ. Some neurons send electrical signals along fibers that stretch several feet; other neurons’ branches extend only a few millimeters away from the cell body. Some neurons possess a fractal beauty similar to that of ferns and corals: Purkinje cells, for example, often sport finely branched nets, like a sea fan. But some of their neighbors look more like tangled tumbleweeds. One neuron might appear more or less round under the microscope—like a firework frozen in climax—whereas another might spider through the brain like a daddy longlegs. Neurons not only differ in shape—different types of neurons turn on different sets of genes and not all neurons use the same chemicals to communicate. Excitatory neurons mostly stimulate other cells; inhibitory neurons prefer to stifle. Most neurons fire in patterns, but their tempos vary: some keep a steady beat, others remain largely silent except for the occasional burst of activity and still other cells continually fire like a trigger-happy toddler playing laser tag. To summarize: not all neurons are exactly alike. The brain contains multitudes. mouse-neurons © 2012 Scientific American,

Keyword: Miscellaneous
Link ID: 16794 - Posted: 05.15.2012

by Mairi Macleod IN ELIZABETHAN England, it was common practice for a maiden to peel an apple, place a slice in her armpit to absorb the smell and then present it to a potential suitor as a memento. Traditional Balkan dancing follows a similar principle. In an activity akin to Morris dancing, but with added odour, men put handkerchiefs in their armpits, work up a sweat by dancing hard and then wave their hankies under the noses of young females. Throughout history and across cultures, body odour has played a key role in attraction, just as it does with many other animals. Yet modern societies tend not to appreciate nature's perfume. Many of us go to considerable lengths to expunge our personal smells and replace them with ones we consider to be more appealing. Instead of apples in our armpits, we have deodorants and perfumes that are marketed as smelling of innocence, vivacity, sophistication or whatever attributes we believe will make us more alluring. Is the multibillion-dollar fragrance industry missing a trick? As we discover which elements of body odour are attractive and to whom, the commercial potential of these chemicals is becoming increasingly apparent. Most people don't want to smell of sweat, but it can only be a matter of time before some components of our natural perfumes are bottled. You might think of yourself as a primarily visual animal, relying little on your sense of smell, but in recent years the idea that olfactory communication is not important in humans has been challenged. © Copyright Reed Business Information Ltd

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 16793 - Posted: 05.15.2012

By Laura Sanders A certain genetic signature gives some people the ability to form stronger memories. But that edge also has a dark side: increased risk of post-traumatic stress disorder. Although the genetic effect is small, the results help scientists better understand the link between especially powerful memories and sensitivity to past trauma. Scientists led by neuroscientist Dominique de Quervain of the University of Basel in Switzerland looked at how genetic differences related to a memory task. A population of 723 healthy young Swiss adults viewed 72 photographs. After a 10-minute wait, the volunteers were asked to remember as many images as possible. Volunteers who could remember more pictures carried a particular DNA signature in at least one copy of a gene that encodes protein kinase C alpha. In animal studies, this protein has been shown to play a role in the formation of emotional memories. The volunteers’ heightened recall was true for disturbing, pleasant and neutral pictures. Further evidence came from brain scans performed in a different group of Swiss people. While viewing the pictures, people with the genetic signature had stronger brain activation in parts of the prefrontal cortex compared with those who lacked the genetic feature, the researchers report online the week of May 14 in the Proceedings of the National Academy of Sciences. © Society for Science & the Public 2000 - 2012

Keyword: Stress; Genes & Behavior
Link ID: 16792 - Posted: 05.15.2012

Smoking marijuana may help relieve the muscle tightness and pain of multiple sclerosis, a small U.S. study suggests. Many people with MS often suffer from spasticity, an uncomfortable and disabling condition in which the muscles become tight and difficult to control. Spasticity can be controlled with medications but the symptoms may continue or the anti-spasticity drugs may carry adverse effects such as drowsiness, sedation, and muscle weakness. The medical marijuana used in the study the strength of cigarettes most commonly available in the community at the time of the research. Most trials testing medical marijuana have focused on oral forms. Now a randomized trial has put smoked cannabis to the test against placebo for 30 people with MS whose spasticity resisted treatment. "Using an objective measure, we saw a beneficial effect of inhaled cannabis on spasticity among patients receiving insufficient relief from traditional treatment," Dr. Jody Corey-Bloom, of the department of neuroscience at University of California, San Diego and her co-authors concluded in Monday's issue of the Canadian Medical Association Journal. In the study, the average age of participants was 50 and 63 per cent were female. More than half of the participants needed walking aids and 20 per cent used wheelchairs. Copyright © CBC 2012

Keyword: Multiple Sclerosis; Drug Abuse
Link ID: 16791 - Posted: 05.15.2012

By Jennifer Huget When my daughter was little, she was quite the sleepwalker. Until you have a sleepwalker in the family, you have no idea how terrifying it can be. You worry about whether they’ll safely navigate the stairs when they decide to sleep-stumble from the second-floor bedroom where they’re supposed to be, well, sleeping, to the first-floor family room where you’re watching TV. Or that they’ll open a door and wander outside in the middle of the night — and that you might not hear them leave. Or that they’ll pick up a knife in the kitchen or light a burner. . . . Let’s just say it’s hard to sleep with a sleepwalker around. And if you have ever tried to talk to a sleepwalking child, you know how worrying it is to see how completely out of it they seem. My son never walked in his sleep, and my daughter finally outgrew the behavior, which affects up to 30 percent of children, according to the introduction to a study published Monday afternoon in the journal Neurology. The new research set out to determine how common sleepwalking is among adults. According to the report, the phenomenon has been little studied, so data about its prevalence are quite limited. The best estimate before this new study was that between 2 and 3 percent of adults walk in their sleep; the new research puts the number of adults who have walked in their sleep at least once in the past year at 3.6 percent. And 29.2 percent of those surveyed reported having walked in their sleep at least once in their life. © 1996-2012 The Washington Post

Keyword: Sleep
Link ID: 16790 - Posted: 05.15.2012

Shannon Pettypiece Testosterone replacement has long been prescribed for men who suffer from abnormally low levels of the male sex hormone, but overuse can lead to infertility and can even speed the growth of prostate cancer. That hasn't stopped Michael Murray, a healthy 43-year-old home stager who works in New York and Chicago, from getting frequent testosterone injections to raise his energy level and give his bodybuilding regime a boost. "Am I making a deal with the devil? A little bit, but I have to think about my quality of life," Murray explains. "It is like I'm in my 20s again." In what may become one of the most sought-after lifestyle drugs since the introduction of Pfizer's Viagra 14 years ago, new testosterone drugs from Eli Lilly, Abbott Laboratories, and other drugmakers are hot. Prescriptions for testosterone replacement therapies have more than doubled since 2006 to 5.6 million last year, according to data compiled by Bloomberg. Sales are expected to triple to $5 billion by 2017, forecasts Global Industry Analysts. As many as 13.8 million men older than 45 in the United States have low levels of testosterone, according to a 2006 study in the International Journal of Clinical Practice. The male sex hormone begins to decline after age 30, and tends to drop about 1 percent each year. Lower-than-normal levels can lead to a loss of libido, a decrease in bone and muscle mass, and depression. © 2012 Hearst Communications Inc.

Keyword: Hormones & Behavior; Drug Abuse
Link ID: 16789 - Posted: 05.14.2012

By Jennifer Verdolin Typically we think of eavesdropping as a human endeavor. Individually we all do it to a certain degree. Call it social listening, if you will. Sometimes we can’t help but overhear a conversation. Other times we might deliberately try to listen in on what someone else is saying. I remember as a kid putting a cup up against the door to try and hear what was going on behind closed doors. Collectively as nations we eavesdrop on a massive scale, in times of peace and war. Currently, the military spends a considerable amount of money on ‘electronic intelligence’, so much so that there is an entire center devoted to eavesdropping: Menwith Hill in North Yorkshire. We certainly did not invent this strategy of watching or listening in on others. Like most things, we’ve copied it from nature. Eavesdropping is ubiquitous across the animal kingdom. Whenever substantial time or resources are devoted to an activity there is usually a payoff to be found. This got me wondering, what is the payoff for eavesdropping? Several advantages immediately come to mind. For example, perhaps you can increase your access to resources. One way to do this would be to avoid wasting time going after resources that someone else has already used up. This is frequently observed among competitors searching for similar resources. When one thinks of fierce competitors, two stingless bee species may not be the first thing that comes to mind. © 2012 Scientific American

Keyword: Chemical Senses (Smell & Taste)
Link ID: 16788 - Posted: 05.14.2012

By IAN URBINA WASHINGTON — In what could prove to be one of their most far-reaching decisions, psychiatrists and other specialists who are rewriting the manual that serves as the nation’s arbiter of mental illness have agreed to revise the definition of addiction, which could result in millions more people being diagnosed as addicts and pose huge consequences for health insurers and taxpayers. The revision to the manual, known as the Diagnostic and Statistical Manual of Mental Disorders, or D.S.M., would expand the list of recognized symptoms for drug and alcohol addiction, while also reducing the number of symptoms required for a diagnosis, according to proposed changes posted on the Web site of the American Psychiatric Association, which produces the book. In addition, the manual for the first time would include gambling as an addiction, and it might introduce a catchall category — “behavioral addiction — not otherwise specified” — that some public health experts warn would be too readily used by doctors, despite a dearth of research, to diagnose addictions to shopping, sex, using the Internet or playing video games. Part medical guidebook, part legal reference, the manual has long been embraced by government and industry. It dictates whether insurers, including Medicare and Medicaid, will pay for treatment, and whether schools will expand financing for certain special-education services. Courts use it to assess whether a criminal defendant is mentally impaired, and pharmaceutical companies rely on it to guide their research. © 2012 The New York Times Company

Keyword: Drug Abuse
Link ID: 16787 - Posted: 05.14.2012

By Rachel Ehrenberg Specialized goggles that send information to solar cell–like chips implanted in the eyes may one day help some blind people seeThe new implants, which have been tested in rat retinas in a dish, would require less invasive surgery than similar devices now being tested and offer a higher-resolution view of the world. The new system, reported online May 13 in Nature Photonics, still needs work before being tested in people. But one day it may return partial sight to people suffering from conditions such as retinitis pigmentosa, an inherited disease that can lead to night blindness and tunnel vision, or macular degeneration, in which sharp central vision is lost but peripheral vision remains. In those conditions, vision suffers when light-detecting cells at the back of the inner eye are damaged, even though the nerve cells that send visual information to the brain may remain intact. No current treatments can restore vision for such retinal damage, says Lotfi Merabet, an eye specialist at Massachusetts Eye and Ear in Boston. The new work “is certainly very promising,” he says. Developing the implants took many years and many scientists, says study coauthor James Loudin, an electrical engineer at Stanford University. “The sheer number of new technologies that had to be developed — it’s amazing,” he says. © Society for Science & the Public 2000 - 2012

Keyword: Vision; Robotics
Link ID: 16786 - Posted: 05.14.2012

DULL fingers? Blame your genes. It has just been discovered that sensitivity to touch is heritable, and apparently linked to hearing as well. Gary Lewin and colleagues at the Max Delbrück Center for Molecular Medicine in Berlin, Germany, measured touch in 100 healthy pairs of fraternal and identical twins. They tested finger sensitivity in two ways: by response to a high-frequency vibration and the ability to identify the orientation of very fine grating. Lewin's team found that up to 50 per cent of the variation in sensitivity to touch was genetically determined. Audio tests also showed that those with good hearing were more likely to have sensitive touch. The link between the two is logical, as both touch and hearing rely on sensory cells that detect mechanical forces. Next the researchers studied touch sensitivity in students with congenital deafness. They found that 1 in 5 also had impaired touch, indicating that some genes causing deafness may also dull the sense of touch. When they looked at a subset of individuals who were deaf and blind due to Usher syndrome, they found that mutations in a single gene, USH2A, caused both the disease and reduced sensitivity to touch (PLoS Biology, DOI: 10.1371/journal.pbio.1001318). The next step is to try to identify more genes that affect our sense of touch. "There are many more genes than just the one we found," says Lewin, adding that finding them "will hopefully show us more about the biology of touch". © Copyright Reed Business Information Ltd.

Keyword: Hearing; Pain & Touch
Link ID: 16785 - Posted: 05.14.2012

Jessica Hamzelou, contributor In his latest book The Moral Molecule, neuroeconomist Paul Zak describes oxytocin’s role in trust, bonding and even virtuous behaviour. New Scientist caught up with him about avoiding the term “the cuddle chemical” and trying not to make a bride faint on her wedding day. Why study moral behaviour? Before my mother was my mother she was a nun, so morality was something that was very present. We had very clear top-down guidance: “you do this and you go to heaven, you do that and you go to hell”. Even as a child I felt that that was incredibly harsh and wrong. The idea that there’s some perfect received wisdom to tell the difference between right and wrong just didn’t make any sense to me. I wanted to find a concrete, biological basis for good and bad behaviour in humans. It’s not my place to say whether God exists or not, but it seemed like there were all kinds of good people who weren’t raised Catholic like I was. And that seemed like a deep mystery about life: if there are 2000 religions, why do we see a large number of those having the same kind of prescriptions for what constitutes good behaviour and a good life? That was the deeper, personal reason that, in retrospect, drove ten years of hard labour in the lab and in the field. What got you interested in oxytocin? I had done work in the late 1990s showing that countries in which levels of interpersonal trust were high were richer countries, and countries that were poor were by and large low trust countries. © Copyright Reed Business Information Ltd

Keyword: Emotions; Hormones & Behavior
Link ID: 16784 - Posted: 05.12.2012

Sandrine Ceurstemont, editor, New Scientist TV Think you can tell which way a ballerina is twirling? A new animation by psychophysiologist Marcel de Heer shows that a dancer's silhouette is identical regardless of the direction in which she is spinning. The video starts with two mirror-image ballerinas spinning in opposite ways and a third one in silhouette, which could belong to either dancer. So how does our brain make sense of the ambiguous figure? The perceived direction of motion varies from person to person. According to de Heer, our visual system makes a quick decision on a subconscious level about the direction of rotation and the result of that decision is what we see. "It makes this choice while there is a big chance it is the wrong one," he says. An online study of a similar illusion revealed that most people see the silhouette moving clockwise. However those who initially see it turning counterclockwise are more likely to be able to reverse its direction of motion. In the course of the animation, all three ballerinas become silhouettes, at which point their motion is perceived to be synchronised. The reason for this is unclear but de Heer plans to investigate the phenomenon in future research. © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 16783 - Posted: 05.12.2012