By Juliet Eilperin, Humpback whales on different sides of the southern Indian Ocean are singing different songs, according to a new study conducted by American and Australian researchers. The report challenges the past assumption that whales in the same ocean basin sing songs with similar themes. The humpback songs were recorded during the 2006 breeding season along the coasts of western Australia and Madagascar. The analysis was published in the January edition of the journal Marine Mammal Science. “Songs from Madagascar and western Australia only shared one similar theme; the rest of the themes were completely different,” said lead author Anita Murray, who is pursuing her doctorate at the University of Queensland in Australia. “The reason for this anomaly remains a mystery. It could be the influence of singing whales from other ocean basins, such as the South Pacific or Atlantic, indicating an exchange of individuals between oceans which is unique to the Southern Hemisphere.” The findings could provide new insight into how whale culture spreads. Male humpback whales are generally the ones that sing. The songs include rising and falling wails, moans and shrieks that repeat in cycles lasting up to half an hour. Researchers suspect that individuals from different humpback populations could transmit songs to one another when they are share feeding grounds or cross paths during migration. © 1996-2012 The Washington Post

Keyword: Animal Communication; Language
Link ID: 16357 - Posted: 02.07.2012

By DAVID TULLER When scientists reported in 2009 that a little-known mouse retrovirus was present in a large number of people with chronic fatigue syndrome, suggesting a possible cause of the condition, the news made international headlines. For patients desperate for answers, many of them severely disabled for years, the finding from an obscure research center, the Whittemore Peterson Institute for Neuro-Immune Disease in Reno, Nev., seemed a godsend. “I remember reading it and going, ‘Bingo, this is it!’ ” said Heidi Bauer, 42, a mother of triplets in Huntington, Md., who has had chronic fatigue syndrome since her 20s. “I thought it was going to mean treatment, that I was going to be able to play with my kids and be the kind of mom I wanted to be.” Patients showered praise on the lead researcher, Dr. Judy Mikovits, a former scientist at the National Cancer Institute. They sent donations large and small to the institute, founded by Harvey and Annette Whittemore, a wealthy and politically well-connected Nevada couple seeking to help their daughter, who had the illness. In hopes of treating their condition, some patients even began taking antiretroviral drugs used to treat H.I.V., a retrovirus related to the murine leukemia viruses suddenly suspected of involvement in chronic fatigue syndrome. More recently, however, the hopes of these patients have suffered an extraordinary battering. In a scientific reversal as dramatic and strange as any in recent memory, the finding has been officially discredited; a string of subsequent studies failed to confirm it, and most scientists have attributed the initial results to laboratory contamination. In late December, the original paper, published in the journal Science, and one other study that appeared to support it were retracted within days of each other. © 2012 The New York Times Company

Keyword: Depression
Link ID: 16356 - Posted: 02.07.2012

by Lisa Grossman Clint Eastwood might sound an unlikely candidate to help investigate the evolution of the brain, but he has lent a helping hand to researchers doing just that. It turns out that brain regions that do the same job in monkeys and humans aren't always found in the same part of the skull. Previous studies comparing brains across species tended to assume that human brains were just blown-up versions of monkey brains and that functions are carried out by anatomically similar areas. To test this idea, Wim Vanduffel of Harvard Medical School in Boston and the Catholic University of Leuven (KUL) in Belgium, and colleagues scanned the brains of 24 people and four rhesus monkeys while they watched The Good, The Bad and The Ugly. They compared the brain responses of each individual to the same sensory stimulation, and identified which brain areas had similar functions. The majority of the human and monkey brain maps lined up, but some areas with a similar function were in completely different places. The team say the discovery is crucial to building more accurate models of our evolution. "You can't assume that because A and B are close together in the monkey brain, they need to be close together in the human brain," Vanduffel says. Journal reference: Nature Methods, DOI: 10.1038/nmeth.1868 © Copyright Reed Business Information Ltd.

Keyword: Evolution; Attention
Link ID: 16355 - Posted: 02.07.2012

by Sally Adee Whether you want to smash a forehand like Federer, or just be an Xbox hero, there is a shocking short cut to getting the brain of an expert I'm close to tears behind my thin cover of sandbags as 20 screaming, masked men run towards me at full speed, strapped into suicide bomb vests and clutching rifles. For every one I manage to shoot dead, three new assailants pop up from nowhere. I'm clearly not shooting fast enough, and panic and incompetence are making me continually jam my rifle. My salvation lies in the fact that my attackers are only a video, projected on screens to the front and sides. It's the very simulation that trains US troops to take their first steps with a rifle, and everything about it has been engineered to feel like an overpowering assault. But I am failing miserably. In fact, I'm so demoralised that I'm tempted to put down the rifle and leave. Then they put the electrodes on me. I am in a lab in Carlsbad, California, in pursuit of an elusive mental state known as "flow" - that feeling of effortless concentration that characterises outstanding performance in all kinds of skills. Flow has been maddeningly difficult to pin down, let alone harness, but a wealth of new technologies could soon allow us all to conjure up this state. The plan is to provide a short cut to virtuosity, slashing the amount of time it takes to master a new skill - be it tennis, playing the piano or marksmanship. © Copyright Reed Business Information Ltd.

Keyword: Learning & Memory
Link ID: 16354 - Posted: 02.07.2012

By Gary Stix What if a drug could improve learning and cognition and had no untoward medical consequences? Wouldn’t it be justified to make it widely available? A group of scientists concluded three years ago that it would be. No such drug exists, but the question arises anew because of a brain-stimulation technique that appears on paper to fit the bill. The technology, transcranial direct-current stimulation, involves applying weak electrical currents to the scalp through electrodes. It appears to alter brain activity in a long-lasting way that can enhance cognition. Electrical therapies for the nervous system have a lengthy history. In about 45 AD, the Roman physician Scribonius Largus helped relieve pain by applying electric fish to a patient’s skin. Simple electric stimulation to the scalp appears to have myriad effects, possibly improving motor skills, vision, decision-making, problem-solving attention and mathematical reasoning in healthy individuals. “Where can I get one?” you might ask. Take your choice. You might buy one for less than $1,000. Or you could make your own: it’s really just a 9-volt battery with a few electrodes, seemingly the perfect high-school science project. Seems too good to be true. Let’s go now to the ethicists. “Is anything wrong with this picture?” asks an article in press in Current Biology. [Accessible as a PDF through an Oxford University science blog.] The authors, Roi Cohen Kadosh and a group of scientists and ethicists mostly from Oxford University, note that the electrical brain stimulator really does appear to be pretty safe in healthy adults: there are no reports of seizures, one of the first concerns for any intervention that turns up the volume on neural circuits. © 2012 Scientific American,

Keyword: Learning & Memory
Link ID: 16353 - Posted: 02.07.2012

By Scicurious There are many different factors which go into whether animals (or humans) develop obesity and diabetes. Different sensitivity to different chemicals, in different areas of the body and brain, can cause major differences in feeding behavior, body weight, fat, and insulin sensitivity. And now we’ve learned that changes in one circuit of the hypothalamus could make a big difference in a certain kind of obesity in mice. We’ll start with the db/db mouse, pictured above (on the left). This mouse is genetically designed to develop severe morbid obesity and diabetes soon after birth. This is because it lacks a receptor for a hormone called leptin. Leptin is a hormone that plays a major role in appetite and metabolism. Decreasing your sensitivity to leptin, by decreasing leptin receptors, say (as in the the db/db mouse), produces striking obesity and type 2 diabetes in humans and mice. Increasing your sensitivity to leptin, by, say, increasing your leptin receptors, can rescue this, resulting in lower body weight and more sensitivity to insulin. But these are global changes, throughout the body. The question is, where in the body do these leptin receptor changes really make a difference? Recent papers have suggested that the hypothalamus could play a major role. The hypothalamus, an area of your brain right above your pituitary gland, is a big connection between the brain and the endocrine system, an area where sensitivity to hormones could have a major impact on behavior and body regulation. And the hypothalamus regulates things like sleep, thirst, body temperature, and hunger. © 2012 Scientific American,

Keyword: Obesity
Link ID: 16352 - Posted: 02.07.2012

By Bruce Bower A chimpanzee in need gets help indeed, on two conditions. Another chimp must both see his or her predicament and receive a blatant help request from the needy animal, a new study finds. Observations in the wild and in previous experiments indicate that chimps seldom help others (SN: 8/27/11, p. 10), but that’s not because the chimps don’t understand their peers’ motivations, as some researchers suspect, says primatologist Shinya Yamamoto of Kyoto University in Japan. In a series of lab tests, chimps who saw one of their relatives unsuccessfully reach for a juice box and then request help picked out a useful tool and passed it to their kin, Yamamoto and colleagues report online February 6 in the Proceedings of the National Academy of Sciences. “Chimpanzees can understand others’ goals from obvious cues and then provide help,” Yamamoto says. This ability to grasp that another individual has a goal in mind based on his or her behavior represents one element of what psychologists call theory of mind — an ability to attribute beliefs, desires, pretending and other mental states to oneself and others. Until now, scientists had studied chimps’ understanding of other chimps’ goals only in competitive situations, such as clashes over food and mates. That fueled suspicion that chimps discern others’ goals only in the heat of such struggles. © Society for Science & the Public 2000 - 2012

Keyword: Evolution; Consciousness
Link ID: 16351 - Posted: 02.07.2012

By Victoria Gill Science reporter, BBC Nature Night-time in the Jurassic forest was punctuated by the unmistakable sound of chirping bush crickets. This is according to scientists who have reconstructed the song of a cricket that chirped 165 million years ago. A remarkably complete fossil of the prehistoric insect enabled the team to see the structures in its wings that rubbed together to make the sound. The international team report their findings in the journal PNAS. Scientists from the US and China discovered the tiny fossil and named their newly discovered species Archaboilus musicus , because the music-making structures in its body were so clearly visible. When insect expert Dr Fernando Montealegre Zapata, from the University of Bristol, found out that his colleagues had such a remarkable fossil, he was keen to see it. "I was very surprised," he told BBC Nature, "because those [structures] are very very small - at the microscopic level." Dr Zapata studies sound production and communication in living insects, working out how the musical instruments contained in many insects' bodies produce a particular sound, and exactly how that sound is made. He immediately asked the question: "Could we reproduce the sounds [this insect made] from that fossil?" BBC © 2012

Keyword: Sexual Behavior; Animal Communication
Link ID: 16350 - Posted: 02.07.2012

By Theodoric Meyer Fifty-five high school students sat silently in a Columbia University auditorium on Saturday afternoon, listening to the first question: “About how many cells are in the human brain?” The room echoed with a slight scraping sound as the students scribbled out their answers on brightly colored sheets of paper, then fell silent again. “The answer,” Michael E. Goldberg, a professor of neuroscience at Columbia, said into a microphone, “is 100 million.” It was the first of many questions to test students’ knowledge of neuroscience in this year’s New York City Regional Brain Bee, which drew students from each borough and Westchester County. The contest works a bit like its more familiar cousins, the spelling and geography bees: Eight rounds, five questions each. Thirty seconds to answer. Spelling, however, doesn’t count. The first two rounds proved fairly easy. Students needed to get only two of the five questions correct to move on, and only a few of them were eliminated. But the competition picked up during the third and fourth rounds, when students needed three correct answers for each round. Dr. Goldberg, a diminutive man in a tweed coat with black-framed glasses and thick white hair, seemed to relish his role as moderator and often supplied scientific asides to the questions. © Copyright 2012 The New York Times Company

Keyword: Miscellaneous
Link ID: 16349 - Posted: 02.07.2012

Steve Connor Scientists have identified a genetic mutation in one of the 23,000 human genes that can double the risk of a stroke, which kills more than six million people worldwide each year and is the second top cause of death in developed countries. A study of thousands of stroke patients in Britain and Germany found a link between the most common type of stroke – a blocked blood vessel leading to the brain – and a genetic variation in a gene known as HDAC9. Although strokes are known to run in families, this is one of the first studies to identify a precise DNA variant in the human genetic code that doubles a person's risk of developing a blocked artery supplying vital oxygen to the brain. The HDAC9 gene was already known to be involved in the formation of muscle tissue and the development of the heart, but the latest research suggests it is also implicated in a particular kind of illness called large-artery ischaemic stroke. Scientists said the DNA variation occurs on about 10 per cent of the chromosomes carrying the HDAC9 gene. People who inherit two copies of the variant, one from their mother and one from their father, face twice the risk of developing this type of stroke than people with no copies of the gene variant, they said. The study, published in Nature Genetics and funded by the Wellcome Trust charity, used a relatively new scientific technique of genome-wide association studies to compare the DNA of some 10,000 stroke patients with the DNA of 40,000 people who have not had a stroke. © independent.co.uk

Keyword: Stroke; Genes & Behavior
Link ID: 16348 - Posted: 02.06.2012

By MELISSA FAY GREENE In May 1999, Donnie Kanter Winokur, 43, a writer and multimedia producer, and her husband, Rabbi Harvey Winokur, 49, beheld the son of their dreams, the child infertility denied them. Andrey, a pale dark-eyed 1-year-old in a cotton onesie, held in a standing position by a caregiver, appeared in a short videotape recorded in a Russian orphanage. If the couple liked the little boy, they could begin the legal process of adopting him. They liked the little boy very much. Four months later, the Winokurs flew to Russia from their home in Atlanta to adopt Andrey, whom they renamed Iyal, and to adopt an unrelated little girl two days younger, whom they named Morasha. All four appear in another orphanage video: the beaming new parents on the happiest day of their lives, the toddlers passive in the arms of the strangers cradling and kissing them. In August 1999, the family arrived home to congratulations, gifts and helium balloons. “Sometime after their 3rd birthdays, our wonderful fairy tale of adopting two Russian babies began to show cracks,” said Donnie Winokur, who is now 55. She is pert and trim, with cropped brown hair and a pursed-lips, lemony expression softened by wearying experience. Unlike bright and cheery Morasha, Iyal grew oppositional and explosive. He was a sturdy, big-hearted boy with a wide and open face, shiny black hair in a bowl cut and a winning giggle. But, triggered by the sight of a cartoon image on a plastic cup, or an encounter with Morasha’s Barbie dolls, he threw tantrums that shook the house. He stuffed himself at mealtimes with an inexplicable urgency. In a fast-moving car, he unfastened his seat belt and tried to jump out. He awoke every night in a rage. “I had panic attacks in the night when I heard him coming,” she said. “I assumed everything was my fault, that I was not a good-enough mother.” © 2012 The New York Times Company

Keyword: Development of the Brain; Drug Abuse
Link ID: 16347 - Posted: 02.06.2012

Robert H. Lustig, Last September, the United Nations declared that, for the first time in human history, chronic non-communicable diseases such as heart disease, cancer and diabetes pose a greater health burden worldwide than do infectious diseases, contributing to 35 million deaths annually. This is not just a problem of the developed world. Every country that has adopted the Western diet — one dominated by low-cost, highly processed food — has witnessed rising rates of obesity and related diseases. There are now 30% more people who are obese than who are undernourished. Economic development means that the populations of low- and middle-income countries are living longer, and therefore are more susceptible to non-communicable diseases; 80% of deaths attributable to them occur in these countries. Many people think that obesity is the root cause of these diseases. But 20% of obese people have normal metabolism and will have a normal lifespan. Conversely, up to 40% of normal-weight people develop the diseases that constitute the metabolic syndrome: diabetes, hypertension, lipid problems, cardiovascular disease andnon-alcoholic fatty liver disease. Obesity is not the cause; rather, it is a marker for metabolic dysfunction, which is even more prevalent. The UN announcement targets tobacco, alcohol and diet as the central risk factors in non-communicable disease. Two of these three — tobacco and alcohol — are regulated by governments to protect public health, leaving one of the primary culprits behind this worldwide health crisis unchecked. Of course, regulating food is more complicated — food is required, whereas tobacco and alcohol are non-essential consumables. The key question is: what aspects of the Western diet should be the focus of intervention? © 2012 Nature Publishing Group,

Keyword: Obesity
Link ID: 16346 - Posted: 02.06.2012

By Daisy Yuhas This has been a big week in Alzheimer's news as scientists put together a clearer picture than ever before of how the disease affects the brain. Three recently published studies have detected the disease with new technologies, hinted at its prevalence, and described at last how it makes its lethal progress through the brain. The existence of two forms of Alzheimer's—early- and late-onset—has long baffled scientists. Of the estimated five million Americans who suffer from Alzheimer's, only a few thousand are diagnosed with an early-onset form of the affliction, which affects people before the age of 65. This rare early-onset form is thought to be hereditary and scientists have associated multiple genetic mutations contributing to its occurrence. Late-onset Alzheimer's, although more common, has been the bigger mystery. One variant of the APOE gene-—sometimes known as the Alzheimer's gene—is linked to the late-onset disease. But the APOE gene, unlike dominant early-onset genes, does not determine whether a person will ultimately have dementia. Now there's evidence that late-onset Alzheimer's has a genetic basis similar to that of early-onset Alzheimer's. By sequencing select genes associated with the latter, along with frontotemporal dementia, researchers at Washington University in Saint Louis and other institutions found that patients with late-onset Alzheimer's carry some of the same genetic mutations as those with the early-onset form. The evidence, published on Wednesday in PLoS ONE, bolsters the argument that the forms of Alzheimer's that appear at different life stages should be classified as the same disease. As to why the disease appears earlier in some cases, the scientists speculated that those patients diagnosed relatively early in life carry more genetic risk factors for the disease. © 2012 Scientific American,

Keyword: Alzheimers
Link ID: 16345 - Posted: 02.06.2012

By Katherine Harmon A car accident, a rough tackle, an unexpected tumble. The number of ways to bang up the brain are almost as numerous as the people who sustain these injuries. And only recently has it become clear just how damaging a seemingly minor knock can be. Traumatic brain injury (TBI) is no longer just a condition acknowledged in military personnel or football players and other professional athletes. Each year some 1.7 million civilians will suffer an injury that disrupts the function of their brains, qualifying it as a TBI. About 8.5 percent of U.S. non-incarcerated adults have a history of TBI, and about 2 percent of the greater population is currently suffering from some sort of disability because of their injury. In prisons, however, approximately 60 percent of adults have had at least one TBI—and even higher prevalence has been reported in some systems. These injuries, which can alter behavior, emotion and impulse control, can keep prisoners behind bars longer and increases the odds they will end up there again. Although the majority of people who suffer a TBI will not end up in the criminal justice system, each one who does costs states an average of $29,000 a year. With more than two million people in the U.S. currently locked up—and millions more lingering in the justice system on probation or supervision—the widespread issue of TBI in prison populations is starting to gain wider attention. © 2012 Scientific American

Keyword: Brain Injury/Concussion
Link ID: 16344 - Posted: 02.06.2012

By Antonio Damasio, Special to CNN (CNN) -- How do living organisms become conscious of what is happening to them and around them? How is it that I as well as you, reader of these words, can be conscious of our respective existences and of what is going on in our minds — in my case, ideas about how the brain generates consciousness, about the fact that I was asked to prepare this particular text for a specific deadline, along with the fact that I happen to be in Paris, at the moment, not Los Angeles, and that I am writing this on a cold January day. The biological mechanisms behind the phenomena of consciousness remain unclear although it is fair to say that recently our understanding has made remarkable progress. What are we are certain of understanding and where is it that our understanding fails? On the side of understanding, we can point to the process of sensory representation as an important part of consciousness. Most of what we are conscious of (conceivably all that we are conscious of) consists of representations of objects and events in the sensory modalities in which our brains trade, for example, vision, hearing, touching, smelling, taste, sensing the state of our body's interior. Mapping, in other words. Our brains, at all the levels of their organization, are inveterate makers of maps, simple and not so simple, and as far as I can gather, we only become conscious of the things and actions that the sensory systems help us map. CNN© 2012 Cable News Network.

Keyword: Consciousness
Link ID: 16343 - Posted: 02.06.2012

For the first time, scientists have tracked the activity, across the lifespan, of an environmentally responsive regulatory mechanism that turns genes on and off in the brain's executive hub. Among key findings of the study by National Institutes of Health scientists: genes implicated in schizophrenia and autism turn out to be members of a select club of genes in which regulatory activity peaks during an environmentally-sensitive critical period in development. The mechanism, called DNA methylation, abruptly switches from off to on within the human brain's prefrontal cortex during this pivotal transition from fetal to postnatal life. As methylation increases, gene expression slows down after birth. Epigenetic mechanisms like methylation leave chemical instructions that tell genes what proteins to make –what kind of tissue to produce or what functions to activate. Although not part of our DNA, these instructions are inherited from our parents. But they are also influenced by environmental factors, allowing for change throughout the lifespan. “Developmental brain disorders may be traceable to altered methylation of genes early in life,” explained Barbara Lipska, Ph.D., a scientist in the NIH’s National Institute of Mental Health (NIMH) and lead author of the study. “For example, genes that code for the enzymes that carry out methylation have been implicated in schizophrenia. In the prenatal brain, these genes help to shape developing circuitry for learning, memory and other executive functions which become disturbed in the disorders. Our study reveals that methylation in a family of these genes changes dramatically during the transition from fetal to postnatal life – and that this process is influenced by methylation itself, as well as genetic variability. Regulation of these genes may be particularly sensitive to environmental influences during this critical early life period.”

Keyword: Genes & Behavior; Development of the Brain
Link ID: 16342 - Posted: 02.04.2012

by Michael Marshall In one of philosophy's greatest facepalm moments, the normally quite intelligent Arthur Schopenhauer wrote that "women are defective in the powers of reasoning and deliberation". If you find it hard to believe that a well-educated and original thinker could hold such a view, his essay Of Women leaves no doubt about it. Oddly enough, he never married. However, Schopenhauer might have had a point, if only he had been a three-spined stickleback living in Lake Mývatn in Iceland. In this one population, the males have brains much larger than those of the females. They are the only species known where there is such a big disparity between the two sexes' brains. What's surprising is that there aren't more animals like this. Species differ enormously in brain size, after all, and males and females often have different lifestyles that make different demands on their brains. Why do these few fish buck the trend? Most three-spined sticklebacks live in the sea and only visit fresh water to breed, but others – like the Mývatn population – spend all their lives in fresh water. Behavioural scientists have studied them for decades because of their elaborate mating rituals. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior
Link ID: 16341 - Posted: 02.04.2012

Andy Coghlan, reporter Ever wondered what's going on in the brain of a mouse? Now brain cells have been captured sending and receiving signals in high resolution for the first time, essentially showing its brain in action. To make the tiniest anatomical details of neurons visible, Katrin Willig and her team at the Max Planck Institute for Biophysical Chemistry in Göttingen, Germany, gave mice an extra gene that generates a yellow glow. When their brains were viewed with a special microscope through a glass-sealed window in the skull, the signal junctions in neurons lit up. At these intersections, tiny spines sprout from longer branching fibers, called dendrites, and exchange signals by linking up with spines on neighbouring cells. The movie spans a 20 to 30 minute period, during which a live mouse was anaesthetised. The spines physically move and wobble at the top and base as they form and break connections with neighbouring spines. "There are always connections breaking and forming and it's the natural movement of the spine," says Willig. "It may be the mouse thinking". Brain cells have been imaged in live animals before, but the latest movie is the first to reveal parts of neurons in such fine detail - down to a resolution of 70 nanometers. © Copyright Reed Business Information Ltd.

Keyword: Brain imaging
Link ID: 16340 - Posted: 02.04.2012

by Andy Coghlan A simple, cheap procedure for repairing damaged nerves in the leg can help paralysed rats walk normally within a few days – a dramatic reduction in recovery time. Within minutes of the rats waking up after the operation, they began to move their damaged limb, and 98 per cent of them had recovered 60 to 70 per cent of leg function within two to four weeks. Conventional treatments would never give the rats such a level of recovery. After a nerve is severed it is important to reconnect the two ends as quickly as possible, because the disconnected section withers away after a few days of isolation. The usual technique is to stitch the loose ends together – but the body's own repair system can stand in the way of a successful mend. Earlier studies by George Bittner of the University of Texas at Austin and his team revealed where the fault lies: it's with the tiny spheres called vesicles that the body creates in the nerve stumps. "Normally, the vesicles would repair each of the two cut ends," says Bittner. But if they do so before the two ends can be brought back into contact, the vesicles simply seal the two stumps off, making it difficult to create a connection between them later on. If calcium is excluded from the injury site, though, the vesicles don't form and the body's self-repair process is aborted. This leaves the damaged nerve ends unsealed and in a better state for surgical reattachment. © Copyright Reed Business Information Ltd.

Keyword: Regeneration
Link ID: 16339 - Posted: 02.04.2012

Caitlin Stier, video intern The animation, created by Douglas Reedy of Dublin, Ohio, is based on a static illusion developed by Baingio Pinna from the University of Sassari in Italy and Lothar Spillmann from University Hospital Freiberg in Germany. The illusion is created due to the tilt of tiny squares that make up the outline of each circle. When they lean in opposite directions in alternating rings, a spiral is perceived. Tweaking their angle of inclination creates a spiral with a different orientation. The squares in a circle also alternate in colour, which seems to intensify the effect compared to the same pattern in a uniform colour. When the squares are shifted upright, the illusion vanishes. The effect is stronger at the edges of your gaze compared to the center, which gives insight into how it works. Alvin Raj from the Perceptual Science Group at MIT and his team have been investigating the phenomenon by testing a denser version of the illusion with more squares and rings. Raj suggests that the way we size up the image in our peripheral vision causes a calculation error that accounts for the perceived swirl. "Some of the strange things you see might be a by-product of your visual system losing some information and trying to make the best of it," explains collaborator Benjamin Balas of North Dakota State University. © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 16338 - Posted: 02.04.2012