by Jim Giles YOU are playing a video game, and your avatar is creeping into a haunted house at the dead of night. Suddenly, you freeze in your chair. Something is crawling up your back... Whether this idea appeals or not, researchers at Disney have made such sensations possible by inventing a system that fools players into thinking that objects are moving against their skin. Their brainchild, known as Tactile Brush, creates the illusion of being touched by anything from falling rain to crawling insects. One of the illusions the team employs is called apparent tactile motion. If two vibrating objects are placed close together on skin in quick succession, people often experience this as a single vibration moving between the two points of contact. In a related illusion, known as a phantom tactile sensation, a pair of stationary vibrations is sensed as a single stimulus placed in between the two. Apparent motion has been around since the early 1900s and phantom sensation since 1957, but this is the first time anyone has used them to provide precise tactile feedback. Ali Israr and Ivan Poupyrev at Disney Research Pittsburgh studied these illusions with the help of volunteers who sat in a chair backed by a grid of 12 vibrating coils. By operating the coils in different sequences and at different intensities, they worked out how to induce the sensations of apparent motion and also persuade the volunteers that they were feeling extra coils that didn't exist, which creates a more realistic effect. Israr and Poupyrev incorporated these two illusions into software that controlled the coils, which convinced the person sitting in the chair that shapes were moving across their back. © Copyright Reed Business Information Ltd.

Keyword: Pain & Touch
Link ID: 15369 - Posted: 05.26.2011

By Emily Chung, CBC News Blind people who navigate using clicks and echoes, like bats and dolphins do, recruit the part of the brain used by sighted people to see, a new study has found. While few blind people use echolocation — emitting a sound and then listening for the echo to get information about objects in the surroundings — some that do are so good at it that they can use the ability to hike, mountain bike and play basketball, said Melvyn Goodale, one of the co-authors of the study published Wednesday in PloS One. Daniel Kish, 43, went blind at the age of 13 months from retinoblastoma, the same eye cancer that affected the late Canadian musician Jeff Healey. Melvyn Goodale says Kish can't remember a time when he didn't echolocate, and seems to have taught himself at a very young age. "His parents say that when he was about 18 months old, they noticed he was making these clicking noises." Kish is now president of World Access for the Blind, a non-profit group based in Encino, Calif., that teaches echolocation or Flash Sonar, mobility and life skills to blind youth and adults. He has taught echolocation in many countries around the world, including Canada, the U.K., and India. Goodale, a psychology professor and the director of the Centre for Brain and Mind at the University of Western Ontario in London, Ont., said he was amazed by the abilities of the two blind men in the study. © CBC 2011

Keyword: Hearing; Vision
Link ID: 15368 - Posted: 05.26.2011

A man walks into a bar, catches a girl's eye, and immediately looks gloomy, moody and averts his eyes. The woman is overcome with sexual attraction. Not your usual love story but maybe a more realistic one. Turns out, a winning smile isn't the way to a woman's heart; men who swagger and look gloomy are more likely to set pulses raising. That's according to Jessica Tracy at the University of British Columbia, Canada, who asked more than 1000 adults to rate the sexual attractiveness of hundreds of photos of the opposite sex. The images showed men and women in various displays of happiness, with big smiles and puffed out chests or shameful glances, lowered heads and averted eyes. In an interview with UK newspaper The Daily Telegraph, co-author Alec Beall, also at British Columbia said: "We did not ask participants if they thought these targets would make a good boyfriend or wife - we wanted their gut reactions on carnal, sexual attraction." The study found that women were not attracted to smiling, happy men, preferring those who looked proud and powerful or moody and ashamed. In an interview with Reuters, Tracy said: "To the extent that men think that smiling is a good thing to do if they want to be found sexually attractive our findings suggest that's not the case." © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Emotions
Link ID: 15367 - Posted: 05.26.2011

By Rachael Rettner In a finding that won't surprise many mothers, a new study says breast-feeding may help secure the bond between mother and child. But the study also offers one explanation how: through a change in the mother's brain. The brains of breast-feeding mothers show a greater response to the sound of their babies' cries than do the brains of mothers who do not breast-feed, the study researchers say. This boost in brain activity is seen in brain regions associated with mothering behaviors. The finding adds to a growing list of the benefits of breast-feeding. Breast milk is considered the best source of nutrition for babies, and breast-feeding has been linked with better test scores and better health for the child later in life. The results suggest this brain activity facilitates greater sensitivity from the mother toward her infant as the baby begins to socially interact with the world, the researchers say. The study may help people to "recognize that it's important to support mothers who do want to breast-feed," said study researcher Pilyoung Kim, of the National Institute of Mental Health. © 2011 msnbc.com

Keyword: Attention; Sexual Behavior
Link ID: 15366 - Posted: 05.26.2011

By GRETCHEN REYNOLDS Why, as we grow older, do we forget where we parked the car, and could exercise sharpen our recall? Those questions, of considerable interest to any of us who possess a brain as well as those with cars, is motivating a series of remarkable new experiments by researchers at Johns Hopkins University and the Center for the Neurobiology of Learning and Memory at the University of California, Irvine, during which young and older volunteers watch pictures flash onto a screen, while the scientists watch their brains. Creating and accessing memories are complicated processes, with the specific physiological mechanisms still largely unknown. But, using brain scans, neuroscientists already have established that quite a bit of the electrical activity and blood flow associated with memory processing occurs in the dentate gyrus, a part of the brain within the hippocampus, a larger portion of the brain known to be involved with learning and thinking. So for their latest study, published this month in Proceedings of the National Academy of Sciences, the researchers used advanced magnetic resonance imaging machines to scan the dentate gyrus and other areas within the brains of people at the very moment that they were in the process of trying to create and store certain new memories. Specifically, the volunteers, wearing head sensors, were shown a series of pictures of everyday objects, like computers, telephones, pineapples, pianos and tractors, and asked to press a button indicating whether each object typically was found indoors or outside. © 2011 The New York Times Company

Keyword: Learning & Memory; Alzheimers
Link ID: 15365 - Posted: 05.26.2011

By SUSAN DOMINUS It was bedtime for Krista and Tatiana Hogan, and the 4-year-old twin girls were doing what 4-year-olds everywhere do at bedtime. They were stalling, angling for more time awake. Their grandmother, Louise McKay, who lives with the girls and their parents in Vernon, a small city in British Columbia, was speaking to them in soothing tones, but the girls resorted to sleep-deferring classics of the toddler repertory. “I want one more hug!” Krista said to their grandmother, and then a few minutes later, they both called out to her, in unison, “I miss you!” But in the dim light of their room, a night light casting faint, glowing stars and a moon on the ceiling, the girls also showed bedtime behavior that seemed distinctly theirs. The twins, who sleep in one specially built, oversize crib, lay on their stomachs, their bottoms in the air, looking at an open picture book on the mattress. Slowly and silently, in one synchronized movement, they pushed it under a blanket, then pulled it out again, then back under, over and over, seeming to mesmerize each other with the rhythm. Suddenly the girls sat up again, with renewed energy, and Krista reached for a cup with a straw in the corner of the crib. “I am drinking really, really, really, really fast,” she announced and started to power-slurp her juice, her face screwed up with the effort. Tatiana was, as always, sitting beside her but not looking at her, and suddenly her eyes went wide. She put her hand right below her sternum, and then she uttered one small word that suggested a world of possibility: “Whoa!” © 2011 The New York Times Company

Keyword: Attention; Development of the Brain
Link ID: 15364 - Posted: 05.26.2011

by Greg Miller Any would-be cure for Alzheimer’s disease or other brain disorder faces a daunting obstacle: the blood-brain barrier. This nearly impenetrable lining in the capillaries of the brain keeps out viruses and other bad guys, but it also denies entry to many potential drugs and other treatments. Now researchers have devised a way to trick one of the gatekeepers in this cellular defense system into escorting a potentially beneficial antibody into the brain. They report that their method can reduce levels of amyloid-β, the prime suspect in Alzheimer’s disease, by up to 50% in the brains of mice. The new strategy targets an enzyme that helps produce amyloid-β. Efforts to inhibit this enzyme, called β-secretase 1 (BACE1), with small molecule drugs have met with limited success so far, says Ryan Watts, a neurobiologist at the biotech company Genentech in South San Francisco, California, and one of the leaders of the new research. That’s partly because these drugs also interfere with other enzymes and cause side effects. A better strategy, Watts and colleagues reasoned, might be to target BACE1 with antibodies, immune system sharpshooters that can be designed to attack very specific molecular targets. There’s a big problem with that idea, though: antibodies are too big to cross the blood-brain barrier. To overcome that obstacle, the Genentech team tried a strategy first demonstrated about 20 years ago. It took advantage of the brain’s own mechanism for getting a necessary nutrient, iron, across the lining of endothelial cells that form the blood-brain barrier. Iron in the bloodstream is bound to a bulky molecule called transferrin. The endothelial cells have a receptor for transferrin that acts like a gatekeeper: When transferrin binds to a receptor on the blood side of the barrier, the endothelial cell transports it (and its iron cargo) to the other side and spits it out into the brain. © 2010 American Association for the Advancement of Science.

Keyword: Alzheimers
Link ID: 15363 - Posted: 05.26.2011

By Jason Castro With age and enough experience, we all become connoisseurs of a sort. After years of hearing a favorite song, you might notice a subtle effect that’s lost on greener ears. Perhaps you’re a keen judge of character after a long stint working in sales. Or maybe you’re one of the supremely practiced few who tastes his money’s worth in a wine. Whatever your hard-learned skill is, your ability to hear, see, feel, or taste with more nuance than a less practiced friend is written in your brain. But where, and how, exactly? What are the biological pen strokes that spell perceptual expertise? One classical line of work has tackled these questions by mapping out changes in brain organization following intense and prolonged sensory experience. In rough overview, many of these studies support a model of learning that might be in line with your intuition. Namely, the parts of the brain allotted for discrete sensory skills - hearing the note middle C, feeling a piano key on your thumb tip - expand when those skills are repeatedly called upon. Or, shamelessly dispensing with the biological details: practice makes bigger, and bigger means better. But don’t adopt that slogan quite yet. In a recent study from the University of Texas at Dallas, Dr. Michael Kilgard’s lab questions the tidy relationship between altered size and enhanced skill. Studying the auditory cortex of rats, they found that the expansion of a ‘skill-specific’ brain area with training is only short lived, even when changes in ability are long lasting. Instead of working like a muscle, where training adds size and size begets prowess, learning seems to involve some heavy duty trimming as well. In fact, if Kilgard’s theory of learning holds up, both the biology of learning and our experience of it share a common principle: skill must be culled from a string of mistakes. Lots of them. © 2011 Scientific American

Keyword: Learning & Memory
Link ID: 15362 - Posted: 05.26.2011

By Tina Hesman Saey NEW ORLEANS — Brain cells may be the latest victim of a bacterial bad guy already charged with causing ulcers and stomach cancer. Helicobacter pylori, a bacterium that lives in the stomachs of about half the people in the world, may help trigger Parkinson’s disease, researchers reported May 22 at a meeting of the American Society for Microbiology. Parkinson’s disease is a neurological disorder that kills dopamine-producing cells in some parts of the brain. People with the disease have trouble controlling their movements. About 60,000 new cases of the disease are diagnosed each year in the United States. Some previous studies have suggested that people with Parkinson’s disease are more likely than healthy people to have had ulcers at some point in their lives and are more likely to be infected with H. pylori. But until now those connections between the bacterium and the disease have amounted to circumstantial evidence. Now researchers are gathering evidence that may pin at least some blame for Parkinson’s disease on the notorious bacterium. Middle-aged mice infected with the ulcer-causing bacterium developed abnormal movement patterns over several months of infection, said Traci Testerman, a microbiologist at Louisiana State University Health Sciences Center in Shreveport. Young mice infected with the bacterium didn’t show any signs of movement problems. Testerman’s colleague, neuroscientist Michael Salvatore, found that Helicobacter-infected mice make less dopamine in parts of the brain that control movement, possibly indicating that dopamine-making cells are dying just as they do in Parkinson’s disease patients. © Society for Science & the Public 2000 - 2011

Keyword: Parkinsons
Link ID: 15361 - Posted: 05.24.2011

By Rachel Ehrenberg Chemists have synthesized in the lab a pain-relieving extract from the bark of a tropical shrub, paving the way for new drugs that lack the unwanted side effects of many opiate-based pain meds. There were hints that the compound, called conolidine, might be an effective pain medication, but studying the stuff has been tough. Isolating conolidine from the bark of the crepe jasmine plant returns pathetically meager yields, and the compound’s particular ringed structure has made lab synthesis difficult. Now researchers have overcome those difficulties and constructed conolidine in the lab from a cheap and readily available chemical building block. The molecular Tinkertoy-like construction is accomplished in just nine steps and yields large quantities of the compound, researchers report online May 23 in Nature Chemistry. Extracts from crepe jasmine, Tabernaemontana divaricata, have long been used in traditional medicine, but how this particular compound alleviates pain remains a puzzle. Despite its name, the plant isn’t closely related to scented jasmine. Instead it comes from a plant family rich in alkaloids, compounds that are often poisonous but have been commandeered as medicine for treating malaria, cancer and other maladies. Various tests designed to elucidate where and how conolidine does its stuff in mice suggest that the compound doesn’t hit the same cellular machinery as the classic pain-relieving alkaloids codeine and morphine. Yet conolidine does lessen both acute pain and pain from inflammation, the team from Scripps Research Institute’s campus in Jupiter, Fla., reports. The compound might be hitting one unknown cellular target or perhaps several, says organic chemist Glenn Micalizio, a coauthor of the new work. © Society for Science & the Public 2000 - 2011

Keyword: Pain & Touch
Link ID: 15360 - Posted: 05.24.2011

By Jesse Bering It may seem to you that, much like their barnyard animal namesake, men’s reproductive organs the world over participate in a mindless synchrony of stiffened salutes to the rising sun. In fact, however, such "morning wood" is an autonomic leftover from a series of nocturnal penile tumescence (NPT) episodes that occur like clockwork during the night for all healthy human males—most frequently in the dream-filled rapid eye movement (REM) periods of sleep from which we’re so often rudely awakened in the A.M. by buzzers, mothers, or others. For those with penises, you may be surprised to learn how frequently your member stands up while the rest of your body is rendered catatonic by the muscular paralysis that keeps you from acting out your dreams. (And thank goodness for that. Carlos Schenck and his colleagues [pdf] from the University of Minnesota Regional Sleep Disorders Center describe the case of a 19-year-old with sleep-related dissociative disorder crawling around his house on all fours, growling, and chewing on a piece of bacon—he was ‘dreaming’ of being a jungle cat and pouncing on a slab of raw meat held by a female zookeeper.) Scientists have determined that the average 13- to 79-year-old penis is erect for about 90 minutes each night, or 20 percent of overall sleep time. With your brain cycling between the four sleep stages, your "sleep-related erections" appear at 85-minute intervals lasting, on average, 25 minutes. (It’s true; they used a stopwatch.) I didn’t come upon any evolutionary theories or a proposed "adaptive function" of NPT, but we do know that it’s not related to daytime sexual activity, it declines (no pun intended) with age, and it’s correlated positively with testosterone levels. Females similarly exhibit vaginal lubrication during their REM-sleep, presumably with many dreaming of erect penises. Now, you may not think that such tedious biological details would be fodder for a moral quandary, but you underestimate our species’ massive confusion when it comes to understanding how its coveted free will articulates with its genitalia. © 2011 Scientific American

Keyword: Sleep; Sexual Behavior
Link ID: 15359 - Posted: 05.24.2011

By Larry Greenemeier Nanoparticles have been investigated in recent years as tools for defending the brain against neurotoxic proteins that may contribute to the onset of several different neurodegenerative disorders including Alzheimer's disease. Such proteins, in particular amyloid-beta peptides, are thought to play a role depositing fibrous plaques on the brain that damage synapses (the contact points between neurons) and lead to a decline in cognitive capabilities. During the onset of Alzheimer's, amyloid beta collects in the brain centers that form new memories. As the disease progresses, these toxic protein fragments block neurotransmitters from reaching receptors on neurons. The promise of nanoparticles is that their capacity to mimic some biological functions as well as penetrate the blood–brain barrier will enable them to stop the growth of neuron-blocking fibrils better than drug compounds that might contain some variation of short peptides, antibodies or proteins—such as human serum albumin (HSA) protein. (There currently are no anti-Alzheimer's drugs on the market.) Whereas such compounds have been shown to interfere with fibril formation, researchers are hoping that inorganic nanoparticles can do so more effectively. Although the nanotech approach has great potential, the challenges are many, including finding a nanoparticle material that is effective yet also biocompatible and nontoxic. Another source of controversy: some nanoparticles that have been studied, including quantum dots and carbon nanotubes, seem to actually promote or accelerate fibrillation rather than prevent it. © 2011 Scientific American,

Keyword: Alzheimers
Link ID: 15358 - Posted: 05.24.2011

Crossing your arms across your body after injury to the hand could relieve pain, researchers suggest. The University College London team, who undertook a proof-of-concept study of 20 people, say the brain gets confused over where pain has occurred. In the journal Pain, they suggest this is because putting hands on the "wrong" sides disrupts sensory perception. Pain experts say finding ways of confusing the brain is the focus of many studies. The team used a laser to generate a four millisecond pin-prick of pain to participants' hands, without touching them. Each person ranked the intensity of the pain they felt, and their electrical brain responses were also measured using electroencephalography (EEG). The results from both participants' reports and the EEG showed that the perception of pain was weaker when the arms were crossed over the "midline" - an imaginary line running vertically down the centre of the body. Dr Giandomenico Iannetti, from the UCL department of physiology, pharmacology and neuroscience, who led the research, said: "In everyday life you mostly use your left hand to touch things on the left side of the world, and your right hand for the right side of the world. BBC © 2011

Keyword: Pain & Touch
Link ID: 15357 - Posted: 05.24.2011

By RICHARD A. FRIEDMAN, M.D. No sooner had Dominique Strauss-Kahn been arrested on sexual assault charges in New York than a parade of psychiatrists stepped forward to offer their expert opinion in the news media. Mr. Strauss-Kahn, who subsequently resigned as chief of the International Monetary Fund, will experience “a terrible grief because he is in prison,” said one. Another offered that he would have “terrible mourning” for “the loss of social status, image and glory.” Of course, it’s only natural for the media to seek comment from experts. But as a psychiatrist, I cringe at statements like these, for they cross an ethical line that goes back to a presidential campaign nearly half a century ago. Just before the 1964 election, a muckraking magazine called Fact decided to survey members of the American Psychiatric Association for their professional assessment of Senator Barry Goldwater of Arizona, the Republican nominee against President Lyndon B. Johnson. Ralph Ginzburg, the magazine’s notoriously provocative publisher, had heavily advertised the issue in advance, saying it would call Mr. Goldwater’s character into question. A.P.A. members were asked whether they thought Mr. Goldwater was fit to be president and what their psychiatric impressions of him were. It was not American psychiatry’s finest hour. © 2011 The New York Times Company

Keyword: Schizophrenia; Depression
Link ID: 15356 - Posted: 05.24.2011

By SEAN B. CARROLL I am not a big fan of reality TV, but I will confess that I am a loyal viewer of the Discovery Channel’s “Deadliest Catch” series. The show chronicles the adventures of the crews of several crabbing boats of the Alaskan fleet as they pursue red king crabs on the Bering Sea. What fascinates me, and I suspect other viewers, is the vicarious experience of watching the crews working for long stretches in unimaginable conditions. I know that this landlubber would not last an hour on any boat as it heaved in 30-foot seas, let alone while hauling 800-pound crab pots on an ice-covered deck, in 60-mile-an-hour winds, for 20 to 30 hours straight. That’s definitely not for me. My crab-catching is limited to plucking hermit crabs the size of golf balls off the sands of some quiet Florida beach in 80-degree weather. One might think that not only is there no comparison between my beachcombing and the dangerous business of Alaska crab fishing, but that the two kinds of crabs involved have very little in common. The typically diminutive hermit crabs have to contort their bodies into abandoned snail shells, while the four- to nine-pound red king crabs, the largest of the more than 100 species of king crabs, freely prowl the ocean bottom in search of worms, clams, mussels, starfish and other prey. Looking at those monsters of the deep, safely steamed on your plate at Red Lobster, one might think that such tasty beauties would be more closely related to other crabs on the menu, like stone crabs, than to the largely inedible hermit crabs. © 2011 The New York Times Company

Keyword: Evolution
Link ID: 15355 - Posted: 05.24.2011

by Sara Reardon The pianist's languid solo entwines itself with the smoke and the muffled laughter from the bar. Like a shadow, the musician's fingers glide effortlessly across the keys, and he has no sheet music in front of him. Has he memorized the piece, or is he making it up as he goes along? It’s almost impossible to tell, but if you're a jazz musician and can imagine yourself playing the music, your brain’s emotional centers might help you answer this question, a new study suggests. The ability to distinguish planned actions from spontaneous ones helps us judge whether a person is deliberately lying and might also help us value creativity. But it’s unclear how the brain makes these judgment calls, especially when it has little context to work with. To study how musicians judge spontaneity, psychologists Annerose Engel and Peter Keller of the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany, recorded six jazz pianists as each one played improvised jazz over a backing track. Then the researchers transcribed the pieces, handed out the sheet music, had the pianists practice until they could replicate their colleagues’ improv perfectly, and recorded their performances. A computer analysis of the recordings showed that each improvised piece was more erratic in its loudness and speed than its rehearsed counterpart. So a machine could tell the difference between the improvised solos and the rehearsed reproductions. But could another musician? When a second set of 22 jazz musicians listened to all the improvised and rehearsed pieces in a random order, they could correctly guess which was which only about 55% of the time—only slightly better than chance—the researchers report in Frontiers in Psychology this month. However, the guessers who rated themselves in a questionnaire as more “empathetic” were better at picking out the improvisations. Similar correlations held true of those who had played with bands, as opposed to playing only as soloists. © 2010 American Association for the Advancement of Science.

Keyword: Emotions; Hearing
Link ID: 15354 - Posted: 05.24.2011

Sperm whales speak in distinct regional dialects that appear closely linked to different "cultural groups," a Canadian researcher says. "The animals in the Caribbean sound different than the animals in the Pacific — even the Gulf of Mexico, which is right beside the Caribbean," said Shane Gero, a researcher at Dalhousie University in Halifax. "In a lot of ways, that's very similar to us. We can identify someone from the U.K. versus Canada because they say 'lorry' and not 'truck.'" Sperm whales from many different regions meet in some "multicultural" areas of the ocean but tend to associate with whales that speak their own dialect, Gero told CBC's Quirks & Quarks in an interview that airs Saturday. "Their society really is divided based on culture," he said. "Animals that have different dialects behave differently. They feed on different things. They raise their babies differently." Gero has been studying sperm whales in the Caribbean for his PhD thesis. He and his collaborators in Canada and Scotland have been trying to decode sperm whale language by recording the voices of pairs of animals talking to one another and noting differences among the sounds they make. Female sperm whales spend all year in family groups in subtropical regions of the ocean, while males roam all over the world. When two whales encounter each other, they make patterns of clicks called codas. © CBC 2011

Keyword: Animal Communication; Evolution
Link ID: 15353 - Posted: 05.21.2011

By Deborah Kotz, Binge drinking has been named by university presidents as the single biggest problem on college campuses, responsible for accidental injuries, unintended pregnancies, date rapes, and alcohol poisoning. If that's not enough to stop students from drinking excessively, perhaps they'll be influenced by this new Spanish study: College students who binge drink have a slightly lowered ability to remember lists of words when the alcohol wears off compared with those who don't binge drink. While it's not clear from the study if binge drinking actually caused these memory defects, this and previous research "supports that possibility," says Aaron White, a college drinking prevention researcher at the US National Institute on Alcohol Abuse and Alcoholism who is familiar with the study. And that could mean that students, say, have trouble remembering a list of dates for history class or an equation in math class. How many drinks is a binge? Five or more servings of alcohol in a day for a man and four or more servings for a woman, according to Harvard researchers who studied alcohol's effects on different genders. A serving of alcohol is defined as 12 ounces of beer, 8 ounces of malt liquor, 5 ounces of wine, or 1.5 ounces, or a shot, of spirits or liquor (rum, vodka, whiskey). "This is not about getting drunk one time but binging with some regularity," says White. "The strongest evidence we have suggests that those at greatest risk for memory impairment drink heavily and often -- often to the point of developing withdrawal symptoms." © 2011 NY Times Co.

Keyword: Drug Abuse; Learning & Memory
Link ID: 15352 - Posted: 05.21.2011

Fix your eyes on the red dot in the animation above. As the circular pattern turns, it may appear to jump backwards but the skipping motion is all in your mind. What's actually happening in this illusion, created by Mark Wexler from Paris Descartes University, France, is that the random lines that make up the circle are suddenly replaced by a different pattern. In the video above, you can see a few variations of the illusion that demonstrate that the effect is perceived regardless of the rotation's direction. "The jumps can also be seen if white lines are suddenly made black and vice versa," says Wexler: "If the lines are randomised again for a slightly longer duration, the jumps seem to go further back." There is currently no known explanation for this brain trick. But Wexler thinks it's a type of motion after-effect, with two main differences. Typically, the illusory motion is much slower than the main one but in this case it's extremely fast. In addition, many observers reported a change in amplitude accompanying the switch whereas motion after-effects don't usually involve a change in position. By making the change of pattern occur more slowly, Wexler found that many people perceived a net motion in the opposite direction to the original rotation. He says: The illusory motion is more pronounced than the (real) motion we put in: a perceptual, perpetual motion machine! © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 15351 - Posted: 05.21.2011

by Miguel Nicolelis ANSWER quickly: what links the internet, the stock market, democratic elections, a perfect soccer play, the big bang theory, the frescoes of the Sistine Chapel and the iPad? Most people guess that the only possible link is they are all created by humans. While this is technically correct, it doesn't credit the true creator of such macro structures and exquisite tools: the human brain. As well as the almost infinite catalogue of artificial tools and beliefs that rule most of our lives, our cherished social, political, and economic systems also blossom as by-products of the incessant electrochemical storms brewed by the brain circuits formed by billions of interconnected cellular elements. These neurons make up an organic structure so majestic and mysterious that its only true rival in complexity and power is the cosmos that hosts us all. For the past 200 years or so, neuroscientists have been obsessed with understanding how the roots of all our glory and disgrace, as individuals and as a species, emerge from waves of neuronal electrical activity that propagate through a neural ocean. Just how do they morph into what is conventionally known as thinking, the main currency of our primate brains? In the early 19th century, Franz Joseph Gall in Germany and Thomas Young in Britain pioneered the modern age of neuroscience with opposing theories of how the brain worked. Gall's phrenology proposed that brain functions were localised in particular spatial territories of the human cortex, the most superficial part of the nervous system, just beneath the skull. Gall and his disciples made a living by claiming to ascertain the key personality traits of his patients by palpating the bumps on their heads. © Copyright Reed Business Information Ltd.

Keyword: Robotics
Link ID: 15350 - Posted: 05.21.2011