By Science News Staff Cats look to the edge Cats may not seem like planners, but they do look ahead when walking. Three adult cats with magnetic devices strapped to their heads walked across slats, giving scientists the first data on where cats look when they walk. The cats looked a few rungs ahead at the edges of the slats, found Trevor Rivers, now at Bowdoin College in Brunswick, Maine. "They don't say 'I want to step right there.' They are looking at where not to be," Rivers said November 14. — Tina Hesman Saey Moms protected from stress New mothers might not believe it, but being a mom may help protect against some negative consequences of stress. Tracey Shors of Rutgers University in Piscataway, N.J., and colleagues tested the effect of stress on female rats' ability to learn to blink when they hear a particular sound. Stress renders virgin female rats incapable of learning the task. But mothers, including virgin female foster mothers, are protected against learning deficits. And the protection lasts a lifetime, Shors said November 13. The researchers don't yet know what about motherhood is responsible for the protection. — Tina Hesman Saey Vitamin D is good for aging brain Vitamin D may keep mental gears greased during middle age. Middle-aged rats fed high, low or standard amounts of vitamin D performed similarly on memory tests in which the animals had to find a submerged platform in a water tank, Nada Porter of the University of Kentucky and colleagues found. But when the rats had to learn a new location, "the high vitamin D guys just made a beeline" for the new spot while rats in the other two groups swam aimlessly, Porter said during a presentation November 12. — Tina Hesman Saey © Society for Science & the Public 2000 - 2011

Keyword: Miscellaneous
Link ID: 16044 - Posted: 11.17.2011

by Carl Zimmer Neuroscientists these days regularly make spectacular discoveries about how the brain gets sick. They know much more today about brain cancer, Alzheimer’s disease, Parkinson’s disease, and a host of other neurological disorders than they did just a few years ago. And from such discoveries come all sorts of encouraging possibilities for treating or even curing these diseases. If 
only we could break down some rogue protein or bind a drug to 
a troublesome receptor, it seems as if all would be well. There’s just one little hitch: Even if scientists invented the perfect cure, they 
probably couldn’t get it into the brain to do its work. Drugs can cross easily out of the bloodstream into most organs of the body. The brain is a glaring exception because it is protected by an intricate shield known as the blood-brain barrier. The blood-brain barrier serves a vital function: It keeps our brains free for the most part from infections or toxins that find their way into other parts of the body. Unfortunately, the brain’s barrier also gets in the way of most medicines that could help heal it. Neurologists sometimes open up the skull and inject drugs directly. That brute-force approach can work in an emergency, but it is hardly a practical solution for people who need to take drugs every day at home. There is reason for hope that the blood-brain barrier will not block medicine’s path forever, though. Some scientists are working on ways to penetrate it—either by sneaking drugs through the barrier or by temporarily opening channels through which the drugs can pass. © 2011, Kalmbach Publishing Co.

Keyword: Miscellaneous
Link ID: 16043 - Posted: 11.17.2011

When the Society for Neuroscience gets together for their annual meeting each year, a city of scientists suddenly forms for a week. This year’s meeting has drawn 31,000 people to the Washington DC Convention Center. The subjects of their presentations ranged from brain scans of memories to the molecular details of disorders such as Parkinson’s and autism. This morning, a scientist named Svante Paabo delivered a talk. Its subject might make you think that he had stumbled into the wrong conference altogether. He delivered a lecture about Neanderthals. Yet Paabo did not speak to an empty room. He stood before thousands of researchers in the main hall of the convention center. His face was projected onto a dozen giant screens, as if he were opening for the Rolling Stones. When Paabo was done, the audience released a surging crest of applause. One neuroscientist I know, who was sitting somewhere in that huge room, sent me a one-word email as Paabo finished: “Amazing.” You may well know about Paabo’s work. In August, Elizabeth Kolbert published a long profile in the New Yorker. But he’s been in the news for fifteen years. I’ve also followed his work since the mid-1990s, having written about pieces of Paabo’s work in newspapers, magazines, and books. But it was bracing to hear him bring together the scope of his research in an hour–including new experiments that Paabo’s colleagues are presenting at the meeting. He has changed the way scientists study human evolution. Along with fossils, they can now study genomes that belonged to people who died 40,000 years ago. They can do experiments to see how some of those individual genes helped to make us human. During his talk, Paabo used this new research to sketch out a sweeping vision of how our ancestors evolved uniquely human brains as they swept out across the world. © 2011, Kalmbach Publishing Co.

Keyword: Evolution
Link ID: 16042 - Posted: 11.17.2011

The thought of being trapped in a lifeless body, unable to communicate, is a terrifying prospect. It happened to Roy Hayim, a surveyor, who became dangerously ill after eating an airline meal. Mr Hayim contracted botulism, a rare bacterial infection. He was left paralysed and blind for several days, although he could hear everything that was happening - even a news report on the radio which said he was fighting for his life. After about 10 days Mr Hayim was able to move his thumb and for the next eight months he used this method to communicate with his wife Caroline and hospital staff. He spent nearly a year in hospital but made a full recovery. This all happened 20 years ago, but Roy remembers it vividly. Awareness "I felt trapped, afraid and terribly concerned. I didn't know whether I would survive or not," he said. I went to meet Mr Hayim to get his insight on what it is like to be unable to communicate. My visit was prompted by research in the Lancet which shows that electroencephalography - EEG - can be used to communicate with some patients who were diagnosed as vegetative. BBC © 2011

Keyword: Attention; Robotics
Link ID: 16041 - Posted: 11.15.2011

By Laura Sanders WASHINGTON — Magic tricks prey on people’s subpar powers of perception, but new work finds that the brain has tricks of its own up its sleeve: People notice more than they think. In the research, presented November 12 at the annual meeting of the Society for Neuroscience, Luis Martinez of CSIC- Miguel Hernandez University in Spain and colleagues amazingly “read minds” with the Princess Card Trick, invented by magician Henry Hardin in 1905. Volunteers mentally chose a playing card from a panel of six cards, which then disappeared. When a second group of cards appeared, the researchers had miraculously figured out which card a person had in mind and removed it. Few people caught the trick: All the cards in the second set were different, not just the card people had chosen. A few seconds after viewing the two panels of cards, participants were asked which of two new cards was present in the first panel. None of the volunteers could consciously recall which card was present. Despite these avowals of ignorance, when forced to choose, people got the right answer about 80 percent of the time. “People say they don’t know, but they do,” Martinez said. “The information is still there, and we can use it unconsciously if we are forced to.” To see whether this unconscious knowledge works for objects other than cards, Martinez and his colleagues performed a similar experiment with pictures of men’s faces. A similar kind of visual short-term memory helped people choose which face they had seen before, even when volunteers didn’t perceive that they knew the correct answer. © Society for Science & the Public 2000 - 2011

Keyword: Attention
Link ID: 16040 - Posted: 11.15.2011

by Catherine de Lange How kind you are could be affected by a change in a single gene. What's more, others can tell if you have the gene even if you don't speak a single word. There are several variations of the gene that codes for the receptor for the hormone oxytocin. Aleksandr Kogan at the University of Toronto, Canada, and colleagues wanted to check whether these variations influence behaviour, since high levels of oxytocin are believed to make people more sociable. Kogan's team asked 116 volunteers to watch 23 silent videos that were 20 seconds long. Each showed a person's response to their partner telling them a story of personal suffering. The volunteers were asked to rate how kind and trustworthy the person in the video appeared to be. People with the so-called GG version of the oxytocin receptor gene were judged to be kinder than those with GA or AA versions. The difference? Those with GG variations used significantly more non-verbal empathetic gestures in their storytelling such as smiling and nodding. Kogan expects that this is what influenced the observers' judgements. Further research will be needed to identify the effect of the different genetic variations on oxytocin levels. Journal reference: Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.111265810 © Copyright Reed Business Information Ltd.

Keyword: Hormones & Behavior; Emotions
Link ID: 16039 - Posted: 11.15.2011

By JAMES GORMAN NEW IBERIA, La. — In a dome-shaped outdoor cage, a dozen chimpanzees are hooting. The hair on their shoulders sticks straight up. “That’s piloerection,” a sign of emotional arousal, says Dr. Dana Hasselschwert, head of veterinary sciences at the New Iberia Research Center. She tells a visitor to keep his distance. The chimps tend to throw pebbles — or worse — when they get excited. Chimps’ similarity to humans makes them valuable for research, and at the same time inspires intense sympathy. To research scientists, they may look like the best chance to cure terrible diseases. But to many other people, they look like relatives behind bars. Biomedical research on chimps helped produce a vaccine for hepatitis B, and is aimed at one for hepatitis C, which infects 170 million people worldwide, but there has long been an outcry against the research as cruel and unnecessary. Now, because of a major push by advocacy organizations, a decision to stop such research in the United States could come within a year. As it is, the United States is one of only two countries that conduct invasive research on chimpanzees. The other is the central African nation of Gabon. “This is a very different moment than ever before,” said Wayne Pacelle, president and chief executive of the Humane Society of the United States. “Now is the time to get these chimps out of invasive research and out of the labs.” © 2011 The New York Times Company

Keyword: Animal Rights
Link ID: 16038 - Posted: 11.15.2011

By RONI CARYN RABIN Jan Brehm lives in rainy Portland, Ore., and she has always dreaded this time of year, when the days get shorter, her mood plummets and all she wants to do is crawl into bed and eat cookie dough. She and her husband were considering moving to Arizona or Colorado — anywhere with more sunlight — until last year, when she purchased her first artificial light box. She keeps it on her desk, and every morning, before she starts her workday, she turns it on and basks in the bright artificial light for about 30 to 45 minutes while catching up on her reading. The boxes come in different sizes; Ms. Brehm’s is about 15 inches high and 12 inches wide, and she keeps it a foot or more from her face. “I still say to myself, ‘It’s a dark crummy day,’ when the clouds roll in,” Ms. Brehm, a 57-year-old actress and entrepreneur, said. “The difference is, I don’t feel like going back to bed.” For the millions of Americans who suffer from mild to severe winter blues — a condition called seasonal affective disorder, or S.A.D. — bright-light therapy is the treatment of choice, with response rates comparable with those of antidepressants. “Your natural clock is usually longer than 24 hours, and you need light in the morning to set it and keep it on track,” said Dr. Alfred Lewy, a professor of psychiatry at Oregon Health and Science University and an expert on seasonal depression and light therapy. © 2011 The New York Times Company

Keyword: Depression; Biological Rhythms
Link ID: 16037 - Posted: 11.15.2011

By EDDY NAHMIAS Is free will an illusion? Some leading scientists think so. For instance, in 2002 the psychologist Daniel Wegner wrote, “It seems we are agents. It seems we cause what we do… It is sobering and ultimately accurate to call all this an illusion.” More recently, the neuroscientist Patrick Haggard declared, “We certainly don’t have free will. Not in the sense we think.” And in June, the neuroscientist Sam Harris claimed, “You seem to be an agent acting of your own free will. The problem, however, is that this point of view cannot be reconciled with what we know about the human brain.” Such proclamations make the news; after all, if free will is dead, then moral and legal responsibility may be close behind. As the legal analyst Jeffrey Rosen wrote in The New York Times Magazine, “Since all behavior is caused by our brains, wouldn’t this mean all behavior could potentially be excused? … The death of free will, or its exposure as a convenient illusion, some worry, could wreak havoc on our sense of moral and legal responsibility.” Indeed, free will matters in part because it is a precondition for deserving blame for bad acts and deserving credit for achievements. It also turns out that simply exposing people to scientific claims that free will is an illusion can lead them to misbehave, for instance, cheating more or helping others less. [1] So, it matters whether these scientists are justified in concluding that free will is an illusion. © 2011 The New York Times Company

Keyword: Attention
Link ID: 16036 - Posted: 11.15.2011

By Hannah Tepper These days, we seem to be living in a new golden age of choice. One moment we’re tweeting, the next we are changing our profile picture. We get a hankering for hummus and next thing we know, it’s off to Yelp the nearest falafel place. In every choice and action we make, online or off, we have the unique sense that we are in control. This is what it feels like to have free will. But many neuroscientists have maintained a long-standing opinion that what we experience as free will is no more than mechanistic patterns of neurons firing in the brain. Although we feel like free agents contemplating and choosing, they would argue that these sensations are merely an emotional remnant that brain activity leaves in its wake. If these neuroscientists are right, then free will isn’t worth much discussion. Michael S. Gazzaniga, professor and director of the SAGE Center for the Study of the Mind at the University of California at Santa Barbara, seriously disagrees. In his new book out this month, “Who’s In Charge: Free Will and the Science of the Brain,“ Gazzaniga uses a lifetime of experience in neuroscientific research to argue that free will is alive and well. Instead of reducing free will to the sum of its neurological parts, he argues that it’s time for neuroscience to consider free will as a scientific fact in its own right. Through fascinating examples in chaos theory, physics, philosophy and, of course, neuroscience, Gazzaniga makes this interesting claim: Just as you cannot explain traffic patterns by studying car parts, neuroscience must abandon its tendency to reduce macro-level phenomena like free will to micro-level explanations. Along the way he provides fascinating and understandable information from brain evolution to studies involving infants and patients with severed brain hemispheres (split-brain patients). The final chapters of the book consider neuroscience as it implicates social responsibility, justice and how we treat criminal offense. © 2011 Salon Media Group, Inc.

Keyword: Attention
Link ID: 16035 - Posted: 11.15.2011

By Tina Hesman Saey WASHINGTON — For young people, snoozing means big gains in memory. But in older folks some of sleep’s memory-boosting abilities are erased, a new study finds. Sleep has been shown in a wide variety of studies to increase people’s ability to recall words and objects and to improve physical skills. But that boost may be available only to the young, Lauri Kurdziel and Rebecca Spencer of the University of Massachusetts Amherst reported November 13 at the Society for Neuroscience annual meeting. Previously, the researchers had shown that a night of sleep improved young people’s ability to learn a series of button presses similar to playing a piano. Adults in the over-50 age group didn’t get a bump in performance from sleeping. But that difference may have been due to older folks’ slower reaction times. A new study, though, suggests that it’s sleep’s memory benefits that are reduced with age. Kurdziel and Spencer had a group of 18- to 30-year-olds and a group of 50- to 80-year-olds learn a sequence of colored doors that would lead them through 10 virtual rooms. The researchers then tested the participants’ memories 12 hours later, either in the evening of the same day or after a night of sleep. Young people who took the test after being awake all day made about 10 errors on average, but a night of sleep nearly halved the number of mistakes. In the over-50 group, a night of sleep didn’t help. The people made just as many errors after sleeping all night as they did if they took the test after being awake for 12 hours. © Society for Science & the Public 2000 - 2011

Keyword: Sleep; Learning & Memory
Link ID: 16034 - Posted: 11.14.2011

By Nathan Seppa ORLANDO, Fla. — Women who report having had forced sex at a young age have an elevated risk of heart disease as adults. Some of the higher cardiac risk is traceable to behavioral and lifestyle factors, but much of it goes unexplained, researchers reported October 13 at a meeting of the American Heart Association. “This tells us that the immediacy of the tragedy is being followed by risk that may have implications in later life,” says Clyde Yancy, a cardiologist at Northwestern University School of Medicine in Chicago who was not involved in the study. “That’s very disconcerting.” The researchers analyzed data from more than 67,000 women who were age 25 to 42 when they volunteered to participate in a large healthcare study in 1989. Questionnaire responses revealed that 11 percent answered yes when asked whether they had had “forced sexual activity” during childhood or adolescence, the years through age 17. After following the women in adulthood for 18 years and tabulating any heart problems they encountered in that time, the scientists were able to discern that women who had had at least one episode of forced sexual contact when young faced roughly a 56 percent greater risk in cardiovascular disease than did women with no history of childhood sex abuse. © Society for Science & the Public 2000 - 2011

Keyword: Stress; Development of the Brain
Link ID: 16033 - Posted: 11.14.2011

By Laura Sanders WASHINGTON — Like the fictional detective Carrie Wells on the TV show Unforgettable, some real-life people can remember every day of their lives in detail. Those superrememberers have more bulk in certain parts of their brains, possibly explaining the remarkable ability to recall minutiae from decades ago, researchers said November 13 at the annual meeting of the Society for Neuroscience. One brain region involved in such incredible recall has been implicated in obsessive-compulsive disorder, hinting that OCD and superior memory might have a common architecture in the brain. Scientists have long studied people with memory deficits, but there haven’t been many studies on people with exceptional memories. “Looking at memory from a deficit gave us a lot of insight into memory,” said study coauthor Aurora LePort of the University of California, Irvine. “Looking at memory from a superior perspective gives us a new tool. It may just broaden our knowledge and ability to know what’s going on.” In 2006, UC Irvine neuroscientist Larry Cahill and collaborators published a report on a woman who could remember detailed accounts of her life. Cahill and colleagues then began hearing from many people who claimed to have extraordinary memories. After sifting through and eliminating the impostors, the team was left with 11 people who scored off the charts for autobiographical memory. These people could effortlessly remember, for instance, what they were doing on November 2, 1989, and could also tell you that it was a Thursday. “They’re not going home and saying ‘OK, let me write down what I did today and memorize it,’ ” LePort said. © Society for Science & the Public 2000 - 2011

Keyword: Learning & Memory; Brain imaging
Link ID: 16032 - Posted: 11.14.2011

By Laura Sanders WASHINGTON — Tricking people with severe arthritis into thinking their sore hand is healthy dampens their pain, a new study suggests. If confirmed, the preliminary results may offer a powerful and inexpensive way to fight persistent arthritis pain. “The results are really exciting,” said pain expert Candy McCabe of the University of Bath in England, who wasn’t involved in the study. “The whole thing is visual trickery, but the science behind it is strong.” The new technique, described November 12 at the annual meeting of the Society for Neuroscience, is a type of mirror therapy, in which the illusion of a pain-free hand makes people feel better. So far, visual feedback from mirrors has been shown to reduce some kinds of chronic pain, notably the pain felt in “phantom limbs” of amputees. But it was unclear whether mirror therapy could reduce pain produced by arthritic, inflamed joints. In the new work, Laura Case, V.S. Ramachandran and colleagues at the University of California, San Diego recruited eight volunteers who had osteo- or rheumatoid arthritis. The volunteers saw a reflection of Case’s healthy hand in the same place where their sore hand should have been. To strengthen the sensation of the hand-swap, the researchers simultaneously touched Case’s hand and the volunteer's hand, creating a unified sensation of seeing and feeling the touch. The volunteer then mimicked a series of slow hand movements made by the researcher. © Society for Science & the Public 2000 - 2011

Keyword: Pain & Touch
Link ID: 16031 - Posted: 11.14.2011

By Neil Bowdler Health reporter, BBC News An international study has linked an industrial solvent to Parkinson's disease. Researchers found a six-fold increase in the risk of developing Parkinson's in individuals exposed in the workplace to trichloroethylene (TCE). Although many uses for TCE have been banned around the world, the chemical is still used as a degreasing agent. The research was based on analysis of 99 pairs of twins selected from US data records. Parkinson's can result in limb tremors, slowed movement and speech impairment, but the exact cause of the disease is still unknown, and there is no cure. Research to date suggests a mix of genetic and environmental factors may be responsible. A link has previously been made with pesticide use. 'Significant association' The researchers from institutes in the US, Canada, Germany and Argentina, wanted to examine the impact of solvent exposure - specifically six solvents including TCE. They looked at 99 sets of twins, one twin with Parkinson's, the other without. Because twins are similar genetically and often share certain lifestyle characteristics, twins were thought to provide a better control group, reducing the likelihood of spurious results. BBC © 2011

Keyword: Parkinsons; Neurotoxins
Link ID: 16030 - Posted: 11.14.2011

Ian Sample, science correspondent A professional cellist who lost nearly all of his memory after a virus destroyed parts of his brain has astonished doctors with his remarkable recall of music. The 71-year-old, known only as PM, had played with a major German orchestra before contracting the infection that devastated his brain's memory centres in 2005. The illness left the musician with such profound amnesia he could remember almost nothing of his past and was unable to plan for the future. The only people he recognised were his brother and a care worker. "He can hardly remember a thing. He has no memory of any personal or professional events," Carsten Finke, a neurologist at Charité university hospital in Berlin, told the Guardian. "He is living in the moment, more or less. He has lost his whole life." Doctors made their discovery when they tested PM's ability to recall musical information and found he could identify the scales, rhythms and intervals of pieces they played him. The man went on to score normally on a standard test for musical memory. But it was later tests that surprised doctors most, when the cellist showed he could learn new pieces of music, even though he failed to remember simple information, such as the layout of his flat, who his doctors were and what medicines he should take. Neighbours said the man still played the cello in his apartment, but he refused to play in front of doctors, perhaps because he felt he was no longer any good, Finke said. © 2011 Guardian News and Media Limited

Keyword: Learning & Memory; Hearing
Link ID: 16029 - Posted: 11.14.2011

By Gary Stix They go by many names: Brain worms, sticky music (thanks Oliver Sacks), cognitive itch, stuck song syndrome. But the most common (if also the most repugnant) is earworms, a literal translation from Ohrwurm, a term used to describe the phenomenon (and perhaps bring to mind an immediate association with corn earworms). If you’re an academic, you might refer to it as Involuntary Musical Imagery, which, of course, gets condensed to INMI. What are we talking about? Again, back to the academics, specifically, C. Phillip Beaman and Tim I. Williams from the University of Reading, who in a 2010 paper, explain it like this: “Simply, an earworm is the experience of an inability to dislodge a song and prevent it from repeating itself in one’s head.” Oh, thaaat. In the last five years, earworms have become the subject of peer-reviewed scientific studies. In 2006, Steven Brown of Simon Fraser University even studied his own earworms and observed in the Journal of Consciousness Studies that they could be used as a basis for understanding how conscious experience can be split into multiple parallel streams. In 2008, moreover, Finnish researchers published a study that used the Interrnet to survey age, gender, personality and musical and linguistic competence of 12,420 countrymen who experienced the endless loops in their heads. © 2011 Scientific American,

Keyword: Hearing; Attention
Link ID: 16028 - Posted: 11.12.2011

Daniel Cressey In 2008, the world’s media was captivated by a study apparently showing that cows like to align themselves with magnetic fields. But attempts to replicate this finding have left two groups of researchers at loggerheads, highlighting the problems faced by scientists working to replicate unusual findings based on new methods of data analysis. Magneto-reception has been detected in animals from turtles to birds. Three years ago, Hynek Burda, a zoologist at the University of Duisburg-Essen, Germany, and his colleagues added cattle to the magnetic family with a paper in Proceedings of the National Academy of Sciences. The team used data from Google Earth to show that domestic cattle seem to prefer to align their bodies along Earth’s magnetic field lines1, and showed a similar phenomenon in field observations of deer. A follow-up study by Burda and his colleagues showed no such alignment near electric power lines, which might be expected to disrupt magneto-sensing in cattle2. Cow conundrum Earlier this year, a group of Czech researchers reported their failed attempt to replicate the finding using different Google Earth images3. The Czech team wrote in the Journal of Comparative Physiology A: “Two independent groups participated in our study and came to the same conclusion that in contradiction to the recent findings of other researchers, no alignment of the animals and of their herds along geomagnetic field lines could be found.” © 2011 Nature Publishing Group,

Keyword: Animal Migration
Link ID: 16027 - Posted: 11.12.2011

by Susan Watts Yet another survey has revealed surprisingly large numbers of people using drugs to boost their mental powers. What should be done? MOST of us want to reach our full potential. We might drink a cup of coffee to stay alert, or go for a run to feel on top of the job. So where's the harm in taking a pill that can do the same thing? So-called cognitive-enhancing drugs are usually prescribed to treat medical conditions, but they are also known for their ability to improve memory or focus. Many people buy them over the internet, which is risky because they don't know what they are getting. We also know next to nothing about their long-term effects on the brains of healthy people, particularly the young. But some scientists believe they could have a beneficial role to play in society, if properly regulated. So who's taking what? The BBC's flagship current affairs show Newsnight and New Scientist ran an anonymous online questionnaire to find out. I also decided to try a cognitive enhancer for myself. The questionnaire was completed by 761 people, with 38 per cent saying they had taken a cognitive-enhancing drug at least once. Of these, nearly 40 per cent said they had bought the drug online and 92 per cent said they would try it again. Though not representative of society, the survey is an interesting, anecdotal snapshot of a world for which there is little data. The drugs people said they had taken included modafinil, normally prescribed for sleep disorders, and Ritalin and Adderall, taken for ADHD. The range of experiences is striking. © Copyright Reed Business Information Ltd.

Keyword: ADHD; Attention
Link ID: 16026 - Posted: 11.12.2011

Caitlin Stier, video intern The hearts in this animation appear to have a pulse but that's only because of the changing background. Created by psychophysiologist Marcel de Heer, the shapes enlarge when a dark area is behind them and compress when a lighter shade moves in. To investigate the effect, researcher Stuart Anstis of the University of California, San Diego, made his own heart animations. In one variation, where a heart's interior changes in brightness, the shape also appears to beat (see second animation in video). "The changing gradient across the heart converts the lightening and darkening into apparent expansion and contracting," explains Anstis. The illusion is caused by the response of retinal cells in our eyes as the boundary changes in brightness. But processing in the visual cortex is also likely to play a role. Simone Gori of the University of Padua previously discovered a similar effect where a gradient affects how we perceive brightness. The smooth pulse induced by a gradual background change is also illustrated in an award-winning illusion where a pattern made up of brains appears to shift. © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 16025 - Posted: 11.12.2011