Mike Marshall As part of our special issue on music, Daniel Levitin has written The Music Illusion, which looks at auditory illusions and how they can help us understand the workings of the human brain. Here we have compiled five of the most striking auditory illusions discovered so far. We had a big pool to choose from, from the mysterious quintina (fifth voice) heard in some types of throat-singing, to the saxophone solo that isn't on Lady Madonna (it's actually the Beatles singing into their cupped hands) and the soaring guitar sound of Pink Floyd's Dave Gilmour. Listen to our top 5 below, and read our explanations of the effects involved. 1 Barber's shop illusion (Listen with headphones) This is a demonstration of the stereo effect. Listening to it, you feel as though you are in a barber's chair, with the barber moving around you, clipping away at your hair. As the barber "moves" to your right, the volume increases slightly in the right channel and decreases in the left. Similarly, increases in the volume of sound from the clippers give the impression that he is bringing them closer and closer to each ear. The illusion demonstrates our ability to locate sounds in space; by comparing the inputs to the two ears, we can work out where a sound is coming from. 2 Phantom words (Listen through stereo separated loudspeakers, best placed some distance apart) © Copyright Reed Business Information Ltd

Keyword: Hearing
Link ID: 11328 - Posted: 06.24.2010

New research finds both men and women can lower the risk of stroke by engaging in even moderate exercise. Previous studies on fitness and strokes have focused more on men, but the new research says benefits apply to women, too. The research data covers 61,000 adults at an aerobics centre in Dallas, who were followed for an average of 18 years. The study found for those with moderate levels of fitness, the stroke risk went down by 15 to 30 per cent for men and 23 to 57 per cent for women. The lower risks were true even considering such other risk factors as smoking, weight and high blood pressure. Study leader Steven Hooker of the University of South Carolina's Prevention Research Centre says most people can become moderately fit by walking briskly for 30 minutes a day, five times a week. Stroke is the third-leading cause of death in the U.S. and doctors say physical activity can help prevent blockages in blood vessels that can cause it. In Canada, strokes kill 50,000 people a year, according to the Heart and Stroke Foundation of Canada. © The Canadian Press, 2008

Keyword: Stroke
Link ID: 11327 - Posted: 06.24.2010

LA CROSSE, Wis. - For as long as he can remember, Brad Williams has been able to recall the most trifling dates and details about his life. For example, he can tell you it was Aug. 18, 1965, when his family stopped at Red Barn Hamburger during a road trip through Michigan. He was 8 years old at the time. And he had a burger, of course. “It was a Wednesday,” recalled Williams, now 51. “We stayed at a motel that night in Clare, Michigan. It seemed more like a cabin.” To Williams and his family, his ability to recall events — and especially dates — is a regular source of amusement. But according to one expert, Williams’ skill might rank his memory among the best in the world. Doctors are now studying him, and a woman with similar talents, hoping to achieve a deeper understanding of memory. Williams, a radio anchor in La Crosse, seems to enjoy having his memory tested. Name a date from the last 40 years and, after a few moments, he can typically tell you what he did that day and what was in the news. Exercise your mind “Let’s see,” he mused, gazing into the distance for about five seconds. “That would be around when Magic Johnson announced he had HIV. Yes, a Thursday. There was a big snowstorm here the week before.” © 2008 The Associated Press.

Keyword: Learning & Memory
Link ID: 11326 - Posted: 06.24.2010

You’ve seen the TV shows and movies, someone implanted with electronic devices that give them super human powers, including super vision. In reality, the best we can do is a set of binoculars, or strap-on night vision goggles. But that all could change as engineers work to supercharge contact lenses. “If you look at the structure of a contact lens,” says Babak Parviz, University of Washington assistant professor of eleectrical engineering, “ more or less it’s just a polymer that … does vision correction.” Since the group was already working on incorporating micron-scale devices onto unconventional substrates including plastics, he says, “we saw the opportunity to integrate these on a contact lens.” Parviz adds that much of the micro technology that would have to fit on a contact lens is already available and says, “To look at the semi-conductor industry and what we have in opto-electronics and micro machines, we already have a lot… (but) one thing we have not done is to put those things on a contact.” Parviz imagines a whole list of things a supercharged contact lens might do, explaining, “I can see this exponentially growing and having many, many applications; from lenses that are quote-unquote intelligent and can help the user who’s had a cataract surgery to see better, to amplified vision, to all sorts of gaming applications and interfacing with your iPod and lots of things.” © ScienCentral, 2000-2008.

Keyword: Vision; Robotics
Link ID: 11325 - Posted: 06.24.2010

A computer does better than a doctor at diagnosing certain brain diseases, research has suggested. Experts taught a standard computer how to diagnose Alzheimer's from brain scans, and got a 96% success rate. The accuracy of diagnosis from standard scans, blood tests and interviews carried out by a clinician is 85%. The findings, published in the journal Brain, could lead to earlier diagnosis and more successful treatment of dementias, say scientists. Researchers from the Wellcome Trust Centre for Neuroimaging at University College London say computers have several advantages for diagnosing Alzheimer's - a condition caused by the build-up of plaques and tangles of tissue in the brain. Professor Richard Frackowiak said the computers were better able to distinguish signs of Alzheimer's than humans, and proved cheaper, faster and more accurate than current methods. "It's beginning to look like it will have to come into clinical practice," he said. "Machines are clearly able to do that sort of thing better." The method involves teaching a standard computer the difference between brain scans from patients with proven Alzheimer's disease and people with no signs of the disease at all. The two conditions can be distinguished with a high degree of accuracy on a single clinical MRI scan without the need for time consuming follow-up tests, say the scientists. (C)BBC

Keyword: Brain imaging; Alzheimers
Link ID: 11324 - Posted: 02.22.2008

Strokes have tripled in recent years among middle-aged women in the U.S., an alarming trend doctors blame on the obesity epidemic. Nearly two per cent of women ages 35 to 54 reported suffering a stroke in the most recent federal health survey, from 1999 to 2004. Only about half a per cent reported strokes in the previous survey, from 1988 to 1994. The percentage is small because most strokes occur in older people. But the sudden spike in middle-age and the reasons behind it are ominous, doctors said in research presented Wednesday at a medical conference. In a "pre-stroke population" of middle-age women, a tripling of cases is "an alarming increase," said Dr. Ralph Sacco, neurology chief at the University of Miami Miller School of Medicine. The spike in middle-aged strokes happened even though more women in the recent survey were on medicines to control their cholesterol and blood pressure — steps that lower the risk of stroke. The new research means "we need to redefine our textbooks about stroke in women," because they may now be more at risk in middle-age than men, said Dr. Philip Gorelick, neurology chief at the University of Illinois in Chicago and chairman of the stroke conference. © The Canadian Press, 2008

Keyword: Stroke
Link ID: 11323 - Posted: 06.24.2010

A better understanding of how memory works is emerging from a newfound ability to link a learning experience in a mouse to consequent changes in the inner workings of its neurons. Researchers, supported in part by the National Institutes of Health's National Institute of Mental Health (NIMH), have developed a way to pinpoint the specific cellular components that sustain a specific memory in genetically-engineered mice. "Remarkably, this research demonstrates a way to untangle precisely which cells and connections are activated by a particular memory," said NIMH Director Thomas Insel, M.D. "We are actually learning the molecular basis of learning and memory." For a memory to last long-term, the neural connections holding it need to be strengthened by incorporating new proteins triggered by the learning. Yet, it's been a mystery how these new proteins — born deep inside a neuron — end up becoming part of the specific connections in far-off neuronal extensions that encode that memory. By tracing the destinations of such migrating proteins, the researchers located the neural connections, called synapses, holding a specific fear memory. In the process, they discovered these synapses are distinguished by telltale molecular tags that enable them to capture the memory-sustaining proteins. Mark Mayford, Ph.D., and Naoki Matsuo, Ph.D., of the Scripps Research Institute, report on their findings in the February 22, 2008 issue of the journal Science.

Keyword: Learning & Memory
Link ID: 11322 - Posted: 06.24.2010

Matt Kaplan An accidental encounter with a pod of sleeping sperm whales has opened researchers’ eyes to some unknown sleep behaviours of these giant sea creatures. Counter to previous assumptions, and unlike smaller cetaceans, the whales seem to enter a period of full sleep. But they also sleep for a very limited time per day, hinting that they could be the least sleep-dependent mammals known. A team led by Luke Rendell at the University of St Andrew’s, UK, were monitoring calls and behaviour in sperm whales (Physeter macrocephalus ) off the northern Chile coast when they accidentally drifted into the middle of a pod of whales hanging vertically in the water, their noses poking out of the surface. At least two of the whales were facing the boat, but not a single animal responded. “It was actually pretty scary. The boat had drifted into the group with its engine off [while] I was below decks making acoustic recordings,” says Rendell. “Once I saw the situation I decided the best thing to do was to try and sail our way out of the group rather than turn the engine on and have them all react.” The researchers was almost successful, but unfortunately they nudged one of the whales on the way out. “We had no idea how they would react; each of the animals probably weighed up to twice as much as our boat, and could have sunk us. If they had decided to take action collectively — sperm whales do engage in communal defence [against] killer whales — then we could have been in real trouble,” Rendell says. Fortunately for everyone on board, after an initial jolt of activity the whales timidly moved away, and within fifteen minutes were bobbing peacefully at the surface again. © 2008 Nature Publishing Group

Keyword: Sleep; Evolution
Link ID: 11321 - Posted: 06.24.2010

Even the shortest of catnaps may be enough to improve performance in memory tests, say German scientists. Just six minutes "shut-eye" for volunteers was followed by significantly better recall of words, New Scientist magazine reported. "Ultra-short" sleep could launch memory processing in the brain, they suggested. One UK researcher disagreed, saying that longer sleep was needed to have an impact on memory. Dozens of studies have probed the relationship between sleep and memory, with clear evidence that body's natural sleep-wake cycle plays an important role. The team from the University of Dusseldorf wanted to see just how short a sleep could have any discernable impact. They used a group of students who were asked to remember a set of words, then given an hour's break before testing. During that hour, some of the students were allowed to sleep for approximately six minutes, while the rest were kept awake. Remarkably, on waking, the napping students performed better in the memory test. Some theories suggests that the processing of memories takes place in deep sleep, a phase which does not normally start until at least 20 minutes after falling asleep. However, the team, led by Dr Olaf Lahl, said that it was possible that the moment of falling asleep triggered a process in the brain that continued regardless of how long the person actually stayed awake. "To our knowledge, this demonstrates for the first time that an ultra-brief sleep episode provides an effective memory enhancement," he wrote. (C)BBC

Keyword: Sleep; Learning & Memory
Link ID: 11320 - Posted: 02.21.2008

By ANDREW POLLACK Scientists reported on Wednesday that they were able to control diabetes in mice by harnessing human embryonic stem cells. The work raised the prospect that the embryonic cells might one day be used to provide insulin-producing replacement cells to treat the disease in people. The scientists, at the biotechnology company Novocell, turned the stem cells into cells that produced insulin in the mice. Those cells kept blood sugar in check after the mice’s own insulin-producing cells were destroyed. “For those who say there is not much evidence that embryonic stem cells can cure diabetes, there you go,” said Dr. Camillo Ricordi, director of the Diabetes Research Institute at the University of Miami, who was not involved in the research. Still, a small number of the mice developed tumors, and some experts said the cells might not be well-characterized enough for use in people. In any event, Novocell said it would be several years before any human tests could begin. Doctors are already experimenting with transplants of insulin-producing islet cells from cadavers for patients with Type 1 diabetes, a disease that destroys a person’s own islet cells. In some cases, the transplant recipients have not needed daily injections of insulin, at least for a while. Copyright 2008 The New York Times Company

Keyword: Obesity; Stem Cells
Link ID: 11319 - Posted: 06.24.2010

By Darren Waters Gamers will soon be able to interact with the virtual world using their thoughts and emotions alone. A neuro-headset which interprets the interaction of neurons in the brain will go on sale later this year. "It picks up electrical activity from the brain and sends wireless signals to a computer," said Tan Le, president of US/Australian firm Emotiv. "It allows the user to manipulate a game or virtual environment naturally and intuitively," she added. The brain is made up of about 100 billion nerve cells, or neurons, which emit an electrical impulse when interacting. The headset implements a technology known as non-invasive electroencephalography (EEG) to read the neural activity. Ms Le said: "Emotiv is a neuro-engineering company and we've created a brain computer interface that reads electrical impulses in the brain and translates them into commands that a video game can accept and control the game dynamically." Headsets which read neural activity are not new, but Ms Le said the Epoc was the first consumer device that can be used for gaming. "This is the first headset that doesn't require a large net of electrodes, or a technician to calibrate or operate it and does require gel on the scalp," she said. "It also doesn't cost tens of thousands of dollars." The use of Electroencephalography in medical practice dates back almost 100 years but it is only since the 1970s that the procedure has been used to explore brain computer interfaces. (C)BBC

Keyword: Robotics; Emotions
Link ID: 11318 - Posted: 02.21.2008

By Larry Greenemeier For all their sophistication, computers still can't compete with nature's gift—a brain that sorts objects quickly and accurately enough so that people and primates can interpret what they see as it happens. Despite decades of development, computer vision systems still get bogged down by the massive amounts of data necessary just to identify the most basic images. Throw that same image into a different setting or change the lighting and artificial intelligence is even less of a match for good old gray matter. These shortcomings become more pressing as demand grows for security systems that can recognize a known terrorist's face in a crowded airport and car safety mechanisms such as a sensor that can hit the brakes when it detects a pedestrian or another vehicle in the car's path. Seeking the way forward, Massachusetts Institute of Technology researchers are looking to advances in neuroscience for ways to improve artificial intelligence, and vice versa. The school's leading minds in both neural and computer sciences are pooling their research, mixing complex computational models of the brain with their work on image processing. This cross-disciplinary approach began to yield fruit a year ago, when a group of researchers led by Tomaso Poggio, a professor in M.I.T.'s Department of Brain and Cognitive Sciences and an investigator at the school's McGovern Institute for Brain Research, used a brain-inspired computer model to interpret a series of photographs. © 1996-2008 Scientific American Inc.

Keyword: Vision; Robotics
Link ID: 11317 - Posted: 06.24.2010

Listening to music in the early stages after a stroke can improve a patient's recovery, research suggests. The researchers compared patients who listened to music for a couple of hours a day, with those who listened only to audio books, or nothing at all. The music group showed better recovery of memory and attention skills, and a more positive general frame of mind. Writing in journal Brain, the Finnish team who studied 60 patients said music could be a useful addition to therapy. Lead researcher Teppo Sarkamo, from the University of Helsinki, said music could be particularly valuable for patients not yet ready for other forms of rehabilitation. It also had the advantage of being cheap and easy-to-conduct. The study focused on 60 stroke patients who took part in the research as soon as possible after they had been admitted to hospital. Dot Johnson, 60, had a stroke 15 years ago, and spent seven months in hospital. She had physiotherapy and other treatments, but she remembers that music and sound from the television were always on in her room. She thinks that stimulated her mind, and helped her get better. She said: "I genuinely think that music actually helped." The aim was to offer music therapy before the changes in the brain that can take place in the aftermath of a stroke had a chance to kick in. Most of the patients had problems with movement and with cognitive processes, such as attention and memory. Patients in the music group were able to chose the type of music they listened to. All patients received standard stroke rehabilitation. After three months, verbal memory improved by 60% in the music group, compared with18% in the audio book group, and 29% in the non-listeners. (C)BBC

Keyword: Stroke; Regeneration
Link ID: 11316 - Posted: 02.20.2008

By CARL ZIMMER WOODS HOLE, Mass. — The cuttlefish in Roger Hanlon’s laboratory were in fine form. Their skin was taking on new colors and patterns faster than the digital signs in Times Square. Dr. Hanlon inspected the squidlike animals as he walked past their shallow tubs, stopping from time to time to ask, “Whoa, did you see that?” One cuttlefish added a pair of eye spots to its back, a strategy cuttlefish use to fool predators. The spots lingered a few seconds, then vanished. When Dr. Hanlon stuck his finger into another tub, three squirrel-size cuttlefish turned to chocolate, and one streaked its back and arms with wavy white stripes. “Look at the pattern on that guy,” he said with a smile as they lunged for his finger. In other tubs, the cuttlefish put on subtler but no less sophisticated displays. Dr. Hanlon’s students had put sand in some tubs, and there the cuttlefish assumed a smooth beige. On top of gravel, their skins were busy fields of light and dark. Dr. Hanlon likes to see how far he can push their powers of camouflage. He sometimes put black and white checkerboards in the tubs. The cuttlefish respond by forming astonishingly sharp-edged blocks of white. Copyright 2008 The New York Times Company

Keyword: Vision; Animal Communication
Link ID: 11315 - Posted: 06.24.2010

By REED ABELSON For more than four decades, on telethons featuring celebrity performers and children in wheelchairs, Jerry Lewis has been raising money each Labor Day for the Muscular Dystrophy Association and the disease that helped make “poster child” part of the American idiom. On the most recent telethon, which was staged in Las Vegas and raised $63.8 million, the “Law and Order” actress Mariska Hargitay spoke of patients’ “hope that M.D.A. research will lead to treatments and cures.” Mr. Lewis, who has never disclosed why he chose this disease as his cause, once again closed the broadcast with an emotional rendition of the song “You’ll Never Walk Alone.” But for all the money collected toward a cure, Duchenne muscular dystrophy, the most common form of the disease, still confines thousands of boys in this country to wheelchairs in their early teens. Many do not live past their 20s. It is a stark reminder of how American medicine — with its focus on breakthrough treatments — can sometimes fail a complex, rare and stubbornly uncurable disease. Single-minded in their pursuit of a cure, doctors and researchers for years all but ignored the necessary and unglamorous work of managing Duchenne (pronounced doo-SHEN) as a chronic condition. Copyright 2008 The New York Times Company

Keyword: Muscles; Genes & Behavior
Link ID: 11314 - Posted: 06.24.2010

Is a woman's choice of valentine really a choice? As this ScienCentral news video explains, researchers studying mice have found that alpha males can trigger growth of new brain cells in females — that make them want only alpha males. "It turns out that male mice do actually belong to two kind of categories — the dominant and the subordinate. The dominant male mouse will in fact bully, scratch and push around the subordinate male mice," says neuroscientist Samuel Weiss, director of Hotchkiss Brain Institute in Canada. "Females choose dominant mice, male mice, over subordinate male mice in order to mate with the dominant male mouse so that more of her babies will be dominant as well," explains Weiss. Weiss and colleagues wanted to find out the mechanism behind female mouse preference for alpha males. Weiss wondered if female mice's choice of dominant males had something to do with pheromones, chemical signals found in the urine of male mice. (Pheromones have been found in mouse tears as well by other researchers.) He says that dominant mice and subordinate mice have what he calls different "pheromonal signatures." First, Weiss took virgin female mice and exposed them for a few days to a mix of the bedding from both dominant and subordinate mice, because the bedding contains the male pheromones. He found that that had no effect on the brains of the females. © ScienCentral, 2000-2008.

Keyword: Chemical Senses (Smell & Taste); Neurogenesis
Link ID: 11313 - Posted: 06.24.2010

Rowan Hooper Do animals think like autistic savants? Intriguing as that question is, it now seems as if they don't, despite the "savant-like" behaviour many show. The question was raised in a book by animal scientist Temple Grandin, of Colorado State University, Fort Collins. Animals in Translation became a best-seller, and Grandin's views gained widespread attention. Grandin herself is autistic, and it is her experience of processing memories using images rather than words that forms the basis of her theory. "If you want to understand animals, you have to get away from language," she says. There is no doubt that some animals have amazing abilities. Birds such as Clark's nutcrackers can remember the locations of thousands of caches of nuts; Australian magpies are able to mimic the entire song of a different species after just one listen. But is this savant-like, or an evolutionary adaptation? Giorgio Vallortigara, of the University of Trento, Italy, and colleagues think it is the latter. "Autism is a pathological condition," he says. "The extraordinary feats of remembering thousands of caches or sounds shown by some animal species are exhibited by healthy animals." If Grandin is right, there should be similarities between the brains of autistic people and animals. Autism is often associated with a malfunction of the brain's left hemisphere, which can lead to an over-emphasis on details at the expense of an understanding of the big picture. Vallortigara and colleagues give the example of an autistic boy who learned the concept of "giraffe" by concentrating on the pattern of the coat. This led him to misidentify a leopard as a giraffe. © Copyright Reed Business Information Ltd.

Keyword: Intelligence; Autism
Link ID: 11312 - Posted: 06.24.2010

Sid Perkins More than one-fifth of living mammal species are bats, and most of those use echolocation to track prey or avoid obstacles. The fossil record of these delicate-boned creatures is sparse, but analyses hint that even the earliest known bats—those flitting through the skies between 54 million and 50 million years ago—could echolocate, says Nancy B. Simmons, a vertebrate paleontologist at the American Museum of Natural History in New York City. In fact, of the six bat species previously known from that era and with enough remains to analyze, all apparently were sonar capable, she notes. Evidence includes a large cochlea, or inner ear, that enabled the bats to detect the echoes of their high-pitched squeaks. Paleontologists have long debated whether bats' ability to fly preceded, followed, or evolved in tandem with their ability to echolocate. Now, in the Feb. 14 Nature, Simmons and her colleagues describe the almost complete fossils of a creature that suggests the "flight-first" hypothesis is correct. The ancient bat, dubbed Onychonycteris finneyi, had a 30-centimeter-wingspan and lived in what is now western Wyoming about 52.5 million years ago, says Simmons. Onychonycteris, which means "clawed bat" in Greek, refers to the creature's most distinctive feature: It has claws on all five digits of its forelimbs, whereas all living bats and previously studied fossil bats have claws on no more than two digits. The name finneyi honors the fossil collector who excavated the specimens, says Simmons. ©2008 Society for Science & the Public.

Keyword: Hearing; Evolution
Link ID: 11311 - Posted: 06.24.2010

Diabetes is known to impair the cognitive health of people, but now scientists have identified one potential mechanism underlying these learning and memory problems. A new National Institutes of Health (NIH) study in diabetic rodents finds that increased levels of a stress hormone produced by the adrenal gland disrupt the healthy functioning of the hippocampus, the region of the brain responsible for learning and short-term memory. Moreover, when levels of the adrenal glucocorticoid hormone corticosterone (also known as cortisol in humans) are returned to normal, the hippocampus recovers its ability to build new cells and regains the "plasticity" needed to compensate for injury and disease and adjust to change. The study appears in the Feb. 17, 2008, issue of Nature Neuroscience and was conducted by the NIA's Mark Mattson, Ph.D., and colleagues. "This research in animal models is intriguing, suggesting the possibility of novel approaches in preventing and treating cognitive impairment by maintaining normal levels of glucocorticoid," said Richard J. Hodes, M.D., NIA director. "Further study will provide a better understanding of the often complex interplay between the nervous system, hormones and cognitive health." Cortisol production is controlled by the hypothalamic-pituitary axis (HPA), a hormone-producing system involving the hypothalamus and pituitary gland in the brain and the adrenal gland located near the kidney. People with poorly controlled diabetes often have an overactive HPA axis and excessive cortisol produced by the adrenal gland. To study the interaction between elevated stress hormones and the hippocampal function, researchers tested the cognitive abilities and examined the brain tissue in animal models of rats with Type 1 diabetes (insulin deficient) and mice with Type 2 diabetes (insulin resistant).

Keyword: Learning & Memory; Hormones & Behavior
Link ID: 11310 - Posted: 02.20.2008

By GINA KOLATA One of the great unanswered questions in physiology is why muscles get tired. The experience is universal, common to creatures that have muscles, but the answer has been elusive until now. Scientists at Columbia say they have not only come up with an answer, but have also devised, for mice, an experimental drug that can revive the animals and let them keep running long after they would normally flop down in exhaustion. For decades, muscle fatigue had been largely ignored or misunderstood. Leading physiology textbooks did not even try to offer a mechanism, said Dr. Andrew Marks, principal investigator of the new study. A popular theory, that muscles become tired because they release lactic acid, was discredited not long ago. In a report published Monday in an early online edition of Proceedings of the National Academy of Sciences, Dr. Marks says the problem is calcium flow inside muscle cells. Ordinarily, ebbs and flows of calcium in cells control muscle contractions. But when muscles grow tired, the investigators report, tiny channels in them start leaking calcium, and that weakens contractions. At the same time, the leaked calcium stimulates an enzyme that eats into muscle fibers, contributing to the muscle exhaustion. In recent years, says George Brooks of the University of California, Berkeley, muscle researchers have had more or less continuous discussions about why muscles fatigue. It was his work that largely discredited the lactic-acid hypothesis, but that left a void. Copyright 2008 The New York Times Company

Keyword: Muscles
Link ID: 11309 - Posted: 02.20.2008