A new study from Georgia Tech shows that when patients with macular degeneration focus on using another part of their retina to compensate for their loss of central vision, their brain seems to compensate by reorganising its neural connections. Age - related macular degeneration is the leading cause of blindness in the elderly. The study appears in the December edition of the journal Restorative Neurology and Neuroscience. 'Our results show that the patient's behaviour may be critical to get the brain to reorganise in response to disease,' said Eric Schumacher, assistant professor in Georgia Tech's School of Psychology. 'It's not enough to lose input to a brain region for that region to reorganise; the change in the patient's behaviour also matters.' In this case, that change of behaviour comes when patients with macular degeneration, a disease in which damage to the retina causes patients to lose their vision in the centre of their visual field, make up for this loss by focusing with other parts of their visual field. Previous research in this area showed conflicting results. Some studies suggested that the primary visual cortex, the first part of the cortex to receive visual information from the eyes, reorganises itself, but other studies suggested that this didn't occur. Schumacher and his graduate student, Keith Main, worked with researchers from the Georgia Tech/Emory Wallace H. Coulter Department of Biomedical Engineering and the Emory Eye Centre. They tested whether the patients' use of other areas outside their central visual field, known as preferred retinal locations, to compensate for their damaged retinas drives, or is related to, this reorganisation in the visual cortex. © 2007—2008 Agency Science.

Keyword: Vision
Link ID: 12263 - Posted: 06.24.2010

by Ewen Callaway If you can't tell Angelina Jolie from Jennifer Aniston, total ignorance of pop culture might not be the only culprit. People with a rare condition called "face blindness" lack connections in a brain area responsible for recognising faces, new research shows. Officially termed prosopagnosia, face blindness takes two forms: acquired and inherited. People who develop the condition later in life have usually suffered a stroke or an injury in a brain region important for facial recognition called the fusiform gyrus, says Cibu Thomas, a neuroscientist who led the study while at Carnegie Mellon University in Pittsburgh, Pennsylvania. The inherited form – which may affect up to one out of 50 people – is far more mysterious. Tests of facial recognition can diagnose inherited prosopagnosiacs, but functional brain scans have revealed few differences between their brains and those of people who can pick out celebrities and loved ones. "Here's a brain that looks normal in an MRI, and in some cases they have difficulty in recognising their own spouse," says Thomas, who is now at the Harvard Medical School. © Copyright Reed Business Information Ltd

Keyword: Miscellaneous
Link ID: 12262 - Posted: 06.24.2010

Irene Pepperberg is associate research professor at Brandeis University and the author of a new book, Alex and Me. She and Jonah Lehrer, the editor of Mind Matters, discuss what Alex and other African Grey Parrots can teach us about the evolution of intelligence and the concept of zero. LEHRER: What first got you interesting in study avian intelligence? After all, to say someone has a "bird brain" is insulting. PEPPERBERG: I had parakeets as pets as a child, and I knew they were quite smart. For instance, they could learn to say words and phrases in context. But I didn't connect that to science at the time. I trained in chemistry at MIT and chemical physics at Harvard, not even knowing that a new field, animal cognition, was developing in psychology. It wasn't until I saw the first NOVA programs, in 1974, on ape signing, dolphin intelligence and the one on "Why Do Birds Sing?" that I realized that one could look at animal-human communication and animal intelligence in a scientific way. That’s when I realized that no one was looking at parrots, which could actually talk. I decided to use their ability to produce human speech sounds to examine their cognitive processes. LEHRER: Were you surprised by Alex's talents? PEPPERBERG: In general, no. But occasionally he would do something that was really impressive, jumping beyond the task at hand, transferring his knowledge unexpectedly from one domain to another. That’s when I’d get surprised. © 1996-2008 Scientific American Inc.

Keyword: Language; Evolution
Link ID: 12261 - Posted: 06.24.2010

By Rachel Zelkowitz Biology has an easy explanation for Don Juan's motives--having many lovers lets him produce the greatest number of offspring. But scientists have long wondered why the females of many species seek out multiple mates, because each coupling can cost them precious time and energy without necessarily increasing the number of offspring they can bear. New research shows how, at least in flies, such female promiscuity can reduce the chances that the offspring will inherit bad genes. Females take multiple partners, a behavior called polyandry, in many species, including mice. Some researchers have suggested that polyandry evolved to help females boost the likelihood that their offspring will carry certain positive traits such as virility. They can collect sperm through multiple matings, and only the most competitive of this "sperm cocktail" will fertilize their eggs, says Nina Wedell, an evolutionary biologist at the University of Exeter in the United Kingdom. An alternative explanation is that cheating evolved to spare the offspring from potentially negative traits. Wedell and her colleagues examined one cause of such problematic traits: "selfish" genes. These genes break the 50-50 inheritance rule by being passed onto offspring more often than not. Selfish genes "fight" other genes to get passed on to the next generation, often harming the carrier by causing problems such as reduced fertility. For example, male fruit flies can carry a selfish gene that destroys all of their sperm with a Y chromosome, so they produce fewer sperm and can father only daughters. Yet, male fruit flies with the selfish gene are physically identical to those without it. © 2008 American Association for the Advancement of Science.

Keyword: Sexual Behavior; Evolution
Link ID: 12260 - Posted: 06.24.2010

Kerri Smith An electrode implanted into the brain of a man who is unable to move or communicate has enabled him to use a speech synthesizer to produce vowel sounds as he thinks them. The work could one day help similar patients to produce whole sentences using signals from their brains, say the researchers. Brain scanA paralysed man has been able to use a voice synthesizer thanks to an electrode implanted in his brain.GETTY Frank Guenther of Boston University in Massachusetts and his colleagues worked with a patient who has locked-in syndrome, a condition in which patients are almost completely paralysed — often able to move only their eyelids — but still fully conscious. Guenther and his team first had to determine whether the man's brain could produce the same speech signals as a healthy person's. So they scanned his brain using functional magnetic resonance imaging (fMRI) while he attempted to say certain vowels. Once the researchers were happy that the signals were the same, they implanted an electrode — designed by neuroscientist Philip Kennedy of the firm Neural Signals in Duluth, Georgia — into the speech-production areas of the man's brain. The electrode will remain there for the forseeable future. © 2008 Nature Publishing Group

Keyword: Hearing; Language
Link ID: 12259 - Posted: 06.24.2010

By Bruce Bower WASHINGTON — It takes years for children to master the ins and outs of arithmetic. New research indicates that this learning process triggers a large-scale reorganization of brain processes involved in understanding written symbols for various quantities. The findings support the idea that humans' ability to match specific quantities with number symbols, a skill required for doing arithmetic, builds on a brain system that is used for estimating approximate quantities. That brain system is seen in many nonhuman animals. When performing operations with Arabic numerals, young adults, but not school-age children, show pronounced activity in a piece of brain tissue called the left superior temporal gyrus, says Daniel Ansari of the University of Western Ontario in London, Canada. Earlier studies have linked this region to the ability to associate speech sounds with written letters, and musical sounds with written notes. The left superior temporal gyrus is located near the brain’s midpoint, not far from areas linked to speech production and understanding. In contrast, children solving a numerical task display heightened activity in a frontal-brain area that, in adults, primarily serves other functions. Ansari presented his findings November 19 at the annual meeting of the Society for Neuroscience. © Society for Science & the Public 2000 - 2008

Keyword: Miscellaneous
Link ID: 12258 - Posted: 06.24.2010

By Tom Siegfried At the end of The Matrix trilogy, Neo and Agent Smith are engaged in one final, interminable scene of surreal combat, a surrogate competition for an eternal battle between humans and machines. “It’s pointless to keep fighting,” Agent Smith declares to Neo. “Why do you persist?” “Because I choose to,” Neo replies, just before the computer-generated Smith meets his demise in a cinematic celebration of human free will’s superiority to the programming that enslaves machines. Machines are mindless. The brain is a decider. All very inspiring, except that the brain itself is a machine, a network of cells that computes its choices based on the sum of sensory inputs and their interactions with neural anatomy. “Free will” is not the defining feature of humanness, modern neuroscience implies, but is rather an illusion that endures only because biochemical complexity conceals the mechanisms of decision making. Yet belief in free will persists as stubbornly as Neo’s resistance to electronic tyranny. Whether supposedly free choice is actually a Matrix-like mirage remains one of the great questions of human philosophical history. For centuries that question was assessed mostly with thought —uninformed by actual neurobiological knowledge. Nowadays, though, the inner workings of the brain are revealing themselves to modern methods of neuroinquiry, and free will seems merely to emerge from electrochemical networks of neuronal interactions. But like tourists exploring a strange city without a GPS map, scientists don’t know how all the neural neighborhoods are connected and occasionally encounter surprising enclaves—such as a place in the brain called the lateral habenula. © Society for Science & the Public 2000 - 2008

Keyword: Attention
Link ID: 12257 - Posted: 06.24.2010

by Rachel Nowak INFRARED light can stimulate neurons in the inner ear as precisely as sound waves, a discovery that could lead to better cochlear implants for deaf people. A healthy inner ear uses hair cells that respond to sound to stimulate neurons that send signals to the brain. But hair cells can be destroyed by disease or injury, or can contain defects at birth, leading to deafness. In such cases, cochlear implants can directly stimulate neurons. The hearing provided by today's implants is good enough to enable deaf children to develop speech skills that are remarkably similar to hearing children's. Implant users still find it tough to appreciate music, communicate in a noisy environment and understand tonal languages like Mandarin, however. That's because the implants use only 20 or so electrodes, a small number compared to the 3000-odd hair cells in a healthy ear. More sources of stimulation should make hearing clearer but more electrodes cannot be packed in because tissue conducts electricity, so signals from different electrodes would interfere. In contrast, laser light targets nerves more precisely and doesn't spread, which could allow an implant to transmit more information to the neurons. © Copyright Reed Business Information Ltd.

Keyword: Hearing
Link ID: 12256 - Posted: 06.24.2010

By Alan Mozes (HealthDay News) -- A compound that boosts growth hormone levels in Alzheimer's patients may not slow the disease, new research suggests. The study, funded by drug giant Merck, was spurred by promising animal research that had suggested that the compound, called MK-677, might help curb Alzheimer's effect on the brain. However, "the study suggests that targeting this hormone system may not be an effective approach at slowing the rate of Alzheimer's disease progression," said study author Dr. J.J. Sevigny, associate director of clinical neuroscience at Merck Research Laboratories in North Wales, Pa. His team reported its finding in the Nov. 18 issue of Neurology. ad_icon "In a similar vein, the study challenges a commonly held theory that hormones may attack beta-amyloid plaque in the brain," Sevigny added. "That was the premise of this research: that by giving this medication we'd be able to influence the beta-amyloid in the brain. And we didn't receive this result in this study." Based on the findings, Merck has now stopped investigating MK-677 for use against Alzheimer's. SOURCES: J.J. (Jeffrey) Sevigny, M.D, associate director, clinical neuro-science, Merck Research Laboratories, North Wales, Pa.; Maria Carrillo, Ph.D., director, medical & scientific relations, Alzheimer's Association, National Office, Chicago; Nov. 18, 2008, Neurology © 2008 Scout News LLC.

Keyword: Alzheimers; Hormones & Behavior
Link ID: 12255 - Posted: 06.24.2010

By GARDINER HARRIS WASHINGTON — Powerful antipsychotic medicines are being used far too cavalierly in children, and federal drug regulators must do more to warn doctors of their substantial risks, a panel of federal drug experts said Tuesday. More than 389,000 children and teenagers were treated last year with Risperdal, one of five popular medicines known as atypical antipsychotics. Of those patients, 240,000 were 12 or younger, according to data presented to the committee. In many cases, the drug was prescribed to treat attention deficit disorders. But Risperdal is not approved for attention deficit problems, and its risks — which include substantial weight gain, metabolic disorders and muscular tics that can be permanent — are too profound to justify its use in treating such disorders, panel members said. “This committee is frustrated,” said Dr. Leon Dure, a pediatric neurologist from the University of Alabama School of Medicine who was on the panel. “And we need to find a way to accommodate this concern of ours.” The meeting on Tuesday was scheduled to be a routine review of the pediatric safety of Risperdal and Zyprexa, popular antipsychotic medicines made, respectively, by Johnson & Johnson and Eli Lilly & Company. Food and Drug Administration officials proposed that the committee endorse the agency’s routine monitoring of the safety of the medicines in children and support its previous efforts to highlight the drugs’ risks. Copyright 2008 The New York Times Company

Keyword: Schizophrenia; Development of the Brain
Link ID: 12254 - Posted: 06.24.2010

Hustling up the escalator, I didn't have time to appreciate the irony of my situation: I was running late to a session on stress. It was with more than strictly professional interest then, that I settled in to hear 5 researchers discuss their latest findings on stress and the brain. In some ways, stress is all in our heads, said Bruce McEwen, a neuroendocrinologist at Rockefeller University in New York City, since our brains are responsible for recognizing and responding to stressors. Three sections in particular: the amygdale, the hippocampus, and the prefrontal cortex work with the hypothalamus to flip on (and hopefully shut down) production of stress hormones and other automatic responses to stress, like increased heart rate. But researchers are now learning how stressors can physically alter our brains, which in turn, may impact how we learn, form memories, and even make decisions. The effects are sometimes reversible but sometimes not, the scientists reported. Stress the monkey. Simona Spinelli of the National Institutes of Health in Bethesda, Maryland and colleagues placed 13 young monkeys in the care of their peers for 6 months, while another 15 monkeys spent the same time with their mothers. Both sets of monkeys then rejoined typical social groups, and the researchers scanned their brains after several months of exposure to the normal environment. The monkeys raised under Lord of the Flies-like conditions showed enlarged brain regions in areas related to stress, compared to the control group, even after spending time in the normal environment. This suggests that early stress can have long-lasting impacts on the brain, Spinelli says, though follow-up studies in humans are necessary. © 2008 American Association for the Advancement of Science.

Keyword: Stress
Link ID: 12253 - Posted: 06.24.2010

By Christof Koch What is consciousness? What is this ineffable, subjective stuff—this thing, substance, process, energy, soul, whatever—that you experience as the sounds and sights of life, as pain or as pleasure, as anger or as the nagging feeling at the back of your head that maybe you’re not meant for this job after all. The question of the nature of consciousness is at the heart of the ancient mind-body problem. How does subjective consciousness relate to the objective universe, to matter and energy? Consciousness is the only way we experience the world. Without it, you would be like a sleepwalker in a deep, dreamless sleep, acting in the world, speaking, having babies, but without feeling anything. You would feel nothing, nada, nichts, rien. Indeed, in the most famous deduction of Western thought, philosopher and mathematician René Descartes concluded that because he was conscious he existed. That was his only unassailable proof that he wasn’t just a chimera. Maybe he didn’t have the body he thought he had, maybe he had fake memories (premonitions of The Matrix), but because he was conscious he must exist. Yet the questions go on. Are only people conscious? What about a fetus? What about a neurological patient in a persistent vegetative state, such as Terri Schiavo (who died in 2005), who can’t do much more than open and close her eyes? Although many are willing to accord sentience, consciousness, to our beloved cats and dogs, what about apes, monkeys, whales, mice, bees and all the other critters on the planet? Can a fly be conscious? What about artificial consciousness? Is your cool iPhone sentient? Can machines ever become conscious, as is widely assumed in so many science-fiction novels and movies? © 1996-2008 Scientific American Inc.

Keyword: Attention; Emotions
Link ID: 12252 - Posted: 06.24.2010

By Susana Martinez-Conde and Stephen L. Macknik Scientists did not invent the vast majority of visual illusions. Rather, they are the work of visual artists, who have used their insights into the workings of the visual system to create visual illusions in their pieces of art. We have previously pointed out in our essays that, long before visual science existed as a formal discipline, artists had devised techniques to “trick” the brain into thinking that a flat canvas was three-dimensional, or that a series of brushstrokes in a still life was in fact a bowl of luscious fruit. Thus the visual arts have sometimes preceded the visual sciences in the discovery of fundamental vision principles, through the application of methodical—although perhaps more intuitive—research techniques. In this sense, art, illusions and visual science have always been implicitly linked. It was only with the birth of the op art (for “optic art”) movement that visual illusions became a recognized art form. The movement arose simultaneously in Europe and the U.S. in the 1960s, and in 1964 Time magazine coined the term “op art.” This style became hugely popular after the Museum of Modern Art in 1965 held an exhibition called “The Responsive Eye.” In it, op artists explored many aspects of visual perception, such as the relations between geometrical shapes, variations on “impossible” figures that could not occur in reality, and illusions concerning brightness, color and shape perception. But “kinetic,” or motion, illusions drew particular interest. In these eye trick, stationary patterns give rise to the powerful but subjective perception of (illusory) motion. © 1996-2008 Scientific American Inc.

Keyword: Vision
Link ID: 12251 - Posted: 06.24.2010

by David Robson WOMEN may be fed up with being stereotyped as the chattier sex, but the cliche turns out to be true - in female-centric monkey groups at least. The gossipy nature of female macaques also adds weight to the theory that human language evolved to forge social bonds. Many researchers think that language replaced grooming as a less time-consuming way of preserving close bonds in ever-growing societies. Nathalie Greeno and Stuart Semple from Roehampton University in London hypothesised that if this was true then in species of animals with large social networks, such as macaques, vocal exchanges should be just as important as grooming. The duo listened to a group of 16 female and eight male macaques living on Cayo Santiago island off Puerto Rico for three months. They counted the grunts, coos and girneys - friendly chit-chat between two individuals - while ignoring calls specific to the presence of food or a predator. The team found that females made 13 times as many friendly noises as males. "The results suggest that females rely on vocal communication more than males due to their need to maintain the larger social networks," Greeno says. Females rely on vocal communication more than males due to their need to maintain larger social networks © Copyright Reed Business Information Ltd.

Keyword: Language; Evolution
Link ID: 12250 - Posted: 06.24.2010

The dietary supplement Ginkgo biloba was found to be ineffective in reducing the development of dementia and Alzheimer's disease in older people, according to a study published in the Journal of the American Medical Association1. Researchers led by Steven T. DeKosky, M.D., formerly of the University of Pittsburgh, vice president and dean of the School of Medicine at the University of Virginia in Charlottesville, conducted the trial known as the Ginkgo Evaluation of Memory (GEM) study at four clinical sites over the course of 8 years. GEM is the largest clinical trial ever to evaluate ginkgo's effect on the occurrence of dementia. This research was co-funded by five components of the National Institutes of Health (NIH): National Center for Complementary and Alternative Medicine (NCCAM); National Institute on Aging (NIA); National Heart, Lung, and Blood Institute; National Institute of Neurological Disorders and Stroke, and the Office of Dietary Supplements. "We have made enormous progress in understanding the basic mechanisms involved in Alzheimer's disease, and we continue to pursue a vigorous program to translate what we know into the development and testing of new potential therapies for this devastating disease," said Richard Hodes, M.D., director of the NIA. "However, it is disappointing that the dietary supplement tested in this study had no effect in preventing Alzheimer's disease."

Keyword: Alzheimers; Learning & Memory
Link ID: 12249 - Posted: 11.20.2008

-- Biologists on Wednesday explained how the larvae of marine zooplankton can see with just two cells, using what is believed to be the world's simplest vision system. Zooplankton are tiny creatures such as copepods and krill that drift in the ocean's water columns, swimming up from the depths towards the light in order to graze on marine plants called phytoplankton near the surface. This movement, called phototaxis, is the biggest biomass displacement in the world. In a study published by the British-based journal Nature, European scientists looked at the larvae of the marine ragworm Platyneris dumerilii to try to explain how plankton are able to do the phototaxis trick. The larva has just two eye cells, consisting of a pigment cell and a light-sensitive cell, say the investigators. The cells are unable to form images but enable the plankton to sense the difference between light and dark and send appropriate signals to its swimming mechanism, say the investigators. © 2008 Discovery Communications, LLC.

Keyword: Vision; Evolution
Link ID: 12248 - Posted: 06.24.2010

by Ewen Callaway The female brain has a clever way of mitigating the stress experienced during menstruation: it flip-flops. The region of the brain used for coping with stress flips to the opposite side of the brain during a woman's period - from an area linked to negative emotion to one that usually deals with cheerier thoughts. Such a change could help women cope with the hormonal maelstrom going on in their bodies without causing huge behavioural shifts. Oestrogen levels levels, in particular, plummet around menstruation. Jen-Chuen Hsieh, a neuroscientist at National Yang-Ming University in Taipei, Taiwan, and colleagues studied 14 women using a magnetoencephalograph ¬ a machine that measures magnetic waves created by brain activity. All their subjects were right-handed, to ensure that the left-right orientation of their brains matched. When the women were shown frightening images, they normally triggered activity in the right half of the women's brains. This side of the brain tends to process negative feelings, such as anxiety. During the women's menstrual periods, however, the images activated areas in the left half of their brains, which handles positive emotions. © Copyright Reed Business Information Ltd.

Keyword: Stress; Hormones & Behavior
Link ID: 12247 - Posted: 06.24.2010

Scientists have identified a molecule which could be key to understanding the cause of motor neurone disease (MND) and other neurodegenerative disorders. The Proceedings of the National Academy of Sciences study raise the hope of new treatments being developed. The London-based team showed the molecule, Wnt3, plays a key role in establishing connections between nerve cells and the muscles they control. These connections become progressively weaker in MND patients. Without properly-formed connections - or synapses - the muscle cannot receive the nerve signal that tells it to contract. This results in the muscle weakness that is typical of MND. However, scientists have not been clear how synapses are formed in normal circumstances and this has made it very difficult to pin down what goes wrong in MND. The researchers, from University College London and King's College London, identified Wnt3 as key to the process. It assists a second molecule, called Agrin, which co-ordinates construction of the connection - or synapse. Lead researcher Professor Patricia Salinas said: "The work we are publishing today puts an important piece of the puzzle in place and offers up a new possibility for developing drugs to treat MND and other neurodegenerative diseases. "If we can build up a thorough picture to show how synapses are normally formed between nerves and muscles we can start to look for any elements that aren't working properly in people with MND. This might also lead to strategies for nerve repair after an injury." (C)BBC

Keyword: ALS-Lou Gehrig's Disease
Link ID: 12246 - Posted: 11.18.2008

A handful of people reach old age with razor-sharp brains. Scientists call them "super aged." But what makes them special? In a new study, researchers examined the brains of five dead people who were considered super aged because after age 80 they had performed higher on memory tests than others their age. The scientists compared these brains to those from some "normal," non-demented elderly folks who had died. Story continues below ↓advertisement | your ad here The super aged brains had fewer fiber-like tangles than the brains of people who had aged normally. The tangles consist of a protein called tau that accumulates inside brain cells and is thought to eventually kill them, the researchers explained in what they're calling a preliminary finding. Tangles are found in at least moderate numbers in the brains of all elderly people, but they are more prevalent in the brains of Alzheimer's disease patients. "It was always assumed that the accumulation of these tangles is a progressive phenomenon through the aging process. But we are seeing that some individuals are immune to tangle formation and that the presence of these tangles seems to influence cognitive performance," said Changiz Geula, principal investigator of the study and a research professor of neurology at the Cognitive Neurology and Alzheimer's Disease Center at Northwestern's Feinberg School in Illinois. © 2008 LiveScience.com.

Keyword: Alzheimers
Link ID: 12245 - Posted: 06.24.2010

By JOHN TIERNEY Last year, a team of researchers at Harvard made headlines with an experiment testing unconscious bias at hospitals. Doctors were shown the picture of a 50-year-old man — sometimes black, sometimes white — and asked how they would treat him if he arrived at the emergency room with chest pains indicating a possible heart attack. Then the doctors took a computer test intended to reveal unconscious racial bias. The doctors who scored higher on the bias test were less likely than the other doctors to give clot-busting drugs to the black patients, according to the researchers, who suggested addressing the problem by encouraging doctors to test themselves for unconscious bias. The results were hailed by other psychologists as some of the strongest evidence that unconscious bias leads to harmful discrimination. But then two other researchers, Neal Dawson and Hal Arkes, pointed out a curious pattern in the data. Even though most of the doctors registered some antiblack bias, as defined by the researchers, on the whole doctors ended up prescribing the clot-busting drugs to blacks just as often as to whites. The doctors scoring low on bias had a pronounced preference for giving the drugs to blacks, while high-scoring doctors had a relatively small preference for giving the drugs to whites — meaning that the more “biased” doctors actually treated blacks and whites more equally. Copyright 2008 The New York Times Company

Keyword: Emotions
Link ID: 12244 - Posted: 06.24.2010