Carina Dennis To sense where the various parts of our body are, we sometimes rely on signals that originate in our brain rather than in our fingers or toes, a new study shows. The so-called sixth sense, known as proprioception, is essential to many basic actions, including walking without having to look at your feet or touching your nose with your eyes closed. But scientists have long pondered how this sense works. It is generally accepted that sensors in the skin, muscles and joints send information to the brain that is crucial to sensing limb position. Now researchers in Australia have evidence of the importance of outgoing messages from the brain. "This will provoke debate, because the idea that the sense of position is mostly the result of the sensory receptors is well-entrenched," says Timothy Miles, a physiologist at the University of Adelaide, Australia, who is independent of the study. Janet Taylor from the University of New South Wales in Sydney and her colleagues strapped the forearm and hand of volunteers into a covered apparatus that prevents the subject from seeing the position of their hand. Under normal conditions, the subject could accurately tell if and how their hand had been moved by an experimenter or by themselves. ©2006 Nature Publishing Group

Keyword: Pain & Touch
Link ID: 8697 - Posted: 06.24.2010

By Shankar Vedantam Antidepressants fail to cure the symptoms of major depression in half of all patients with the disease even if they receive the best possible care, according to a definitive government study released yesterday. Significant numbers of patients continue to experience symptoms such as sadness, low energy and hopelessness after intensive treatment, even as about an equal number report an end to such problems -- a result that quickly lent itself to interpretations that the glass was either half empty or half full. The $35 million taxpayer-funded study was the largest trial of its kind ever conducted. It provided what industry-sponsored trials have rarely captured: Rather than merely ask whether patients are getting better, the study asked what patients most care about -- whether depression can be made to disappear altogether. The study has been eagerly awaited by physicians, patients and the pharmaceutical industry. According to government statistics, depression afflicts 15 million Americans a year. About 189 million prescriptions for antidepressants were written last year, and the disease costs the nation $83 billion annually because of treatment costs, lost productivity, absenteeism and suicide. David Rubinow, a professor and the chairman of the psychiatry department at the University of North Carolina at Chapel Hill, said the results are an "illuminating and disconcerting" window into the affliction that is thought to fuel many of the 30,000 suicides committed each year in the United States. © 2006 The Washington Post Company

Keyword: Depression
Link ID: 8696 - Posted: 06.24.2010

By GARDINER HARRIS GAITHERSBURG, Md., — Stimulants like Ritalin lead a small number of children to suffer hallucinations that usually feature insects, snakes or worms, according to federal drug officials, and a panel of experts said on Wednesday that physicians and parents needed to be warned of the risk. The panel members said they hoped the warning would prevent physicians from prescribing a second drug to treat the hallucinations caused by the stimulants, which one expert estimated affect 2 to 5 of every 100 children taking them. Instead, they said, the right thing to do in such cases was to stop prescribing the stimulants. On Feb. 9, a different advisory committee voted 8 to 7 to recommend that the Food and Drug Administration place its most serious warning label, a so-called black box, on the labels of stimulants to warn that they could have dangerous effects on the heart, particularly in adults. That recommendation grew out of reports that 25 people, mostly children, had died suddenly while taking the drugs. The twin conclusions come more than 50 years after Ritalin was first approved to treat attention deficit disorder and hyperactivity. Since then, stimulants have become among the most widely prescribed medicines in the world. In the United States alone, about 2.5 million children and 1.5 million adults take them; as many as 10 percent of boys ages 10 to 12 do. Copyright 2006 The New York Times Company

Keyword: ADHD
Link ID: 8695 - Posted: 06.24.2010

Three decades after Richard Dawkins revolutionised our understanding of living things with The Selfish Gene, evidence has accumulated to back his cold-eyed vision of how bodies, families and society are shaped by the simple "duplicate me" message in our genetic instructions. His book, which has sold more than a million copies, did not mean to imply that genes have actual motives, only that their effects can be described as if they do: the genes that get passed on to the next generation are the ones whose consequences serve their own interests, not necessarily those of the societies or even the organisms in which they find themselves. We are merely vehicles to help replicate DNA, according to the Oxford University biologist. A Cambridge University team reported the consequences for meerkats, those loveable stars of natural history films, a day or two before Prof Dawkins marked the 30th birthday of his book last week, with a packed Darwin@LSE event with Ian McEwan, Dan Dennett, Matt Ridley, Sir John Krebs and Melvyn Bragg at the London School of Economics. A meerkat group is closely related and this is why they look out for each other. But the image of caring creatures standing on endless sentry duty to protect their pups and family does not quite tell the full story, according to an eight-year study carried out on the Kuruman River Reserve by Dr Andrew Young and Prof Tim Clutton-Brock. © Copyright of Telegraph Group Limited 2006.

Keyword: Evolution; Sexual Behavior
Link ID: 8694 - Posted: 06.24.2010

New research shows that one in three to four people who do not achieve a full remission of symptoms from an initial antidepressant became symptom-free after changing to or adding a second antidepressant. Phase two results of the four-phase study on treatments for depression – the largest of its kind – appear online in two companion articles in today's New England Journal of Medicine. "The message to the patient is: 'Hang in there. If the first treatment does not relieve your symptoms, consider changing or adding another medication. Follow instructions from your doctor, and don't give up,' " said Dr. A. John Rush, vice chairman of clinical sciences and professor of psychiatry at UT Southwestern. He is principal investigator of the study and lead author of one of the articles. "For a depressed individual, it may not matter so much what drug is being prescribed, but that the person moves forward and keeps trying." Designed to assess the effectiveness of various treatments for depression in "real-world" settings for people who also have other medical and psychiatric conditions, the $35 million, six-year study – designated STAR*D (Sequenced Treatment Alternatives to Relieve Depression) and funded by the National Institute of Mental Health (NIMH) – involved nearly 3,000 patients at 41 primary-care and psychiatric clinics. Researchers at 14 medical institutions worked together under the direction of UT Southwestern as the national coordinating center.

Keyword: Depression
Link ID: 8693 - Posted: 06.24.2010

Findings could help identify cause of schizophrenia, Parkinson's, drug addiction Amid reports that a drug used to treat Parkinson's disease has caused some patients to become addicted to gambling and sex, University of Pittsburgh researchers have published a study that sheds light on what may have gone wrong. In the current issue of Proceedings of the National Academy of Sciences, Pitt professor of neuroscience, psychiatry, and psychology Anthony Grace and Pitt neuroscience research associate Daniel Lodge suggest a new mechanism for how the brain's reward system works. The main actor in the reward system is a chemical called dopamine. When you smell, touch, hear, see, or taste a pleasurable stimulus, the dopamine neurons in your brain start firing in bursts. So-called "burst firing" is how the brain signals reward and modulates goal-directed behavior. But just how the stimulus you perceive causes neurons to switch into or out of this mode has been a mystery. Using anesthetized rats, Lodge and Grace found that one area in the brain stem, known as the laterodorsal tegmental nucleus, is critical to normal dopamine function. "We've found, for the first time, the brain area that acts as the gate, telling neurons either to go into this communication mode or to stop communicating," says Grace. "All the other parts of the brain that talk to the dopamine neurons can only do it when this area puts them into the communication mode."

Keyword: Drug Abuse
Link ID: 8692 - Posted: 03.23.2006

Sending tiny electric pulses to a part of the brain controlling motor function helps ischemic stroke survivors regain partial use of a weakened hand, new Oregon Health & Science University research shows. But coupling the technique known as cortical stimulation with aggressive rehabilitation is key to reversing the impairment, doctors say. "It's the coolest thing in stroke I've seen in a long time," said Helmi Lutsep, M.D., associate professor of neurology and associate director of the Oregon Stroke Center, OHSU School of Medicine. In a study examining the safety of cortical stimulation therapy, Lutsep and co-investigators found that stroke patients who received stimulation with rehabilitation improved "significantly" better in hand mobility and strength tests than people undergoing rehabilitation alone. "Everybody improved to some degree, because even in the subjects who received some rehabilitation, we did see improvement," Lutsep said. "What the data suggested is those who received the (stimulation) implant improved more." The study was published this month in the journal Neurosurgery. Lutsep's co-investigators were Jeffrey A. Brown, M.D., of Wayne State University, Detroit, Martin Weinand, M.D., of the University of Arizona, Tucson, and Steven C. Cramer, M.D., of the University of California, Irvine.

Keyword: Stroke
Link ID: 8691 - Posted: 03.23.2006

BUFFALO, N.Y. -- Researchers at the University at Buffalo and the University of Pennsylvania were the first to demonstrate that two intracellular events, both stimulated by the same cell receptor, can provoke different behaviors in mammals. The broad implication of the findings may alter the way behavioral neuroscientists think about sub-cellular underpinnings of mammalian behavior, according to the researchers. The study, "Divergent Behavioral Roles of Angiotensin Receptor Intracellular Signaling Cascades," was published in the journal Endocrinology (Vol. 146, No. 12). It can be found online at http://endo.endojournals.org/cgi/content/full/146/12/5552. The co-authors of the study are Derek Daniels, assistant professor of psychology at the University at Buffalo, and Daniel K. Yee, research associate professor, Department of Animal Biology, University of Pennsylvania School of Veterinary Medicine. Daniels says, "The research highlights the importance of intracellular events in the regulation of behavioral states and provides new information about the means through which a single hormone can influence multiple mammalian behaviors like learning and memory, eating, drinking, reproduction and social interaction." © 2006 University at Buffalo.

Keyword: Hormones & Behavior
Link ID: 8690 - Posted: 06.24.2010

A two-year-old can quickly link an object--whether a flashy rattle or a boring latch--to a word. Even a one-year-old can follow a parent's gaze to an object and match it with a word being spoken. But although anecdotal evidence seems to show that babies younger than one year can learn words, it remains unclear whether they are in fact mastering language. Now a new study reveals that 10-month-old infants can link words and objects, but only if the object is already interesting to them. Psychologist Kathy Hirsh-Pasek of Temple University and her colleagues tested 44 infants for the ability to learn words. The infants averaged an understanding of nearly 14 words already, according to their mothers. But the researchers paired four novel objects--a blue sparkle wand and a white cabinet latch, a pink party clacker and a beige bottle opener--with four nonsensical words--modi, glorp, dawnoo and blicket--to test their ability to associate new words with new objects. Sitting on their mothers' laps, the infants were exposed to the objects. First, they were allowed to play with an interesting and boring object pair followed by seeing the two objects placed on a rotating board. This was done to assess which object was more interesting to the babies and, as expected, they preferred the brightly-colored, noisy ones. Then the researchers placed the two objects on a table in front of the infant. If the baby was in one group, the experiment leader pointed to the interesting object and labeled it with one of the nonsense words. If the baby was a member of the other group, the researcher pointed to the boring object and labeled it with the same nonsense word. Regardless of the researchers’ efforts, the infants looked at the object they found interesting. © 1996-2006 Scientific American, Inc.

Keyword: Language; Development of the Brain
Link ID: 8689 - Posted: 06.24.2010

In a series of experiments designed help scientists understand the brain chemicals that guide mate selection, Pfaff and his colleagues exposed female mice to odors of either a male mouse alone or a male mouse with a female. The females consistently preferred the scent of males linked to other females. "Our data suggest that female mice may use, or even copy, the interests of other females based on olfactory cues," says Pfaff, who is head of the Laboratory of Neurobiology and Behavior. "It could also be seen as a female trusting the mate choice of another female." That one female's choice of mate could influence the choices of other females is well documented in birds and fish, but had not been documented for any mammalian species. Pfaff says that the female mice's mate preference was so strong that they even preferred the combined male/female scent when it was tainted with the scent of infectious parasites, opting for that over the scent of a healthy lone male. "Male odors can provide female mice with information on their quality, condition, health and suitability as a potential mate," says Pfaff. "This type of 'public information' uses cues inadvertently provided by an individual, such as odor, which others observe use to make decisions such as mate choice, food location, or presence of danger. Specifically in birds and fish, 'public information' has been shown play a role in when and what to eat and with whom to mate with, but its use in mate choice has not been seen in mammals."

Keyword: Sexual Behavior; Chemical Senses (Smell & Taste)
Link ID: 8688 - Posted: 03.22.2006

—Penn State researchers have created an elegantly simple model of an axon--the extension of a neuron that communicates with other neurons--and have used this model to reproduce a change in the axon's shape that is characteristic of neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. This achievement is the first of its kind in a highly simplified biophysical model system. The model provides a novel avenue for investigating the specific mechanisms that contribute to complex brain diseases. It also provides a means of discovering new kinds of drugs for the treatment of these disorders. The research will be described in a paper to be published in the 4 April 2006 issue of the Proceedings of the National Academy of Science. This model, produced in the laboratory of Paul S. Weiss, Distinguished Professor of Chemistry and Physics at Penn State, has the essential features of an axon, including a lipid membrane that encloses a "cytoskeleton" scaffolding, which produces the axon's shape. The outer membrane was prepared to contain a very small amount of dye molecules that are sensitive to ultraviolet light. Shining light on the artificial axons initiated a photochemical reaction that produced highly reactive "free radicals" and triggered a catastrophic oxidative-stress reaction. The result was that the previously protruding microtubule cytoskeleton collapsed into a constricted and deformed structure resembling a string of beads--the same morphology observed during the degeneration of actual neurons. Surprisingly, the model reproduced this highly characteristic "beading" or "pearling" even though it does not include proteins that were previously thought to be essential for causing this kind of axon destruction.

Keyword: Parkinsons; Alzheimers
Link ID: 8687 - Posted: 06.24.2010

By Ingrid Wickelgren The next time you drive in the fog, check your speedometer. You may be speeding and not know it. That's because--when the visual landscape lacks contrast--people perceive objects moving much slower than they actually are. A new study debuts the first convincing, quantitative explanation for this potentially dangerous visual mistake. In 1982, psychologist Peter Thompson of York University, United Kingdom, first noticed that when two objects of different contrast are moving at the same speed, people always say the higher contrast object is moving faster. Researchers brushed off this misperception, dubbed "the Thompson effect," as a kink in an otherwise precisely tuned visual machine. But a few years ago, Eero Simoncelli, a computational neuroscientist at New York University in New York City, and his colleagues wondered if they could explain this phenomenon using basic principles of human vision. Simoncelli knew that the eye does not simply record light patterns like a camera does: Instead, what people see depends greatly on past experience (a cloud looks like a boat to one person and a truck to another, for example). So he and colleagues suspected that, when real information is sketchy (as it is in low-contrast situations), people rely even more heavily on their expectations. In a 2002 paper, the researchers used Bayesian statistics--a branch of mathematics that shows the ideal way to combine expectations with new information--to prove that this was indeed the case. It could also account for the Thompson effect, they argued. © 2006 American Association for the Advancement of Science

Keyword: Vision
Link ID: 8686 - Posted: 06.24.2010

Two risk factors that place males at greater risk for heart disease than women appear to be influenced by genes on the X chromosome, report researchers at the NIH and the University of Texas Southwestern Medical School. The finding appears in a Research Letter in the Journal of the American Medical Association. In a separate Research Letter, the researchers at the NIH and at Thomas Jefferson University in Philadelphia also report that women who lack functioning ovaries — either because of a hereditary condition or due to an illness — are more likely than are other women to experience shyness and anxiety in social situations. In the first report, researchers studied women with Turner syndrome, a hereditary condition in which women are missing all or part of one X chromosome, explained the senior author of both reports, Carolyn Bondy, Chief of the Developmental Endocrinology Branch at NIH’s National Institute of Child Health and Human Development. The researchers tested whether the women had inherited their single normal X chromosome from their mothers or from their fathers. Women normally inherit one of their two X chromosomes from their mother and one from their father. Men normally inherit a single X chromosome from their mothers. The researchers also measured the women’s body fat distribution patterns and their cholesterol and triglyceride levels. Dr. Bondy explained that men have a greater tendency than do women to accumulate fat within their abdomens, while women tend to accumulate fat around their hips, buttocks, and thighs. Proportionally higher abdominal fat distribution is associated with cholesterol levels that increase the chances of cardiovascular disease.

Keyword: Genes & Behavior; Obesity
Link ID: 8685 - Posted: 06.24.2010

By Jennifer Viegas, Discovery News — A Scotsman with a heavy brogue may speak the same language as a Texas cowboy, but each has a distinct accent; now researchers have discovered that female whipbirds in Australia sing the same basic songs, but with regional accents. Female birds in general rarely sing, so that find itself is unusual. The determination is doubly noteworthy because the scientists observed that the males of this species, Psophodes olivaceus, sing with no accent whatsoever. "It is so intriguing to see both of these opposite patterns occurring within the same species," said lead researcher Daniel Mennill, a professor of behavioral ecology at the University of Windsor in Canada. "You wouldn't be shocked to visit one town and hear people speak with a twang, and then visit another town and hear a drawl ... .," he said. "But can you imagine if, in your travels, you found that females sounded different in each town, but males had the same brogue? These whipbirds demonstrate such a pattern." Mennill and his colleague Amy Rogers measured eastern whipbird recordings from 16 different populations along the east coast of Australia. For each of the 112 birds that they recorded, they measured the song's number of syllables, the length of the first syllable, the highest and lowest frequency of the last syllable, the time between these frequency extremes and other characteristics. © 2006 Discovery Communications Inc.

Keyword: Language
Link ID: 8684 - Posted: 06.24.2010

Children with personalities marked by aggressiveness, mood swings, a sense of alienation and a need for excitement may be at greater risk for attention deficit hyperactivity disorder or conduct disorder, according to a new Florida State University study. FSU psychology professors Jeanette Taylor and Chris Schatschneider, FSU doctoral student Kelly Cukrowicz and University of Minnesota Professor William Iacono found that children with ADHD or conduct disorder had more negative emotions - aggressiveness, tension and feelings of being exploited, unlucky or poorly treated - and lower constraints - a tendency to break rules and engage in thrill-seeking behavior - than children with neither of the disorders. Not surprisingly, those children who have both ADHD and conduct disorder had the most extreme personality profiles. "This helps us to understand that personality is part of the bigger picture of these disorders," Taylor said. "That could help with initial assessments or lead to unexpected discoveries or potential interventions. We're saying to researchers and clinicians, 'Think about personality when you look at these issues.' " The study, published in the Journal of Child Psychology and Psychiatry, is the first to investigate personality trait patterns among children who have ADHD, conduct disorder or a combination of both. It is important to learn more about the co-occurrence of ADHD and conduct disorder because the consequences are so severe, Taylor said.

Keyword: ADHD; Aggression
Link ID: 8683 - Posted: 03.22.2006

ANN ARBOR, Mich.—It was once thought that only humans gestured to direct another person’s attention, but such “referential” gesturing was recently observed in wild chimpanzees. John Mitani, University of Michigan anthropology professor, and colleague Simone Pika, a postdoctoral fellow in psychology at University of St. Andrews in Scotland, observed male chimps habitually using “directed scratches” to request grooming of specific areas on the body. The findings suggest that our closest living relatives may be capable of mental-state attribution, making inferences about the knowledge of others. Up until now, scientists saw directed scratching only in captive chimps and language-trained apes who interacted with humans, Mitani said. “The more we learn, the more we see chimpanzees employing remarkable, seemingly human-like behaviors,” Mitani said. “To me that is one of the lessons of this little paper.” The findings appear in today’s issue of Current Biology, in a paper entitled “Referential Gestural Communication in Wild Chimpanzees.” Copyright © 2005 The Regents of the University of Michigan

Keyword: Evolution
Link ID: 8682 - Posted: 06.24.2010

The songs of the humpback whale are among the most complex in the animal kingdom. Researchers have now mathematically confirmed that whales have their own syntax that uses sound units to build phrases that can be combined to form songs that last for hours. Until now, only humans have demonstrated the ability to use such a hierarchical structure of communication. The research, published online in the March 2006 issue of the Journal of the Acoustical Society of America, offers a new approach to studying animal communication, although the authors do not claim that humpback whale songs meet the linguistic rigor necessary for a true language. With limited sight and sense of smell in water, marine mammals are more dependent on sound—which travels four times faster in water than air—to communicate. For six months each year, all male humpback whales in a population sing the same song during mating season. Thought to attract females, the song evolves over time. Suzuki and co-authors John Buck and Peter Tyack applied the tools of information theory—a mathematical study of data encoding and transmission—to analyze the complex patterns of moans, cries, and chirps in the whales' songs for clues to the information being conveyed. Buck is an electrical engineer who specializes in signal processing and underwater acoustics at the University of Massachusetts Dartmouth, and Tyack is a biologist at Woods Hole Oceanographic Institution in Massachusetts. © 2006 Howard Hughes Medical Institute

Keyword: Hearing; Language
Link ID: 8681 - Posted: 06.24.2010

A 24-year-old Norfolk woman hopes to be among the first British patients to overcome a severe stammer by using a special electronic device. Heidi King is volunteering for the treatment in New York, the British Stammering Association (BSA) said. BSA chief executive Norbert Lieckfeldt said the device, like a hi-tech hearing aid, would be fitted in her inner ear. It then mimics the user's voice after research showed stammerers are helped by speaking in unison with others. Test revealed singing or saying the same words together - the so-called "choral effect" - can help people stop stammering. The phenomenon was first identified in the 1950s and the earpiece would convert the way Heidi, from Norwich, hears her own voice into a chorus-like sound. The device, called SpeechEasy, is not available in the UK and is not funded by the National Health Service. On Monday Miss King said she needed to raise about £5,000 to cover the costs of her treatment and the three weeks she would need to stay in New York. (C)BBC

Keyword: Language
Link ID: 8680 - Posted: 03.21.2006

The image of a twitchy nervous liar touching his nose and stroking his hair may itself be a lie, a study says. Italian and British researchers found when people lied they tended to stay still as they were acutely aware their body language might give them away. The team monitored 130 volunteers as they were asked to make a series of honest and dishonest statements. The study, in Journal of Nonverbal Behaviour, found liars touched their noses 20% less than truth tellers. Psychologist Dr Samantha Mann, who co-authored the study, said there was a popular perception that when people lie they scratch their nose and play with their hair more. These movements are known as self-adaptor gestures which serve to comfort a person feeling vulnerable or exposed. Instead of giving into these urges, she claimed, liars tried very hard to stay still and were just as likely as an honest person to look the questioner in the eye. She added: "People expect liars to be nervous and shifty and to fidget more, but our research shows that is not the case. "People who are lying have to think harder, and when we think harder we tend to be a lot stiller, with fewer movements, because we are concentrating harder." She added: "As soon as we know that we are lying we suddenly become very aware of our behaviour. Most people tend to refrain from making movements at all." The team from the universities of Portsmouth and Bergamo in Italy, also looked for changes in seven categories of hand gestures in their volunteers. They found liars literally went to huge lengths to cover their tracks, especially when they were challenged over whether they were telling the truth. Those under strong suspicion used certain types of hand gestures more in order reinforce the point. (C)BBC

Keyword: Stress
Link ID: 8679 - Posted: 03.21.2006

By Sandra G. Boodman The pocket-watch-sized device is billed as "a pacemaker for the brain," the newest cutting-edge treatment for as many as 4 million adults whose severe depression is not relieved by psychotherapy, drugs or even shock treatments. Since its approval under unusual circumstances eight months ago by the Food and Drug Administration (FDA), more than 550 Americans have undergone surgery to have a vagus nerve stimulator (VNS) implanted in their chests to activate parts of their brains. Another 7,000 people -- aided by a network of nurses hired by Cyberonics, the Houston-based manufacturer of the device -- are seeking approval from their insurance companies for the $25,000 operation. More than 3,700 psychiatrists, including doctors affiliated with Suburban, Georgetown, Sheppard Pratt and Howard University hospitals, have been trained in the use of VNS, the first device ever approved to treat depression. It consists of a battery-operated generator attached to an electrode implanted in the vagus nerve in the neck. The generator emits regular pulses of electricity that are supposed to stimulate serotonin and other brain chemicals believed to regulate mood, according to Cyberonics. Yet despite the imprimatur of the FDA and an aggressive marketing campaign mounted by the company, the most basic question about the treatment remains unanswered: Does it work? Is VNS a lifesaving treatment for chronic depression, as some patients and doctors maintain, or an unproven and potentially harmful treatment based on flimsy science, as critics contend? © 2006 The Washington Post Company

Keyword: Depression
Link ID: 8678 - Posted: 06.24.2010