By GINA KOLATA IN a way it all seems so obvious. Your friend found a lump in her breast, so you have that long-delayed mammogram. One by one your friends stop smoking, so you stop, too. Of course people are affected by their friends’ habits and their health. But what seems obvious in the abstract can lead to surprising findings. A recent study found that obesity can spread from friend to friend much like a virus. When one person gains weight, close friends tend to gain weight, too. The study, published recently in The New England Journal of Medicine, involved a detailed analysis of a large social network of 12,067 people who had been closely followed for 32 years, from 1971 to 2003. Now, scientists believe that social networks not only can spread diseases, like the common cold, but also may influence many types of behavior — negative and positive — which then affect an individual’s health, as well as a community’s. “In the past few years we have been seeing a network revolution,” says Albert-Laszlo Barabasi, a physics professor at the University of Notre Dame. “People sensed that networks were out there, but they never had large enough data sets to start understanding them in a quantitative fashion.” Copyright 2007 The New York Times Company

Keyword: Obesity
Link ID: 10574 - Posted: 06.24.2010

By EMILY BAZELON Caitlyn & Marguerite sat knee to knee in a sunny room at the Hawks Camp in Park City, Utah. On one wall was a white board with these questions: What’s your favorite vacation and why? What’s your favorite thing about yourself? If you could have any superpower, what would it be? Caitlyn, who is 13, and Marguerite, who is 16 (I’ve used only their first names to protect their privacy), held yellow sheets of paper on which they had written their answers. It was the third day of the weeklong camp, late for icebreakers. But the Hawks are kids with autistic disorders accompanied by a normal or high I.Q. And so the main goal of the camp, run on a 26-acre ranch by a Utah nonprofit organization called the National Ability Center, is to nudge them toward the sort of back and forth — “What’s your favorite video game?” — that comes easily to most kids. Along with Caitlyn and Marguerite, there were nine boys in the camp between the ages of 10 and 18. They also sat across from one another in pairs, with the exception of one 18-year-old who was arguing with a counselor. “All I require is a purple marker,” the boy said over and over again, refusing to write with the black marker he had been given. A few feet away, an 11-year-old was yipping and grunting while his partner read his answers in a monotone, eyes trained on his yellow paper. Another counselor hurried over to them. Marguerite was also reading her answers without eye contact or inflection. “My favorite vacations were to India and Thailand my favorite thing about myself is that I’m nice to people if I could choose any superpower I’d be invisible,” she said in an unbroken stream. She looked up from her paper and past Caitlyn. The girls didn’t look uncomfortable, just unplugged. Copyright 2007 The New York Times Company

Keyword: Autism
Link ID: 10573 - Posted: 06.24.2010

By Christoph Uhlhaas Could you buy a used car online, sight unseen and without a test-drive? How about a plane? A vehicle changes hands on eBay Motors every 60 seconds, including one private business jet that sold for $4.9 million. Every second buyers collectively swap more than $1,839 for products through eBay, sending money to complete strangers with no guarantee that the goods they buy will in fact arrive, let alone in the condition they expect. As a rule, they are not disappointed. To some economists, this is a borderline miracle, because it contradicts the concept of Homo economicus (economic man) as a rational, selfish person who single-mindedly strives for maximum profit. According to this notion, sellers should pocket buyers’ payments and send nothing in return. For their part, buyers should not trust sellers—and the market should collapse. Economist Axel Ockenfels of the University of Cologne in Germany and his colleagues have spent the past several years figuring out why this does not happen. It turns out that humans do not always behave as if their sole concern is their personal financial advantage—and even when they do, they consider social motives in the profit-making equation. As Ockenfels has discovered, a sense of fairness often plays a big role in people’s decisions about what to do with their money and possessions, and it is also an essential part of what drives trust in markets full of strangers such as eBay. © 1996-2007 Scientific American, Inc

Keyword: Emotions
Link ID: 10572 - Posted: 06.24.2010

By Nikhil Swaminathan Researchers have discovered how the brain chunks an unbroken river of information. It's a classic cocktail party conundrum: How do our brains decide where we should train our attention when people are milling all about us chatting away—some to us, some to others? In an attempt to find out, researchers at Stanford University and McGill University in Montreal scanned the brains of 18 subjects who were listening to classical music by 18th-century British composer William Boyce. "You have to kind of segment these streams [of information] into chunks," says senior study author Vinod Menon, an associate professor of psychiatry and behavioral science at Stanford. The process of slicing the data, he continues, requires that you "identify something that's interesting and then you have to switch on the attentional network." "Memory doesn't work like video recorder, it's more like DVD," in how it recalls events as discrete chapters, explains study co-author Daniel Levitin, a psychology professor at McGill. But why music? Simple, says Sridhar Devarajan, a Stanford neuroscience graduate student involved in the project. "Transitions between musical movements," he notes, "offer an ideal setting to study the dynamically changing landscape of activity in the brain during this segmentation process." © 1996-2007 Scientific American, Inc.

Keyword: Hearing; Attention
Link ID: 10571 - Posted: 06.24.2010

Bruce Bower Look, up in the trees. A barrel-chested, long-limbed creature covered with wispy, reddish hair sits on a branch far above the ground. The animal rises to a fully erect posture, reaches up to grab an overhead branch for balance, and promenades across the precarious platform. Upon reaching a cluster of hanging fruit, the animal plucks off a snack with a free hand. Still standing, it consumes the treat with gusto. Then it saunters back the way it came, striding from one padded foot to the other while continuing to grasp branches above its head. Witness the red-ape stroll, as practiced by an orangutan living on the Indonesian island of Sumatra. New field observations of these animals, conducted by anthropologist Susannah K.S. Thorpe of the University of Birmingham in England and her colleagues, show that orangutans, unlike knuckle-walking chimpanzees and gorillas, at times walk upright much as people do. This suggests to the researchers that two-legged walking, or bipedalism, evolved in a common ancestor of all living apes at least 20 million years ago. Among scientists who study hominids, the fossil ancestors of people, that's a heretical notion. These investigators have long assumed that an upright stance is a unique trait of hominids, a skeletal smoking gun that separates members of our evolutionary family from other ancient primates. From this perspective, hominids that walked on two legs evolved from a chimplike ancestor with a body structure suited to scooting across the ground on all fours. ©2007 Science Service.

Keyword: Evolution
Link ID: 10570 - Posted: 06.24.2010

By Jeanna Bryner Our brains can fathom the beginning of time and the end of the universe, but is any brain capable of understanding itself? With billions of neurons, each with thousands of connections, one's noggin is a complex, and yes congested, mental freeway. Neurologists and cognitive scientists nowadays are probing how the mind gives rise to thoughts, actions, emotions and ultimately consciousness. The complex machine is difficult for even the brainiest of scientists to wrap their heads around. But the payoff for such an achievement could be huge. “If we understand the brain, we will understand both its capacities and its limits for thought, emotions, reasoning, love and every other aspect of human life,” said Norman Weinberger, a neuroscientist at the University of California, Irvine. According to Scott Huettel of the Center for Cognitive Neuroscience at Duke University, the standard answer to this question goes something like: “The human brain is the most complex object in the known universe ... complexity makes simple models impractical and accurate models impossible to comprehend.” While that stock answer is correct, Huettel said, it’s incomplete. The real snag in brain science is one of navel gazing. Huettel and other neuroscientists can’t step outside of their own brains (and experiences) when studying the brain itself. © 2007 LiveScience.com.

Keyword: Miscellaneous
Link ID: 10569 - Posted: 06.24.2010

By Susan Brink, Los Angeles Times Staff Writer Her front brain is telling her he's trouble. Look at the facts, it says. He's never made a commitment, he drinks too much, he can't hold down a job. But her middle brain won't listen. Man, it swoons, he looks great in those jeans, his black hair curls onto his forehead so adorably, and when he drags on a cigarette, he's so bad he's good. His front brain is lecturing, too: She's flirting with every guy in the place, and she can drink even you under the table, it says. His mid-brain is unresponsive, distracted by her legs, her blouse and her come-hither stare. "What could you be thinking?" their front brains demand. Their middle brains, each on a quest for reward, pay no heed. Alas, when it comes to choosing mates, smart neurons can make dumb choices. Sure, if the brain's owner is in her 40s and has been around the block a few times, she might grab her bag and scram. If the guy has reached seasoned middle age, he might think twice about that cleavage-baring temptress. Wisdom -- at least a little -- does come with experience. Copyright 2007 Los Angeles Times

Keyword: Sexual Behavior; Drug Abuse
Link ID: 10568 - Posted: 08.03.2007

Lauran Neergaard, Associated Press — It's called the "word spurt," that magical time when a toddler's vocabulary explodes, seemingly overnight. New research offers a decidedly un-magical explanation: Babies start really jabbering after they've mastered enough easy words to tackle more of the harder ones. It's essentially a snowball effect. That explanation, published in Friday's edition of the journal Science, is far simpler than scientists' assumptions that some special brain mechanisms must click to trigger the word boom. Instead, University of Iowa psychology professor Bob McMurray contends that what astonishes parents is actually the fairly guaranteed outcome of a lot of under-the-radar work by tots as they start their journey to learn 60,000 words by adulthood. If McMurray is right, it could have implications for parents bombarded with technology gimmicks that claim to boost language. He thinks simply talking and reading to a child a lot is the key. "Children are soaking up everything," he said. "You might use 'serendipity' to a child. It will take that child maybe hundreds of exposures, or thousands, to learn what 'serendipity' means. So why not start early?" © 2007 Discovery Communications

Keyword: Language; Development of the Brain
Link ID: 10567 - Posted: 06.24.2010

From The Economist print edition PEOPLE remember emotionally charged events more easily than they recall the quotidian. A sexual encounter trumps doing the grocery shopping. A mugging trumps a journey to work. Witnessing a massacre trumps pretty well anything you can imagine. That is hardly surprising. Rare events that might have an impact on an individual's survival or reproduction should have a special fast lane into the memory bank—and they do. It is called the á2b-adrenoceptor, and it is found in the amygdala, a part of the brain involved in processing strong emotions such as fear. The role of the á2b-adrenoceptor is to promote memory formation—but only if it is stimulated by adrenaline. Since emotionally charged events are often accompanied by adrenaline secretion, the á2b-adrenoceptor acts as a gatekeeper that decides what will be remembered and what discarded. However, the gene that encodes this receptor comes in two varieties. That led Dominique de Quervain, of the University of Zurich, to wonder if people with one variant would have better emotional memories than those with the other. The short answer, just published in Nature Neuroscience, is that they do. Moreover, since the frequencies of the two variants are different in different groups of people, whole populations may have different mixtures of emotional memory. The reason Dr de Quervain suspected the variants might work differently is that the rarer one looks like the commoner one when the latter has a memory-enhancing drug called yohimbine attached to it. His prediction, therefore, was that better emotional memory would be associated with the rarer version. © The Economist Newspaper Limited 2007.

Keyword: Emotions; Learning & Memory
Link ID: 10566 - Posted: 06.24.2010

By Jenny Marder 4 years ago, Russell Romeo committed a small act of subterfuge. Without telling his boss, he ordered 60 white lab rats from an animal research facility in Harlan, NY, and had them shipped to his laboratory at Rockefeller University. They arrived, 10 to a box, on a crisp, cloudless Tuesday in March. He gave them a week to recover from the move. Then he started an experiment that would change the course of his career. Romeo was only 31 at the time, and as a young neuroscientist working in one of the best stress research labs in the country, he was fascinated by recent research on the vast remodeling that takes place in the human brain during adolescence. Rats, Romeo felt, would provide a good model for better understanding the adolescent stress response in humans. For humans and rats, the same brain regions - the hypothalamus, hippocampus, and amygdala - are engaged under stress. Likewise, the same neuroendocrine glands - the pituitary and the adrenal - are activated. The impacts of adrenal steroid hormones on the adult rat brain had been widely studied, but hardly anything was known about stress and the adolescent brain. Was it possible that stress affected young brains and older brains differently, in ways that researchers and clinicians had overlooked? © 1986-2007 The Scientist

Keyword: Stress; Development of the Brain
Link ID: 10565 - Posted: 06.24.2010

A type of cell found in the eye has stem cell properties and could be used within the next decade to regrow damaged retinas and restore vision, British researchers say. Certain Muller glial cells can migrate to the retina and morph into different retinal cells, potentially rebuilding damaged tissue, according to the study, published Wednesday in the journal Stem Cells. Retinal disease is one of the primary causes of blindness. Researchers were able to extract the cells from deceased adult donors and develop them in vitro into all the types of neurons found in the retina. In studies on rats with diseased retinas, the grafted cells travelled to the retina and took on the characteristics of surrounding neurons. "Muller cells with stem cell properties could potentially restore sight to someone who is losing or has lost their sight due to diseased or damaged retina," Dr. Astrid Limb, who led the study, said in a news release. "Our findings have enormous potential." Researchers are now exploring what barriers exist in the human body that prevent the cells from regenerating. © CBC 2007

Keyword: Vision; Regeneration
Link ID: 10564 - Posted: 06.24.2010

By BENEDICT CAREY A 38-year-old man who spent more than five years in a mute, barely conscious state as a result of a severe head injury is now communicating regularly with family members and recovering his ability to move after having his brain stimulated with pulses of electric current, neuroscientists are reporting. “I still cry every time I see him, but now it’s tears of joy,” said the man’s mother, in a conference call with reporters on Wednesday; her name was withheld, to protect the patient’s privacy. “He can speak, he can watch movies without falling asleep, he can say ‘Mom’ and ‘Pop,’ and ‘I love you, Mommy.’ ” He eats without the assistance of a feeding tube. He has regained some movement in his arms. When he speaks, usually with only a word or two, he is engaged in the conversation. He recently recited the first 16 words of the Pledge of Allegiance. The new report, which appears in the journal Nature, provides the first rigorous evidence that any procedure can initiate and sustain recovery in such a severely disabled person, years after the injury occurred. An estimated 100,000 to 300,000 Americans subsist in states of partial consciousness, and most are written off as beyond help. Copyright 2007 The New York Times Company

Keyword: Attention; Sleep
Link ID: 10563 - Posted: 06.24.2010

Michael Hopkin Brain function has been improved in a patient who was in a minimally conscious state, by electrically stimulating a specific brain region with implanted electrodes. The achievement raises questions about the treatment of other patients who have been in this condition for years, the researchers say. Patients in a minimally conscious state, often the result of severe brain trauma, show only intermittent evidence of awareness of the world around them. Typically, they are assumed to have little chance of further recovery if they show no improvement during their initial 12-month rehabilitation programme. In the latest case study, neuroscientists describe how they implanted electrodes in the brain of a 38-year-old man who had been in a minimally conscious state for more than six years following a serious assault. By electrically stimulating a brain region called the central thalamus, they were able to help him name objects on request, make precise hand gestures, and chew food without the aid of a feeding tube (see 'Behavioural improvements with thalamic stimulation after severe traumatic brain injury'). The thalamus is involved in motor control, arousal and in relaying sensory signals — from the visual systems, for example — to the cerebral cortex, the part of the brain involved in consciousness. Nicholas Schiff of Weill Cornell Medical College in New York, and his colleagues chose the patient because they believed his condititon was due to impairment of the arousal system, and that despite considerable damage to his cerebral cortex, many essential areas were preserved. ©2007 Nature Publishing Group

Keyword: Attention
Link ID: 10562 - Posted: 06.24.2010

Rowan Hooper Gina gestured for the banana. When Erica offered her a stick of celery instead, single mother Gina, 42, impatiently gestured again. When Erica held up the banana, Gina clapped. She's better behaved than Theodora, a feisty teenager who throws sand when she is misunderstood. Gina and Theodora are orang-utans, two of six females that have now been found to communicate with gestures in the same way as people do when playing the game charades. Erica Cartmill and Richard Byrne at the University of St Andrews, UK, presented the apes with one tasty and one not-so-tasty food item that could only be reached with human help. As in charades, when the orang-utans' signals were completely misunderstood, they broadened the range of signals used and avoided the one that had "failed". When they were partially understood – when they were offered celery instead of a banana, for example – they narrowed down the range of signals used and repeated them. "The different communication strategies employed by the orang-utans in our study demonstrated that our subjects were acting on the mental state of the experimenter," says Cartmill, who designed the experiment to study whether the animals could modify their communication when misunderstood. © Copyright Reed Business Information Ltd

Keyword: Language; Evolution
Link ID: 10561 - Posted: 06.24.2010

By Hannah Devlin If you have ever wondered at the expert hand-eye coordination of a professional juggler, you are not alone. Neuroscientists have long been puzzled by how our brains work out the three-dimensional (3D) shape and position of objects from 2D retinal images, a talent needed to plan precise hand movements such as catching a ball midflight. Now a research team has identified the brain region responsible for 3D visual processing. In order to guess the depth and 3D shape of objects, primates rely on two principal visual cues: first, the slightly different image seen by each eye, a phenomenon known as spatial binocular disparity, and second, the way the perceived shape of an object changes as it moves. It has been unclear how our brains integrate these two pieces of information, however. In a study in the 2 August issue of Neuron, neuroscientist Guy Orban of the Catholic University of Leuven in Belgium and his colleagues show that a brain region known as the anterior intraparietal cortex (AIP) is uniquely sensitive to both these visual cues. The researchers conducted two separate experiments in which the brains of monkeys were scanned using functional magnetic resonance imaging (fMRI) while the animals viewed images of 3D objects. In the first experiment, Orban and his colleagues studied the influence of motion on 3D perception. The monkeys viewed rotating images of connected lines, such as partially unfolded paper clips, that only appeared in the field of view of one eye at a time. In the second experiment, the monkeys used both eyes to view computer simulations of small complex objects, a task that required them to rely upon binocular disparity to perceive depth structure in the images. "We found that these different bits of processing converged on one brain region: the AIP," says Orban, who notes that the AIP lit up in fMRI during both tasks. © 2007 American Association for the Advancement of Science.

Keyword: Vision
Link ID: 10560 - Posted: 06.24.2010

Maia Szalavitz Just what did a new study on marijuana and schizophrenia actually say – and what did the media leave out? Watching the media cover marijuana is fascinating, offering deep insight into conventional wisdom, bias and failure to properly place science in context. The coverage of a new study claiming that marijuana increases the risk of later psychotic illnesses like schizophrenia by 40% displays many of these flaws. What are the key questions reporters writing about such a study needs to ask? First, can the research prove causality? Most of the reporting here, to its credit, establishes at some point that it cannot,though you have to read pretty far down in some of it to understand this. Second – and this is where virtually all of the coverage falls flat –, if marijuana produces what seems like such a large jump in risk for schizophrenia, have schizophrenia rates increased in line with marijuana use rates? A quick search of Medline shows that this is not the case-- in fact, as I noted here earlier, some experts think they may actually have fallen. Around the world, roughly 1% of the population has schizophrenia (and another 2% or so have other psychotic disorders), and this proportion doesn’t seem to change much. It is not correlated with population use rates of marijuana. Since marijuana use rates have skyrocketed since the 1940’s and 50’s, going from single digit percentages of the population trying it to a peak of some 60% of high school seniors trying it in 1979 (stabilizing thereafter at roughly 50% of each high school class), we would expect to see this trend have some visible effect on the prevalence of schizophrenia and other psychoses.

Keyword: Drug Abuse; Schizophrenia
Link ID: 10559 - Posted: 06.24.2010

By William J. Kole VIENNA, Austria - Ever whacked your thumb with a hammer, or wrenched your back after lifting a heavy box, and blamed the full moon? It’s a popular notion, but there’s no cosmic connection, Austrian government researchers said Tuesday. Robert Seeberger, a physicist and astronomer at the Ministry of Economic Affairs, said a team of experts analyzed 500,000 industrial accidents in Austria between 2000 and 2004 and found no link to lunar activity. “The full moon does not unfavorably affect the likelihood of an accident,” Seeberger said. The study, released Tuesday by the General Accident Insurance Office, said that on average there were 415 workplace accidents registered per day. Yet on days when the moon was full, the average actually dipped to 385, though the difference was not statistically significant. The lunar influence theory dates at least to the first century A.D., when the Roman scholar Pliny the Elder wrote that his observations suggested “the moon produces drowsiness and stupor in those who sleep outside beneath her beams.” Seeberger, who advises the Austrian government on accident prevention, said he and fellow researcher Manfred Huber decided to take a closer look because the full moon theory kept surfacing “again and again.” © 2007 MSNBC.com © 2007 Microsoft

Keyword: Biological Rhythms
Link ID: 10558 - Posted: 06.24.2010

By WILLIAM GRIMES All branches of science search for origins. Biologists want to know how life on earth began. Astronomers want to know how the universe got started. Even in mathematics, questions about how different numerical systems came to be constitute a legitimate line of inquiry. Linguists are different. In the middle of the 19th century, the main professional bodies governing linguistic research formally banned any investigation into the origins of language, regarding it as pointless. The topic remained disreputable for more than a century, but in the last decade or so, language evolution has eased toward the front burner, attracting the attention of linguists, neuroscientists, psychologists and geneticists. Their search is the subject of “The First Word,” Christine Kenneally’s lucid survey of this expanding field, dedicated to solving what she calls “the hardest problem in science today.” One nut to crack is the nature of language itself, and here Ms. Kenneally introduces the unignorable presence in virtually every linguistic debate, Noam Chomsky. Mr. Chomsky and his many adherents regard language as a uniquely human endowment, centered in a specific area of the brain. It gives every living person the ability, unsought, to generate infinite strings of sentences in infinite combinations. Animals, in this view, do not have language, nor do they think. The reasons that humans speak, or how language might have made its way to the human brain, do not matter. It may simply be that in a linguistic version of the big bang, a language mutation suddenly appeared, and that was that. Copyright 2007 The New York Times Company

Keyword: Language; Evolution
Link ID: 10557 - Posted: 06.24.2010

Heidi Ledford Barn owls are better at tracking sounds that move horizontally than those that move vertically, researchers have found. The technique used to make the discovery could one day be used to assess hearing and cognitive skills in humans who cannot communicate. The work, published in PLoS ONE1, relies on a phenomenon noted by Ivan Pavlov, of salivating dog fame, in the 1920s. Pavlov saw that animals respond to stimuli such as sudden movements or novel noises with a set of automatic responses, including muscle tensing and pupil dilation. Avinash Bala, a neurologist at the University of Oregon in Eugene, and his colleagues have used this response to monitor when barn owls (Tyto alba) recognize a new sound. The researchers played the owls sounds whose positions differed either horizontally or vertically, and measured the birds' pupil dilation using a beam of infrared light bounced off the cornea. Owls were about twice as sensitive to horizontal shifts compared with vertical changes. The birds could detect a change in location as small as 3º when the source was moved horizontally, compared with 7.5º when the source was moved vertically. ©2007 Nature Publishing Group

Keyword: Hearing
Link ID: 10555 - Posted: 06.24.2010

By Julie Steenhuysen CHICAGO (Reuters) - Scientists have found a second gene that helps predict whether people with depression will respond to a commonly prescribed antidepressant, U.S. researchers said on Tuesday. On its own, the gene variation plays only a small role in predicting a patient's response to Forest Laboratories Inc.'s Celexa, known generically as citalopram. But when a patient also had a variation of another gene, they were 23 percent more likely to benefit, according to the study which appears in the American Journal of Psychiatry. The finding may one day give doctors a better shot at choosing the right antidepressant for the right patient, helping to eliminate the trial-and-error process many people undergo before they find an effective treatment. "This is definitely a step ahead," said Dr. Gonzalo Laje, a researcher at the National Institute of Mental Health, in a telephone interview. He said depression will be the second-leading cause of disability by the year 2020. "It's huge. It costs the U.S. over $43 billion every year in terms of direct and indirect medical costs." © 1996-2007 Scientific American, Inc.

Keyword: Depression; Genes & Behavior
Link ID: 10554 - Posted: 06.24.2010