By THE NEW YORK TIMES Dr. Robert A. King and Dr. James F. Leckman of the Yale School of Medicine recently joined the Consults blog to answer readers’ questions about Tourette’s syndrome. Here, Dr. Leckman and Dr. King respond to readers asking about living with the strange movements, tics and vocalizations of Tourette’s, which can be socially difficult and, in some cases, lifelong. Do You Tell a Teacher About Tourette’s? Jen from Brookline, Mass., asks: My daughter started exhibiting tics at age 2 and was diagnosed with Tourrette’s at age 3. Now she’s 5 and will start kindergarten in September. I wrestle with whether to tell her teachers about it right off the bat, or wait and see if it becomes an issue. Her symptoms, so far, have been mild and not always evident. I would hate for her to be “labeled” unnecessarily (with whatever negatives come with that), but on the other hand, I feel that not being forthright is dishonest, and could equally be a disservice to my daughter. Any advice from those who have recently BTDT? Dr. King and Dr. Leckman respond: Tics wax and wane. For some, the tics will subside early in life. For others, the worst-ever tics occur at around 10 years of age or later in life. Unlike your daughter, some children with Tourette’s who begin school have had bad periods during which the tics are severe. It is likely that such children will have bad periods in the future. If the tics are pronounced enough that a teacher or peers are likely to notice and comment, it is better to be proactive and to be prepared. Copyright 2010 The New York Times Company

Keyword: Tourettes; Development of the Brain
Link ID: 13866 - Posted: 06.24.2010

WASHINGTON - Vaccines that contain a mercury-based preservative called thimerosal cannot cause autism on their own, a special U.S. court ruled on Friday, dealing one more blow to parents seeking to blame vaccines for their children's illness. The special U.S. Court of Federal Claims ruled that vaccines could not have caused the autism of an Oregon boy, William Mead, ending his family's quest for reimbursement. "The Meads believe that thimerosal-containing vaccines caused William's regressive autism. As explained below, the undersigned finds that the Meads have not presented a scientifically sound theory," Special Master George Hastings, a former tax claims expert at the Department of Justice, wrote in his ruling. Story continues below ↓advertisement | your ad here The Meads had filed a civil lawsuit in Oregon state court against a number of pharmaceutical companies alleging that the thimerosal additive in many pediatric vaccines significantly contributed to the development of William's autism, Hastings wrote. While the state court determined the autism was vaccine-related, Hastings said overwhelming medical evidence showed otherwise. The theory presented by the Meads and experts who testified on their behalf "was biologically implausible and scientifically unsupported", Hasting wrote. Copyright 2010 Reuters.

Keyword: Autism; Neurotoxins
Link ID: 13865 - Posted: 03.13.2010

By Jesse Emspak A drug targeting dopamine receptors might be able to "kick-start" an injured brain, enabling certain kinds of vegetative and minimally conscious patients to recover faster. Esteban Fridman of the FLENI hospital in Buenos Aires thinks the crux of the problem for such patients lies in their neuron-connecting axons. They are so badly damaged that they have a difficult time carrying chemical signals, or neurotransmitters, from neuron to neuron. Axons get disrupted when they are subject to stresses such as cranial impact—as when a fighter gets hit in the head or a driver smacks into the steering wheel in a car accident. As a possible treatment for such damage, Fridman has focused on apomorphine, which binds to the brain's dopamine receptors. Dopamine, a neurotransmitter well known for its role in Parkinson's disease, is part of the mechanism controlling arousal and motivated behavior; it also plays a role in consciousness disorders. Fridman hypothesizes that apomorphine might work by acting in place of dopamine. Flooding the injured brain with the chemical might stimulate it enough to repair the connections, enabling the patients to reach full consciousness. He notes the drug wouldn't work in cases where the brain has been deprived of oxygen or blood, because the damage is more widespread. Terri Schiavo, a Florida woman whose care sparked a nationwide controversy that peaked in 2005, was in a vegetative state caused by that kind of injury. © 2010 Scientific American,

Keyword: Attention
Link ID: 13864 - Posted: 06.24.2010

By Rachel Ehrenberg People deceive their taste buds every day — a dash of Sweet'N Low in the coffee, perhaps, a diet soda or a stick of sugarless gum. These little white lies seem to cover up harmless, even healthy choices. After all, fooling the mouth with artificial sweeteners provides a fix without the calories or the cavities. But these sweeteners aren’t just tricking the taste buds on the tongue. Taste, scientists are discovering, is a whole-body sensation. There are taste cells in the stomach, intestine and, evidence suggests, the pancreas, colon and esophagus. These sensory cells are part of an ancient battalion tasked with guiding food choices since long before nutrition labels, Rachael Ray or even agriculture existed. While taste cells in the mouth make snap judgments about what should be let inside, new work suggests that gut taste cells serve as specialized ground forces, charged with preparing the digestive system for the aftermath of the tongue’s decisions. Stimulating these gut cells triggers a complex series of events that can dial down, or amp up, the digestion and absorption of the body’s fuel. When hit by bitter — potentially toxic — substances, gut taste cells sound an alarm that may lead to slower absorption or spur vomiting. And when the gut’s taste sensors encounter something sweet, they send a “prepare for fuel” missive that results in cranked-up insulin levels in the blood. Though scientists don’t fully understand what follows, studies hint at a tantalizing, if convoluted, connection between gut taste cell activity and metabolism. © Society for Science & the Public 2000 - 2010

Keyword: Chemical Senses (Smell & Taste); Obesity
Link ID: 13863 - Posted: 06.24.2010

By Huw Williams Researchers say they've solved the mystery of why some chickens hatch out half-male and half-female. About one in every 10,000 chickens is gynandromorphous, to use the technical term. In medieval times, they might have been burned at the stake, as witches' familiars. But now these chickens are shedding important new light on how birds, and perhaps reptiles, develop. It used to be thought that hormones instructed cells to develop in male or female-specific ways. That's what happens in mammals, including humans, and it leads to secondary sexual characteristics like facial hair for men or breasts for women. But scientists at the Roslin Institute and the University of Edinburgh say they have discovered that bird cells don't need to be programmed by hormones. Instead they are inherently male or female, and remain so even if they end up mixed together in the same chicken. It means a half-and-half chicken will have totally different plumage, body shape, and muscle structure on the two halves of its body. It even affects the wattles on the bird's head, and the spurs on its legs. They will be larger on the cockerel half, and smaller on the hen half, of the same bird. Dr Michael Clinton of the Roslin Institute led the research, which has just been published in the scientific journal Nature. He said the findings were a surprise. Dr Clinton explained: "We looked at these birds initially expecting them not to be half-male and half-female. We thought there'd be a mutation on one side of the body. But we found that they were half-male and half-female and that's what actually showed us that the system was different in birds and mammals." (C)BBC

Keyword: Sexual Behavior
Link ID: 13862 - Posted: 03.12.2010

By JUDITH WARNER If you’re the parent of a child who’s having trouble learning or behaving in school, you quickly find yourself confronted with a series of difficult choices. You can do nothing — and watch your child flounder while teachers register their disapproval. Or you can get help, which generally means, first, an expensive and time-consuming evaluation, then more visits with more specialists, intensive tutoring, therapies, perhaps, or, as is often the case with attention issues, drugs. For many parents — particularly the sorts of parents who are skeptical of mainstream medicine and of the intentions of what one mother once described to me as “the learning-disability industrial complex” — this experience is an exercise in frustration and alienation. These parents often don’t trust the mental-health professionals who usually treat children with “issues,” as we euphemistically tend to refer to problems like learning disabilities, attention-deficit hyperactivity disorder, autism or other developmental difficulties. They find offensive the prospect of having a child “labeled” when his or her development doesn’t correspond to what seem like random, overly restrictive norms. They find the notion of putting children on psychotropic medication frightening and unacceptable. They want to find concrete causes for their children’s diffuse, often difficult-to-understand problems and, ideally, to find cures. They want their children to achieve, and they’re dissatisfied with what they feel are the palliative half-measures offered by pediatricians, psychiatrists, psychologists and learning specialists. That’s why some of these parents end up seeking the services of people like Stanley A. Appelbaum. Copyright 2010 The New York Times Company

Keyword: ADHD; Dyslexia
Link ID: 13861 - Posted: 06.24.2010

by Shanta Barley Octopuses make for discerning TV viewers: it seems they prefer high-definition to traditional cathode ray images (CRT). What's more, the first study using video to trick octopuses, finds that they may be the Jekyll and Hydes of the oceans: aggressive one day, shrinking violets the next. "People have been trying for over a decade to get proper behavioural responses from octopuses and other cephalopods using videos," says Roger Hanlon, an octopus researcher at the Marine Resources Center, Woods Hole, Massachusetts, who was not involved in the study. "But this is the first time anyone has managed it." Gloomy octopuses (Octopus tetricus) reacted to films shown on liquid crystal high definition television (HDTV) as if they were seeing the real thing, according to a new study by Renata Pronk at Macquarie University in Sydney, Australia, and colleagues. "They lunge forwards to attack crabs and back off from other octopuses, much as they do in the wild," says Hanlon. Surprisingly, an octopus that was bold, aggressive and exploratory on one day was just as likely to be shy, submissive and stationary the next. "This suggests that the gloomy octopus does not have personality," writes Pronk in the new study. No personality By "personality", researchers mean consistency in behaviour. You might expect an individual to respond to crabs, other octopuses, jars, for example, by being consistently bold, shy or aggressive. © Copyright Reed Business Information Ltd

Keyword: Emotions; Evolution
Link ID: 13860 - Posted: 06.24.2010

by Andy Coghlan OBESITY kills, everyone knows that. But is it possible that we've been looking at the problem in the wrong way? It seems getting fatter may be part of your body's defence against the worst effects of unhealthy eating, rather than their direct cause. This curious insight comes at the same time as several studies distancing obesity itself from a host of diseases it has long been blamed for, including heart disease and diabetes. Instead, these studies point the finger at excess fat in the bloodstream, either when the fat cells of obese people finally get overloaded or when lean people who can't store a lot of fat eat too much. This seems to have a destructive effect by provoking the body's immune response. None of this changes the fact that too much rich food and too little exercise is bad for you. But viewing obesity as a symptom of an unhealthy diet, rather than the direct cause of disease and death, plus a better appreciation of the immune system's reaction to fat, should radically change our understanding of what is shaping up to be one of modern society's biggest health scourges. The findings also point to new ways to treat diabetes, heart disease and other diet-linked conditions. In recent years, most rich countries, and some poorer ones, have seen a massive rise in so-called "metabolic syndrome", whose symptoms can include insulin resistance, high blood cholesterol and an increased risk of diabetes, heart disease and stroke. That the syndrome goes hand in hand with obesity is well known, but exactly how all these conditions are linked is unclear. © Copyright Reed Business Information Ltd.

Keyword: Obesity
Link ID: 13859 - Posted: 06.24.2010

by Gisela Telis Your thoughts leave a trace—and it’s visible. Researchers have successfully identified the memory a person is recalling by analyzing their brain activity. The result offers new insights into how and where the brain records memories and may help scientists understand memory impairments caused by injuries, aging, and neurological conditions, such as a stroke. Cognitive neuroscientist Eleanor Maguire and her colleagues at University College London are no strangers to mind reading. Their recipe of functional magnetic resonance imaging (fMRI) and a specific computer algorithm has gleaned the secrets of the hippocampus, a brain region that tracks where a person is and also plays a role in memory and learning. The technological tag team works like this: fMRI measures the brain's blood flow—associated with neuron activity—on the scale of voxels, three-dimensional "pixels" that each include roughly 10,000 neurons. The algorithm then interprets the changes voxel by voxel to learn the brain's patterns of activity over time. Last year, Maguire used the method to pinpoint where a person was "standing" in a virtual-reality room. Now, Maguire's team has turned from spatial orientation to a more complex function of the hippocampus: so-called episodic memory of specific experiences, such as seeing the ocean for the first time. To test whether they could capture episodic memories, the researchers needed 10 volunteers to share the same ones. To do this, they showed them three 7-second movies and asked them to memorize what they saw. Each movie showed a different actress doing a simple task, such as rummaging in a handbag and then dropping an envelope in a mailbox. The volunteers were prompted to remember each movie while the fMRI scanned their brains so that the computer algorithm could match the pattern of activity to each memory. Then they were allowed to recall whichever movie they chose. © 2010 American Association for the Advancement of Science.

Keyword: Learning & Memory; Brain imaging
Link ID: 13858 - Posted: 06.24.2010

By Jesse Bering Surprisingly little evolutionarily informed research has been done on our species’ strange love affair with sports. Why do we care so much about such arbitrary and ostensibly functionless displays of physical and mental prowess? Although data derived directly from evolutionary hypotheses are scant, theories abound. In a recent issue of Perspectives in Biology and Medicine , for example, Andreas de Block and Siegfried Dewitte from the University of Leuven in Belgium seek to explain why our obsession with competitive athletics is such a predictable expression of human nature. Before we get into de Block and Dewitte’s claims, though, a disclosure from yours truly—one that might well slant this story. In the wake of this Olympics season, this will undoubtedly render me abhorrent among a broad swath of Scientific American’s audience and beyond. But the truth is, I care very little for sports. It’s not that I actively dislike athletics; I’m just utterly indifferent. I can’t help it. The prospect of watching a sporting event, any sporting event, is about as appealing to me as is spending my free time reading the crawling news ticker at the bottom of C-SPAN. It’s been like this for as long as I can remember. In central Ohio where I spent much of my childhood, being a fan of the Ohio State Buckeyes was like being a member of a religious congregation; it’s perhaps little wonder that the same glossy, creepily cultish eyes of the average sports fan there tended to share a common head with the evangelical churchgoer. My father used to drag me along to OSU basketball games, where I’d spend hours spying on the other people in the stands with my binoculars—their private, subtle behaviors massively more interesting to me than anything happening on the court below. © 2010 Scientific American,

Keyword: Evolution; Aggression
Link ID: 13857 - Posted: 06.24.2010

THE possibility of operating a machine using thought control has long fascinated researchers. It would be the ultimate video-game controller, for one thing. On a more practical level, it would help disabled and paralysed people use computers, artificial limbs, motorised wheelchairs or robots. New developments in brain-to-machine interfaces show that such possibilities are getting closer. For many years it has been possible for people to manipulate relatively simple devices—such as a computer’s on-screen cursor—by thinking about moving them. One way is by implanting electrodes into the brain to measure the electrical activity associated with certain movements. Another uses electroencephalography (EEG), which detects the same activity using electrodes placed on the scalp. In both cases, a computer learns to associate particular brain signals with intended actions. The trouble is that non-invasive methods, which obviously have far broader appeal, are less precise than using implanted electrodes, which produce a clearer signal. Recent advances in sensors and signal processing, however, have helped close the gap, making the EEG-based approach more accurate and easier to learn how to use. In one of the latest studies, José Contreras-Vidal and his colleagues at the University of Maryland were able to obtain enough EEG data from volunteer button pushers to reconstruct the associated hand motions in three dimensions. For their study, reported in the Journal of Neuroscience, the researchers put something that looks like a swimming cap containing 34 EEG sensors on the heads of five people. The volunteers were asked to press eight buttons randomly as their brain’s electrical signals were recorded, along with their hand movements. When the volunteers were then asked to think about pressing one of the eight buttons, the resulting EEG data could be compared with the data produced during actual button-pushing, and the computer could determine which button they had in mind. © The Economist Newspaper Limited 2010.

Keyword: Robotics
Link ID: 13856 - Posted: 06.24.2010

By RANDOLPH E. SCHMID WASHINGTON - Nicotine builds up gradually in smokers' brains rather than spiking after each puff, according to a study that might help point to new ways to help people quit smoking. Dr. Jed E. Rose of Duke University reports in Monday's online edition of Proceedings of the National Academy of Sciences that nicotine buildup in the brain was gradual over several minutes. Scientists have theorized that there is a spike of nicotine in the brain about seven seconds after each puff, but almost no measurements had been taken until now, Rose said in a telephone interview. "We were surprised to find that the rate of uptake was much different from what one commonly hears," said Rose, who directs the Duke Center for Nicotine and Smoking Cessation Research, a part of the university's School of Medicine. Rose used brain scans to measure the nicotine levels in 13 regular smokers and 10 people who smoke only occasionally, an indication they were not addicted to nicotine. Maximum brain levels of nicotine were reached in 3 to 5 minutes, and built up slower in addicted smokers than in casual ones, the researchers found. "This slower rate resulted from nicotine staying longer in the lungs of dependent smokers, which may be a result of the chronic effects of smoke on the lungs," Rose suggested. Copyright 2010 The Associated Press.

Keyword: Drug Abuse
Link ID: 13855 - Posted: 03.09.2010

By RONI CARYN RABIN Older people are more likely to suffer a decline in their cognitive abilities after being hospitalized for an illness than they would otherwise, a new study reports. The study, published last month in The Journal of the American Medical Association, followed almost 3,000 people 65 and older for more than a decade. All of the participants lived in the Seattle area; none had dementia at the start of the study. Those who were hospitalized for a critical condition like severe infection or cardiac arrest experienced a statistically significant drop in scores on a cognitive performance test given later, when compared with people who had not been hospitalized. Those who had been hospitalized for a noncritical illness faced a statistically significant 40 percent increase in dementia after the hospitalization, when compared with those who had not been hospitalized. While some of the cognitive impairment could stem from the illness itself, the researchers said, side effects of hospitalization and treatment could also play a role. Copyright 2010 The New York Times Company

Keyword: Alzheimers
Link ID: 13854 - Posted: 03.09.2010

By YUDHIJIT BHATTACHARJEE PITTSBURGH — On a cold, wet afternoon not long ago, Aron Reznick sat in the lounge of a home for the elderly here, his silver hair neatly combed, his memory a fog. He could not remember Thanksgiving dinner with his family, though when he was given a hint — “turkey” — it came back to him, vaguely, like a shadow in the moonlight. Two years ago, Mr. Reznick, who has early-stage Alzheimer’s disease and is now 82, signed up for an experiment intended to help people with Alzheimer’s and other memory disorders. The concept was simple: using digital pictures and audio to archive an experience like a weekend visit from the grandchildren, creating a summary of the resulting content by picking crucial images, and reviewing them periodically to awaken and strengthen the memory of the event. The hardware is a little black box called the Sensecam, which contains a digital camera and an accelerometer to measure movement. Worn like a pendant around the neck, it was developed at Microsoft’s research lab in Cambridge, England. Vicon, a British company that has licensed the technology, wants to market it to young people interested in logging their lives and posting the results to Web sites like Facebook and YouTube. For the elderly, though, it could herald a new kind of relationship between mind and machine: even as plaque gets deposited on the brain, everyday experience is deposited on silicon, then retrieved. Copyright 2010 The New York Times Company

Keyword: Alzheimers; Learning & Memory
Link ID: 13853 - Posted: 06.24.2010

By GINA KOLATA For years, a prevailing theory has been that one of the chief villains in Alzheimer’s disease has no real function other than as a waste product that the brain never properly disposed of. The material, a protein called beta amyloid, or A-beta, piles up into tough plaques that destroy signals between nerves. When that happens, people lose their memory, their personality changes and they stop recognizing friends and family. But now researchers at Harvard suggest that the protein has a real and unexpected function — it may be part of the brain’s normal defenses against invading bacteria and other microbes. Other Alzheimer’s researchers say the findings, reported in the current issue of the journal PLoS One, are intriguing, though it is not clear whether they will lead to new ways of preventing or treating the disease. The new hypothesis got its start late one Friday evening in the summer of 2007 in a laboratory at Harvard Medical School. The lead researcher, Rudolph E. Tanzi, a neurology professor who is also director of the genetics and aging unit at Massachusetts General Hospital, said he had been looking at a list of genes that seemed to be associated with Alzheimer’s disease. Copyright 2010 The New York Times Company

Keyword: Alzheimers; Neuroimmunology
Link ID: 13852 - Posted: 06.24.2010

by Ewen Callaway The canine phrase book has collected its first entries. Dogs understand the meaning of different growls, from a rumble that says "back off" to playful snarls made in a tug-of-war game. Proving that animal vocalisations have specific meanings – and what they could be – is challenging. In 2008, Péter Pongrácz, a behavioural biologist at Eötvös Lorand University in Budapest, Hungary, monitored dogs' heart rates to show that they seem to notice a difference between barks aimed at strangers and those directed at nothing in particular. Now he has gone a step further and shown that dogs respond differently to different vocalisations. Pongrácz's team recorded growls from 20 pet dogs in three different situations: a tug-of-war game with their owner, competing with another dog for a bone and growling at an approaching stranger. Growls may convey more meaning than barks, says Pongrácz: wolves rarely bark, and he says dogs may have learned to bark to get human attention. The team played the recordings to 36 other dogs that had each been left to gnaw on a bone. Only those that heard the food-guarding growls tended to back off from the bone and stay away. "It seems dogs can understand something about the context," Pongrácz says. Back to the bone © Copyright Reed Business Information Ltd

Keyword: Animal Communication; Language
Link ID: 13851 - Posted: 06.24.2010

by Sujata Gupta Moms-to-be think a lot about what they eat and how it might affect their growing fetus. Now, new research suggests that boys are more sensitive than girls to the diet their mother ingested while they were in utero. Previous studies hinted that maternal diet affects the health of male and female fetuses differently. For example, Cheryl Rosenfeld, a reproductive biologist at the University of Missouri, Columbia, conducted a study in 2003 showing that expectant mouse moms who consume low-calorie diets tend to carry more females to term than males—indicating that male fetuses are the more sensitive sex in utero and miscarry at higher rates. That made Rosenfeld wonder if diet causes genes to behave differently in wombs with male or female fetuses. To find out, Rosenfeld and her team studied pregnant mice that were divvied up into three dietary groups: very high fat, high carbohydrate/low fat, and moderate fat. About 12.5 days after conception—or about halfway through the gestational period and before the fetus starts to produce sex hormones that, like diet, can also alter gene expression, the scientists terminated the pregnancies and removed the animals' placentas. The researchers scanned 40,000 genes in the placentas to determine whether their activity varied depending on a mom's diet. They found that 211 genes differed significantly between the low-fat and high-fat groups. The genes changed expression most often from the low-fat to the high-fat female placentas, suggesting that placentas nourishing females do a better job of responding to diet—and potentially protecting the fetus from harmful ingredients—than do those connected to males. So, in a classic double-edged sword, high-fat maternal diets appear to help male fetuses survive to term, but that same diet may expose male fetuses to harmful compounds. © 2010 American Association for the Advancement of Science.

Keyword: Obesity; Development of the Brain
Link ID: 13850 - Posted: 06.24.2010

By Laura Sanders One form of a common genetic variant may ratchet up pain sensitivity in people who have it, researchers report online March 8 in the Proceedings of the National Academy of Sciences. The discovery could lead to more powerful pain treatments that lack the debilitating side effects of current drugs. “We could fill our clinics many times over with people with chronic pain that we can’t help with our current medications,” says neurologist and neuroscientist Stephen Waxman of Yale University School of Medicine and the Veterans Affairs Connecticut Hospital in West Haven. In the new study, researchers led by clinical geneticist Geoffrey Woods of the Cambridge Institute for Medical Research in the United Kingdom examined the DNA of 578 people with the painful condition osteoarthritis. Woods and his colleagues searched for genetic variations that might be linked to how much pain a patient reported feeling — a subjective measure, Woods says, but currently the best researchers can do. The team found that people who reported higher levels of pain were more likely to carry a particular DNA base, an A instead of a G, at a certain location in the gene SCN9A. The A version is found in an estimated 10 to 30 percent of people, Woods says, though its presence varies in populations of different ancestries. This gene version may set the pain threshold, he says. “You’re more sensitive to pain.” © Society for Science & the Public 2000 - 2010

Keyword: Pain & Touch; Genes & Behavior
Link ID: 13849 - Posted: 06.24.2010

One of our closest primate relatives, the bonobo, has been shown to voluntarily share food, scientists report. This sort of generous behaviour was previously thought by some to be an exclusively human trait. But a team has carried out an experiment that revealed that bonobos were more likely to choose to share their food than opt to dine alone. The research is published in the journal Current Biology. Dr Brian Hare from Duke University, US, and Suzy Kwetuenda from Lola y Bonobo, a centre for orphaned bonobos in the Democratic Republic of Congo, gave a hungry bonobo access to a room with some food in it. This room was adjacent to another two rooms, which the creature could easily see into. One of these rooms was empty while the other contained another bonobo. Scientists want to find out what drives this behaviour The hungry primate could then choose to eat the food alone or unlock the door by removing a wooden peg and share his fare with the other bonobo. Dr Hare wrote in Current Biology: "We found that the test subjects preferred to voluntarily open the recipient's door to allow them to share the highly desirable food that they could have easily eaten alone." (C)BBC

Keyword: Evolution
Link ID: 13848 - Posted: 03.08.2010

By Judy Foreman At mushy Hallmark commercials when the son finally gets home on Christmas Eve. At weddings, because everybody’s so happy. At funerals, because everybody’s so sad. Even watching the Olympics, when I bond with the skaters who get teary because they’ve finally won. But why, really, do I - do any of us - cry? It turns out, say evolutionary biologists and neuroscientists, the main reason we cry is that we’re human. As far as scientists can tell, no other critter on earth cries emotional tears, as opposed to tears that merely lubricate the eyes, the way we humans do - despite scattered reports of an elephant or gorilla not just vocalizing in distress but actually shedding tears. (Intrigued by one such report of an Indian elephant crying after being captured, Charles Darwin sent a colleague to check it out; he couldn’t confirm it.) If emotional tears are indeed a uniquely human phenomenon, there must be an evolutionary advantage to crying, and possibly, a big one. But what? Does crying signal submission and thus disarm aggressors? Does it increase empathy and bonding, promoting community? Do tears promote health by relieving stress, giving a survival advantage to the weepy? What is it about the human brain that creates this ability to cry? Relatively little study has been done on the subject, though some researchers are plunging in, with fascinating results. © 2010 NY Times Co.

Keyword: Emotions; Evolution
Link ID: 13847 - Posted: 06.24.2010