When press releases from NEJM, NIMH and Mass General came in the email alerting me that antidepressants are no more effective than placebo for bipolar patients on a mood stabilizer, my first reaction wasn't, oh good, we can save 15 bucks a month in Zoloft co-pays. It was, don't tell my wife, because it's unpleasant enough when she runs out of them for a few days. When I also received a phone call from a media-relations person inquiring whether I'd received the email, it was obvious she would find out anyway, so I figured I better follow up. Gary Sachs, the lead investigator, was really nice. He reassured me that no one is suggesting that my sweetie should mess with the medication combination that's brought her a year of sanity after many years of hell. "I think the message for people who are doing well is we always believe in staying with what's working," he said. "On the other hand, if you're having a new episode of depression you should not feel there's any particular reason why you have to be treated with these drugs called antidepressants, because if you have bipolar depression they have not been shown to work for you. That doesn't mean they necessarily won't in every case, it doesn't mean you won't get better. It also is pretty clear that if you add them to a mood stabilizer they appear to be quite safe." © ScienCentral, 2000-2007

Keyword: Depression; Schizophrenia
Link ID: 10144 - Posted: 06.24.2010

For depressed people with bipolar disorder who are taking a mood stabilizer, adding an antidepressant medication is no more effective than a placebo (sugar pill), according to results published online on March 28, 2007 in the New England Journal of Medicine. The results are part of the large-scale, multi-site Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD), a $26.8 million clinical trial funded by the National Institutes of Health's National Institute of Mental Health (NIMH). Bipolar disorder, a sometimes debilitating illness marked by severe mood swings between depression and mania, is usually treated with mood stabilizers such as lithium, valproate, carbamazepine or other medications that reduce mania. However, depression is more common than mania in bipolar disorder, and depressive episodes tend to last longer than episodes of mania. Antidepressant medications are often used in addition to a mood stabilizer for treating bipolar depression, but they are thought to confer a serious risk of a switch from a depressive episode to a manic episode. Finding the right treatment balance for people with bipolar disorder is a constant challenge; STEP-BD aims to identify the best treatment options. "Treating depression in people with bipolar disorder is notoriously difficult," said NIMH Director Thomas R. Insel. "STEP-BD sought to determine if adding an antidepressant to a mood stabilizer is effective and safe in treating depressive episodes. The results suggest that antidepressants are safe but not more effective than placebo as assessed in a large number of people with bipolar disorder. "

Keyword: Depression; Schizophrenia
Link ID: 10143 - Posted: 03.29.2007

John Whitfield The extinction of the dinosaurs had little impact on the evolution of today's mammals, say researchers. After building a family tree of nearly every living mammal, they show that the main groups arose millions of years before the dinosaurs went extinct, and did not become dominant until millions of years after they disappeared. The wipe-out of the dinosaurs at the end of the Cretaceous period some 65 million years ago opened up room and resources for others. But it did not specifically clear a path for the diversity of animals that would evolve into today's mammals, including humans, says evolutionary biologist Olaf Bininda-Emonds of the Technical University of Munich, Germany: "After the dinosaurs went extinct, they still didn't diversify." There was a burst of mammal evolution just after the dinosaur extinction, Bininda-Emonds and colleagues report in Nature1. But it occurred in groups that have either gone extinct, such as a group of hoofed carnivores called the mesonychids, or which now have few species, such as the sloths. The currently successful mammal groups, including primates, kept a quiet profile; they didn't start branching out until about 50 million years ago. ©2007 Nature Publishing Group

Keyword: Evolution
Link ID: 10142 - Posted: 06.24.2010

Kickboxing can cause damage to the part of the brain which controls hormone production, a study has shown. Around a million people around the world take part in the sport. The Turkish study found head injuries in kickboxing can cause damage to the pituitary gland, which affects the body's metabolism and stress response. In Clinical Endocrinology, researchers say amateurs with head injuries should be screened. But kickboxers say they are unaware of such injuries. The pituitary is a pea-sized gland, weighing no more than a gram, which is found at the base of the brain, just behind the bridge of the nose. It produces a range of hormones which control, among other things, the body's regulation of metabolism, coping with daily stress, general wellbeing and sex drive amongst other areas. The team at Erciyes University Medical School in Turkey measured the levels of these hormones in 22 amateur kickboxers (16 men and six women) and compared these to healthy people of the same age and sex. It was found that 27% - six - of the kickboxers were deficient in at least one hormone compared with the healthy group. The researchers say the head is one of the most common sites of injury for both amateur and professional kickboxers. They said more research was needed to understand how the pituitary gland is damaged and to develop more effective head protection gear for kickboxers. (C)BBC

Keyword: Brain Injury/Concussion; Hormones & Behavior
Link ID: 10141 - Posted: 03.29.2007

By Daniel Engber The sports world's latest doping scandal began last month, when federal and state agents raided a seedy office building in Jupiter, Fla., and a pharmacy in Orlando. According to a pair of embedded reporters from Sports Illustrated, the investigators busted up a "massive illegal distribution network" for performance-enhancing drugs; the fallout, they say, "promises to rock sports." It's worth noting that what SI touted as a "Steroid Sting" has produced very little evidence of, well, steroids. Instead, the disclosures and public shamings have focused on human growth hormone, an almost-undetectable substance that has recently replaced anabolic steroids as the trendy, performance-enhancing boogeyman. SI's ongoing series of reports has fingered baseball players Jerry Hairston Jr. and Gary Matthews Jr., pro wrestlers Edge and the Hurricane, and boxing champion Evander Holyfield for ordering HGH. Even fictional athletes have had their reputations tainted by the stuff. A few weeks ago, Sylvester Stallone, portrayer of Rocky Balboa, was charged with importing 48 vials of synthetic growth hormone into Australia. The media haven't spent much time making a distinction between HGH and steroids. An AP story, titled "After BALCO, Another Steroid Scandal," glosses over any differences between the two, drawing a straight line from the BALCO investigation to the busts in Florida. But Jerry Hairston isn't Barry Bonds. Sure, both of these guys probably took banned substances in an effort to boost their stats, and both were involved in major drug busts involving large numbers of Major League players. But it's just plain wrong to put growth hormone in the same category as anabolic steroids. In the sports version of the war on drugs, Bonds was shooting heroin while Hairston was smoking marijuana. 2007 Washington Post.Newsweek Interactive Co. LLC

Keyword: Hormones & Behavior
Link ID: 10140 - Posted: 03.29.2007

Jennifer Viegas, Discovery News — Thin may be in now, but prehistoric men 15,000 years ago prefered full-figured gals, suggest dozens of flint figurines excavated from a Paleolithic hunting site in Poland. Since almost identical depictions have been found elsewhere throughout Europe, the figurines indicate a shared artistic tradition existed even then. The findings are published in the current issue of the journal Antiquity. Co-author Romuald Schild explained that the artifacts offer "a cultural inventory" for the late Magdalenian era (18,000-10,000 years ago). In the paper, Schild and colleagues Bodil Bratlund, Else Kolstrup and Jan Fiedorczuk describe the carvings as "stylized voluptuous female outlines" that "are cut out of flint flakes." The same symbolic representations of women displayed in the artifacts extend across Europe, added Schild, a researcher in the Institute of Archaeology and Ethnology at the Polish Academy of Sciences. Because the site, near the Polish village of Wilczyce, served as a late autumn/early winter hunting camp, it is likely men created the figurines when they were taking breaks from hunting arctic foxes, woolly rhinoceros and other game. © 2007 Discovery Communications Inc.

Keyword: Sexual Behavior; Evolution
Link ID: 10139 - Posted: 06.24.2010

By Joshua Davis BILL CHOISSER WAS 48 when he first recognized himself. He was standing in his bathroom, looking in the mirror when it happened. A strand of hair fell down – he had been growing it out for the first time. The strand draped toward a nose. He understood that it was a nose, but then it hit him forcefully that it was his nose. He looked a little higher, stared into his own eyes, and saw … himself. For most of his childhood, Choisser thought he was normal. He just assumed that nobody saw faces. But slowly, it dawned on him that he was different. Other people recognized their mothers on the street. He did not. During the 1970s, as a small-town lawyer in the Illinois Ozarks, he struggled to convince clients that he was competent even though he couldn't find them in court. He never greeted the judges when he passed them on the street – everyone looked similarly blank to him – and he developed a reputation for arrogance. His father, also a lawyer, told him to pay more attention. His mother grew distant from him. He felt like he lived in a ghost world. Not being able to see his own face left him feeling hollow. One day in 1979, he quit, left town, and set out to find a better way of being in the world. At 32, he headed west and landed a job as a number cruncher at a construction firm in San Francisco. The job isolated him – he spent his days staring at formulas – but that was a good thing: He didn't have to talk to people much. With 1,500 miles between him and southern Illinois, he felt a measure of freedom. He started to wear colorful bandannas, and he let his hair grow. When it got long enough, he found that it helped him see himself. Before that, he'd had to deduce his presence: I'm the only one in the room, so that must be me in the mirror. Now that he had long hair and a wild-looking scarf on his head, he could recognize his image. He felt the beginnings of an identity. © 2007 CondéNet Inc.

Keyword: Miscellaneous
Link ID: 10138 - Posted: 06.24.2010

By RICHARD WASSERSUG, M.D. My daughter and I were talking about outing oneself — the act of disclosing one’s inner identity. The discussion was not purely academic. “Dad, when most people out themselves, they open the closet door and just come out,” she said. “You, Dad, you went through the wall.” I had just told my daughter that I was a eunuch. It all started with a diagnosis of prostate cancer in 1998, when I was 52. Two years later, after failed surgery and radiation, I started hormonal therapy. This meant taking chemicals that slow the growth of prostate cancer cells by depriving them of androgen — in effect, castrating the patient. Chemical castration is the common treatment for advanced prostate cancer, and more than 250,000 American men are taking these drugs. But few people know of any men taking them, simply because we hide. It is shameful to be castrated. My initial response to the therapy was typical. My mood plummeted along with my testosterone level. Hair vanished from my arms and legs. Muscle disappeared, fat appeared. My memory suffered. Not only was I now more likely to lose my car keys, I occasionally couldn’t remember where I left the car. Copyright 2007 The New York Times Company

Keyword: Hormones & Behavior
Link ID: 10137 - Posted: 06.24.2010

By JOHN TIERNEY ALEXANDRIA, Va., March 26 — The case of the United States v. William Eliot Hurwitz, which began in federal court here on Monday, is about much more than one physician. It’s a battle over who sets the rules for treating patients who are in pain: narcotics agents and prosecutors, or doctors and scientists. Dr. Hurwitz, depending on which side you listen to, is either the most infamous doctor-turned-drug-trafficker in America or a compassionate physician being persecuted because a few patients duped him. When Dr. Hurwitz, who is now 62, was sent to prison in 2004 for 25 years on drug trafficking and other charges, the United States attorney for Eastern Virginia, Paul J. McNulty, called the conviction “a major achievement in the government’s efforts to rid the pain management community of the tiny percentage of doctors who fail to follow the law and prescribe to known drug dealers and abusers.” Siobhan Reynold, the president of an advocacy group called the Pain Relief Network, hailed Dr. Hurwitz’s singular dedication and compared his plight to Galileo’s. Some of the country’s foremost researchers in pain treatment and addiction supported his appeal for a retrial, which was ordered because the jury in the first case was improperly instructed to ignore whether Dr. Hurwitz had acted in “good faith.” These scientists say they are upset by how their research has been distorted by prosecutors in this case, and suppressed by the Drug Enforcement Administration in its campaign against the misuse of OxyContin and other opioid painkillers. Copyright 2007 The New York Times Company

Keyword: Pain & Touch; Drug Abuse
Link ID: 10136 - Posted: 06.24.2010

Roxanne Khamsi Just like Goldilocks, mice have an innate sense of what makes a good bed: a specific group of cells in their brains becomes active when they see a potential nesting spot – but only if it perfectly matches their size. This set of brain cells responds regardless of whether the bed has a circular or square shape, suggesting that mice can understand abstract concepts, such as the idea of a bed, according to researchers. Joe Tsien at Boston University in Massachusetts, US, and colleagues used probes to record the electrical activity of brain cells in mice as the animals wandered around their cages. Each probe picks up on the signalling activity of roughly 200 cells at a time. They noticed that a probe in one mouse recorded a storm of brain cell activity each time the animal stepped into its nesting container. Mice prefer to sleep in small, containers – typically, a bowl the size of their body. The probe that picked up on the cell activity in response to the nesting container recorded specifically from the middle of a brain region known as the hippocampus, which processes memories. © Copyright Reed Business Information Ltd.

Keyword: Sleep
Link ID: 10135 - Posted: 06.24.2010

Heidi Ledford As a general rule, a man who learns that his children are genetically his brother's offspring would have good cause for distress. But for one group of primates, that wouldn't necessarily mean that mum has been unfaithful, a new study finds. The reason, says Corinna Ross of the University of Texas Health Science Center in San Antonio, is that these primates are often genetic mosaics containing some cells that belonged to their siblings. And when those cells happen to be sperm, a male can sire offspring that are genetically nephews and nieces rather than sons and daughters. This strange genetic mixing could be one of the reasons why these animals tend to raise their families in large collectives, with everyone lending a hand; animals are thought to generally give more parental attention to children with a strong genetic similarity to themselves. The discovery was made accidentally when Ross was studying small, tree-dwelling primates called black tufted-eared marmosets (Callithrix kuhlii) at the University of Nebraska in Lincoln. The marmosets that she studied were being kept in captivity, with two senior males for every reproducing female. Ross wanted to test the paternity of the colony's offspring, to find out which male was the father of each child; to do this, she looked at hair samples of various animals to determine their genetic make-up. ©2007 Nature Publishing Group

Keyword: Sexual Behavior
Link ID: 10134 - Posted: 06.24.2010

By STEVE LOHR Confident multitaskers of the world, could I have your attention? Think you can juggle phone calls, e-mail, instant messages and computer work to get more done in a time-starved world? Read on, preferably shutting out the cacophony of digital devices for a while. Several research reports, both recently published and not yet published, provide evidence of the limits of multitasking. The findings, according to neuroscientists, psychologists and management professors, suggest that many people would be wise to curb their multitasking behavior when working in an office, studying or driving a car. These experts have some basic advice. Check e-mail messages once an hour, at most. Listening to soothing background music while studying may improve concentration. But other distractions — most songs with lyrics, instant messaging, television shows — hamper performance. Driving while talking on a cellphone, even with a hands-free headset, is a bad idea. In short, the answer appears to lie in managing the technology, instead of merely yielding to its incessant tug. Copyright 2007 The New York Times Company

Keyword: Attention
Link ID: 10133 - Posted: 06.24.2010

By DANIEL B. SMITH Angelo, a London-born scientist in his early 30s with sandy brown hair, round wire-frame glasses and a slight, unobtrusive stammer, vividly recalls the day he began to hear voices. It was Jan. 7, 2001, and he had recently passed his Ph.D. oral exams in chemistry at an American university, where, for the previous four and a half years, he conducted research into infrared electromagnetism. Angelo was walking home from the laboratory when, all of a sudden, he heard two voices in his head. “It was like hearing thoughts in my mind that were not mine,” he explained recently. “They identified themselves as Andrew and Oliver, two angels. In my mind’s eye, I could see an image of a bald, middle-aged man dressed in white against a white background. This, I was told, was Oliver.” What the angels said, to Angelo’s horror, was that in the coming days, he would die of a brain hemorrhage. Terrified, Angelo hurried home and locked himself into his apartment. For three long days he waited out his fate, at which time his supervisor drove him to a local hospital, where Angelo was admitted to the psychiatric ward. It was his first time under psychiatric care. He had never heard voices before. His diagnosis was schizophrenia with depressive overtones. Angelo remembers his time at the hospital as the deepening of a nightmare. On top of his natural confusion and fear over the shattering of his psychological stability, Angelo did not react well to the antipsychotic he’d been prescribed, risperidone, which is meant to alleviate the symptoms of schizophrenia by reducing the level of dopamine in the brain. In Angelo’s case, the pills had a predominantly negative effect. His voices remained strong and disturbing — an unshakable presence, quiet only in sleep — while he grew sluggish and enervated. “If you think of the mind as a flowing river of thoughts,” he told me in an e-mail message, “the drug made my mind feel like a slow-moving river of treacle.” Several days into his stay, Angelo’s parents flew to the United States from London and took him back home. Copyright 2007 The New York Times Company

Keyword: Schizophrenia
Link ID: 10132 - Posted: 06.24.2010

Alan Searleman In the scientific literature, the term eidetic imagery comes closest to what is popularly called photographic memory. The most common way to identify eidetikers (as people with eidetic imagery are often called) is by the Picture Elicitation Method. In it, an unfamiliar picture is placed on an easel and a person carefully scans the entire scene. After 30 seconds have elapsed, the picture is removed from view, and the person is asked to continue to look at the easel and to report anything that they can observe. People possessing eidetic imagery will confidently claim to still "see" the picture. In addition, they can scan it and examine different parts of it just as if the picture were still physically present. Consequently, one of the hallmarks of eidetic imagery is that eidetikers use the present tense when answering questions about the missing picture, and they can report in extraordinary detail what it contained. Eidetic images differ from other forms of visual imagery in several important ways. First, an eidetic image is not simply a long afterimage, since afterimages move around when you move your eyes and are usually a different color than the original image. (For example, a flash camera can produce afterimages: the flash is bright white, but the afterimage is a black dot, and the dot moves around every time you move your eyes.) In contrast, a true eidetic image doesn’t move as you move your eyes, and it is in the same color as the original picture. Second, a common visual image that we can all create from memory (such as an image of a bedroom) does not have the characteristics of most eidetic images, which almost always fade away involuntarily and part by part. Also, it is not possible to control which parts of an eidetic image fade and which remain visible. Unlike common visual images created from memory, most eidetic images last between about half a minute to several minutes only, and it is possible to voluntarily destroy an eidetic image forever by the simple act of blinking intentionally. Furthermore, once gone from view, rarely can an eidetic image ever be retrieved. © 1996-2007 Scientific American, Inc.

Keyword: Learning & Memory
Link ID: 10131 - Posted: 06.24.2010

Mark A. W. Andrews An itch, also known as pruritus, is a general sensation arising from the irritation of skin cells or nerve cells associated with the skin. While it can be a nuisance, pruritus serves as an important sensory and self-protective mechanism, as do other skin sensations such as touch, pain, vibration, cold and heat. It can alert us to harmful external agents, but can become unbearable if not treated. Pruritus is a dominant symptom of many skin diseases and also occurs in some diseases that affect the entire body. An itching sensation of the skin arises due to stimulation of pruriceptors—itch-sensing nerve endings—by mechanical, thermal or chemical mediators. These include: Chemicals for immune response (histamines) and pain relief (opiods) Neuropeptides, which include pain-regulating messengers released within the brain, such as endorphins The neurotransmitters acetylcholine and serotonin Prostaglandins, which are lipids that, among other functions, create the sensation of pain in spinal nerve cells Stimulation by any of these agents is typically related to inflammation, dryness or other damage to the skin, mucous membranes or conjunctiva of the eye. In general, pruritus involves activation of the pruriceptors of specialized nerve cells called C-fibers. These C-fibers are identical to those associated with the sensation of pain, but they are functionally distinct and only convey the itch sensation—they comprise about 5 percent of the total C-fibers in human skin. © 1996-2007 Scientific American, Inc.

Keyword: Pain & Touch
Link ID: 10130 - Posted: 06.24.2010

By Stephen Cave If I had free will, I would choose to be funnier. I would choose always to have the right witty riposte ready to disarm adversaries and delight friends. But sadly, it is not so. My lot is for the same lame old gags to hobble out whether I will them to or not, like embarrassing aunts at a wedding. Indeed if we had free will, we might all choose to have the punning powers of the Two Ronnies, combined with the benevolence of Bob Geldof. But we do not. And that is a fact, laboratory proven. But of course we have free will, you might be thinking. You could prove it by, for example, choosing to raise your arm at some point in the next five seconds. Go on then. Done it? There, that was easy. Of your own volition, at the time of your choice, you moved your arm: QED. But the American neuroscientist Benjamin Libet has shown that before every such movement, there is a distinctive build-up of electrical activity in the brain. And this build-up happens about half a second before your conscious ”decision” to move your arm. So by the time you think, ”OK, I’ll move my arm,” your body is halfway there. Which means your conscious experience of making a decision - the experience associated with free will - is just a kind of add-on, an after-thought that only happens once the brain has already set about its business. In other words, your brain is doing the real work, making your hands turn the pages of this magazine or reach over for your cup of tea, and all the time your conscious mind is tagging along behind. Copyright The Financial Times Limited 2007

Keyword: Miscellaneous
Link ID: 10129 - Posted: 06.24.2010

CHICAGO - The arch of an eyebrow or the curve of a lip tells chimps a lot about each other, a finding that may give scientists new understanding about the evolution of human communication, researchers reported Friday. Human faces can be easy to read, but sometimes people must look in different places on the face to get an accurate picture. “What we know from humans is that even a single movement added to an expression can change the entire meaning,” said Lisa Parr, director of the Yerkes National Primate Research Center at Emory University in Atlanta. “It can significantly affect the outcome of interactions.” Until now, little research has been done on understanding how chimpanzees communicate through facial expressions, said Parr, speaking at an international conference of chimpanzee cognition at Chicago’s Lincoln Park Zoo. “There could be a whole realm of chimp communication we don’t have the capability of understanding,” she said. Chimpanzees are humans’ closest relatives, with just a 1.23 percent difference between the genetic codes of people and chimps. Scientists believe studying the behavior of chimpanzees lends insights into human evolution. © 2007 MSNBC.com

Keyword: Emotions
Link ID: 10128 - Posted: 06.24.2010

By MARIA CHENG LONDON -- New "landmark" research finds that alcohol and tobacco are more dangerous than some illegal drugs like marijuana or Ecstasy and should be classified as such in legal systems, according to a new British study. In research published Friday in The Lancet magazine, Professor David Nutt of Britain's Bristol University and colleagues proposed a new framework for the classification of harmful substances, based on the actual risks posed to society. Their ranking listed alcohol and tobacco among the top 10 most dangerous substances. Nutt and colleagues used three factors to determine the harm associated with any drug: the physical harm to the user, the drug's potential for addiction, and the impact on society of drug use. The researchers asked two groups of experts _ psychiatrists specializing in addiction and legal or police officials with scientific or medical expertise _ to assign scores to 20 different drugs, including heroin, cocaine, Ecstasy, amphetamines, and LSD. Nutt and his colleagues then calculated the drugs' overall rankings. In the end, the experts agreed with each other _ but not with the existing British classification of dangerous substances. Heroin and cocaine were ranked most dangerous, followed by barbiturates and street methadone. Alcohol was the fifth-most harmful drug and tobacco the ninth most harmful. Cannabis came in 11th, and near the bottom of the list was Ecstasy. © 2007 The Associated Press

Keyword: Drug Abuse
Link ID: 10127 - Posted: 06.24.2010

Fresh evidence that suggests monkeys can learn skills from each other, in the same manner as humans, has been uncovered by a University of Cambridge researcher. Dr Antonio Moura, a Brazilian researcher from the Department of Biological Anthropology, has discovered signs that Capuchin monkeys in Brazil bang stones as a signalling device to ward off potential predators. While not conclusive, his research adds to a mounting body of evidence that suggests other species have something approaching human culture. A strong case has already been made for great apes having a capacity for social learning, but until now there has been no evidence of material culture among the “new world” primates of Central or South America, which include Capuchins. Dr Moura carried out his research in the Serra da Capivara National Park, in the Piaui state of north-east Brazil, during which he observed bouts of stone-banging, primarily among a group of 10 monkeys. As he approached, the monkeys would first search for a suitable loose stone, then hit it on a rock surface several times. The act was apparently an aggressive one, directed at Dr Moura as a potential predator, but as the group became used to his presence in the area the stone-banging decreased. Furthermore, in a large minority of cases, adults and juvenile monkeys were seen banging the stones together without paying him any attention at all – suggesting that the younger monkeys were learning the skill from their more experienced elders. Captive monkeys released into the area that joined the study group also appeared to be learning to bang stones from the others. © University of Cambridge 1998-2006

Keyword: Evolution; Aggression
Link ID: 10126 - Posted: 06.24.2010

Philip Ball The wonderful acoustics for which the ancient Greek theatre of Epidaurus is renowned may come from exploiting complex acoustic physics, new research shows. The theatre, discovered under a layer of earth on the Peloponnese peninsula in 1881 and excavated, has the classic semicircular shape of a Greek amphitheatre, with 34 rows of stone seats (to which the Romans added a further 21). Its acoustics are extraordinary: a performer standing on the open-air stage can be heard in the back rows almost 60 metres away. Architects and archaeologists have long speculated about what makes the sound transmit so well. Now Nico Declercq and Cindy Dekeyser of the Georgia Institute of Technology in Atlanta say that the key is the arrangement of the stepped rows of seats. They calculate that this structure is perfectly shaped to act as an acoustic filter, suppressing low-frequency sound — the major component of background noise — while passing on the high frequencies of performers' voices1. It's not clear whether this property comes from chance or design, Declercq says. But either way, he thinks that the Greeks and Romans appreciated that the acoustics at Epidaurus were something special, and copied them elsewhere. ©2007 Nature Publishing Group

Keyword: Hearing
Link ID: 10125 - Posted: 06.24.2010