by Dave Munger Imagine being trapped in a small pressurized underwater chamber (like a diving bell) where you were fed once a day by an octopus that tossed food in from the opening in the floor. Each day an octopus also reached in to poke you gently with a stick. Suppose this went on for two weeks. Do you think you’d be able to figure out that there were actually two octopuses—one “poker” and one “feeder”? Would you be able to tell the difference between the two? Octopuses are so different from humans that it might actually be rather difficult for you to tell them apart—especially since you would only be able to see them through the distorting lens of the water. On the other hand, if you did manage to figure out which octopus was which, you might be able to get out of the way of the stick when the “poker” showed up. You also might be able to demonstrate to the octopuses that you were “intelligent,” perhaps inspiring them to treat you better while in captivity. Obviously this is just a thought experiment, and the real research was done in reverse, but hopefully this example gives you some sense of how difficult the problem of octopus intelligence really is. Because octopus brains evolved independently from human brains, their anatomical structure is very different from our own, so understanding whether octopuses are “intelligent” is not a simple task. How would you tell if an eight-legged alien from another planet was intelligent? ©2005-2009 Seed Media Group LLC.

Keyword: Intelligence; Evolution
Link ID: 14296 - Posted: 07.27.2010

By Marita Vera There is nothing more exhilarating for a boxing audience than to see a fighter hit the mat in a knockout. But being on the losing end of a KO punch can damage a lot more than a pugilist's pride—research suggests that the blows that cause knockouts can be debilitating to a boxer's short and long-term health. Repeated blows to the brain can cause chronic damage such as personality changes and dementia. If the punches have enough impact to cause uncontrollable brain swelling or hemorrhage, the fighter could even die. So what causes a knockout? Concussions, and lots of them. While it often seems as though the effect is caused by a single well-placed shot, it is usually the result of many quick punches. Each punch creates a concussion (technically defined as any head injury that causes a disruption of neurological function), and each concussion brings the boxer closer to a state of darkness. Here's how it happens: The body contains dissolved sodium, potassium and calcium, collectively known as electrolytes, which are responsible for conducting impulses along neurons. Every time a fighter receives a blow to a nerve, potassium leaves the cell and calcium rushes in, destabilizing the electrolyte balance, while the brain does all it can to keep these levels in balance. With each successive blow, this balance becomes harder and harder to maintain, and more and more energy must be spent in the process. When the body reaches the point where the damage outweighs the body's ability to repair itself, the brain shuts down to conserve enough energy to fix the injured neurons at a later point. ©2010 Hearst Communication, Inc.

Keyword: Brain Injury/Concussion
Link ID: 14295 - Posted: 07.27.2010

By Sandra G. Boodman As he picked up the phone to make the call, Wayne Curtis worried that his doctor might think he was a hypochondriac. Three weeks earlier, Curtis, then 48, had consulted Baltimore internist Charles Locke about a pulled muscle. Now the real estate agent had a new and seemingly trivial complaint: He couldn't hear anything out of his left ear, which seemed blocked. Curtis assumed that his problem was related to the thick coating of tree pollen that blanketed his downtown Baltimore neighborhood. Normally Curtis, who has long battled spring allergies, would have toughed it out and waited several weeks to see if his hearing returned as the pollen counts dropped. But a newly formed choral quartet of which Curtis was a member was about to have its first concert, and the tenor, who has performed with the Boston Symphony Orchestra, was concerned that his impaired hearing was affecting his singing. "I expected him to put me on a stronger decongestant, not to tell me to come in the very next day," said Curtis, who was taken aback by Locke's emphatic response. "It's probably a classic case of 'It's better to be lucky than good,' " Locke quipped. His sense of urgency was fueled by a memorable patient he had seen more than a decade earlier. Curtis's season of misery was as perennial as the pollen, and he was accustomed to loading up on antihistamines and decongestants every spring to get through it. © 2010 The Washington Post Company

Keyword: Hearing
Link ID: 14294 - Posted: 07.27.2010

By Matt Walker Bowhead whales have a previously undiscovered ability to smell the air. The finding could change our understanding of how baleen whales locate prey, as scientists suspect the bowhead whales sniff out krill swarms. The whales' sense of smell was revealed when scientists dissected their bodies and found olfactory hardware linking the brain and nose, and functional protein receptors required to smell. Previously, whales and dolphins were thought to lack the ability. Details are published in the journal Marine Mammal Science. Cetacean expert Professor Hans Thewissen of the Northeastern Ohio Universities College of Medicine and colleagues based in Japan and Alaska made the discovery while evaluating the brain size of bowhead whales. The whales had been landed as part of the biannual Inupiat subsistence hunt along the north coast of Alaska, and Prof Thewissen's team was allowed to dissect the brain cavities, to evaluate how much of the brain casing a bowhead whale's brain actually fills. "Upon taking a brain out, I noticed that there were olfactory tracts, which, in other mammals, connect the brain to the nose," Prof Thewissen told the BBC. "I followed those to the nose, and noted that all the olfactory hardware is there." BBC © MMX

Keyword: Chemical Senses (Smell & Taste); Evolution
Link ID: 14293 - Posted: 07.27.2010

by Michael Balter Why does human conversation come so easily? A new study chalks it up to a sort of "mind meld" between participants. Researchers have found that the brains of speakers and listeners become synchronized as they converse and that this "neural coupling" is key to effective communication. Scientists have traditionally considered talking and listening to be two independent processes. The idea is that speech is produced in some parts of the brain, including a region known as Broca's area, and understood in others, including a region known as Wernicke's area. But recent studies suggest that there's actually much more overlap. For example, partners in a conversation will unconsciously begin imitating each other, adopting similar grammatical structures, speaking rates, and even bodily postures. This overlap helps people establish a "common ground" during conversation and may even help them predict what the other is going to say next, argue psychologist Martin Pickering of the University of Edinburgh and psychologist Simon Garrod of the University of Glasgow, both in the United Kingdom. Some researchers think that so-called mirror neurons, which fire when one individual observes the actions of another, might be involved in these interactions. To test some of these hypotheses, a team led by Princeton University psychologist Uri Hasson used magnetic resonance imaging (MRI) to compare the brain activation patterns of speakers and listeners. Graduate student Lauren Silbert placed her head in an MRI machine and related a 15-minute, unrehearsed story about various adventures she had while in high school, which included two boys fighting over who was going to take her to the prom and an encounter with a police officer after a car accident. The team recorded Silbert's story, using a specially designed microphone that filtered out the loud noise of the MRI machine, and then played it back to 11 subjects while their brains were also scanned. © 2010 American Association for the Advancement of Science.

Keyword: Language
Link ID: 14292 - Posted: 07.27.2010

by Dolly J. Krishnaswamy Seven months ago, a 51-year-old woman known only to the public as patient LI1 suffered a severe stroke and lost her ability to communicate with the outside world. She couldn't even blink her eyes. But now, thanks to a new technology, the woman can write long, emotional e-mails to her loved ones just by sniffing. Like many quadriplegics, patient LI1's stroke damaged a region high up on her spinal column, paralyzing her from the neck down. But LI1's injury was so extensive that she also lost the ability to speak. Such patients are referred to as "locked-in" because they can't communicate with the outside world, even though their brain functions normally. Some can blink to answer simple yes or no questions or even string words together by picking out letters as someone recites them (as in the case of Jean-Dominique Bauby, author of The Diving Bell and the Butterfly). But this isn't an option for Patient LI1. So neurobiologist Noam Sobel of the Weizmann Institute of Science in Rehovot, Israel, turned to sniffing. He and colleagues had been studying the human sense of smell and had developed a device, which looks like the oxygen tubes patients wear in the hospital, that releases an odor when a subject sniffs forcefully. Sobel's team soon realized that the device could be configured to respond to various types of sniffing, such as sniffing harder or softer. And that meant it could have applications for locked-in patients. "We thought you could use this sniff to control anything, " Sobel says. "You could even fly a plane." © 2010 American Association for the Advancement of Science.

Keyword: Movement Disorders; Chemical Senses (Smell & Taste)
Link ID: 14291 - Posted: 07.27.2010

By SARAH KERSHAW ALBUQUERQUE — Her car is racing at a terrifying speed through the streets of a large city, and something gruesome, something with giant eyeballs, is chasing her, closing in fast. It was a dream, of course, and after Emily Gurule, a 50-year-old high school teacher, related it to Dr. Barry Krakow, he did not ask her to unpack its symbolism. He simply told her to think of a new one. “In your mind, with thinking and picturing, take a few minutes, close your eyes, and I want you to change the dream any way you wish,” said Dr. Krakow, founder of the P.T.S.D. Sleep Clinic at the Maimonides Sleep Arts and Sciences center here and a leading researcher of nightmares. And so the black car became a white Cadillac, traveling at a gentle speed with nothing chasing it. The eyeballs became bubbles, floating serenely above the city. “We call that a new dream,” Dr. Krakow told Ms. Gurule. “The bad dream is over there” — he pointed across the room — “and we’re not dealing with that. We’re dealing with the new dream.” The technique, used while patients are awake, is called scripting or dream mastery and is part of imagery rehearsal therapy, which Dr. Krakow helped develop. The therapy is being used to treat a growing number of nightmare sufferers. In recent years, nightmares have increasingly been viewed as a distinct disorder, and researchers have produced a growing body of empirical evidence that this kind of cognitive therapy can help reduce their frequency and intensity, or even eliminate them. Copyright 2010 The New York Times Company

Keyword: Sleep
Link ID: 14290 - Posted: 07.27.2010

By ALAN SCHWARZ The National Football League is producing a poster that bluntly alerts its players to the long-term effects of concussions, using words like “depression” and “early onset of dementia” that those close to the issue described as both staggering and overdue. The poster, soon to be hung in locker rooms leaguewide, becomes by far the N.F.L.’s most definitive statement on the cognitive risks of football, which it had discredited for most of the past several years as academic studies and reports of deceased players’ brain damage mounted. The new document also warns players that repeated concussions “can change your life and your family’s life forever,” a clear nod to retired players’ wives who have spoken out on the issue, occasionally before Congress. A draft of the poster also features photographs of unnamed youngsters in various sports with the reminder, “Other athletes are watching.” The new poster, which will also become a brochure given to all players, presents a stark change in league approach. It replaces a pamphlet given since 2007 that said, “Current research with professional athletes has not shown that having more than one or two concussions leads to permanent problems if each injury is treated properly,” and also left open the question of “if there are any long-term effects of concussion in N.F.L. athletes.” Copyright 2010 The New York Times Company

Keyword: Brain Injury/Concussion
Link ID: 14289 - Posted: 07.27.2010

By KENNETH CHANG For caterpillars, what you see on the outside as they crawl is not necessarily what Shaped something like an accordion, the tobacco hornworm caterpillar moves one segment at a time. First, the back legs on the last segment step forward, then the second-to-last segment and so on until finally the front segment with its head moves forward. Researchers at Tufts University and Virginia Tech were curious about the interior biomechanics of this form of movement, so they stuck the caterpillars on a treadmill within a powerful X-ray light source at Argonne National Laboratory in Illinois. For most creatures, including people, the innards and the outer parts are connected to something rigid like a skeleton or carapace, and the movements of the inside and the outside are synchronized. But caterpillars are almost entirely squishy, and the researchers were surprised when they saw that the guts of the caterpillar move differently. “It amazes me and blows my mind that there are still very unusual things to discover about such a humble creature,” said Michael A. Simon, a researcher at Tufts University in Boston who is the lead author of a paper describing the caterpillar locomotion, to be published in the journal Current Biology. Copyright 2010 The New York Times Company

Keyword: Muscles
Link ID: 14288 - Posted: 07.27.2010

By ALIYAH BARUCHIN On July 9, 2009, Steve Wulchin went to wake his 19-year-old son, Eric, in their home in Boulder, Colo. Eric had been given a diagnosis of epilepsy three years earlier, but other than that, his father said, “there was nothing out of the ordinary.” His seizures had been well controlled; he had not had one in six months. Yet that morning, Mr. Wulchin found Eric lying on the floor. CPR and paramedics were too late; Eric had died at about 2:30 a.m. The cause of Eric’s death was ultimately listed as Sudep, for sudden unexplained death in epilepsy. The syndrome accounts for up to 18 percent of all deaths in people with epilepsy, by most estimates; those with poorly controlled seizures have an almost 1 in 10 chance of dying over the course of a decade. Yet many patients and their families never hear about Sudep until someone dies. Mr. Wulchin said none of Eric’s four neurologists ever mentioned it to the family. “The message we got back was, ‘There’s no reason why he can’t live a long and normal life,’ ” he said. “It never occurred to me that this was a possibility.” Now, physicians, researchers, advocates and relatives like Mr. Wulchin, a technology executive, are trying to raise awareness about Sudep. One of their goals is to establish registries of deaths and autopsy results, building databases to support future research. Copyright 2010 The New York Times Company

Keyword: Epilepsy
Link ID: 14287 - Posted: 07.27.2010

By Karen Weintraub A leading antiaging researcher, Leonard Guarente, believes he has found a potential new approach for treating Alzheimer’s disease. For more than 15 years, the MIT biology professor has been researching proteins called sirtuins, which slow an animal’s aging clock during times of scarcity — stalling the animal at a younger and more fertile stage until food becomes more plentiful and reproductive success is more likely. Drug companies, including Cambridge-based Sirtris Pharmaceuticals Inc., a subsidiary of GlaxoSmithKline PLC, have been developing medications for diabetes and metabolic disorders based on this idea. In a paper published in the current issue of the journal Cell, Guarente and several students have shown that amping up one of the sirtuins, known as SIRT1, appears to treat Alzheimer’s in mice. Guarente, who cochairs Sirtris’s scientific advisory board, said his paper suggests that companies like Sirtris should be investigating whether sirtuins could be used against Alzheimer’s in people. “This would give us another completely new shot on goal, so I hope drug companies do try to develop such drugs,’’ he said. “Neurodegenerative diseases are now on the table.’’ © 2010 NY Times Co

Keyword: Alzheimers
Link ID: 14286 - Posted: 07.27.2010

by Linda Geddes IF YOU thought depression was caused by low serotonin levels, think again. It looks as if the brain chemistry of a depressed person is much more complex, with mounting evidence suggesting that too much serotonin in some brain regions is to blame. If correct, it might explain some of the negative side-effects associated with selective serotonin re-uptake inhibitors (SSRIs), antidepressants like Prozac which increase the amount of the neurotransmitter serotonin in some parts of the brain. The traditional view of depression was largely based on the observation that SSRIs boost mood- although why they do so is unknown. "Because antidepressants increase serotonin in some parts of the brain, people assumed that depression must be the result of low serotonin levels," says Christopher Lowry of the University of Boulder in Colorado. But the discovery of multiple types of serotonin-releasing neurons in the brain, along with high levels of serotonin recorded in people with depression, is prompting a rethink. "What's more likely is that there are subgroups of serotonin neurons that are overactive in depressed patients, rather than underactive as we have all been assuming," says Lowry. One of the first clues that something might be amiss with the traditional theory came three years ago, when Murray Esler at the Baker Heart Research Institute in Melbourne, Australia, and colleagues found that the level of serotonin in the brains of people with panic disorder was four times higher than in healthy volunteers (Stress, DOI: 10.1080/10253890701300904), and in depressed people who were not receiving treatment it was two times higher than in volunteers (Archives of General Psychiatry, vol 65, p 38). © Copyright Reed Business Information Ltd.

Keyword: Depression
Link ID: 14285 - Posted: 07.24.2010

by Sujata Gupta WHAT happens when you take blind mice and see how they run? It turns out they can identify objects using receptors in the eye that were previously thought to have no role in forming images. Since humans possess the same receptors, the finding could point the way to giving blind people some ability to see. Mice, and humans, have three types of light-detecting receptor in the eye. Rods and cones detect light, darkness, shape and colour, and make normal sight possible. Receptors of the third type, the melanopsin-containing ganglion cells (MCGCs), were until now thought only to respond to light over longer periods of time, to help moderate patterns of sleep and wakefulness. To investigate their role in vision, Samer Hattar of the Krieger School of Arts and Sciences at Johns Hopkins University in Baltimore, Maryland, and colleagues engineered mice to lack rods and cones. When these mice were placed in a maze, they were able to identify a lever with a visible pattern on it which allowed them to escape. Mice that lacked rods, cones and MCGCs could not find the lever. In another task, the team found that the MCGC mice could follow the movement of a rotating drum (Neuron, DOI: 10.1016/j.neuron.2010.05.023). This suggests MCGCs can form "low-acuity yet measurable images", Hatter says. Tom Cronin at the University of Maryland notes that the mice in the experiment behave like people with "blindsight", who can navigate round objects without consciously perceiving them. "It's mind-boggling but I suspect that the mice are doing something like that," he says. © Copyright Reed Business Information Ltd.

Keyword: Biological Rhythms; Vision
Link ID: 14284 - Posted: 07.24.2010

by Mairi Macleod FROM feckless fathers and teenaged mothers to so-called feral kids, the media seems to take a voyeuristic pleasure in documenting the lives of the "underclass". Whether they are inclined to condemn or sympathise, commentators regularly ask how society got to be this way. There is seldom agreement, but one explanation you are unlikely to hear is that this kind of "delinquent" behaviour is a sensible response to the circumstances of a life constrained by poverty. Yet that is exactly what some evolutionary biologists are now proposing. There is no reason to view the poor as stupid or in any way different from anyone else, says Daniel Nettle of the University of Newcastle in the UK. All of us are simply human beings, making the best of the hand life has dealt us. If we understand this, it won't just change the way we view the lives of the poorest in society, it will also show how misguided many current efforts to tackle society's problems are - and it will suggest better solutions. Evolutionary theory predicts that if you are a mammal growing up in a harsh, unpredictable environment where you are susceptible to disease and might die young, then you should follow a "fast" reproductive strategy - grow up quickly, and have offspring early and close together so you can ensure leaving some viable progeny before you become ill or die. For a range of animal species there is evidence that this does happen. Now research suggests that humans are no exception. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Evolution
Link ID: 14283 - Posted: 07.24.2010

By NICHOLAS WADE A potentially promising approach to treating Alzheimer’s disease has been developed by researchers studying sirtuin, a protein thought capable of extending lifespan in laboratory animals. Using mice prone to developing Alzheimer’s, the researchers showed that activating sirtuin suppressed the disease and that destroying sirtuin made it much worse. The finding was made by Gizem Donmez, Leonard Guarente and colleagues at the Massachusetts Institute of Technology, who say it raises the hope of treating Alzheimer’s, and possibly other neurodegenerative diseases like Parkinson’s and Huntington’s, with drugs that activate sirtuin. Researchers not involved in the study agreed. “We think it is a scientifically compelling story that ties the sirtuins to the biology of Alzheimer’s disease,” said Dr. Dennis J. Selkoe, an Alzheimer’s expert at Harvard Medical School. But the therapeutic implications, Dr. Selkoe added, “remain quite up in the air.” Another expert, Dr. Juan C. Troncoso of Johns Hopkins University School of Medicine, said the finding “opens a very good avenue, but it’s not without a lot of technical challenges.” Drugs that activate sirtuin already exist, including resveratrol, a minor ingredient of red wine and other foods, and small-molecule chemicals designed to mimic resveratrol. Sirtris, the company that developed the drugs, is testing them against diabetes and other diseases. This generation of drugs does not cross the blood-brain barrier so would not work against Alzheimer’s. Copyright 2010 The New York Times Company

Keyword: Alzheimers; Huntingtons
Link ID: 14282 - Posted: 07.24.2010

By Emily Anthes Perhaps the most unlikely hero to emerge from this summer’s World Cup was Paul the octopus, a lightly spotted invertebrate living in an aquatic center in Germany. Paul earned worldwide fame for successfully “predicting” the winner of eight out of eight soccer games, including the final match. Before each game, Paul’s keepers would place two food-filled boxes, each of which was decorated with one team’s national flag, in the creature’s tank. Whichever box Paul ate from first was considered to be his pick. The octopus nailed it all eight times. Though Paul’s success seems mainly to have been luck — evidence for psychic sports forecasting ability in octopuses is, well, somewhat lacking — if you were looking to consult a brainy animal, you could do worse than an octopus. Research is increasingly revealing that there’s something sophisticated going on inside the octopus’s soft and squishy head. The critters, it seems, are surprisingly smart. Octopuses “make decisions all the time, complicated decisions,” says Roger Hanlon, a senior scientist at the Marine Biological Laboratory in Woods Hole. “People don’t expect that from a creature related to an oyster.” What scientists are discovering about the octopus calls into question many of our assumptions about intelligence. Partly this is because the creatures are so different from the kinds of animals — social vertebrates, especially mammals — that have long been seen as having a monopoly on smarts. Octopuses are members of a class of creatures known as cephalopods, which appeared on the planet even before the first fish, and they are almost as far removed from us primates as another animal can get. And although it has long been theorized that intelligence evolved in social creatures as a way for species that live in groups to navigate the complex social world, the octopus leads a solitary life. © 2010 NY Times Co.

Keyword: Intelligence; Evolution
Link ID: 14281 - Posted: 07.24.2010

In humans, throwing a ball, typing on a keyboard, or engaging in most other physical activities involves the coordination of numerous discrete movements that are organized as action sequences. Scientists at the National Institutes of Health and the Gulbenkian Institute in Portugal have identified brain activity in mice that can signal the initiation and termination of newly learned action sequences. The findings appear online today in the current issue of Nature. “This interesting report should advance our understanding of the neurobiology of movement disorders, and open new avenues of research for their treatment and prevention,” says Kenneth R. Warren, Ph.D., acting director of the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the NIH. The study was conducted by Xin Jin, Ph.D. an investigator in the NIAAA Laboratory for Integrative Neuroscience, and Rui M. Costa, D.V.M, Ph.D., principal investigator of the Champalimaud Neuroscience Program at the Gulbenkian Institute. The researchers trained mice to press a lever exactly eight times to receive a sugar-water reward. As the mice learned this task, the researchers monitored brain cell activity in the animals' basal ganglia, deep brain structures that are known to help start and control movement. “We recorded activity in the dorsal striatum and substantia nigra during the learning of novel action sequences,” explained Dr. Jin. “Although previous studies have reported changes in neural activity in these areas during movement, their role in the initiation and termination of newly learned action sequences has not been explored.”

Keyword: Movement Disorders
Link ID: 14280 - Posted: 07.24.2010

By Nicholette Zeliadt Down's syndrome (DS) is an incurable, heritable disorder affecting an estimated 400,000 people in the U.S. It is characterized by impaired cognitive ability and abnormal physical growth. Whereas scientists have long known that DS is caused by inheriting an extra copy of all or part of chromosome 21, the underlying cause of the brain defects common in Down's patients has not been fully gleaned. Now, a collaborative team of scientists working with a mouse model of DS has discovered that just two genes are responsible for the majority of the brain abnormalities present in their animals. The scientists hope that their findings will help scientists understand brain defects in humans with the disorder as well as aid in the development of drugs to treat the cognitive impairment in Down's patients. Previous studies suggest that brain defects in DS mice occur very early, while the mice are still developing embryos. These defects result from abnormalities in how brain neurons communicate with each other—either via excitatory signals, which stimulate other neurons to communicate, or inhibitory signals, which act to prevent other neurons from firing. During embryonic development, the proper ratio of excitatory and inhibitory neurons is established for optimal brain function. These electrical circuits are the basis for memory formation and learning. Human chromosome 21 has more than 300 genes on it. Some of the features of DS—including cognitive deficits, heart defects, gastrointestinal problems and poor muscle tone—could therefore result from having either an additional copy of a single gene on chromosome 21; combinations of extra genes; or from the effects some redundant genes may exert on other chromosomes' genes. This complexity has significantly slowed the pace of researchers' attempts to understand the genetic basis of how such a diverse array of symptoms and abnormalities arise. © 2010 Scientific American,

Keyword: Development of the Brain; Genes & Behavior
Link ID: 14279 - Posted: 07.24.2010

Janelle Weaver A tool that automatically assesses young children's vocalizations should enable faster and more objective measures of language learning in natural environments than current methods allow. And its developers claim that the new tool may also help the early detection of autism by detecting speech abnormalities associated with it. The new method will allow scientists to assess more quickly how children develop speech and language in response to the talk they hear around them, says Kim Oller of the University of Memphis in Tennessee, whose team published its work today in the Proceedings of the National Academy of Sciences1. Because past investigations of language development in natural settings have been hindered by the time-consuming transcription of audio recordings, "their approach could change the field of language development research," says Dorothy Bishop, an expert in developmental language disorders at the University of Oxford, UK. The objective measure of vocal quality could also help to detect speech abnormalities and autism in children, the authors suggest. Previous research has shown that children with Autism Spectrum Disorder have unusual articulation and prosody (patterns of rhythm and sound), but standard diagnostic tests do not cite specific vocal deficiencies. Quantifying vocal abnormalities in autistic children and translating them into a diagnostic procedure has been challenging, says Gordon Ramsay, a speech scientist at Yale University in New Haven, Connecticut. "One of the great goals for years now has been to find objective measures of characteristics or behaviours that can be used to diagnose autism," he says. "This study is the first application of objective measures to detect autism based on speech." © 2010 Nature Publishing Group,

Keyword: Autism; Language
Link ID: 14278 - Posted: 07.20.2010

By NICHOLAS WADE Some 300 million years ago, the living ancestor of humans was a reptile. Like turtles and alligators today, it let the temperature at which its eggs were incubated decide their sex. Birds and mammals, two groups that descended from the reptiles, put sex under the more reliable control of genes, not of temperature. But sex-determining genes pose a severe problem for the organization of a genome. In a series of experiments over the past 15 years, David Page of the Whitehead Institute has reconstructed many of the steps in the evolution of the human sex chromosomes, which he calls “an infinitely rich experiment of nature.” He has now started to analyze a parallel experiment, the sex chromosomes of birds. In humans, men have an X and a Y chromosome, and women two X’s. In reptilian times, the X and the Y were an ordinary pair of chromosomes until the male-determining gene landed on the Y. Thereupon the Y started shedding the genes it held in common with the X and shriveled to a fraction of its former size. Birds have evolved a similar system with a twist — it’s the male that has two of the same chromosomes. Their sex chromosomes are called the Z and W, with males having two Z’s and females a Z and a W. The Z and W are derived from a different pair of ancestral chromosomes than the X and Y, a team led by Daniel W. Bellott and Dr. Page report in the current issue of Nature. The Z’s evolution has in several ways paralleled that of the X, even though each is associated with a different sex. Copyright 2010 The New York Times Company

Keyword: Sexual Behavior
Link ID: 14277 - Posted: 07.20.2010