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

By Bruce Bower As St. Patrick’s Day approaches, it may pay to keep in mind that there is a kernel of truth to the stereotype that large men are especially prone to being DWI — dangerous while intoxicated. When they were drunk, bigger men became especially aggressive when given the opportunity to administer electric shocks to a fictitious opponent in a laboratory contest, say psychologist Nathan DeWall of the University of Kentucky in Lexington and his colleagues. Yet larger men showed no aggression increases after downing a nonalcoholic placebo drink. Intoxicated women showed little taste for shocking another person in the same experimental contest regardless of their weight, DeWall’s team reports in a paper published online February 25 in the Journal of Experimental Social Psychology. Big men under the influence don’t always behave badly, DeWall emphasizes. “There will inevitably be scrawny, intoxicated brawlers and big, nice boozed-up imbibers,” he says. But the new findings suggest that, in general, the bigger the guy, the greater the chances of alcohol-related mayhem. His findings fit with a theory proposed by psychologist Aaron Sell of the University of California, Santa Barbara, that physically imposing individuals — usually men — can get their way in interpersonal disputes through force, making them prone to anger and to feeling entitled to special treatment. © Society for Science & the Public 2000 - 2010

Keyword: Drug Abuse; Aggression
Link ID: 13846 - Posted: 06.24.2010

A technique that "washes out" the brains of severely ill premature babies may aid survival, a study suggests. Bleeding in the brain is one of the most feared complications for the most premature babies as it can lead to brain damage or death. The Bristol University study of 77 babies found the technique - involving draining the brain while introducing new fluid - could reduce the risk. It is thought the technique could benefit about 100 babies a year. The technique is carried out over a couple of days and requires close monitoring to ensure the pressure in the baby's brain does not rise too high, researchers say. Experts have described the findings as encouraging. It would be used only on the most premature babies with large haemorrhages, which cause the brain and head to expand excessively - a condition called hydrocephalus. Standard treatment currently involves repeatedly inserting needles into the head or spine to remove the build up of fluid over a number of months before a shunt is inserted to drain fluid into the abdomen. But the study, published in the Pediatrics journal, found the new treatment called Drift was more effective. Of the 39 babies to receive the treatment, by the age of two 54% had died or were severely disabled, compared with 71% who were given the standard treatment. Paediatric neurosurgeon Ian Pople, one of the lead researchers, said he hoped the technique would soon be used in the NHS. "This is the first time that any treatment anywhere in the world has been shown to benefit these very vulnerable babies." One of the first babies to be given the treatment before the study took place was nine-year-old Isaac Walker-Cox, from South Gloucestershire. He was given a 1% chance of survival when he was born 13 weeks early. (C)BBC

Keyword: Development of the Brain
Link ID: 13845 - Posted: 03.08.2010

By Clare Kingston Cooking is something we all take for granted but a new theory suggests that if we had not learned to cook food, not only would we still look like chimps but, like them, we would also be compelled to spend most of the day chewing. Without cooking, an average person would have to eat around five kilos of raw food to get enough calories to survive. The daily mountain of fruit and vegetables would mean a six-hour chewing marathon. It is already accepted that the introduction of meat into our ancestors' diet caused their brains to grow and their intelligence to increase. Meat - a more concentrated form of energy - not only meant bigger brains for our ancestors, but also an end to the need to devote nearly all their time to foraging to maintain energy levels. As a consequence, more time was available for social structure to develop. Harvard Professor Richard Wrangham believes there is more to it than simply discovering meat. He thinks that it is not so much a change in the ingredients of our diet, but the way in which we prepare them that has caused the radical evolution of our species. "I think cooking is arguably the biggest increase in the quality of the diet in the whole of the history of life," he says. "Our ancestors most probably dropped food in fire accidently. They would have found it was delicious and that set us off on a whole new direction." To understand how and when our bodies changed, we need to take a closer look at what our ancestors ate by studying the fossil records. Our earliest ancestor was the ape-like Australopithecus. Australopithecus had a large belly containing a big large-intestine, essential to digest the robust plant matter, and had large, flat teeth which it used for grinding and crushing tough vegetation. (C)BBC

Keyword: Evolution; Obesity
Link ID: 13844 - Posted: 03.06.2010

By Mary Carmichael Jack Shafer, the media columnist at Slate, is famous for pointing out "bogus trend stories," especially those involving drug use. Of them, he once said, "Whenever I fall into a funk over the press corps' abysmal coverage of illicit drugs, I console myself with the knowledge that, as awful as the coverage is, it's always been that way." He's even blasted drug coverage in sister publications The Washington Postand What would he make of all the recent stories about K2, or "fake marijuana," which is essentially a legal, smokable form of psychoactive potpourri? Breathless news reports about the substance have been popping up all over in the last few days. If you live in Arizona, Arkansas, Florida, Georgia, Illinois, Michigan, Missouri, Kansas, or Wisconsin, you've probably seen one. Maybe you even caught a Missouri detective's panicked prediction that K2 is "going to end up killing somebody." As far as we know, though, it hasn't. Why is it suddenly getting all this attention? There's a legitimate news hook for some of these stories: Kansas became the first state to ban K2 last week, and there are similar bills pending in Nebraska and North Dakota. But why the states are banning the stuff now is unclear. K2 isn't new. It's been around since the mid-'90s, when John Huffman, a Clemson University chemist, synthesized a substance he called JWH-018. The chemical was structurally similar to THC, the active ingredient in pot, and apparently quite a bit more potent. (There's a good explanation of the science here.) Like its illicit cousin, JWH-018 made users mellow and euphoric. Pot enthusiasts picked up on Huffman's work, mixed or bought batches of JWH-018 themselves, and started spraying it onto varying mixes of dried herbs, flowers, and tobacco leaves. The result was K2—a.k.a. "Spice," "Genie," or "Zohai"—which quickly caught on in head shops and on the Internet as a way to get high without breaking the law. Although the federal Drug Enforcement Agency has listed K2 as a "drug or chemical of concern," it isn't officially "scheduled," and that makes it legal (unless you're buying it in Kansas). © 2010 Newsweek, Inc.

Keyword: Drug Abuse
Link ID: 13843 - Posted: 06.24.2010

By HENRY FOUNTAIN Lizards are not the most loquacious of animals. Aside from the geckos, which make chirping noises to communicate among themselves, they don’t vocalize. Yet most lizards have well-developed ears. So that raises the obvious question: if they don’t use sounds to communicate, what do they use the ears for? Ryo Ito and Akira Mori of Kyoto University in Japan supply one answer: to eavesdrop on other animals. Writing in The Proceedings of the Royal Society B, they describe how the Madagascan spiny-tailed iguana overhears the alarm calls of nearby birds to protect itself from predators. The researchers studied iguanas in a dry deciduous forest in northwestern Madagascar, an area teeming with vertebrate species, including the Madagascar paradise flycatcher. The iguana and the flycatcher live in proximity but have no real ecological interaction — one doesn’t feast on the other, and they don’t share parasites or compete for food. They are, however, hunted by the same predators, raptors like hawks and buzzards. Unlike the iguanas, the flycatchers are very vocal, particularly when a predator is nearby. They exhibit “mobbing” behavior, approaching and harassing the enemy bird and shifting from their normal songs to alarm calls that alert other birds of the danger. In a series of experiments, the researchers tested whether iguanas in the field responded to recorded flycatcher alarm calls. They found that an iguana becomes more vigilant — most often moving its head while keeping the rest of the body still. Copyright 2010 The New York Times Company

Keyword: Hearing; Evolution
Link ID: 13842 - Posted: 06.24.2010

By Christof Koch Each new generation of astronomers discovers that the universe is much bigger than their predecessors imagined. The same is also true of brain complexity. Every era’s most advanced technologies, when applied to the study of the brain, keep uncovering more layers of nested complexity, like a set of never ending Russian dolls. We now know that there are up to 1,000 different subtypes of nerve cells and supporting actors—the glia and astrocytes—within the nervous system. Each cell type is defined by its chemical constituents, neuronal morphology, synaptic architecture and input-output processing. Different cell types are wired up in specific ways. For example, a deep layer 5 pyramidal neuron might snake its gossamer-thin output wire, the axon, to a subcortical target area while also extending a connection to an inhibitory local neuron. Understanding how the brain’s corticothalamic complex creates any one conscious sensation necessitates delineating these underlying circuits for the 100 billion cells in the brain. Bulk tissue technologies such as functional brain imaging or electroencephalography identify specific brain regions related to vision, pain or memory. Yet they are unable to resolve details at the all-important circuit level. Brain imaging tracks the power consumption of a million neurons, irrespective of whether they are excitatory or inhibitory, project locally or globally, and so on. For progress on consciousness, something drastically more refined is needed. © 2010 Scientific American,

Keyword: Brain imaging
Link ID: 13841 - Posted: 06.24.2010

by Ewen Callaway If you want to live to a grand old age, then smile – and make sure you mean it. Pro baseball players in the 1950s who genuinely beamed in their official photographs tended to outlive more sullen-looking sportsmen and those who put on fake smiles. Players from the US major league with honest grins lived an average of seven years longer than players who didn't smile for the camera and five years longer than players who smiled unconvincingly, conclude Ernest Abel and Michael Kruger at Wayne State University in Detroit, Michigan. It's known that happy people tend to be healthy too. Kruger and Abel wondered whether this relationship would be reflected in the smiles and longevity of baseball players. Genuine smiles are known as Duchenne smiles after the 19th-century neurologist who defined them in detail. They engage muscles both near the corners of the mouth and around the eyes – the zygomatic major and the orbicularis oculi respectively. Fake, "non-Duchenne" smiles exercise only mouth muscles. Smile survival With training, these muscles are easy to recognise in photographs. So Abel and four colleagues who were not aware of what the study was investigating, but were trained to analyse smiles, looked at vintage photographs of 230 major leaguers who played in the 1952 season. The researchers classified them as non-smilers, Duchenne smilers or non-Duchenne smilers. Then they looked up the lifespans of the 184 players who had already died. © Copyright Reed Business Information Ltd

Keyword: Emotions
Link ID: 13840 - Posted: 06.24.2010

Greg Miller Diagnoses of mental disorders in children and adolescents rose dramatically during the past 2 decades. Juvenile cases of bipolar disorder, once thought to strike only in adulthood, jumped 40-fold between 1993 and 2004 in the United States, according to one widely cited study. Autism estimates leapt from 1 in 1500 to as high as 1 in 90 over a similar time period. Such figures have fueled an intense debate about whether the surge is real or reflects a trend toward overzealous diagnoses and a tendency to pathologize normal youthful behavior. Against this backdrop, the clinicians and researchers working on revisions to the psychiatrists' bible, the Diagnostic and Statistical Manual of Mental Disorders (DSM), have been wrestling with how to improve the diagnosis of mental disorders in these age groups. It's not clear how their suggestions, released last month (Science, 12 February, p. 770), would affect the prevalence of mental disorders if adopted, but they are already altering the discussion. The most substantial proposals include a reclassification of autism spectrum disorders, a new diagnosis of post-traumatic stress disorder (PTSD) tailored to preschool children, and a brand-new diagnosis called temper dys-regulation disorder with dysphoria (TDD) that members of the DSM work group hope will stem what they see as a false epidemic of juvenile bipolar disorder. © 2010 American Association for the Advancement of Science

Keyword: Autism; Schizophrenia
Link ID: 13839 - Posted: 06.24.2010

National Institutes of Health (NIH) scientists investigating how prion diseases destroy the brain have observed a new form of the disease in mice that does not cause the sponge-like brain deterioration typically seen in prion diseases. Instead, it resembles a form of human Alzheimer's disease, cerebral amyloid angiopathy, that damages brain arteries. The study results, reported by NIH scientists at the National Institute of Allergy and Infectious Diseases (NIAID), are similar to findings from two newly reported human cases of the prion disease Gerstmann-Straussler-Scheinker syndrome (GSS). This finding represents a new mechanism of prion disease brain damage, according to study author Bruce Chesebro, M.D., chief of the Laboratory of Persistent Viral Diseases at NIAID’s Rocky Mountain Laboratories. Prion diseases, also known as transmissible spongiform encephalopathies, primarily damage the brain. Prion diseases include mad cow disease or bovine spongiform encephalopathy in cattle; scrapie in sheep; sporadic Creutzfeldt-Jakob disease (CJD), variant CJD and GSS in humans; and chronic wasting disease in deer, elk and moose. The role of a specific cell anchor for prion protein is at the crux of the NIAID study. Normal prion protein uses a specific molecule, glycophosphoinositol (GPI), to fasten to host cells in the brain and other organs. In their study, the NIAID scientists genetically removed the GPI anchor from study mice, preventing the prion protein from fastening to cells and thereby enabling it to diffuse freely in the fluid outside the cells.

Keyword: Prions
Link ID: 13838 - Posted: 06.24.2010

By Jennifer Viegas Male mice drive females wild with ultrasonic love songs, suggests a new study. Since song quality varies, the mice world has its Justin Timberlake-like stars that impress females with their talents more than other willing, but not so able, males do. While no one is yet certain what makes a "hit love song" in the mice world, lead author Kerstin Musolf told Discovery News that "it could be a question of different syllable types or endurance in singing or a combination of both -- all together it could help the female to choose the best mate." Musolf is a researcher in the Konrad Lorenz Institute for Ethology at the Austrian Academy of Sciences. She and her team believe their study, which has been accepted for publication in the journal Animal Behavior, is the first to examine the ultrasonic vocalizations of wild-derived house mice. These calls have frequencies above those of sounds audible to humans and many other animals. Using special equipment, the researchers recorded and observed offspring of house mice caught at three locations in Ganserndorf, Austria. When males got a whiff of scent from available, non-related, adult females, they sang their hearts out at varying degrees. Females were more attracted to songs crooned by unfamiliar males that weren't related to them. Women sometimes flirt by pushing back their hair. Female mice do something similar by cleaning themselves vigorously all over. © 2010 Discovery Communications, LLC.

Keyword: Sexual Behavior; Hearing
Link ID: 13837 - Posted: 06.24.2010

A new hand-held device that delivers a magnetic pulse to the back of the head could become an alternative to drug treatment for people with migraines. A trial found that 40% of patients were pain free two hours after using the device. Research showed there were no serious side-effects and patients found the device easy to use at home. However, doctors say more research is needed to work out the timing of the doses. Experts from the Albert Einstein College of Medicine in New York carried out the trial to assess the safety and effectiveness of the device. Previous trials have only involved large, expensive devices which have to be used in a clinic. The hand-held device emits a single-pulse transcranial magnetic stimulation (sTMS), thought to disrupt the electrical events in the brain which cause the preliminary symptoms of migraines with aura. Auras are sensory or visual disturbances that occur before a migraine headache sets in. These include visual symptoms such as spots of light and zigzag lines. Other symptoms include tingling, numbness and difficulties with speaking. Two hundred patients were asked to use the device to treat migraines with aura over three months. Half of those patients were given placebo treatment. The findings, to be published in The Lancet Neurology, showed that the real magnetic pulse from the device was significantly more effective than placebo treatment. More patients were pain free two, 24 and 48 hours afterwards. (C)BBC

Keyword: Pain & Touch
Link ID: 13836 - Posted: 03.04.2010

Women need to be treated for stroke as soon as possible.Women need to be treated for stroke as soon as possible. (CBC) Women who don't get a clot-busting drug after a stroke might fare worse than men who don't receive the drug, a University of Calgary study suggests. Both sexes fared equally well when given the drug known as tissue plasminogen activator, or tPA, which breaks up the blood clots that cause a stroke. "It's exactly analogous to you [having] a blocked kitchen sink," study author Dr. Michael Hill said in an interview. "You put some Drano in there, it churns up the clot and your sink works again." The researchers' findings were reported in this week's issue of the journal Neurology. The study looked at data on 2,113 stroke sufferers collected by the Canadian Stroke Network. Of these, 232 were treated with tPA within three hours of their stroke and 44 per cent of them were women. The three hours is the maximum window recommended under the guidelines for administering tPA. "Women need to be treated for stroke as soon as possible," Hill said in news release. "We found that women who weren't treated had a worse quality of life after stroke than men. However, the good news is that women who were treated responded just as well as men to the treatment." © CBC 2010

Keyword: Stroke; Sexual Behavior
Link ID: 13835 - Posted: 06.24.2010

by Jessica Hamzelou PAIN intensity, the most personal of experiences, can now be measured from the outside, say researchers who scanned the brains of young men who were fresh out of the operating theatre. Their claim reopens the debate over whether pain can be measured objectively. It might even be possible to gauge the pain felt by newborn babies, fetuses, "locked-in" patients, who can't communicate with the outside world, and animals. "The definition of pain is that it is subjective, and until now an objective measurement has remained elusive," says Morten Kringelbach of the University of Oxford, who has previously worked on a method of objective pain measurement and was not involved in the most recent work. Functional MRI scans have been used before to identify brain areas that "light up" when someone is in pain. Because oxygenated and deoxygenated blood have different levels of magnetisation they look different under MRI. A technique for analysing fMRI scans called BOLD, for blood-oxygen-level dependent, exploits this difference to determine which areas are most active: high oxygen is a sign that a brain region is particularly active. While BOLD can reveal if the amount of oxygen flowing to a particular region has increased or decreased, it doesn't measure by how much. © Copyright Reed Business Information Ltd.

Keyword: Pain & Touch; Brain imaging
Link ID: 13834 - Posted: 06.24.2010