by Curtis Abraham, Uganda Large areas of northern Uganda are experiencing an outbreak of nodding syndrome, a mysterious disease that causes young children and adolescents to nod violently when they eat food. The disease, which may be an unusual form of epilepsy, could be linked to the parasitic worm responsible for river blindness, a condition that affects some 18 million people, most of them in Africa. The current outbreaks are concentrated in the districts of Kitgum, Pader and Gulu. In Pader alone, 66 children and teenagers have died. More than 1000 cases were diagnosed between August and mid-December. Onchocerca volvulus, a nematode worm that causes river blindness, is known to infest all three affected districts. Nearly all the children with nodding syndrome are thought to live near permanent rivers, another hint of a connection with river blindness. The link is not clear cut, though. "We know that [Onchocerca volvulus] is involved in some way, but it is a little puzzling because [the worm] is fairly common in areas that do not have nodding disease," says Scott Dowell, who researches paediatric infectious diseases and is lead investigator into nodding syndrome with the US Centers for Disease Control and Prevention. There is no known cure for nodding syndrome, so Uganda's Ministry of Health has begun using anticonvulsants such as sodium valproate to treat its signs and symptoms. Meanwhile the disease is continuing to spread, say Janet Oola, Pader's health officer, and Sam William Oyet, the district's medical entomology officer. © Copyright Reed Business Information Ltd.

Keyword: Movement Disorders
Link ID: 16177 - Posted: 12.23.2011

by Sarah C. P. Williams When a rattlesnake shakes its tail, does it hear the rattling? Scientists have long struggled to understand how snakes, which lack external ears, sense sounds. Now, a new study shows that sound waves cause vibrations in a snake's skull that are then "heard" by the inner ear. "There's been this enduring myth that snakes are deaf," says neurobiologist Bruce Young of the University of Massachusetts, Lowell, who was not involved in the new research. "Behavioral studies have suggested that snakes can in fact hear, and now this work has gone one step further and explained how." In humans, sound waves traveling through the air hit the eardrum, causing the movement of tiny bones and vibrations of tiny hair cells in the inner ear. These vibrations are then translated into nerve impulses that travel to the brain. Snakes have fully formed inner ear structures but no eardrum. Instead, their inner ear is connected directly to their jawbone, which rests on the ground as they slither. Previous studies have shown that vibrations traveling through the ground—such as the footsteps of predators or prey—cause vibrations in a snake's jawbone, relaying a signal to the brain via that inner ear. It was still unclear, however, whether snakes could hear sounds traveling through the air. So Biologist Christian Christensen of Aarhus University in Denmark took a closer look at one particular type of snake, the ball python (Python regius). Studying them wasn't easy. "You can't train snakes to respond to sounds with certain behaviors, like you might be able to do with mice," says Christensen. Instead, he and his colleagues used electrodes attached to the reptiles' heads to monitor the activity of neurons connecting the snakes' inner ears to their brains. Each time a sound was played through a speaker suspended above the snake's cage, the researchers measured whether the nerve relayed an electrical pulse (the snakes showed no outward response to the sounds). The nerve pulses were strongest, the researchers found, with frequencies between 80 and 160 hertz—around the frequency for the lowest notes of a cello, though not necessarily sounds that snakes encounter often in the wild. © 2010 American Association for the Advancement of Science

Keyword: Hearing; Evolution
Link ID: 16176 - Posted: 12.23.2011

By Courtney Humphries A video screen shows a man in his late 60s lying awake on an operating table. Just outside the camera's view, a doctor is moving his finger in front of the man's face, instructing him to follow it back and forth with his eyes. Seconds later, after a dose of the powerful anesthetic drug propofol, his eyelids begin to droop. Then his pupils stop moving. Only the steady background beeping of the heart monitor serves as a reminder that the man isn't dead. "He's in a coma," the doctor, Emery Brown, explains. "General anesthesia is a drug-induced reversible coma." As an anesthesiologist at Massachusetts General Hospital (MGH), Brown is constant witness to one of the most profound and mysterious feats of modern medicine. Every day, nearly 60,000 patients in the United States undergo general anesthesia, enabling them to survive even the grisliest operations unaware and free of pain. But though doctors have been putting people under for more than 150 years, what happens in the brain during general anesthesia is a mystery. Scientists don't know much about the extent to which these drugs tap into the same brain circuitry we use when we sleep, or how being anesthetized differs from other ways of losing consciousness, such as slipping into a coma following an injury. Are parts of the brain truly shutting off, or do they simply stop communicating with each other? How is being anesthetized different from a state of hypnosis or deep meditation? And what happens in the brain in the transition between consciousness and unconsciousness? "We know we can get you in and out of this safely," Brown says, "but we still can't quite tell you how it works." © 2011 Technology Review

Keyword: Sleep
Link ID: 16175 - Posted: 12.23.2011

By Eric Niiler A new light bulb in the works could avoid tinkering with your body's sleep patterns. As late-night workers and long-distance travelers already know, shifting time zones or work periods throws the body's natural clock out of whack. Even regular folks often find it nearly impossible to get a restful sleep for several hours after sitting under bright lights after the sun has gone down (some call it the Fenway Park phenomena). Now a Florida inventor is testing a new LED bio-bulb that could regulate the body's circadian rhythm by helping control the production of melatonin, the body's sleep hormone that tells us when it's nighttime. This can be done by eliminating a small segment of the blue wavelength of light (around 465 to 485 nanometers) produced by the lightbulb, according to Fred Maxik, founder and chief technology officer of Lighting Science Group Corp., a Satellite Beach, Fla., firm. "We're looking at a way to filter out that part of the spectrum, and still have a white light," Maxik said. "Our ability to restore the natural position of where we were and natural hormonal secretions is an appealing one." Nearly 20 years ago, medical researchers discovered that the eye has a separate photoreceptor that picks up wavelengths of light, and then sends a signal to the hypothalamus which secretes melatonin. © 2011 Discovery Communications, LLC.

Keyword: Biological Rhythms; Sleep
Link ID: 16174 - Posted: 12.20.2011

By BARRON H. LERNER, M.D. Most of us recall lobotomies as they were depicted in the movie “One Flew over the Cuckoo’s Nest”— horrifying operations inappropriately used to control mentally ill patients. But in the 1950s, surgeons also used them to treat severe pain from cancer and other diseases. Now a Yale researcher has uncovered surprising new evidence of a famous patient who apparently received a lobotomy for cancer pain during that time: Eva Perón, the first lady of Argentina, who was known as Evita. The story is an interesting, sad footnote in the history not only of lobotomy, but of pain control. The nature of Perón’s illness was initially shrouded in silence. Her doctors diagnosed advanced cervical cancer in August 1951, but as was common at the time, the patient was told only that she had a uterine problem. According to the biographers Nicholas Fraser and Marysa Navarro, secrecy was so paramount that an American specialist, Dr. George Pack, performed Perón’s cancer operation without her or the public ever knowing. He entered the operating suite after she was under anesthesia. Despite surgery, radiation and chemotherapy, Perón gradually worsened, dying in late July 1952 at age 33. Only then was it revealed that she had died of cervical cancer, although details of her treatment, including Dr. Pack’s involvement, remained concealed. In a 1972 biography, Erminda Duarte, Perón’s sister, claimed she had suffered intense pain and distress. © 2011 The New York Times Company

Keyword: Schizophrenia
Link ID: 16173 - Posted: 12.20.2011

By NICHOLAS WADE Social behavior among primates — including humans — has a substantial genetic basis, a team of scientists has concluded from a new survey of social structure across the primate family tree. The scientists, at the University of Oxford in England, looked at the evolutionary family tree of 217 primate species whose social organization is known. Their findings, published in the journal Nature, challenge some of the leading theories of social behavior, including: ¶ That social structure is shaped by environment — for instance, a species whose food is widely dispersed may need to live in large groups. ¶ That complex societies evolve step by step from simple ones. ¶ And the so-called social brain hypothesis: that intelligence and brain volume increase with group size because individuals must manage more social relationships. By contrast, the new survey emphasizes the major role of genetics in shaping sociality. Being rooted in genetics, social structure is hard to change, and a species has to operate with whatever social structure it inherits. If social behavior were mostly shaped by ecology, then related species living in different environments should display a variety of social structures. But the Oxford biologists — Susanne Shultz, Christopher Opie and Quentin Atkinson — found the opposite was true: Primate species tended to have the same social structure as their close relatives, regardless of how and where they live. © 2011 The New York Times Company

Keyword: Genes & Behavior; Aggression
Link ID: 16172 - Posted: 12.20.2011

By BENEDICT CAREY SMYRNA, Del. — The taste of cocaine and the slow-motion sensation of breaking the law were all too familiar, but the thrill was long gone. Antonio Lambert was not a young hoodlum anymore but a family man with a career, and here he was last fall, high as any street user, sneaking into his workplace at 9 o’clock at night, looking for — what, exactly? He didn’t really know. He left the building with a few cellphones (which he threw away) and a feeling that he was slipping, falling back down into a hole. He walked in the darkness, walked with no place to go, and then he began to do what he has taught others in similar circumstances to do: turn, face the problem, and stand back up. “I started talking to myself, out loud; that’s one of my coping strategies, and one reason I relapsed is I had forgotten to use those,” said Mr. Lambert, 41, a mental health educator who has a combined diagnosis — mood disorder with drug addiction — that is among the scariest in psychiatry. He texted a friend, someone who knew his history and could help talk him back down. And he checked himself into a hospital. “I know when it’s time to reach out for help.” The mental health care system has long made use of former patients as counselors and the practice has been controversial, in part because doctors and caseworkers have questioned their effectiveness. But recent research suggests that peer support can reduce costs, and in 2007, federal health officials ruled that states could bill for the services under Medicaid — if the state had a system in place to train and certify peer providers. © 2011 The New York Times Company

Keyword: Drug Abuse
Link ID: 16171 - Posted: 12.20.2011

by Nicholas Mackintosh NEUROSCIENTISTS seek to understand how the brain underpins our behaviour, thoughts and feelings. Given that the law is also concerned with human behaviour, albeit for quite different reasons, it is hardly surprising that remarkable advances in our understanding of the brain have led many to believe that neuroscience is becoming increasingly relevant to the law. In the US, a number of universities teach courses on the interface between neuroscience and the law, and the Chicago-based MacArthur Foundation has invested several million dollars to fund research in this area. In the UK, the Royal Society has just published a report on neuroscience and the law. Some argue that neuroscience has already cast doubt on the idea of free will, and therefore raises questions about the legitimacy of punishing people for actions over which they had no control. In the US there is a steady increase in defence attorneys seeking to introduce neuroscientific evidence. So is "my brain made me do it" a legitimate defence in a criminal trial? There will surely be cases where such evidence is relevant. Most countries specify an age of criminal responsibility somewhere between 6 and 16; in England and Wales it is 10. Brain imaging studies have shown that the brain continues to develop throughout adolescence, with the prefrontal cortex, implicated in impulse control and decision-making, not reaching maturity until 20 or so. Such studies have also shown that there are huge individual differences. It is hard to believe that all 10-year-olds should be held fully responsible when they break the law. © Copyright Reed Business Information Ltd.

Keyword: Attention; Aggression
Link ID: 16170 - Posted: 12.20.2011

By Alan Boyle Nothing focuses your attention on the future like a forecast, especially when it comes to the technologies that will be changing daily life in the years to come. Five years, to be exact. That's why forecasts like IBM's annual "Five in Five" are so thought-provoking, even if they're occasionally wrong. Actually, IBM's record is pretty good: This month marks the five-year anniversary of IBM's first list of five technologies that were expected to make the most impact in five years' time. The company nailed 2006's predictions on the rise of telemedicine, location-aware mobile devices, real-time speech translation and nanotechnology. But the fifth prediction, which focused on the rise of virtual 3-D environments, hasn't worked out the way IBM expected. Sure, Second Life is still around — in fact, I'll be hosting my next "Virtually Speaking Science" show in Second Life on Jan. 4. But such virtual worlds haven't become the principal vehicle for real-world commerce ... yet. "It's not perfect," admitted Bernie Meyerson, IBM's vice president of innovation. Sometimes the company's researchers latch onto a idea whose time has not yet come, and perhaps never will. But for the most part, "this stuff has actually panned out a lot," Meyerson said. Is technological progress always a good thing? Not necessarily, if you're talking about key-logging software on mobile devices, or government-supported spyware. The latest predictions from IBM, issued today, have lots of potential for a dreams-vs.-nightmares debate. © 2011 msnbc.com

Keyword: Brain imaging; Attention
Link ID: 16169 - Posted: 12.20.2011

By Gary Stix What was up with a world leader who thought he could control the weather while engaging in his passion for Elizabeth Taylor movies? No one knows for sure, but a few years ago, two psychologists took a crack at a long-distance analysis. In the September 2009 edition of Behavioral Sciences of Terrorism and Political Aggression (Editor’s note: nice journal name), Frederick L. Coolidge and Daniel L. Segal tried to develop a psychological profile of the “Dear Leader” (in 1992 changed to “Dear Father”). Coolidge had developed a means of psychological evaluation using “informants,” people who knew or had historical or other expertise about a person. This test had been used previously to assess Hitler and Saddam Hussein and had been found to have a high-level of statistical reliability. The two psychologists used the test with a South Korean psychiatrist who was an expert on Kim Jong-il. The results showed that Kim Jong-il had an identical overall statistical measure with Hitler and Saddam on 14 personality disorders (r=7.6). (The top six of the 14 are: sadistic, paranoid, antisocial, narcissistic, schizoid and schizotypal.). Additional analysis showed that Dear Father was more like Saddam than Der Fuhrer. All three also showed evidence of psychotic thinking. Coolidge and Segal make recommendations about how to engage in diplomatic talks with someone with this type of personality. “In negotiations with Kim Jong-il over nuclear weapons, he might trust higher-level government officials more than lower ones,” they write. “Perhaps, more reflective of Kim Jong-il’s narcissistic traits, he initially balked over six-country negotiations, demanding to meet with the United States only. It would be predicted that secondary or lower level emissaries might have immediately been at a disadvantage.” © 2011 Scientific American

Keyword: Aggression; Schizophrenia
Link ID: 16168 - Posted: 12.20.2011

By Scicurious Hi. In a few minutes I’d like you to stand up and give a short public speech to a judgmental group of people. The speech will be about the current national and international effects of Marbury v Madison, with particular focus on violations of interstate commerce. You have 15 minutes to prepare and the speech will have to be 15 minutes long. I hope you’ve done your research. Nervous yet? If you are, you’re not alone. Fear of public speaking (glossophobia, or just stage fright) is one of the most common fears in the Western world. But it’s ok. We’re going to have you sit with your loved one, who will be able to give you encouragement as you prepare. Do you feel a little bit better? I bet you do. But do you really, actually feel better? Does your body react to stress differently when you’ve got a loved one with you to help you out? It turns out that it might. At least, if you’ve got a specific kind of oxytocin receptor gene. Oxytocin gets a lot of press. And well it should. Recent findings on oxytocin have shown effects on trust, on generosity, on behaviors in austistic children even. Not to mention all the effects that oxytocin has on parental bonding and on your sex life. While many of these studies have looked at levels of circulating oxytocin, or the effects of giving oxytocin (usually as a nasal spray) on behavior, people have recently started to look at the other side of oxytocin: the oxytocin receptor. © 2011 Scientific American,

Keyword: Hormones & Behavior; Emotions
Link ID: 16167 - Posted: 12.20.2011

By Sora Song The Louisiana Department of Health and Hospitals is warning people against the improper use of neti pots, following the deaths of two people who were infected with Naegleria fowleri — the so-called “brain-eating amoeba” — after using tap water to irrigate their sinuses. A 53-year-old woman from De Soto Parish and a 20-year-old man from St. Bernard Parish both died after using contaminated water in their neti pots, a popular home remedy that looks like a genie’s lamp and is used for flushing out mucus from the nose and sinuses. “If you are irrigating, flushing or rinsing your sinuses, for example, by using a neti pot, use distilled, sterile or previously boiled water to make up the irrigation solution,” said Louisiana State Epidemiologist, Dr. Raoult Ratard. Tap water is safe for drinking, but not for irrigating your nose, Ratard said. It’s also important to rinse the neti pot after each use and leave it open to air dry. Typically, Naegleria fowleri infection occurs when people go swimming or diving in warm freshwater lakes and rivers, particularly in summer in the southern U.S. Last summer, at least three other people died from Naegleria fowleri infection in Florida, Virginia and Kansas. The amoeba enters through the nose, travels to the brain and starts eating neurons. It sounds scary — and it is — but it’s also exceedingly rare. In the 10 years from 2001 to 2010, only 32 infections were reported in the U.S., despite millions of people swimming in lakes and rivers. Of those infected, 30 people were infected by recreational water sources, and two were infected by water from hot springs. © 2011 Time Inc.

Keyword: Miscellaneous
Link ID: 16166 - Posted: 12.19.2011

By JoNel Aleccia After nearly 10 months, the nationwide shortage of ADHD drugs has taken a toll on Kate Skinn. The 32-year-old Ohio woman had to take a medical leave from college because she can’t focus on her reading. She’s lost income from her job as a waitress because she’s distracted at work. And she’s had to struggle even harder than usual juggling the needs of her boyfriend and their four children, all because she can’t reliably get the Adderall that helps her cope. “It’s impossible to manage all the facets of my life and do my schoolwork,” said Skinn, of Sheffield Lake, Ohio, who was diagnosed with attention-deficit hyperactivity disorder three years ago. “When I can’t take my medicine, I can’t concentrate. I’ll start everything I need to do, but never complete any of it.” She’s among millions of Americans struggling to deal with the worst drug shortage in United States history. ADHD drugs such as Adderall and Ritalin, first reported as scarce last spring, are only a fraction of the 251 medications in short supply so far this year, up from 211 in 2010, according to University of Utah Drug Information Service. The issue drew renewed attention Thursday, when the White House issued an interim rule that requires drugmakers that are the only producers of certain critical medications to report to the Food and Drug Administration all manufacturing interruptions that could disrupt supplies. © 2011 msnbc.com

Keyword: ADHD; Drug Abuse
Link ID: 16165 - Posted: 12.19.2011

Victoria Colliver, Chronicle Staff Writer The standard approach to feeding patients hospitalized with anorexia nervosa - starting with a low number of calories and increasing them very gradually - is being challenged by new research from UCSF. This approach to bringing malnourished patients back to health was based on the long-held notion that pushing food on them too quickly can result in potentially fatal metabolic imbalance, but researchers now say it fails to produce significant and necessary weight gain in the first week of hospitalization and results in longer hospital stays. The UCSF study, published in next month's issue of the Journal of Adolescent Health, suggests that most patients can start at higher calorie levels, tolerate more food and be able to be released from the hospital more quickly. The research is considered the first to test the traditional recommendations against a higher-calorie diet. "The truth is, this is another one of those cases where you have clinical guidelines that are consensus based, but they really aren't based on the evidence," said study lead author Andrea Garber, associate professor of pediatrics in UCSF's adolescent medicine division. The American Psychiatric Association, the American Dietetic Association and other groups recommend the current guidelines, which have been in place since 2000 and stem from studies of prisoners of war in the 1950s. The approach starts with a foundation of about 1,200 calories a day and adds 200 calories every other day. © 2011 Hearst Communications Inc.

Keyword: Anorexia & Bulimia
Link ID: 16164 - Posted: 12.19.2011

By Gary Stix Lawyers and philosophers have already begun debating the ethical implications of an incipient future in which a memory is simply overwritten as if it were a digital file destined for the trash icon on your desktop. Biologists who still work with mice and other living things that don’t function like four-legged flash drives are often left to simply roll their eyes. On Friday, SUNY Downstate’s Symposium on Neuroethics of Memory illustrated the lingering disparity between the two cultures, as C.P. Snow might have phrased it. David Wasserman, the director of research at the Center for Ethics at Yeshiva University, raised the issue of when it might be appropriate to implant a “prosthetic” memory to enhance the verisimilitude in recalling a grandparent whose memory had faded into near oblivion. After hearing this, David Glanzman, a researcher at UCLA who works on testing whether old memories can be damped down in sea slugs, pointed out a couple of oft-cited figures: the human brain has 100 billion neurons, each of which typically extends 10,000 connections to other neurons. Identifying the location of a specific memory to delete would be an overwhelming challenge. Integrating a new memory of grandma into this dense web of neural wiring would be a graduate project for the year 2250 or beyond. “It’s hard for me to understand how you’d add specific memories,” Glanzman commented. “That seems to me impossibly hard.” Downstate had good reason to consider organizing such a conference, however. One researcher there, Todd Sacktor, has done pioneering studies of a biomolecule known as PKMzeta, which serves as a kind of memory preservative. Once a memory is formed, PKMzeta ensures that it persists without degradation over the long haul. © 2011 Scientific American,

Keyword: Learning & Memory
Link ID: 16163 - Posted: 12.19.2011

by Elizabeth Norton We've all seen those color-coded air-quality charts on the news—warnings about smog, ozone, and pollen. Now it may be time to add a new alert to the list: illegal drugs. Researchers have found that regions with greater cocaine and marijuana use have higher levels of these drugs in the surrounding atmosphere. A few studies since the mid-1990s have shown that illicit drugs make their way into the atmosphere. In 2007, for example, analytical chemist Angelo Cecinato and colleagues at the Institute of Atmospheric Pollution Research in Rome, detected small amounts of cocaine in the air of Rome and the city of Taranto on the coast of southern Italy. "We considered it a curiosity," Cecinato says. But further research revealed that atmospheric concentrations of certain drugs were higher wherever drug use was presumed to be more prevalent—leading Cecinato and co-workers to wonder if they had found a better way to estimate the extent of drug abuse in a given area. Currently, authorities must rely on indirect information, such as communitywide surveys or questionnaires and police records. These methods can be time-consuming and expensive, Cecinato explains. Measuring the amount of drugs in the air, his group suspected, might be accurate, fast, and cheap. To find out, Cecinato and colleagues analyzed the air in 20 spots in eight regions of Italy in winter and 39 sites in 14 regions in summer. The investigators collected air samples, extracted the contaminants, and analyzed the results, checking for cocaine and cannabinoids (the active ingredients in marijuana). To rule out false positives caused by other compounds, the team also tested for common pollutants including hydrocarbons, ozone, and nitric oxide. © 2010 American Association for the Advancement of Science.

Keyword: Drug Abuse
Link ID: 16162 - Posted: 12.17.2011

Caitlin Stier, video intern Stare at the ellipses in this video and you'll start to experience trippy effects. The illusion, developed by vision researchers Gideon Caplovitz and Kyle Killebrew of the University of Nevada in Reno, features curved shapes spinning at a constant rate where changes in contrast, width and colour alter your perception. At first, a single thin ellipse multiplies. If you fix your eyes on the centre of the screen, dark smudges may appear to blot out the center of the ellipses as your eyes are quickly exposed to stimuli with highly contrasting colours. Next, the shapes gradually become plumper, a transformation that makes the objects seem to slow down and rotate more fluidly. The animation then appears in different colours which seems to enhance the effect. Focussing on the colourful ellipses while the colours fade can also make them turn into polygons, a change that seems to occur at different times from person to person. According to Caplovitz, the apparent change in speed is caused by how we sample information around us to detect movement. As the ellipses become chubbier, their shape weakens the sense of motion and they appear to move more slowly compared to their elongated counterparts. When colour is added into the mix, it also distracts from picking up movement. As the shapes become nearly circular, they seem to roll like jelly due to ambiguous information about their rotation. © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 16161 - Posted: 12.17.2011

by Carl Zimmer I don’t usually stream Netflix onto my television to probe the 
inner workings of my mind, but it had that effect not long ago. 
While I was catching an old episode of Law & Order: Criminal Intent, the actors’ voices lagged a fraction of a second behind the movement 
of their mouths, making me so disoriented it completely ruined the show. Soon my irritation turned to puzzlement, and some self-observation allowed me to track my frustration to a precise source. I didn’t care that the ominous soundtrack rose half a second late when Vincent D’Onofrio and Kathryn Erbe crept into the subway tunnel where they 
were about to find a body. I didn’t care that the show’s trademark duh-dung! sound marking a new scene was still duh-dung-ing after the scene started. It was only when people talked that I went batty. I would watch the characters speak, and then I’d switch to listening to them, and then I’d watch them speak again. I just couldn’t meld the two streams of information in my head. Thanks to Netflix, I was confronted with one of the most crucial tricks that the human brain uses to make sense of the world: combining input from all five senses into a single, coherent experience, updated many times a second in virtually real time. Because the techniques our brains use to meld the senses are far from perfect, it turns out, we can fall prey to a variety of illusions—and to maddening confusion when Netflix delivers audio and video out of sync. Neuroscientists have come a long way since the mid-1900s, when they launched their first efforts to map out the brain’s sensory pathways. They identified regions of the brain that became active when people saw things, other regions that became active when they heard sounds, and so on through the list of senses. The implications seemed straightforward enough. Separate systems of neurons handled information from different senses. Only after each system had produced a sophisticated representation of the world did the brain combine their perceptions into one experience of reality, like a film editor adding a soundtrack to a movie. © 2011, Kalmbach Publishing Co.

Keyword: Hearing; Vision
Link ID: 16160 - Posted: 12.17.2011

By Bruce Bower A brain-damaged man who can’t remember faces has nosed into a scientific debate about how people learn to recognize other complex objects. Deaf users of sign language also have a hand in this dispute. The brain-damaged man’s facial failures are one symptom of a general inability to perceive configurations of object parts, suggests a new investigation led by psychologist Cindy Bukach of the University of Richmond in Virginia. The man thus stumbles at identifying not only people’s faces but also computer-generated, three-part objects called Greebles, even after extensive training, Bukach’s team reports online December 8 in Neuropsychologia. Bukach and her colleagues studied LR, a man who fails to recognize his daughter when shown a picture of her but remembers distinctive facial features, such as Elvis’ sideburns. Damage in a car accident to a brain area just under the right temple caused this condition, called prosopagnosia. “There are many ways in which face recognition can be disrupted, but our evidence shows that LR’s type of prosopagnosia impairs recognition of objects with multiple parts, with faces as the most obvious example,” Bukach says. Relative positions of the eyes, nose and mouth, as well their shapes, contribute to perceiving a face as a single entity. In a 2006 report, her team designed a collection of eight faces using different combinations of two sets of eyes, noses and mouths. After briefly viewing a face, LR correctly selected it from all eight faces 25 percent of the time — about what would be expected if he based choices on a single facial feature, Bukach says. Further testing showed that LR homed in on the mouth. © Society for Science & the Public 2000 - 2011

Keyword: Vision; Attention
Link ID: 16159 - Posted: 12.17.2011

By Tina Hesman Saey When life gives naked mole rats lemons, the wrinkled, buck-toothed rodents probably don’t care. They are impervious to the sting of acid. But scientists in Berlin are onto the secret of the social rodents’ acid insensitivity. Naked mole rats’ acid sensors work just fine, but a protein responsible for relaying messages about acid’s presence to the nervous system is easily blocked by the same positively charged hydrogen ions that lend substances acidity, researchers report in the Dec. 16 Science. The discovery may give researchers clues about where to target drugs that could relieve pain associated with inflammation. “I’ve been trying to figure out this question in mole rats for a number of years, and the answer has been elusive,” says Thomas Park, a neuroscientist at the University of Illinois at Chicago who was not involved in the study. It was Park who first got Gary Lewin of the Max Delbrück Center for Molecular Medicine in Berlin interested in studying naked mole rats. Lewin and Ewan St. John Smith, a postdoctoral researcher in Lewin’s lab, led the new research. Mole rats live in large social groups in burrows underground. The crowded, confined conditions cause carbon dioxide levels to rise to as high as 8 to 10 percent of the air — a concentration that would cause a person to pass out within five to 10 minutes. High carbon dioxide and low oxygen levels make body tissues acidic, something that is very painful for nearly all mammals. (Inflammation also raises acidity in tissues, producing pain.) If mole rats had not evolved a way to ignore acid the little rodents would be in constant agony, Lewin says. © Society for Science & the Public 2000 - 2011

Keyword: Pain & Touch; Evolution
Link ID: 16158 - Posted: 12.17.2011