In the Human Performance Laboratory at Florida State University's Center for Expert Performance Research, a nursing student is told to care for a simulated patient admitted for chest pain. The dummy patient's vital signs, as well as his voice, are controlled by a nursing professor behind a two-way mirror. When the "patient" suddenly can't breathe, the student gets to experience a novice nurse's nightmare -- a life-or-death situation with no one to take over and rescue the patient, or coach her what to do. Putting both experts and novices through critical scenarios like this, cognitive psychology researchers K. Anders Ericsson and Paul Ward don't just observe the differences in subjects' performance. They also use interviewing techniques they've developed to understand the differences in their minds. "We’re looking at how people think and how that thinking affects how they perform," says Ward. Before a novice or expert participates in the simulation, Ward prepares them for how they will be debriefed afterward. He teaches them how to give a "think-aloud" report of their performance, in which they simply recount what they were thinking throughout the scenario without trying to evaluate or explain it. "That’s when we uncover the expert superiority: their ability to perceive more information, and also, after the fact, remember more of the thought processes than the novices," says Ericsson. © ScienCentral, 2000-2006

Keyword: Learning & Memory
Link ID: 9427 - Posted: 06.24.2010

The concept of whetting the appetite by serving hors d'oeuvres before a meal may have a solid scientific basis, according to a new report in the October issue of the journal Cell Metabolism, published by Cell Press. In a study of rats trained to a strict feeding regime, researchers found that brain activity in important hunger centers spiked with the first bites of food. "The drive to eat is massively stimulated by the start of eating," said Gareth Leng of the University of Edinburgh, who co-led the new study with Louise Johnstone. "This shows the appetizing effect of food itself as hunger circuits are acutely switched on." The imminent expectation of food also activated certain brain cells involved in stimulating hunger in the animals, they found. The rats' optimal window for consumption was brief, however, as brain centers responsible for registering satiety--the feeling of being full or satisfied--switched on almost as soon as food hit their stomachs, Leng said. The new study is the first to chart the sequence of changes in brain activity over the course of a meal, according to the researchers. The researchers provided rats with food for just 2 hours per day. After 10 days on the strict regimen, food intake and body weight stabilized, the researchers reported.

Keyword: Obesity
Link ID: 9426 - Posted: 10.04.2006

Relapse to uncontrolled drinking after periods of sobriety is a defining characteristic of alcoholism and is often triggered by stress. A new study in rats reports that a specific receptor for a stress-response transmitter may play an important role in stress-induced relapse. The study, a collaboration between scientists at the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the National Institutes of Health (NIH), and at Camerino University, Italy, appears online in the Early Edition of the Proceedings of the National Academy of Sciences on October 2, 2006. “This finding helps untangle the complex interplay of genetic and environmental factors that influence relapse,” says NIAAA Director T-K Li, M.D. “It also points to potential approaches for treating individuals at risk for relapse.” Anita C. Hansson, Ph.D., a fellow in NIAAA’s Laboratory of Clinical and Translational Studies, and other NIAAA scientists worked with Camerino University scientists to examine stress-induced relapse in rats that were bred to have a greater-than-normal preference for alcohol. “These animals provide an excellent model for identifying genes involved in stress-mediated relapse,” says Dr. Hansson. “Not only do they voluntarily consume large amounts of alcohol they also display anxiety and depression-like traits, characteristics that are common among human alcoholics and which indicate a maladaptive response to stress.”

Keyword: Drug Abuse; Stress
Link ID: 9425 - Posted: 06.24.2010

Whether specific types of antidepressants are effective for patients with late-life major depression may depend if they have certain genetic variations, according to a study in the October 4 issue of JAMA. Initial drug treatments fail in 30 percent to 40 percent of patients with major depression. Pharmacogenetic (the relation of genetic factors to variations in response to drugs) prediction of response is one possibility for improving antidepressant treatment, according to background information in the article. Polymorphisms (occurrence in more than one form) in the serotonin transporter gene (5-HTT) may influence antidepressant response to selective serotonin reuptake inhibitors (SSRIs – a class of antidepressant drugs). Hyeran Kim, M.D., of Sungkyunkwan University School of Medicine, Seoul, Korea, and colleagues conducted a study to determine whether there were significant associations between the efficacy of norepinephrine reuptake inhibitors (NRIs - a class of antidepressant drugs) and norepinephrine transporter (NET) polymorphisms and also between SSRI efficacy and 5-HTT polymorphisms. If confirmed, these associations could provide a basis for predicting response to certain antidepressants. The study included 241 Korean patients with major depression. They were treated for 6 weeks with an SSRI (fluoxetine or sertraline; n = 136) or an NRI (nortriptyline; n = 105) antidepressant. The average age at onset of major depressive disorder among these patients was in the early to mid-50s.

Keyword: Depression; Genes & Behavior
Link ID: 9424 - Posted: 06.24.2010

Heidi Ledford Efforts to hold back the world's expanding waistline have been dealt another blow this week, as scientists announce disappointing results from a clinical trial of their latest obesity drug. The test shows that the drug, developed by Merck & Co, Inc. in New Jersey and named MK-0557, works — but only a little bit. Overweight or obese patients receiving MK-0557 lost only 1.6 kilograms more than those who were given a placebo over the course of a year. The results, reported in this month's issue of Cell Metabolism, are statistically significant1. But they are also clinically irrelevant. "We consider this a negative study," says Steven Heymsfield, a clinical researcher at Merck who evaluated the drug. The pharmacological rubbish heap has become littered with failed obesity drugs as the pharmaceutical industry rushes to treat the over 1 billion overweight and obese people worldwide. ©2006 Nature Publishing Group

Keyword: Obesity
Link ID: 9423 - Posted: 06.24.2010

For obese people overeating is akin to drug addiction, research suggests. Scans on seven overweight people revealed the regions of the brain that controlled satiety were the same those in drug addicts craving drugs. The US team who carried out the research said the findings could potentially help to uncover new treatments for obesity. The work, led by a New York scientist, is published in the Proceedings of the National Academy of Sciences. The researchers looked at brain impulses in seven overweight individuals. They had all been previously fitted with a weight-reduction device called an implantable gastric stimulator (IGS). The implant sends electronic signals to the vagus nerve which then relays messages of satiety to the brain, thus reducing the desire to eat. To study the interaction between the stomach and the brain, the volunteers received two brain scans spaced two weeks apart, one when the implant was turned on and the other while it was switched off. While the volunteers were feeling full and the implant was turned on, the scan revealed an increased metabolism in the hippocampus, an area of the brain associated with emotional behaviour, learning and memory, the orbitofrontal cortex and the striatum. Lead researcher Dr Gene-Jack Wang, at the Brookhaven National Laboratory, New York, said: "As soon as we saw these scans, immediately it reminded me of what we had studied in drug abuse when people were under a craving situation - the same areas in the brain lit up." (C)BBC

Keyword: Obesity; Drug Abuse
Link ID: 9422 - Posted: 10.03.2006

By Shankar Vedantam Schizophrenia patients do as well, or perhaps even better, on older psychiatric drugs compared with newer and far costlier medications, according to a study published yesterday that overturns conventional wisdom about antipsychotic drugs, which cost the United States $10 billion a year. The results are causing consternation. The researchers who conducted the trial were so certain they would find exactly the opposite that they went back to make sure the research data had not been recorded backward. The study, funded by the British government, is the first to compare treatment results from a broad range of older antipsychotic drugs against results from newer ones. The study was requested by Britain's National Health Service to determine whether the newer drugs -- which can cost 10 times as much as the older ones -- are worth the difference in price. There has been a surge in prescriptions of the newer antipsychotic drugs in recent years, including among children. The study, published in the Archives of General Psychiatry, is likely to add to a growing debate about prescribing patterns of antipsychotic drugs. A U.S. government study last year found that one of the older drugs did as well as newer ones, but at the time, many American psychiatrists warned against concluding that all the older drugs were as good. © 2006 The Washington Post Company

Keyword: Schizophrenia
Link ID: 9421 - Posted: 06.24.2010

By JANE E. BRODY Jenni Ewald and her husband, Russ, both lost their hearing as young children after bouts with meningitis — Jenni when she was 1, Russ more gradually starting at age 3. They met in college, communicating with sign language and lip reading, fell in love, married and had a baby. But neither could hear their baby cry, at least not until Jenni got a cochlear implant at Loyola University Health System in Maywood, Ill. Russ was so impressed with Jenni’s result that he underwent the same procedure a few months later. Now living in Tempe, Ariz., both Ewalds can hear their two young daughters. As victims of profound bilateral sensorineural hearing loss — a destruction of the hair cells in the cochlea of the inner ear that transmit sound signals to the auditory nerve — the Ewalds were not candidates for hearing aids, which simply amplify sounds reaching the ear and depend on normally functioning hair cells. But they benefited from an implant that makes it possible for profoundly deaf people to hear and learn to interpret speech and other sounds. Perhaps as many as one million people in the United States could benefit from a cochlear implant. For children born deaf or who lose their hearing before they are verbal, the implants enable them to learn to talk. Copyright 2006 The New York Times Company

Keyword: Hearing
Link ID: 9420 - Posted: 06.24.2010

By SANDRA BLAKESLEE They are eerie sensations, more common than one might think: A man describes feeling a shadowy figure standing behind him, then turning around to find no one there. A woman feels herself leaving her body and floating in space, looking down on her corporeal self. But according to recent work by neuroscientists, they can be induced by delivering mild electric current to specific spots in the brain. In one woman, for example, a zap to a brain region called the angular gyrus resulted in a sensation that she was hanging from the ceiling, looking down at her body. In another woman, electrical current delivered to the angular gyrus produced an uncanny feeling that someone was behind her, intent on interfering with her actions. The two women were being evaluated for epilepsy surgery at University Hospital in Geneva, where doctors implanted dozens of electrodes into their brains to pinpoint the abnormal tissue causing the seizures and to identify adjacent areas involved in language, hearing or other essential functions that should be avoided in the surgery. As each electrode was activated, stimulating a different patch of brain tissue, the patient was asked to say what she was experiencing. Dr. Olaf Blanke, a neurologist at the École Polytechnique Fédérale de Lausanne in Switzerland who carried out the procedures, said that the women had normal psychiatric histories and that they were stunned by the bizarre nature of their experiences. Copyright 2006 The New York Times Company

Keyword: Emotions
Link ID: 9419 - Posted: 10.03.2006

By MARGARET WERTHEIM When I was a physics major in the late 1970’s, my very few fellow female students and I had high hopes that women would soon stand equal with men in science. But progress has proved slower than many of us imagined. A report last month by the National Academy of Sciences documents widespread bias against women in science and engineering and recommends a sweeping overhaul of our institutions. While there may indeed be subtle biological differences contributing to the scarcity of women in the top ranks of science, interviews make clear that many female scientists continue to experience both overt and covert discrimination. The academy’s report is welcome, yet there is reason to believe that when it comes to the mathematically intensive sciences like physics and astronomy, it is not just bureaucracies that stand in the way. Female physicists, astronomers and mathematicians are up against more than 2,000 years of convention that has long portrayed these fields as inherently male. Though women are no longer barred from university laboratories and scientific societies, the idea that they are innately less suited to mathematical science is deeply ingrained in our cultural genes. Copyright 2006 The New York Times Company

Keyword: Sexual Behavior; Intelligence
Link ID: 9418 - Posted: 06.24.2010

Trevor Butterworth and Rebecca Goldin Ph.D As the evidence for sex discrimination in the sciences mounts, media pundits continue to cite math test scores for innate differences between women and men. Here’s why the numbers don’t add up If you are going to be a provocateur, and your bully pulpit happens to be a forum of academics, a certain grasp of the facts is advisable – especially if you are bent on provoking thought outside your own discipline. This was not merely lost on Larry Summers, the former President of Harvard University, when he ventured to expound on why women were under-represented in math and science departments, and suggested, among other reasons, that women were innately compromised in this kind of cognitive functioning; it was often overlooked by those of the punditocracy, who rallied to his defense in the name of academic freedom. “What is it about the word ‘provoke'’ those Harvard intellectuals don't understand?” asked the editorial page of the Boston Herald. “The transcript of Harvard University president Larry Summers' now infamous remarks about a female's innate scientific capabilities proves he was doing just what he said he was doing, provoking discussion.” If anything should have renewed this discussion – and perhaps drawn it to a conclusion – it was the recent publication of a report by the National Academy of Sciences announcing that innate intelligence had nothing to do with the gender disparities in science and engineering. Rather, bias, discrimination and “outmoded institutional structures” were responsible for holding women back.

Keyword: Sexual Behavior; Intelligence
Link ID: 9417 - Posted: 06.24.2010

By MICHAEL D. LEMONICK, ANDREA DORFMAN You don't have to be a biologist or an anthropologist to see how closely the great apes--gorillas, chimpanzees, bonobos and orangutans--resemble us. Even a child can see that their bodies are pretty much the same as ours, apart from some exaggerated proportions and extra body hair. Apes have dexterous hands much like ours but unlike those of any other creature. And, most striking of all, their faces are uncannily expressive, showing a range of emotions that are eerily familiar. That's why we delight in seeing chimps wearing tuxedos, playing the drums or riding bicycles. It's why a potbellied gorilla scratching itself in the zoo reminds us of Uncle Ralph or Cousin Vinnie--and why, in a more unsettled reaction, Queen Victoria, on seeing an orangutan named Jenny at the London Zoo in 1842, declared the beast "frightful and painfully and disagreeably human." It isn't just a superficial resemblance. Chimps, especially, not only look like us, they also share with us some human-like behaviors. They make and use tools and teach those skills to their offspring. They prey on other animals and occasionally murder each other. They have complex social hierarchies and some aspects of what anthropologists consider culture. They can't form words, but they can learn to communicate via sign language and symbols and to perform complex cognitive tasks. Scientists figured out decades ago that chimps are our nearest evolutionary cousins, roughly 98% to 99% identical to humans at the genetic level. When it comes to DNA, a human is closer to a chimp than a mouse is to a rat. © 2006 Time Inc.

Keyword: Evolution; Genes & Behavior
Link ID: 9416 - Posted: 06.24.2010

Tracy Staedter, Discovery News — An artificial cornea very similar to the real thing could return sight to people with damaged corneas. The lab-made tissue, developed by a team of researchers at Stanford University, imitates the properties of a natural cornea so closely that it may even fool the immune system of the recipient. The prosthetic device could reduce the need for human tissue, especially in developing countries where donors are more scarce. "Our goal is to really replace the need for human cornea tissue," said Christopher Ta, an assistant professor of ophthalmology and ophthalmology residency director at the Stanford University Medical Center. Ta leads the research with Curtis Frank, professor of chemical engineering. Between 10 and 12 million people worldwide have impaired sight because of damaged or diseased corneas — the clear tissue over the eye that protects it from dust and germs and focuses light onto the retina. Almost 45,000 patients worldwide receive corneal transplants each year. In the United States, such donations are plentiful and well organized by eye banks. © 2006 Discovery Communications Inc.

Keyword: Vision
Link ID: 9415 - Posted: 06.24.2010

UPTON, NY -- Researchers at the U.S. Department of Energy's Brookhaven National Laboratory have found new clues to how the brain and the stomach interact with emotions to cause overeating and obesity. By looking at how the human brain responds to "fullness" messages sent to the brain by an implanted device that stimulates the stomach, the scientists have identified brain circuits that motivate the desire to overeat in the obese -- the same circuits that cause addicted individuals to crave drugs. The scientists have also verified that these circuits play a critical role in eating behaviors linked to soothing negative emotions. The study appears in the October 17, 2006 issue of the Proceedings of the National Academy of Sciences, published online in PNAS Early Edition the week of October 2. "This study opens new territory in understanding how the body and brain connect to each other, and how this connection is tied to obesity," said lead author Gene-Jack Wang of Brookhaven Lab's Center for Translational Neuroimaging. "We were able to simulate the process that takes place when the stomach is full, and for the first time we could see the pathway from the stomach to the brain that turns 'off' the brain's desire to continue eating." Wang and colleagues studied the brain metabolism of seven obese individuals who had gastric stimulators implanted for one to two years. The stimulator, an investigational device much like a pacemaker, provides low levels of electrical stimulation to the vagus nerve, causing the stomach to expand and produce peptides that send messages of "fullness" to the brain. The device has been shown to reduce the desire to eat.

Keyword: Obesity
Link ID: 9414 - Posted: 10.03.2006

Howard Hughes Medical Institute researchers have found that mutations in a single structural protein can determine whether an insect develops the highly organized, light-harvesting eye that flies have, or the optically simpler compound eye of a beetle or bee. In their experiments, the scientists showed that flies without this structural protein develop a more primitive eye. This outcome was reversed in the laboratory when researchers supplied the missing protein to a more primitive eye system, inducing it to “evolve” into the more advanced eye. “It’s not unusual to see alterations in regulatory proteins with a profound effect on form and function. This new finding, however, is unique because it illustrates how a change in a single structural protein can lead to such a spectacular change in form and function.” Charles S. Zuker These findings “help illustrate the beauty and power of evolution — how small changes can have such an incredible impact,” said HHMI investigator Charles S. Zuker, who led the study. Zuker and his colleagues at the University of California, San Diego reported their findings October 1, 2006, in an advance online publication in the journal Nature. The lead author of the paper was Andrew Zelhof. Robert Hardy and Ann Becker were co-authors. © 2006 Howard Hughes Medical Institute.

Keyword: Vision; Evolution
Link ID: 9413 - Posted: 06.24.2010

A gene that helps to stave off the effects of multiple sclerosis (MS) has been discovered by scientists. A Danish-UK team found that a known risk gene for MS, called DR2b, is always partnered by a twin gene - DR2a. The researchers, writing in the journal Nature, said DR2a tempers the effects of the risk gene and reduces the severity of MS symptoms. They believe in the future the gene's symptom-fighting features could be exploited for potential treatments. There are about 85,000 people with MS in the UK. The precise cause of the disease, in which the body's immune system attacks the central nervous system, is unknown, but a range of genetic and environmental factors are being explored. Two-thirds of MS sufferers carry the pair of DR2 genes, but carrying the genes does not necessarily mean a person will go on to develop MS. The researchers looked at mice that carried different combinations of the twin genes. They discovered the mice with just the risk gene, DR2b, had a form of multiple sclerosis with extremely aggressive symptoms. Those carrying both genes were less likely to get MS, and if they did, they had a milder form of the disease. The scientists said they believed the two genes were interacting. They said the risk gene, DR2b was "influencing" the immune system to attack the body, while the DR2a gene was counteracting this attack and dampening the effects. (C)BBC

Keyword: Multiple Sclerosis
Link ID: 9412 - Posted: 10.02.2006

ATLANTA -- Emory University researchers have found that giving progesterone to trauma victims shortly following brain injury appears to be safe and may reduce the risk of death and the degree of disability. The results of this study--the first clinical trial of its kind in the world--will be available online in the October issue of the peer-reviewed journal, Annals of Emergency Medicine, on October 2. Researchers say the next step will be to confirm their findings in a much larger group of traumatic brain injury (TBI) patients. "Progesterone treatment for TBI has been extensively studied in laboratory animals for more than 15 years, but this is the world's first use of progesterone to treat brain injury in humans," says Arthur Kellermann, MD, MPH, professor and chair of the Department of Emergency Medicine, Emory University School of Medicine and a co-author of the study. "Emory scientist Donald Stein was the first to discover that progesterone has neuroprotective effects, and much of the foundational work on progesterone for TBI was from his laboratory. Their results were so impressive, that we felt it was time to take this treatment to the bedside for testing in patients who had suffered a serious brain injury. We are grateful to the National Institute of Neurological Disorders and Stroke (a division of the National Institutes of Health) for their support of this work," says Kellermann. Approximately 1.5 to 2 million people in the U.S. sustain a TBI each year, leading to 50,000 deaths and 80,000 new cases of long-term disability. It is also a major cause of death and disability among children and military personnel.

Keyword: Brain Injury/Concussion; Hormones & Behavior
Link ID: 9411 - Posted: 10.02.2006

PITTSBURGH, Although drugs that target the brain's serotonin system are widely used to treat depression, the basic biological mechanism by which they help to alleviate symptoms is poorly understood. Now, new University of Pittsburgh research suggests these drugs work by acting on a specific serotonin receptor called the 5-HT1A autoreceptor, which the study's investigators found plays a key role in regulating the response of the amygdala. The findings, published in the journal Nature Neuroscience, also provide a model of how specific changes in 5-HT1A autoreceptors and associated amygdala reactivity may impact a person's risk for developing depression. Much like a rheostat, these serotonin receptors regulate the brain's emotional responses and may contribute to one's vulnerability for depression and other psychiatric disorders. The amygdala is a critical component of brain circuitry that processes clues from the environment about potential threats and generates appropriate behavioral and physiological responses – such as the "fight or flight" response – to these challenges. Research has indicated that depression and other mood disorders, such as anxiety, are associated with emotional brain circuitry problems involving the amygdala. The 5-HT1A autoreceptor is located on the surface of serotonin neurons, which are responsible for producing the serotonin neurotransmitter and delivering it to several areas of the brain, including the amygdala.

Keyword: Depression
Link ID: 9410 - Posted: 06.24.2010

Scientists have identified gene mutations responsible for a psychiatric disorder that causes people to compulsively pull their own hair. Trichotillomania is often accompanied by other symptoms, such as anxiety, depression, obsessive compulsive disorder or Tourette's syndrome. People with the disorder may have hair loss or bald patches, but often mask their habit. The Duke University study appears in the journal Molecular Psychiatry. The researchers focused on a gene called SLITKR1, as it had previously been linked to Tourette's. They found two mutant versions of the gene were more common in trichotillomania patients. The mutations were found to account for only a small percentage of cases. However, the team believe the findings are significant because they suggest the condition can have a biological basis. Lead researcher Dr Stephan Züchner said "Society still holds negative perceptions about psychiatric conditions such as trichotillomania. "But, if we can show they have a genetic origin, we can improve diagnosis, develop new therapies and reduce the stereotypes associated with mental illness." Currently, there is no specific treatment for trichotillomania, although it is sometimes successfully managed with drugs used for depression and anxiety disorders. The Duke team studied 44 families with one or more members who had trichotillomania. They found the key mutations were found in individuals with the condition, but not in unaffected family members. The SLITRK1 gene is involved in forming connections between brain cells. (C)BBC

Keyword: Emotions; Genes & Behavior
Link ID: 9409 - Posted: 09.30.2006

Bruce Bower The comfortably furnished room in a corner of the Johns Hopkins University School of Medicine in Baltimore seems an unlikely setting for spiritual transcendence. Yet one after another, volunteers last year entered the living room–like space, reclined on the couch, swallowed a pill, and opened themselves to a profound mystical journey lasting several hours. For many of them, the mundane certainty of being a skin-bounded person with an individual existence melted away. In its place arose a sense of merging with an ultimate reality where all things exist in a sacred, unified realm. Participants felt intense joy, peacefulness, and love during these experiences. At times, though, some became fearful, dreading unseen dangers. The pills that enabled these mystical excursions contained psilocybin, the active ingredient in so-called magic mushrooms that some societies have used for centuries in religious ceremonies. Psilocybin boosts transmission of the brain chemical serotonin, much as LSD and some other hallucinogenic drugs do. Johns Hopkins psychopharmacologist Roland R. Griffiths and his colleagues have taken psilocybin out of its traditional context and far from the black-light milieu of its hippie-era heyday. Griffiths' team is investigating the drug's reputed mind-expanding effects in a rigorous, scientific way with ordinary people. In the group's recent test, psilocybin frequently sparked temporary mystical makeovers in volunteers who didn't know what kind of pill they were taking. What's more, some of these participants reported long-lasting positive effects of their experiences. ©2006 Science Service.

Keyword: Drug Abuse
Link ID: 9408 - Posted: 06.24.2010