By Christof Koch All of us, even postmodern philosophers, are naive realists at heart. We assume that the external world maps perfectly onto our internal view of it—an expectation that is reinforced by daily experience. I see a coffee mug on the table, reach for a sip and, lo and behold, the vessel’s handle is soon in my grasp as I gingerly imbibe the hot liquid. Or I see a chartreuse-yellow tennis ball on the lawn, pick it up and throw it. Reassuringly, my dog appears to share my veridical view of reality: she chases the ball and triumphantly catches it between her jaws. That there should be a match between perception and reality is not surprising, because evolution ruthlessly eliminates the unfit. If you routinely misperceive or even hallucinate and act on those misapprehensions, you won’t survive long in a world filled with dangers whose avoidance requires accurate distance and speed assessments and rapid reactions. Whether you are diving into rocky waters or driving on a narrow, two-lane road with cars whizzing by in the opposite direction, small mistakes can be lethal. You probably believe that your eyes register high-fidelity information about the absolute size, speed and distance of visible objects and that you respond based on these impartial data. But although we build robots in this manner—equipping them with sensors and computers to plumb the metric properties of their environments—evolution has taken a more complex route. © 2010 Scientific American,

Keyword: Vision
Link ID: 14342 - Posted: 08.10.2010

By Sonja Lyubomirsky Money can’t buy you love. Worshipping Mammon foments evil ways. Materialists are shallow and unhappy. The greenback finds itself in tough times these days. Whether it’s Wall Street bankers earning lavish multi-million-dollar bonuses or two-bit city managers in Los Angeles County bringing in higher salaries than President Obama the recessionary economic climate has helped spur outrage and revulsion at those of us collecting undeserved lucre. Wealthy people have a bad rep. Sure, there are philanthropists like Warren Buffet and Bill Gates, who have given billions of their net worth away and have made the world a better, healthier, safer place. But, sadly, they are an exception. American families who make over $300,000 a year donate to charity a mere 4 percent of their incomes. The statistic should not be surprising, as studies by University of Minnesota psychologist Kathleen Vohs and her collaborators have shown that merely glimpsing dollar bills makes people less generous and approachable, and more egocentric. Now come a new set of studies that reveal yet another toll that money takes. An international team of researchers led by Jordi Quoidbach report in the August 2010 issue of Psychological Science that, although wealth may grant us opportunities to purchase many things, it simultaneously impairs our ability to enjoy those things. Their first study, conducted with adult employees of the University of Liège in Belgium showed that the wealthier the workers were, the less likely they were to display a strong capacity to savor positive experiences in their lives. © 2010 Scientific American,

Keyword: Emotions
Link ID: 14341 - Posted: 08.10.2010

by Gisela Telis Sound sleepers share a surprising secret: a bustling brain. A new study reports that people who can sleep through anything show more frequent bursts of brain activity called sleep spindles than do their light-sleeping counterparts. Researchers say the discovery could lead to spindle-enhancing techniques that offer lighter sleepers a chance at dead-to-the-world rest. Sleep spindles happen only during sleep, when brain waves slow. Scientists first spotted them in the 1930s, but they didn't suspect they were involved in how deeply people sleep. For decades, researchers instead chalked up the vast variability between light and heavy sleepers to differences in sleep stage; sound sleepers were thought to spend more of their repose in the deeper stages of sleep. Then in the 1990s, scientists tracked down the spindle's source: the thalamus, a brain region that regulates sleep and also processes and relays sensory information to the cerebral cortex. The spindle-thalamus link made it "logical that the sleep spindle would play a role in regulating sensory input while we sleep," says Jeffrey Ellenbogen, a sleep researcher at Harvard Medical School and Massachusetts General Hospital in Boston. "But no one had actually shown this." So Ellenbogen and colleagues invited 12 people to spend 3 nights in his lab's cushy digs. Presented with comfy beds and soundproof rooms, the subjects slept peacefully through the first night while the researchers measured their baseline brain waves. During the next 2 nights, the team played an assortment of 14 different sounds, including flushing toilets, loud conversations, ringing phones, and car traffic, 40 to 50 times throughout the night, gradually raising the volume of each sound until each sleeper stirred. © 2010 American Association for the Advancement of Science.

Keyword: Sleep
Link ID: 14340 - Posted: 08.10.2010

Women are more likely to select clingy clothes when they are ovulating, a study has found. But the University of Minnesota study of 100 women found these hormonal shopping habits were triggered by the proximity of attractive women. The researchers suggest in selecting tighter clothes, the women were trying to stand out from love rivals. The Journal of Consumer Research study said there should be more analysis of how hormones affected shopping habits. Women at different stages of their menstrual cycle were shown images of attractive women living locally or far away. They were then asked to choose clothes and accessories which they would like to buy. Women who were ovulating and who had seen photos of attractive local women were most likely to buy "sexier" clothes compared with those shown photographs of unattractive local women or women who lived more than 1,000 miles (1,600km) away. Dr Kristina Durante, who led the research, said: "The desire for women at peak fertility to unconsciously choose products that enhance appearance is driven by a desire to outdo attractive rival women. If you look more desirable than your competition, you are more likely to stand out." The team said even though the end result was about attracting the best romantic partner available, ovulating women's choice of dress was motivated by the other women in their environment. (C)BBC

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 14339 - Posted: 08.09.2010

By Katherine Harmon Researchers have been searching for decades for a way to mend damage to the spinal cord, an injury that can lead to life-long paralysis. Even the smallest of breaks in these crucial central nerve fibers can result in the loss of leg, arm and other bodily functions. And attempts to prompt healing, through stem cells or growth factors, have yet to achieve widespread success. Previous research had been stepping closer to encouraging neuronal growth—which usually stops after physical maturation. And a 2008 study coauthored by Zhigang He, a neurologist at Children's Hospital Boston, announced success in shutting down a gene that stops neuron cell growth, thus enticing damaged nerves to start growing again. Through that process, the team was able to reestablish a severed optical nerve connection in mice. A new study, coauthored in part by He and other members of the 2008 team, demonstrates that voluntary movement can be reestablished in mice with spinal cord damage after removing a common enzyme that regulates the neuronal cell growth. The results were published online August 8 in Nature Neuroscience (Scientific American is part of Nature Publishing Group). The removed enzyme PTEN, a phosphatase and tensin homolog, helps to dictate activity in the mTOR pathway, which plays a role in cell growth. During maturation, PTEN is activated, halting cell regeneration, but after removing it from a group of experimental mice with spinal cord injury, the neurons grew as they did in the development phase. © 2010 Scientific American,

Keyword: Regeneration
Link ID: 14338 - Posted: 08.09.2010

By Carolyn Y. Johnson In the ever-expanding world of medical devices, early adopters have a new option: a robotic arm. A Cambridge start-up, Myomo Inc., is making an expensive stroke therapy available directly to patients, an effort to encourage use of the novel device. The Myomo arm, based on technology developed at the Massachusetts Institute of Technology, is in many ways a natural extension of research that has shown repetitive-exercise therapy can help stroke patients regain movement. The lightweight prosthesis straps onto the arm and reads signals from the muscles to give a patient an assist when he or she moves the limb. But there is no rigorous scientific evidence demonstrating how well it works. And the $7,000 device casts a spotlight on the hard-to-navigate world of rehabilitation devices — in which patients who are often desperate face a growing number of products whose effectiveness is still being determined. “While there’s some suggestive, tiny studies — that are really pilot studies — that it might be useful, there’s no proof of efficacy using the usual criteria,’’ said Dr. Joel Stein, chairman of the rehabilitation and regenerative medicine department at Columbia University. He is also on Myomo’s scientific advisory board. “I’ve worked with many stroke patients through the years, and I’m careful to not be too paternalistic deciding for them. . . . They feel like the medical system has given up on them, and there’s a fine line between not over-promising and saying we have nothing shown to be helpful, therefore you should just give up.’’ © 2010 NY Times Co

Keyword: Stroke; Robotics
Link ID: 14337 - Posted: 08.09.2010

by Graham Lawton and Clare Wilson Why ask people what they think of a product when you can just scan their brains instead? New Scientist explores the brave new world of neuromarketing TAKE A look at the cover of this week's New Scientist magazine (right). Notice anything unusual? Thought not, but behind the scenes your brain is working overtime, focusing your attention on the words and images and cranking up your emotions and memory. How do we know? Because we tested it with a brain scanner. In what we suspect is a world first, this week's cover was created with the help of a technique called neuromarketing, a marriage of market research and neuroscience that uses brain-imaging technology to peek into people's heads and discover what they really want. You may find that sinister. What right does anyone have to try to read your mind? Or perhaps you are sceptical and consider the idea laughable. But neuromarketing, once dismissed as a fad, is becoming part and parcel of modern consumer society. So we decided to take a good look at it - and try it out ourselves. That is how several New Scientist readers ended up in a darkened room in London, wired up to an electroencephalograph (EEG) machine and being shown various magazine cover designs. Our aim - with the help of the European arm of neuromarketing company NeuroFocus, based in Berkeley, California - was to observe their reactions on a level that would not normally be possible. "I've been involved in market research for about 25 years," says Thom Noble, managing director of NeuroFocus Europe. "Every few years a new methodology comes out. Frankly, they're incrementally different. This is transformationally different." © Copyright Reed Business Information Ltd.

Keyword: Brain imaging; Emotions
Link ID: 14336 - Posted: 08.09.2010

By Dan Vergano, USA TODAY If something offers easy answers for not-so-easy questions, you might be reading a popular science book. Malcom Gladwell's Outliers: The Story of Success, centers around the idea of practicing anything for 10,000 hours to be a genius. SuperFreakonomics: Global Cooling, Patriotic Prostitutes, and Why Suicide Bombers Should Buy Life Insurance discovers that economics explains terrorism and climate change. Sex at Dawn suggests evolution explains straying spouses. And then there's Delusions of Gender: How Our Minds, Society and Neurosexism Create Difference by Cordelia Fine. A research associate at the Centre for Agency, Values and Ethics at Australia's Macquarie University, Fine turns the popular science book formula on its head. Chapter-by-chapter, she introduces ideas about the innate differences between the sexes — "it's all fetal hormones" or "men have better-wired brains" or "brain scans show men's brains light up differently" — and then tartly smacks around the studies supposedly supporting them. In particular, Fine joins critics, such as Nikos Logothetis of Germany's Max Planck Institute for Biological Cybernetics, to argue that brain images constructed from functional magnetic resonance imaging studies, often on just a few dozen people at most, have become the latest way to slap a scientific-sounding paint job on old ideas about women being intrinsically dumber than men. "The main message of the book is that our comforting beliefs about gender — that everything's fair now, that sex inequality should be blamed on 'hardwired' differences between the sexes, and that our failure to rear unisex children just points the same way — just don't bear up to scrutiny," Fine says, by e-mail. Copyright 2010 USA TODAY,

Keyword: Sexual Behavior; Brain imaging
Link ID: 14335 - Posted: 08.09.2010

Neuroscientists have long used EEGs to try to understand the brain.Neuroscientists have long used EEGs to try to understand the brain. (Str Old/Reuters) Psychiatrists and engineers have teamed up to help predict how people with schizophrenia will respond to a medication that can produce serious side-effects. Psychiatrists say clozapine is an effective treatment for chronic medication-resistant schizophrenia, but it can produce side-effects such as seizures, cardiac arrhythmias or bone marrow suppression and blood problems that require weekly to monthly blood tests to monitor. Now researchers at McMaster University in Hamilton have used machine learning to "train" a computer to predict whether a patient will respond to the drug based on the brainwave patterns and responses recorded on an EEG device readily available at hospitals and laboratories. "Now what we can do is predict beforehand whether the person is going to respond, so we only expose the patient to the risk if there's a very good chance the treatment will be effective," said study author James Reilly, a professor of electrical and computer engineering at McMaster. Reilly and his psychiatrist and engineering colleagues at the university were able to correctly predict whether 23 middle-aged people diagnosed with schizophrenia would respond to the drug with an accuracy of about 89 per cent, according to the study published in the current online issue of the journal Clinical Neurophysiology. © CBC 2010

Keyword: Schizophrenia; Depression
Link ID: 14334 - Posted: 08.07.2010

By Laura Sanders Vivid, violent dreams can portend brain disorders by half a century, a new study finds. The result, reported in the Aug. 10 Neurology, highlights how some neurological diseases may take hold decades before a person is diagnosed. Spotting early warning signs of the disease may allow clinicians to monitor and treat patients long before the brain deteriorates. People with a mysterious sleep disturbance called REM sleep behavior disorder, or RBD, experience a sudden change in the nature of dreams. Dreams increasingly become more violent and frequently involve episodes in which an attacker must be fought off. The normal muscle paralysis that accompanies dreams is gone, leaving the dreamer, who is most often male, to act out the dream’s punches, twists and yells. In many cases, a person sharing the dreamer’s bed can be injured. Doctors used to think of RBD as an isolated disorder. But follow-up studies revealed that a striking number of these patients later develop neurodegenerative diseases, including Parkinson’s disease and Lewy body dementia. The exact figures vary, but some studies find that anywhere from 80 to 100 percent eventually get a neurodegenerative disorder. “The consensus among all RBD researchers is that it’s not a matter of if, but when,” says sleep expert Carlos Schenck of the Minnesota Regional Sleep Disorders Center in Minneapolis, who was one of the first researchers to describe RBD. “Basically, the longer you follow these men, the more they will convert to a neurodegenerative disorder.” © Society for Science & the Public 2000 - 2010

Keyword: Sleep; Parkinsons
Link ID: 14333 - Posted: 08.07.2010

by Tyler Bancroft IN A classic Monty Python moment, a chirpy, long-haired man on a crucifix urges others around him in a similar predicament to cheer up. Now neurologists have discovered what might be described as a "Life of Brian" brain mechanism that encourages us to look on the bright side of life - even when confronted by thoughts of mortality. Shihui Han of Peking University, China, found activity in brain regions that normally deal with negative emotions and self-awareness are dampened when we process ideas about death. Han and colleagues placed 20 volunteers in functional MRI brain scanners while death-related words, such as graveyard, corpse, behead and slay, flashed up on a screen. Neutral and negative words were also displayed. Unsurprisingly, words related to death activated brain areas already known to process unpleasant or threatening notions. More interestingly, they were associated with comparatively lower activity in the insula and the mid-cingulate (Neuropsychologia, DOI: 10.1016/j.neuropsychologia.2010.07.026). The insula is associated with sense of self and awareness of sensations and movement. Further tests showed that the more participants associated specific words with death, the lower the activity in the insula. Damage to this region is associated with reduced emotional awareness and expression, sometimes resulting in socially inappropriate behaviour. © Copyright Reed Business Information Ltd.

Keyword: Emotions
Link ID: 14332 - Posted: 08.07.2010

By Emily Anthes One of the first things that anatomy students learn is that the brain is divided down the center. In most people, one half, or hemisphere, plays a dominant role. Handedness has long been a crude measure of hemispheric dominance, because each side of the brain controls the opposite side of the body. Right-handers, for instance, are likely to have dominant left hemispheres. Today researchers are realizing that studying ambidextrous children (who have no dominant hand) could yield insights into the consequences of an unusually symmetrical brain. A team of European researchers recently assessed nearly 8,000 Finnish children and showed that mixed-handed children are at increased risk for linguistic, scholastic and attention-related difficulties. At age eight, mixed-handed kids were about twice as likely to have language and academic difficulties as their peers. By the time the children were 16, they also were twice as likely to have symptoms of ADHD—and their symptoms were more severe than those of right- or left-handed students. Ambidexterity is not causing these problems. Rather “handedness is really a very crude measure of how the brain is working,” says Alina Rodriguez, a clinical psychologist at King’s College London and the study’s lead author. In typical brains, language is rooted in the left hemisphere, and net­works that control attention are anchored in the right—but brains without a dominant hemisphere may be working and communicating differently. © 2010 Scientific American,

Keyword: ADHD; Laterality
Link ID: 14331 - Posted: 08.07.2010

By Katherine Harmon More than 26 percent of American adults were obese as of 2009—compared with less than 20 percent in 2000, according to a new report from the U.S. Centers for Disease Control and Prevention. And the number of U.S. states with more than 30 percent of their population topping a body mass index (BMI) of 30 tripled between 2007 and 2009. With this accelerating epidemic, researchers are looking for clues beyond daily diet and exercise to explain our propensity for extra poundage—and many are finding evidence in the very first stages of life. A growing number of analyses have found a convincing link among a heavier mother-to-be, increases in her baby's birth weight, and the child's later risk of obesity. In many past observational studies, however, basic genetics or environmental factors could be blamed for this association. A new study of 513,501 mothers and 1,164,750 of their children born across 15 years aimed to take genetics out of the equation by assessing maternal and infant weight only for those women who had more than one child. "By making comparisons of two or more infants born to the same mother, we were able to factor out the role of genetics," says David Ludwig, an associate professor of pediatrics, director of the Obesity Program at Children's Hospital Boston and co-author of the new study. Women who gained more than 24 kilograms during a pregnancy (which occurred in about 12 percent of pregnancies) added an average of 147.4 additional grams to their baby's birth weight than those who gained about 7.5 to 10 kilograms. © 2010 Scientific American,

Keyword: Obesity; Development of the Brain
Link ID: 14330 - Posted: 08.07.2010

By NICHOLAS WADE Two research reports published Friday offer novel approaches to the age-old dream of regenerating the body from its own cells. Animals like newts and zebra fish can regenerate limbs, fins, even part of the heart. If only people could do the same, amputees might grow new limbs and stricken hearts be coaxed to repair themselves. But humans have very little regenerative capacity, probably because of an evolutionary trade-off: suppressing cell growth reduced the risk of cancer, enabling humans to live longer. A person can renew his liver to some extent, and regrow a fingertip while very young, but not much more. In the first of the two new approaches, a research group at Stanford University led by Helen M. Blau, Jason H. Pomerantz and Kostandin V. Pajcini has taken a possible first step toward unlocking the human ability to regenerate. By inactivating two genes that work to suppress tumors, they got mouse muscle cells to revert to a younger state, start dividing and help repair tissue. What is true of mice is often true of humans, and although scientists are a long way from being able to cause limbs to regenerate, the research is attracting attention. Jeremy Brockes, a leading expert on regeneration at University College London, said the report was “an excellent paper.” Though there is a lot still to learn about the process, “it is hard to imagine that it will not be informative for regenerative medicine in the future,” he said. Copyright 2010 The New York Times Company

Keyword: Regeneration; Stem Cells
Link ID: 14329 - Posted: 08.07.2010

By DENISE GRADY Americans are continuing to get fatter and fatter, with obesity rates reaching 30 percent or more in nine states last year, as opposed to only three states in 2007, health officials reported on Tuesday. The increases mean that 2.4 million more people became obese from 2007 to 2009, bringing the total to 72.5 million, or 26.7 percent of the population. The numbers are part of a continuing and ominous trend. But the rates are probably underestimates because they are based on a phone survey in which 400,000 participants were asked their weight and height instead of having it measured by someone else, and people have a notorious tendency to describe themselves as taller and lighter than they really are. “Over the past several decades, obesity has increased faster than anyone could have imagined it would,” said Dr. Thomas Frieden, the director of the Centers for Disease Control and Prevention, which issued a report on the prevalence of obesity. Obesity rates have doubled in adults and tripled in children in recent decades, Dr. Frieden said. If the numbers keep going up, he added, “more people will get sick and die from the complications of obesity, such as heart disease, stroke, diabetes and cancer.” The report estimates the medical costs of obesity to be as high as $147 billion a year, and notes that “past efforts and investments to prevent and control obesity have not been adequate.” Copyright 2010 The New York Times Company

Keyword: Obesity
Link ID: 14328 - Posted: 08.05.2010

By GINA KOLATA Will Alzheimer’s disease, a terrible degenerative brain disease with no treatments and no clear guidelines for diagnosis before its end stages, become like heart disease? That might mean early markers of risk, analogous to high cholesterol levels, that predict who is likely to get it. And it might mean drugs that actually prevent it. That is the hope behind new diagnostic guidelines being proposed by the National Institute on Aging and the Alzheimer’s Association. In July, when the groups first announced their proposed guidelines, they were met with some skepticism and anger. Why suggest ways of diagnosing the disease before a person even has symptoms? Why tell people they are doomed? And are those early diagnosis guidelines just a sop to pharmaceutical companies so they can start marketing expensive, and perhaps not very effective, new drugs? So the Alzheimer’s Association, with participation from the National Institute on Aging, held a conference call on Wednesday to clarify their position. They wanted, in particular, to explain why they advocated using so-called biomarkers, like scans for amyloid plaque in the brain, a unique feature of Alzheimer’s, and tests of cerebrospinal fluid. Such brain scans are still experimental. Copyright 2010 The New York Times Company

Keyword: Alzheimers; Brain imaging
Link ID: 14327 - Posted: 08.05.2010

Q. I had migraine diagnosed when I was 24 years old (I’m now 30), but I remember having them since my teens. I usually get them during times when my hormone levels change (e.g., during periods, ovulation). There are also other triggers like stress, too little sleep, etc. If the migraines start during the day, they are often preceded and/or followed by major mood swings, the kind that make me want to go jump off the bridge. The associated depression often recedes with pain and then comes back again after the pain recedes. Afterward, I can feel on top of the world — loving, caring and full of joy. Is this normal? Espoo, Finland A. Dr. Dodick responds: What you are experiencing before and after the headache of a migraine attack is not unusual. I am glad you asked, because it speaks to why I emphasize that migraine is more than just a bad headache. Migraine is too often “bookmarked” by the start and stop of the headache, but migraine is frequently associated with symptoms other than headache before, during and after the onset of head pain. About 75 percent of migraine sufferers will experience non-headache premonitory symptoms prior to the headache pain. Patients experience a range of cognitive, emotional and physical symptoms in this phase; the most common include feeling tired and weary, difficulty concentrating, stiff neck, dizziness, light and noise sensitivity, yawning, and depression or irritability. Copyright 2010 The New York Times Company

Keyword: Pain & Touch; Emotions
Link ID: 14326 - Posted: 08.05.2010

by Alison Motluk OVERSIZED brains are to humans what trunks are to elephants and elaborate tail feathers are to peacocks - our defining glory. What would we be without our superlative, gargantuan, neuron-packed brains? Like Donald Trump without his towers, Simon Cowell without his sneering put-downs or Bridget Jones without her diaries. We would just be ordinary primates. Unquestionably smart ones, of course, just not special. Uncomfortable as it is to contemplate, it is looking increasingly likely that our brains are not something to write home about after all. One group of researchers has scrutinised the primate archaeological record and concluded that the human brain has evolved just as would be expected for a primate of our size. Meanwhile, a biologist who has compared the number of neurons in the brains of all sorts of animals says there is nothing special about the human brain compared with other primates. No one is doubting the fact of human intelligence, but they say it can no longer be attributed to a "supersized" brain. Humans, apparently, are no more than ordinary primates with ordinary-sized brains. These findings undermine a fundamental and long-standing belief about our place in the kingdom of life: that Homo sapiens is the greatest species ever to grace the Earth and that we have become the greatest because our brains are the best ever to have evolved. Admittedly, justifying this assertion has taxed our self-professed ingenuity. Clearly ours is not the biggest brain on the planet in absolute terms - whales and elephants outdo us by up to six times - but we counter this by arguing that bigger animals are bound to have bigger brains. And if you take body size into account our brain is exceptionally large, as much as seven times larger than those of other mammals (Science, vol 121, p 447). The underlying assumption is still that when it comes to intelligence, brain size matters. But does it? © Copyright Reed Business Information Ltd.

Keyword: Evolution
Link ID: 14325 - Posted: 08.05.2010

By Lesley Richardson, Press Association A framework to understand the emotional lives of animals was revealed today. Animal choices can be assessed objectively as evidence of pessimistic or optimistic decision-making which indicates their long-term mood. Professor Mike Mendl and Dr Liz Paul, from the University of Bristol, and Dr Oliver Burman, from the University of Lincoln, looked through papers by experts from Charles Darwin to Paul Ekman and Jaak Panksepp to create the framework which can be used in the field of animal welfare and neuroscience. Professor Mike Mendl, head of the Animal Welfare and Behaviour research group at Bristol University's School of Clinical Veterinary Science, said: "Because we can measure animal choices objectively, we can use optimistic and pessimistic decision-making as an indicator of the animal's emotional state which itself is much more difficult to assess. "Recent studies by our group and others suggest that this may be a valuable new approach in a variety of animal species. Public interest in animal welfare remains high, with widespread implications for the way in which animals are treated, used and included in society. We believe our approach could help us to better understand and assess an animal's emotion." ©independent.co.uk

Keyword: Emotions; Evolution
Link ID: 14324 - Posted: 08.05.2010

NEW YORK — Want to maximize the placebo effect? A good way to do this, according to a new study, is to tell someone they have a decent chance of getting the real treatment instead of a fake pill, but keep them guessing. In the study, Parkinson's disease patients given a placebo after being told they had a 75 percent chance of receiving an active drug produced significant amounts of dopamine, a chemical key to the brain's reward system that is scarce in the brains of patients with this disease. But no dopamine response occurred in patients given placebo after being told they had a 25 percent, 50 percent, or 100 percent chance of getting real treatment. The findings show that expectations directly regulate the power of the placebo effect by kicking the brain's reward system into gear, probably not just in Parkinson's patients but in a number of different illnesses, such as chronic pain and depression, according to Dr. A. Jon Stoessl of the Pacific Parkinson's Research Center in Vancouver, British Columbia, and his colleagues. "The greatest form of reward is really to get better, so expectation of improvement is akin to expectation of reward," Stoessl explained in an interview. Stoessl and his colleagues first demonstrated a relationship between the placebo effect and dopamine release in Parkinson's patients nine years ago. Given dopamine's role in the reward system, he explained, "perhaps it would be important for the placebo effect in other conditions." SOURCE: http://link.reuters.com/cab43n Archives of General Psychiatry, August 2010. Copyright 2010 Reuters.

Keyword: Pain & Touch; Parkinsons
Link ID: 14323 - Posted: 08.05.2010