By Matt McGrath Researchers in the US say that they have solved the mystery of why flies are so hard to swat. They think the fly's ability to dodge being hit is due to its fast acting brain and an ability to plan ahead. High speed, high resolution video recordings revealed the insects quickly work out where a threat is coming from and prepare an escape route. The research suggests that the best way of swatting a fly is to creep up slowly and aim ahead of its location. The study has been published in the journal Current Biology. Most people will have experienced the curiously frustrating sensation of carefully attempting to swat a fly, only to swing and miss while the intrepid insect buzzes off to safety. Over the years there have been different theories put forward to explain the fly's uncanny ability to outwit our whacking endeavours. But scientists at the California Institute of Technology (Caltech) say it is down to quick-fire intelligence and good planning. They filmed a series of experiments with fruit flies and a looming swatter. The researchers discovered that long before the fly leaps it calculates the location of the threat and comes up with an escape plan. Flies put their bodies into pre-flight mode very rapidly - Within 100 milliseconds of spotting the swatter they can position their centre of mass in the right way so that a simple extension of their legs propels them away from any threat. The scientists found that flies were able to put themselves into this rapid reaction position no matter whether they were grooming, feeding or simply walking. According to Caltech's Professor Michael Dickinson this illustrates the speed and complexity of the fly's brain.

Keyword: Miscellaneous
Link ID: 11992 - Posted: 08.30.2008

By Susana Martinez-Conde and Stephen L. Macknik The eyes are the windows to the soul. This fact is why we ask people to look us in the eye and tell us the truth. Or why we get worried when someone gives us the evil eye or has a wandering eye. Our everyday language is full of expressions that refer to where people around us are looking. Particularly if they happen to be looking in our direction. View Eye Illusions Slide Show As social primates, humans are very interested in determining the direction of gaze of other humans. It’s important for evaluating their intentions, and critical for forming bonds and negotiating relationships. Lovers stare for long stretches into each other’s eyes, and infants focus intently on the eyes of their parents. Very young babies look at simple representations of faces (such as smileys) for longer than they look at similar cartoonish faces in which the eyes and other features have been scrambled. In this slide show, we’re going to investigate a series of illusions that take advantage of the way the brain processes eyes and gaze. It turns out that it’s fairly easy to trick us into thinking that someone is looking somewhere else, or that Albert Einstein is actually Marilyn Monroe. © 1996-2008 Scientific American Inc.

Keyword: Vision
Link ID: 11991 - Posted: 06.24.2010

Jonah Berger, a professor of marketing at the University of Pennsylvania, made news a few months ago when he published the results of a study demonstrating that where people cast ballots affects how they vote. Although voters think they are making rational decisions based solely on the issues and facts, they are actually subtly influenced by a long list of other variables, most of which operate at an unconscious level. Mind Matters editor Jonah Lehrer chats with Berger about what this new research can teach us about elections, expensive clothing and the human brain. LEHRER: Your most recent paper found that voters are more likely to approve a sales tax increase when voting in a school. Why? What do you think is driving this effect? BERGER: We build on behavioral priming research, which finds that cues or stimuli in the environment, such as the things we see, can activate related concepts in our mind that carry over to influence behavior, even outside our awareness. In a classic study, for example, participants exposed to elderly related words ended up walking more slowly leaving the experiment. The idea is that the words activated the elderly stereotype, which includes walking slowly, and such thoughts influenced behavior. Similarly, in the case of polling locations, seeing lockers, desks and other things associated with schools might activate norms (such as the urge to take care of children) or identities (that is, being a parent) that then shift people to vote to support school funding. © 1996-2008 Scientific American Inc.

Keyword: Emotions
Link ID: 11990 - Posted: 06.24.2010

Jessica Marshall -- Tiny orange clownfish, made famous by the Disney character Nemo, use the smell of leaves and anemones in the water to find their way home on the coral reef. That's the finding of a new study using a clever apparatus to measure the fishes' preference for water carrying different odors. A team led by Geoffrey Jones of James Cook University in Townsville, Australia surveyed waters around Papua New Guinea for clownfish populations. "The boat captain said, 'If you want to find the orange clownfish, you have to find islands. The fish need to see trees,'" said study lead author Danielle Dixson. The survey confirmed this observation: "There's a huge statistical difference [in the numbers of clownfish] between where there are islands and where there are not islands." For reasons that are unknown, the two types of anemones that the region's clownfish call home only live near islands with trees and beaches and are not found on "islands" made only of reefs. But the fish have to search for these anemones, because after eggs hatch near the parents' home anemone, the larvae are carried away by ocean currents. About 11 days later, the juvenile fish settle back into a new anemone, somehow having found their way to their favored abodes. © 2008 Discovery Communications, LLC.

Keyword: Chemical Senses (Smell & Taste); Animal Migration
Link ID: 11989 - Posted: 06.24.2010

In the long run it’s not a guy’s looks that count. It’s his little clucks in the face of danger. A high rate of calling out in alarm turns out to be one of the clearest signs of a rooster with a successful sex life, says Chris Evans of Macquarie University in Sydney, Australia. A rooster that readily gives warning calls when danger looms tends to rank high in number of times hens accept him as a mate and in number of chicks sired, Evans, David R. Wilson and colleagues report in the September Animal Behaviour. A rooster may waggle a huge, ruby-red comb at hens, but if they’ve had a chance to get to know him, his splendor doesn’t mean success. In tests that mimic real life among fowl, behavior trumps looks. “As far as I know, their paper is the first to address the sexiness of alarm calling,” says Dan Blumstein of the University of California, Los Angeles, who has studied alarm calls in marmots. “Alarm calling is a classic problem in evolutionary biology,” Evans says. Squawking as a hawk circles or a fox sneaks up raises the chances of the squawker getting eaten. While the rest of the neighborhood may benefit, the alarm caller seems to be taking a puzzling altruistic risk. © Society for Science & the Public 2000 - 2008

Keyword: Sexual Behavior; Evolution
Link ID: 11988 - Posted: 06.24.2010

A brain chemical that plays a role in long term memory also appears to be involved in regulating how much people eat and their likelihood of becoming obese, according to a National Institutes of Health study of a rare genetic condition. Brain derived neurotrophic factor (BDNF) is, as its name implies, produced in the brain. Studies of laboratory animals have suggested it also helps control appetite and weight. The NIH study, appearing in the August 28 New England Journal of Medicine, provides the first strong evidence that BDNF is important for body weight in human beings as well. The NIH researchers studied children and adults with WAGR syndrome, a rare genetic condition. The researchers found that some of the people with this syndrome lack a gene for BDNF and have correspondingly low blood levels of the substance. The people in this subgroup also have unusually large appetites and a strong tendency towards obesity. “This is a promising new lead in the search for biological pathways that contribute to obesity,” said Duane Alexander, M.D., director of the NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development. “This finding may eventually lead to the development of new drugs to regulate appetite in people who have not had success with other treatments.”

Keyword: Obesity; Trophic Factors
Link ID: 11987 - Posted: 06.24.2010

By Tina Hesman Saey The protein increases with brain activity as patients recover from brain injury Amyloid-beta is a thinking brain’s protein. A new study involving people with severe brain injuries shows that as neuronal activity increases, levels of amyloid-beta in the brain also go up. A-beta, as the protein is sometimes called, is best known for causing plaques in the brains of people with Alzheimer’s disease. It is a normal component of the brain, but scientists don’t know what it does. Traumatic brain injuries increase the risk for Alzheimer’s disease. So to find out if brain injuries cause a spike in amyloid-beta levels that could lead to plaque formation, a team of researchers from Milan, Italy, and Washington University in St. Louis sampled fluid from the brains of 18 comatose patients. The researchers inserted devices in the patients’ brains to monitor pressure. A small catheter sipped up fluid that gathers between brain cells, and then the researchers tested the fluid for A-beta. What the researchers found was exactly the opposite of what they expected, says David L. Brody, a neurologist at Washington University who led the study with Sandra Magnoni of the Ospedale Maggiore in Milan. Instead of seeing a spike of A-beta soon after brain injury from falls, car accidents, assaults or hemorrhages, levels of the protein started low and rose as the patients improved, the team reports in the Aug. 29 Science. © Society for Science & the Public 2000 - 2008

Keyword: Alzheimers
Link ID: 11986 - Posted: 06.24.2010

By Nathan Seppa A gene variant may guard against a blinding eye disease that strikes the elderly A gene called TLR3 may play a pivotal role in the common form of age-related macular degeneration, the leading cause of blindness in the elderly. The new finding, reported online August 27 in The New England Journal of Medicine, reveals that roughly three in 10 people harbor a variant form of TLR3 that subdues its normal activity, seeming to provide a partial safeguard against the dry, common form of the eye disease. In the dry form of macular degeneration, deposits clutter the center of the retina, or macula, and can lead to cell death. That can damage vision to the point of blindness. A less-common form called wet macular degeneration causes vision loss as rogue blood vessels grow in the eye and leak, clouding the macula. In recent years, scientists have discovered several genes implicated in macular degeneration. With the new finding, TLR3, which encodes the protein Toll-like receptor 3, becomes the first gene associated exclusively with the dry form. Researchers tested more than 2,000 people with wet, dry or no macular degeneration. Those with the dry form were less likely than the others to carry the protective variant form of TLR3. © Society for Science & the Public 2000 - 2008

Keyword: Vision; Genes & Behavior
Link ID: 11985 - Posted: 06.24.2010

Early use of medication may be able to slow down progression of Parkinson's disease, preliminary research suggests. Patients who took the drug rasagiline soon after diagnosis had a less aggressive form of Parkinson's than those who did not take it until later. The international study involved more than 1,000 patients, but doctors stress it could be 10 to 15 years before the long-term benefits become clear. Details were presented at a neurological conference in Madrid. More than 120,000 people in the UK have Parkinson's and around 10,000 new cases are diagnosed each year. Symptoms of the progressive neurological disorder include shakes, memory loss and stiffening of the muscles. Rasagiline, also known as Azilect, is already approved for use by the NHS to ease symptoms of Parkinson's. However, some doctors are reluctant to prescribe medication at an early stage, due to concern that the effect can wane with time. The latest study, presented at the European Federation of Neurological Societies Congress, involved patients from the UK, US and Europe. It found that patients who took rasagiline immediately after diagnosis were in better shape after 18 months than those whose treatment with the drug was delayed by nine months. The researchers believe that the drug could work by creating a long lasting protection for brain cells. However, they stressed that many patients had been taking part in the study for just 18 months, and much more work was required to pin down the long-term impact. (C)BBC

Keyword: Parkinsons
Link ID: 11984 - Posted: 08.28.2008

Fat cells from people who are obese don't work properly compared with those from lean people, medical researchers have found. In Thursday's issue of the journal Diabetes, researchers in Philadelphia said they found major differences in fat cells taken from the upper thighs of six obese people and six lean subjects. "The fat cells we found in our obese patients were deficient in several areas," said the study's lead author, Dr. Guenther Boden, chief of endocrinology at Temple University's School of Medicine. "They showed significant stress on the endoplasmic reticulum, and the tissue itself was more inflamed than in our lean patients." The endoplasmic reticulum, or ER, is found in every cell, helping to synthesize proteins and monitor how they are folded, which is important for proper functioning. When the ER in fat cells were stressed, they produced proteins that lead to insulin resistance, the researchers said. Insulin resistance occurs when the body fails to effectively regulate the metabolism of fats, proteins and sugars. The condition can lead to Type 2 diabetes. © CBC 2008

Keyword: Obesity
Link ID: 11983 - Posted: 06.24.2010

By Ursula Dicke and Gerard Roth As far as we know, no dog can compose music, no dolphin can speak in rhymes, and no parrot can solve equations with two unknowns. Only humans can perform such intellectual feats, presumably because we are smarter than all other animal species—at least by our own definition of intelligence. Of course, intelligence must emerge from the workings of the three-pound mass of wetware packed inside our skulls. Thus, researchers have tried to identify unique features of the human brain that could account for our superior intellectual abilities. But, anatomically, the human brain is very similar to that of other primates because humans and chimpanzees share an ancestor that walked the earth less than seven million years ago. Accordingly, the human brain contains no highly conspicuous characteristics that might account for the species’ cleverness. For instance, scientists have failed to find a correlation between absolute or relative brain size and acumen among humans and other animal species. Neither have they been able to discern a parallel between wits and the size or existence of specific regions of the brain, excepting perhaps Broca’s area, which governs speech in people. The lack of an obvious structural correlate to human intellect jibes with the idea that our intelligence may not be wholly unique: studies are revealing that chimps, among various other species, possess a diversity of humanlike social and cognitive skills. © 1996-2008 Scientific American Inc

Keyword: Intelligence; Evolution
Link ID: 11982 - Posted: 06.24.2010

By Lauren Cahoon Here's a trick to make a rubber hand come to life. Hide your right hand under a cloth and stick the rubber hand where your right hand should be. Now have someone stroke your right hand and the fake hand at the same time. Before you know it, you'll begin to "feel" sensation in the rubber hand. But what happens to your real right hand? New research suggests that your body begins to disown it. Psychologists have used the rubber-hand illusion for years to study how people perceive body boundaries. How, for example, does your brain know where you stop and a bicycle begins? Brain scans reveal that the premotor cortex, the part of the brain that integrates vision and touch, helps the body adopt the rubber hand, but no one had looked at what was going on with the hidden, real hand. Lorimer Moseley, a neuroscientist who studies pain at Oxford University in the U.K., and colleagues repeated the rubber-hand experiment on 11 volunteers, but they added a twist: They took the temperature of the hidden hand. During the 7-minute illusion, the researchers found that the average temperature of the hidden hand dropped 0.27°C in all participants; the temperature of other body parts, including the person's other real hand, remained the same. © 2008 American Association for the Advancement of Science.

Keyword: Miscellaneous
Link ID: 11981 - Posted: 06.24.2010

Ewen Callaway Next time you’re at a blackjack table trying to decide whether to hold or hit, just trust your gut. New research shows that our brains pick up on subliminal signals – a dealer’s tell, for instance – when making risky decisions. “When you think that you are referring to your intuition, actually you just learn an association between subliminal signals in your context and the outcome of your actions,” says Mathias Pessiglione, a neuroscientist at the Centre for Neuroimaging Research in Paris, France, who led the study. Doctors and gamblers may be used to trusting their instincts in make-or-break situations, but scientists have had a tough time proving that the brain can learn subconsciously. To uncover this ability, Pessiglione and colleague Chris Frith, of University College London, tested 20 volunteers with a simple game based on winning and losing small amounts of money. On a computer screen, the volunteers watched an animated abstract pattern for a few seconds, which included one of three symbols part way through. Unbeknownst to the subjects, the symbols indicated whether they would lose or gain £1 or break even if they accepted the gamble. © Copyright Reed Business Information Ltd.

Keyword: Emotions
Link ID: 11980 - Posted: 06.24.2010

Experimental RNA drug may cause blindness Erika Check Hayden An experimental therapy to treat the eye disease macular degeneration might actually cause blindness in some patients, according to a study published today. The treatment uses so-called 'small interfering RNA' molecules (siRNAs) to try and slow down degeneration in the area of the retina that is responsible for central vision. This type of degeneration is the leading cause of vision loss in people over the age of 50 in the United States. The warning that siRNAs might cause more harm than good in the eye has been dismissed by one of the companies testing the therapy. But scientists are concerned because there are no published studies that have tested whether the side-effect is occurring in ongoing human trials. "This study really poses serious concerns about whether siRNAs can cause damage, although this will need to be tested further," says retina specialist David M. Brown of the Methodist Hospital in Houston, Texas, who was not involved in the work. The study, led by Kang Zhang of the University of California, San Diego, adds an extra layer of complexity to the phenomenon of RNA interference, a process in which small pieces of genetic material, such as siRNAs, trigger cells to shut down or silence the activity of certain genes. Two companies — OPKO Health of Miami, Florida, and Allergan of Irvine, California — are testing whether siRNAs could slow the progression of the 'wet' version of macular degeneration, where abnormal blood-vessel growth damages cells in the retina. © 2008 Nature Publishing Group

Keyword: Vision
Link ID: 11979 - Posted: 06.24.2010

By Rachel Zelkowitz A cure for hearing loss could be closer, now that a team of scientists has produced key ear cells in mice--and for the first time verified that the cells work just like natural ones. The inner ear turns sound waves into electrical signals inside the organ of Corti, which is lined with rows of 15,000 to 20,000 hairlike cells. The cells respond to vibrations by producing electrical impulses that travel via nerves to the brain. It's a fragile system; loud noises can damage the hair cells and age can deplete them, resulting in hearing loss. Researchers guessed that they could restore some hearing by replacing those hair cells. Previous studies isolated a protein called Atoh1, which triggers hair-cell growth. But it wasn't clear that the engineered cells would have the same mechanical and electrical properties as normal ones when produced in an animal. To address that concern, John Brigande, a developmental neurobiologist at Oregon Health and Science University in Portland, and colleagues injected embryonic mice with DNA containing several copies of Atoh1. The researchers inserted the genes about a week before birth--after they could identify tissue that would become the inner ear and before the natural development of hair cells had begun. Four days after the mice were born, the researchers examined their hair cells. © 2008 American Association for the Advancement of Science.

Keyword: Hearing; Regeneration
Link ID: 11978 - Posted: 06.24.2010

Devin Powell A strain of noisy laboratory mice shows all the signs of autism that are used to diagnose human beings, according to new research. The mice may help scientists study the complicated genetics of autism. Maria Luisa Scattoni of the National Institute of Mental Health in Bethesda, Maryland, and colleagues, separated baby mice of different laboratory strains from their mothers. The pups, which had not yet opened their eyes, made noises aimed to bring mom back. These ultrasonic sounds – too low for the human ear to detect – come in 10 different types, from clicking to pure tones. Most mice in the study used all 10 categories. But the vocabulary of one strain, called BTBR, was limited to four calls, focusing on "harmonics" that contain multiple, simultaneous sounds - like guitar strings plucked together. BTBR mice also called louder and for longer periods of time. "This is similar to what others have found in autistic infants," says Scattoni. Language problems in human babies with autism lead them to hum and grunt for extended periods, and squeal loudly and inappropriately. These babies may also cry for extended periods. Previous studies from the same group have shown that these mice also show the two other symptoms normally used to diagnose human autism – repetitive behavior and restricted social interaction. "BTBR is the first [mouse strain] to have all three," says Scattoni. © Copyright Reed Business Information Ltd

Keyword: Autism; Language
Link ID: 11977 - Posted: 06.24.2010

Three warnings from Health Canada on the risk of death and stroke among seniors taking antipsychotic drugs failed to reduce the prescription rates of those drugs, according to researchers who suggest health warnings are ineffective at protecting patients. Between October 2002 and June 2005, Health Canada issued three warnings of increased risk of death or stroke in elderly patients with dementia who take atypical antipsychotic drugs. In the 1990s, antipsychotics such as Zyprexa (olanzapine), Seroquel (quetiapine) and Risperdal (risperidone) were developed for schizophrenia and other psychiatric conditions. Of the three drugs, only risperidone is approved by Health Canada to treat symptoms of aggression and psychosis in elderly patients with dementia, although doctors may prescribe conventional and atypical antipsychotic drugs off-label for dementia. "The three warnings about serious adverse events associated with use of atypical antipsychotic agents in elderly people with dementia had a limited effect on the prescription rates of these agents," Dr. Geoffrey Anderson of the department of health policy, management and evaluation at the University of Toronto and his colleagues write in Tuesday's issue of the Canadian Medical Association Journal. © CBC 2008

Keyword: Schizophrenia; Alzheimers
Link ID: 11976 - Posted: 06.24.2010

By ABIGAIL ZUGER, M.D. Doctors get seriously ill just like ordinary people, and some of them never recover from the shock. If of a literary bent, they are often moved to reflect for posterity on this disruption of the natural order, detailing their former hubris and the enlightening misery of health care experienced from the other side of the bed. Against this generally lackluster collection of memoirs, Dr. Thomas Graboys’s stands out as a small wonder. Unsentimental and unpretentious, it manages to hit all its marks effortlessly, creating a version of the old fable as touching, educational and inspiring as if it had never been told before. The story’s success lies partly in its almost mythic dimensions: Dr. Graboys rose high, and he fell hard. Until age 50 he was a medical version of one of Tom Wolfe’s masters of the universe: a noted Harvard cardiologist beloved by colleagues and patients, happily married to a tall, beautiful blonde. He was a marathon runner, a demon on the tennis courts and ski slopes, and, if he says so himself, a particularly handsome guy. Then everything fell apart. Over a terrible two-year period Dr. Graboys’s wife died a lingering death from colon cancer. In his grief he barely noticed that he was not functioning quite as well as usual. Those around him figured his fatigue and uncharacteristic fumbling were only to be expected. He pulled himself together, met another woman, and then collapsed on the wedding day — the beginning of physical problems that could no longer be ignored. It was Parkinson’s disease, the neurological condition that makes the body stiffen and shake, but it took Dr. Graboys many months to take the irrevocable step of giving his problems a name. Copyright 2008 The New York Times Company

Keyword: Parkinsons
Link ID: 11975 - Posted: 06.24.2010

By ANAHAD O’CONNOR Manipulating your neck is supposed to relieve pain, not cause it. But years ago neurologists noticed a strange pattern of people suffering strokes shortly after seeing chiropractors, specifically for neck adjustments. Their hypothesis was that a chiropractic technique called cervical spinal manipulation, involving a forceful twisting of the neck, could damage two major arteries that lead through the neck to the back of the brain. Strokes in people under age 45 are relatively rare, but these cervical arterial dissections are a leading cause of them. Studies that followed suggested a link. One at Stanford that surveyed 177 neurologists found 55 patients who suffered strokes after seeing chiropractors. Another, published in the journal Neurologist, said young stroke patients were five times more likely to have had neck adjustments within a week of their strokes than a control group. It estimated an incidence of 1.3 cases for every 100,000 people under 45 receiving neck adjustments. But other studies have cast doubt. One published this year examined 818 cases of stroke linked to arterial dissections at the back of the neck. Before their strokes, younger patients who saw chiropractors were more likely to have complained beforehand of head and neck pain — symptoms often preceding a stroke — suggesting they had undiagnosed dissections and had sought out chiropractors for relief, not realizing a stroke was imminent. Copyright 2008 The New York Times Company

Keyword: Stroke
Link ID: 11974 - Posted: 06.24.2010

By MICHELLE NIJHUIS Crows and their relatives — among them ravens, magpies and jays — are renowned for their intelligence and for their ability to flourish in human-dominated landscapes. That ability may have to do with cross-species social skills. In the Seattle area, where rapid suburban growth has attracted a thriving crow population, researchers have found that the birds can recognize individual human faces. John M. Marzluff, a wildlife biologist at the University of Washington, has studied crows and ravens for more than 20 years and has long wondered if the birds could identify individual researchers. Previously trapped birds seemed more wary of particular scientists, and often were harder to catch. “I thought, ‘Well, it’s an annoyance, but it’s not really hampering our work,’ ” Dr. Marzluff said. “But then I thought we should test it directly.” To test the birds’ recognition of faces separately from that of clothing, gait and other individual human characteristics, Dr. Marzluff and two students wore rubber masks. He designated a caveman mask as “dangerous” and, in a deliberate gesture of civic generosity, a Dick Cheney mask as “neutral.” Researchers in the dangerous mask then trapped and banded seven crows on the university’s campus in Seattle. In the months that followed, the researchers and volunteers donned the masks on campus, this time walking prescribed routes and not bothering crows. The crows had not forgotten. They scolded people in the dangerous mask significantly more than they did before they were trapped, even when the mask was disguised with a hat or worn upside down. The neutral mask provoked little reaction. The effect has not only persisted, but also multiplied over the past two years. Wearing the dangerous mask on one recent walk through campus, Dr. Marzluff said, he was scolded by 47 of the 53 crows he encountered, many more than had experienced or witnessed the initial trapping. The researchers hypothesize that crows learn to recognize threatening humans from both parents and others in their flock. Copyright 2008 The New York Times Company

Keyword: Learning & Memory
Link ID: 11973 - Posted: 06.24.2010