Sandrine Ceurstemont, editor, New Scientist TV It's the closest any of us are likely to get to telekinesis. New animations created by Stuart Anstis from the University of California, San Diego, are showing how changing your gaze can alter the direction in which objects are moving. If you watch this video normally, the moving circles in the first animation rotate while the shifting dots in the second clip follow a horizontal path. But if you look away and watch the movie out of the corner of your eye, the direction of motion will appear to change. In both cases, the moving objects seem to follow the direction of the background stripes. The illusion proves that we perceive motion very differently when it's in the periphery compared with when it's picked up by the fovea, a tiny area at the back of the eye responsible for central vision. Looking at a scene directly results in the sharpest vision, whereas our peripheral vision is good at picking up motion but poor at making out the details of shapes. "That's why when you wave at someone in a crowded airport, your peripheral motion detectors pick up the motion and an eye movement steers the target onto the fovea for more detailed analysis," says Anstis. The animation was a finalist in the 2012 Best Illusion of the Year Contest and was presented earlier this month at the event gala in Naples, Florida. © Copyright Reed Business Information Ltd

Keyword: Vision
Link ID: 16842 - Posted: 05.26.2012

Why do those first hot days of the year feel so bad? Because our bodies' best methods of coping with heat haven’t been tested in three seasons. But if you’re slogging though your work or workout now, you are already starting the process of acclimatization, which will make you better able to withstand heat all summer. These changes can happen in as little as two weeks, according to Lawrence Armstrong, a bioenergetics expert who has studied heat’s effect on the body since 1982. © 1996-2012 The Washington Post

Keyword: Miscellaneous
Link ID: 16841 - Posted: 05.26.2012

By Susan Milius New high-speed video of the tropical bats swooping toward various frogs and toads shows that the predators deploy a sequence of senses to update their judgment of prey during an attack to avoid eating a toxic amphibian, says behavioral ecologist Rachel Page of the Smithsonian Tropical Research Institute in Gamboa, Panama. The bats proved hard to fool even when researchers played the call of a favorite edible frog while offering up another species, Page and her colleagues report in an upcoming Naturwissenschaften. In the tropics, various bats will nab a frog if given half a chance, but only the fringe-lipped species (Trachops cirrhosus) is known to follow frog calls, such as the “tuuun chuck” call of the túngara frog (Engystomops pustulosus). In tests in Panama, Page and her colleagues found that fringe-lipped bats turned aside in mid-air if researchers broadcast enticing túngara calls but offered up a cane toad (Rhinella marina), which is way too big for a bat to carry off. The possibility that incoming bats might use echolocation to avoid overweight prey intrigues bat specialist Brock Fenton at the University of Western Ontario in Canada. Early studies of these bats largely ignored possible last-minute echolocation, he says. The new tests also revealed that playing túngara calls while offering a right-sized but toxic leaf litter toad (Rhinella alata) led bats to catch and then drop the unpleasant prey. (Both bats and toads survived.) © Society for Science & the Public 2000 - 2012

Keyword: Hearing
Link ID: 16840 - Posted: 05.26.2012

By Ferris Jabr Lia Kvavilashvili sat in her office at the University of Hertfordshire, mentally reviewing a study she had recently published. She knew that there was a particular statistical measure that might have been useful in the study, but she could not remember its name. Frustrated, she got up to make a cup of tea. Suddenly the word "hurdle" popped into her mind, unannounced, uninvited. Kvavilashvili—who grew up in Georgia speaking Georgian, Russian and Estonian, and only started to learn English at age 13—had no idea what "hurdle" meant. She looked it up in her dictionary. The second definition was underlined. Although she had no conscious recollection of it, Kvavilashvili had evidently looked up the meaning of "hurdle" before. Somehow, she concluded, her subconscious knew that the word was relevant to her difficulty remembering the name of the useful statistical measure. She had just experienced what she and a few other psychologists call "mind-pops"—fragments of knowledge, such as words, images or melodies that drop suddenly and unexpectedly into consciousness. In most cases, mind-pops seem completely irrelevant to the moments in time and thought into which they intrude. But Kvavilashvili is discovering that mind-pops are not truly random—they are linked to our experiences and knowledge of the world, albeit with hidden threads. Research on mind-pops is preliminary, but so far studies suggest that the phenomenon is genuine and common. Some people notice their mind-pops far more often than others and frequent mind-popping could quicken problem solving and boost creativity. However, in some people's minds—such as those with schizophrenia—mind-pops might evolve from benign phenomena into unsettling hallucinations. © 2012 Scientific American

Keyword: Learning & Memory; Attention
Link ID: 16839 - Posted: 05.24.2012

By Tina Hesman Saey People may be born with all the smell-sensing brain cells they will ever have, a new study concludes. That makes human brains different from those of rodents, nonhuman primates and other mammals, which constantly make new nerve cells, or neurons, in the odor-processing olfactory bulb. Humans don’t rely on the sense of smell as much as other animals do, so maybe it isn’t surprising that people don’t make new odor-sensing cells, says study author Jonas Frisén, a neuroscientist at the Karolinska Institute in Stockholm. Neurons are born in two areas: a memory-and-learning center called the hippocampus and the subventricular zone, which surrounds the two vacant spaces in the middle of the brain. In mice, neurons from the subventricular zone migrate to the olfactory bulb and wire into neural circuits, helping the animals learn new smells. Some evidence exists already that humans also repopulate their hippocampus with new neurons, but data have been less clear for olfactory neurons. Now, Frisén and colleagues have used the steady decline of radiocarbon produced in 20th century nuclear tests to determine the birth dates of brain cells. The results, published in the May 24 Neuron, show that few if any olfactory neurons are created after a person’s birth. A very small number of neurons may still be born and incorporated in the olfactory bulb, but may not be enough to matter. The researchers calculate that olfactory neurons are replaced at a rate of less than 1 percent per century in humans, compared with about 50 percent annually in rodents. © Society for Science & the Public 2000 - 2012

Keyword: Chemical Senses (Smell & Taste); Neurogenesis
Link ID: 16838 - Posted: 05.24.2012

Researchers have shown in mice how immune cells in the brain target and remove unused connections between brain cells during normal development. This research, supported by the National Institutes of Health, sheds light on how brain activity influences brain development, and highlights the newly found importance of the immune system in how the brain is wired, as well as how the brain forms new connections throughout life in response to change. Disease-fighting cells in the brain, known as microglia, can prune the billions of tiny connections (or synapses) between neurons, the brain cells that transmit information through electric and chemical signals. This new research demonstrates that microglia respond to neuronal activity to select synapses to prune, and shows how this pruning relies on an immune response pathway — the complement system — to eliminate synapses in the way that bacterial cells or other pathogenic debris are eliminated. The study was led by Beth Stevens, Ph.D., assistant professor of neurology at Boston Children's Hospital and Harvard Medical School. The brain is created with many more synapses than it retains into adulthood. As the brain develops, it goes through dynamic changes to refine its circuitry, trimming away the synaptic connections that do not have a lot of activity, and preserving the stronger, more active synapses. This period, known as synaptic pruning, is a key part of normal brain development. Scientists do not have a clear understanding of how these synapses are selected, targeted and then pruned. However, precise elimination of unused synapses and strengthening those that are most needed is essential for normal brain function. Many childhood disorders, such as amblyopia (a loss of vision in one eye that can occur when the eyes are misaligned), various forms of mental retardation, epilepsy and autism are thought to be due to abnormal brain development.

Keyword: Development of the Brain; Glia
Link ID: 16837 - Posted: 05.24.2012

By Stephani Sutherland Amputees who experience phantom limb pain can sometimes get relief from an optical illusion. This trick involves looking in a mirror at the reflection of a healthy limb from a certain angle, which causes it to appear where the missing limb should be. Seeing the limb move freely fools the brain into relieving the pain. Now a study suggests this technique might also work for arthritis pain. Cognitive scientist Laura Case, working in the lab of Vilayanur S. Ramachandran (a member of Scientific American Mind’s board of advisers) at the University of California, San Diego, used a modified version of the mirror technique to superimpose a researcher’s healthy hand over a subject’s arthritic hand, which was painfully constricted or contorted. Subjects mimicked the slow, purposeful movements of the researcher’s hand with their own unseen hand. After experiencing the illusion of their hand moving smoothly, subjects rated their arthritis pain slightly lower than before and had an increased range of motion. The result suggests that the toxic soup of inflammatory molecules bathing an arthritic joint is not the only source of painful sensations. “The brain has learned to associate movement with pain,” says Case, who presented her results at the Society for Neuroscience meeting last November in Washington, D.C. The illusion provides the brain with a way to disconnect the sight from the sensation. Next, the group will investigate whether this type of mirror therapy might provide long-term benefits for arthritis, a condition that affects about 50 million Americans. © 2012 Scientific American,

Keyword: Pain & Touch; Vision
Link ID: 16836 - Posted: 05.24.2012

Meredith Wadman Of the top ten leading causes of death in the United States, Alzheimer’s disease — which ranks sixth — is particularly devastating in that there is no cure, no way to prevent it and no proven way to slow its progression. And with at least 11 million Americans expected to have the disease by the middle of the century (see ‘Degeneration generation’) — boosting the annual costs of health care to more than US$1 trillion — the US government is anxiously looking to researchers to improve the prognosis. Last week, the government set out how it planned to spend a $50-million top-up to this year’s funding for the National Institutes of Health (NIH) in Bethesda, Maryland, announced in February as part of a bid to “prevent and effectively treat Alzheimer’s disease by 2025”. The money adds to the $448 million that the NIH was allocated to spend on the disease this year, and roughly half of it is already being used by scientists funded by the National Human Genome Research Institute and the National Institute on Aging. They are preparing to conduct whole-genome and whole-exome studies to discover mutations that may predispose someone to the disease or protect against it. The scientists are assembling a bank of thousands of DNA samples from patients and other people whose DNA could be informative — such as elderly individuals who carry predisposing mutations but show no sign of the disease. The first results from the effort are expected as early the end of this year. © 2012 Nature Publishing Group,

Keyword: Alzheimers
Link ID: 16835 - Posted: 05.23.2012

By Fergus Walsh Medical correspondent Many patients with advanced cancer and other debilitating conditions are being "under-treated" for their pain, new guidance from the health watchdog says. NICE wants doctors in England and Wales to make more use of morphine and other strong opioids - the only adequate pain relief source for many patients. The guidelines recommend doctors discuss patients' concerns. These may include addiction, tolerance, side-effects and fears that treatment implies the final stage of life. The guidance deals with five opioids: morphine, diamorphine (heroin), buprenorphine, fentanyl and oxycodone. They come either from the opium poppy or are synthetically produced versions. NICE - the National Institute for Clinical Excellence - says "misinterpretations and misunderstanding" have surrounded the use of strong opioids for decades, which has resulted in errors "causing under-dosing and avoidable pain, or overdosing and distressing adverse effects". There is also the legacy of Dr Harold Shipman who used diamorphine to murder his victims. It has made many doctors wary of prescribing strong opioids. NICE says the aim is to improve both pain management and patient safety. BBC © 2012

Keyword: Pain & Touch
Link ID: 16834 - Posted: 05.23.2012

by Peter Aldhous If ever we develop a DeLorean-based time machine, it would be handy to send information into the past revealing what kind of medical research to focus on. For years, actor Michael J. Fox was on the front line of the US's "stem cell wars", arguing that embryonic stem cells could cure conditions like his own – Parkinson's disease. Last week Fox revealed he now believes that other lines of research hold more promise. "There have been some issues with stem cells, some problems along the way," Fox told ABC News. "An answer may come from stem cell research but it's more than likely to come from another area." Complicated business The Michael J. Fox Foundation, based in New York City, is still backing stem cell research, says its chief scientific adviser, Gene Johnson of Washington University in St Louis, but has shifted its emphasis in recent years. "Using stem cells as therapeutic agents is a very complicated business," Johnson says. Obstacles include working out how to get transplanted cells to integrate into the brain, and developing "off-the-shelf" cell lines that can be used for any recipient. Meanwhile, other avenues are speeding towards clinical trials. These include neurotrophic factors – proteins that promote the survival of nerve cells – as well as antibodies that target the alpha-synuclein protein, which may be a cause of the brain damage seen in Parkinson's. © Copyright Reed Business Information Ltd.

Keyword: Parkinsons; Stem Cells
Link ID: 16833 - Posted: 05.23.2012

By Partha Mitra Frontiers are in short supply. No explorer will again catch that first glimpse of the Pacific Ocean with “wild surmise,” take the first steps on the moon, or arrive first at the Challenger deep – the remotest corners of the earth are now tourist attractions. Even in science, great mysteries have fallen – life itself has gone from being the subject of metaphysical speculation about vital substances to the biophysical understanding of cellular processes. Uncharted territories, both physical and metaphorical, are hard to find. Yet there is one largely unmapped continent, perhaps the most intriguing of them all, because it is the instrument of discovery itself: the human brain. It is the presumptive seat of our thoughts, and feelings, and consciousness. Even the clinical criteria for death feature the brain prominently, so it arbitrates human life as well. One would think, that after a century of intensive research, its outlines would be well known to us: after all, colorful pictures of brain activity have been making regular appearances in the news media for some time. However, if one scratches the surface, our knowledge of how the human brain is put together remains limited: not in some esoteric, complicated manner, but in the straightforward sense that we have simply no means to visualize entire neurons in the brain (and the brain, being a collection of neurons, therefore remains a shut book in important ways). We can’t see them in their full glory, even with all our advanced technology. The problem is that compared to other cells visualized under a microscope, neurons are at the same time very small, and very big. While their soma (cell bodies) are like other cells, neurons can send out branches (axons) that travel very long distances, sometimes several feet, which don’t fit into the sections of tissue that we do histology on. © 2012 Scientific American,

Keyword: Brain imaging
Link ID: 16832 - Posted: 05.23.2012

By TARA THEAN Instead of spending the morning loading equipment onto boats and conceptualizing our follow strategy for the day, we spent it cleaning our motel rooms and preparing to leave. We enjoyed winding down at the farewell barbecue last night. The weather was perfect for a cookout: warm and slightly breezy. I particularly enjoyed eating my first hot meal in five days: two burgers and a hot dog. Our packed lunches on the boat had to be portable, sturdy and compact, which means our lunchboxes were filled with sandwiches and cereal bars. By dinnertime, I was always so exhausted that I couldn’t bring myself to eat more than cereal and milk. After we had settled down with food, our program director, Randall Wells, gave us a final debriefing about the week’s work. I was happy to hear that we had sampled and examined 16 dolphins in this round of fieldwork — in a typical field week, we find 10 to 15. Of these 16, four were high-priority animals that we had previously not had a chance to look at: FB274, FB233, FB276 and Boomer. I also found out that one of the dolphins we had thought was female was actually male — thankfully, he had been given the versatile name Pat. We needed plenty of teamwork and persistence to take us through the long, unpredictable days in the field. But even in the revelry of the farewell party, we had work left to do. In the evening, my supervisor, Laela Sayigh, and I hosed down the field gear for storage over the next few months and organized equipment back at the Sarasota Dolphin Research Program base. © 2012 The New York Times Company

Keyword: Animal Communication; Language
Link ID: 16831 - Posted: 05.23.2012

By Meghan Holohan You're drifting off to sleep, when suddenly you feel like you're plunging off a cliff -- and you jerk awake. The jolt is disorienting, and you must try again to fall asleep. As many as 70 percent of people experience sleep starts or hypnic jerks while falling asleep, says Dr. William Kohler, medical director of the Florida Sleep Institute and director of the pediatric sleep services at Florida Hospital, Tampa. “A hypnic jerk or sleep starts are a perfectly normal occurrence that is almost universal,” explains James K. Walsh, executive director and senior scientist at St. Luke’s Sleep Medicine and Research Center in St. Louis. “It involves a total body experience where your muscle contracts therefore your limbs jerk or your body twitches. They generally occur during the transition between wakefulness and sleep. All of these things are very, very brief, lasting a half second or less.” Hypnic jerks are myoclonus twitches, or involuntary muscle spasms, but sleep starts occur during hypnagogia, the stage when the body is falling asleep. While most people have felt hypnic jerks, a small number of people experience the frightfully-named exploding head syndrome, the sensation that there is an explosion, crashing cymbals, or thunder near (or in) one’s head. Exploding head syndrome is so rare that it is mostly reported by individual case studies. While exploding head syndrome distresses people with it, both Walsh and Kohler stress that this, too, is normal and not a sign of any problem, physical or mental. © 2012 msnbc.com

Keyword: Sleep
Link ID: 16830 - Posted: 05.23.2012

By Laura Sanders As every kid knows, the very best toy is the one that someone else is playing with. A new study on covetous adults explains why other people’s possessions always seem better. Seeds of this desire are sown in the mirror neuron system, a part of the brain that is activated in a similar pattern whether a person is performing an action or merely watching someone else do it. “Mimetic desire” was first articulated by the French philosopher René Girard in the 1980s. Envy can spread among people like a disease, a force that explains much of human behavior, Girard proposed. Now, French neuroscientists have verified the phenomenon and even attempted to explain how it happens. “They really take a philosophical theory and make it an experiment,” says neuroscientist Marco Iacoboni of UCLA. Copying other people’s desires is a good way to learn about the environment, says study coauthor Mathias Pessiglione of INSERM in Paris. Eating the food that other people eat, for example, is a simple way to avoid food poisoning. But this adaptive feature can break down when desired objects are in short supply. Pessiglione and his team showed adults one of two videos: a piece of candy sitting on a surface, or a person’s hand reaching toward a different-colored piece of candy. Participants then rated the desirability of each candy they saw. As the mimetic desire theory predicts, people rated the about-to-get-grabbed candy as more desirable. The same effect held for clothes, tools and even toys, the team reports in the May 23 Journal of Neuroscience. © Society for Science & the Public 2000 - 2012

Keyword: Emotions
Link ID: 16829 - Posted: 05.23.2012

By Jeanna Bryner Getting up close and personal with a furry tarantula is probably the very last thing someone with a spider phobia would opt for, but the encounter may be the ticket to busting the brain's resistance to arachnids. A tried-and-true exposure therapy, this one lasting just hours, changed activity in the brain's fear regions just minutes after the session was complete, researchers found. "Before treatment, some of these participants wouldn't walk on grass for fear of spiders or would stay out of their home or dorm room for days if they thought a spider was present," said lead study author Katherina Hauner, postdoctoral fellow in neurology at Northwestern University Feinberg School of Medicine, in a statement. After a single therapy session lasting up to three hours, "they were able to walk right up and touch or hold a tarantula. And they could still touch it after six months," Hauner said. Spider phobia is a type of anxiety disorder called specific phobia, which also includes phobias of blood, needles, snakes, enclosed places and others. About 9.4 percent of the U.S. population has experienced a specific phobia at some point in their lifetime, Hauner said. Hauner told LiveScience she hopes people who have specific phobias, particularly of spiders, will realize that successful treatments are out there, and that their phobias can take just hours to cure (though some cases can take a couple weeks to cure, she noted). "It's still not easy. It involves being motivated to overcome your fear." © 2012 Scientific American

Keyword: Emotions; Learning & Memory
Link ID: 16828 - Posted: 05.23.2012

by Michael Balter Many studies in humans and animals suggest that chronic stress is bad for one’s health, in part because it suppresses the immune system. But nearly 30 years of data on wild baboons shows that top-ranking males, despite showing signs of increased stress, recover more quickly than low-ranking baboons from wounds and illness. The results may help explain why some people escape from the negative effects of stress while others do not. Most studies in humans have shown a clear correlation between higher socioeconomic status and lower risk of death or illness from stress-related diseases such as heart attacks and diabetes. Some of the most famous of these are the so-called Whitehall studies of the British Civil Service, which showed that death and illness rates decreased in a step-wise fashion the higher an employee was on the service’s 6-grade pay and responsibility scale. These and other studies also have found that being at the bottom of the totem pole leads to greater stress as a result of increased work loads and time pressures, as well as more job insecurity. But studies of animals, especially other primates, have shown that the relationship between stress and status largely depends on the social organization of the species in question. For example, in species such as baboons that have rigid social rankings and hierarchies, with so-called alpha males dominating other males and females over extended periods of time, it can apparently be more stressful at the top. In a study reported last year in Science, a team that included ecologist Jeanne Altmann of Princeton University revealed that baboon alpha males had the highest levels of glucocorticoid hormones, such as cortisol, as well as testosterone in their feces, indicators that they were under greater stress than lower-ranking individuals. © 2010 American Association for the Advancement of Science.

Keyword: Stress; Neuroimmunology
Link ID: 16827 - Posted: 05.22.2012

By DOUGLAS QUENQUA If alcoholism is a disease, is there hope of finding the cure in a pill? Yes and no. Having mapped the physical changes the brain undergoes with years of habitual drinking, researchers in recent years have discovered a handful of promising — and some say underused — drugs that, combined with therapy, help alcoholics break the cycle of addiction. To those for whom such remedies work, they certainly can feel like a cure. “I felt like I had found something that finally helped me through the cravings,” said Patty Hendricks, 49, who used one such drug, naltrexone, to help control her drinking habit after four failed rehab attempts. “I don’t think I could have gotten sober without it.” The problem is that alcoholics, like cancer patients, are not a homogeneous group. People drink compulsively for any number of reasons, from genetics to anxiety to post-traumatic stress disorder. The pill that helped Ms. Hendricks get sober might do nothing for, say, a veteran who drinks to ward off nightmares. “Just as breast cancer isn’t just one type of breast cancer,” said Dr. Nora D. Volkow, director of the National Institute on Drug Abuse, “alcoholism is heterogeneous as a disorder, so there’s clearly not one drug that is going to work for everybody.” Instead, some addiction experts now envision a future — possibly no more than a decade away — in which treatment for alcoholism mirrors contemporary approaches to depression: Patients will choose from a range of drugs to find the one that best suits them, then couple it with therapy and other tools to achieve long-term recovery. © 2012 The New York Times Company

Keyword: Drug Abuse
Link ID: 16826 - Posted: 05.22.2012

By Sandra G. Boodman, When she heard her younger son’s quavery cry of “M-o-o-o-m-m-m” drifting down the hall in the middle of the night, Jocelyn Mathiasen stiffened, braced for what lay ahead. Sometimes the little boy would awaken just before dawn shaky and weak, complaining of hunger or thirst; after consuming something he would quickly recover. But on the bad nights Peter Dawson would spend hours lying on the floor of the bathroom clutching his stomach, vomiting intermittently and refusing to drink anything. It took him hours to rebound — and it was never clear what had made him so sick. Mathiasen did not know what to make of these episodes, which at first were only mild and infrequent, blips in the life of her otherwise healthy child. But when Peter turned 5 in 2006 and the family moved to Easton, Conn., from Seattle, Mathiasen asked her new pediatrician whether the episodes were normal. Leveling a hard look at her, he told her that what she was describing was definitely not normal — and might signify a serious problem, such as juvenile, or Type 1, diabetes. But after tests for diabetes were negative, the search for the underlying cause of Peter’s odd problem floundered. It would take nearly five years for a specialist eight states away to figure out what was wrong. The solution was a surprisingly cheap and prosaic remedy — but one that recently drew attention in an airport security line. As an infant, Peter would periodically wake up in the morning in obvious distress, grabbing his bottle and sucking down the contents “in one gulp, like he was desperate,” his mother recalled. © 1996-2012 The Washington Post

Keyword: Obesity; Genes & Behavior
Link ID: 16825 - Posted: 05.22.2012

By NICHOLAS BAKALAR Some studies have linked dietary fat to the development of dementia later in life. A new study suggests that the risk may depend on the type of fat consumed. Scientists studied 6,183 women over age 65, tracking their fat consumption and changes in their mental abilities over four years. The women completed a food questionnaire at the start of the study, then periodically took tests of mental ability. The researchers assigned a “change score” to each volunteer, summarizing changes in memory and abstract thinking over time — the lower the score, the greater the decline. The study appeared online Thursday in the journal Annals of Neurology. After controlling for many health and socioeconomic factors, the researchers found that women who consumed the most saturated fat were 60 percent more likely than those consuming the least to have change scores that put them below the 10th percentile. On the other hand, women who reported consuming the most monounsaturated fat were 44 percent less likely to have change scores in lowest one-tenth. Consumption of polyunsaturated fats and trans fats was not associated with any change, nor was total fat. “People might consider making changes or substitutions in their diet, switching out saturated fats in favor of monounsaturated fats,” said the lead author, Dr. Olivia I. Okereke, an assistant professor of psychiatry at Harvard. Copyright 2012 The New York Times Company

Keyword: Alzheimers; Obesity
Link ID: 16824 - Posted: 05.22.2012

By Daisy Yuhas Worrywarts, beware: all that fretting may be for naught. Anxiety has long been interpreted as a symptom of hyperawareness and sensitivity to danger, but a study published last December in Biological Psychology turns that logic on its head. Tahl Frenkel, a graduate student in psychology at Tel Aviv University, asked 17 students who had anxious per­sonalities and 22 students who were more mellow to identify when they detected fear in a series of increasingly frightened faces. As expected, the anxious group spoke up before their calmer counterparts. The twist, however, came from the volunteers’ brain activity, recorded with electrodes on each student’s scalp. The brains of anxious subjects barely responded to the images until the frightened face had reached a certain obvious threshold, at which point their brains leapt into action as though caught off guard. Meanwhile nonanxious respondents showed increasing brain activity earlier in the exercise, which built up subtly with each increasingly fearful face. Although their behavioral response was slower, their brain activity suggests that the mellow subjects picked up on subtle differences in the images more quickly. The result implies that worriers are less aware of potential danger—challeng­ing the common theory that anxious individuals are hypervigilant. Frenkel be­lieves that worrywarts’ low sensitivity to external warning signs causes them to be startled frequently by the seemingly sudden appearance of threats, which leaves them in a state of chronic stress. The brain activity in nonanxious subjects, Frenkel explains, may be evidence of an “early subconscious warning mechanism,” which keeps them cool, calm and collected. [For more on how to ease chronic worrying, see “Why We Worry,” by Victoria Stern; Scientific American Mind, November/December 2009.] © 2012 Scientific American

Keyword: Emotions; Stress
Link ID: 16823 - Posted: 05.22.2012