Chapter 15. Emotions, Aggression, and Stress
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By Maria Konnikova Last year, Dimitris Xygalatas, the head of the experimental anthropology lab at the University of Connecticut, decided to conduct a curious experiment in Mauritius, during the annual Thaipusam festival, a celebration of the Hindu god Murugan. For the ten days prior to the festival, devotees abstain from meat and sex. As the festival begins, they can choose to show their devotion in the form of several communal rituals. One is fairly mild. It involves communal prayer and singing beside the temple devoted to Murugan, on the top of a mountain. The other, however—the Kavadi—is one of the more painful modern religious rituals still in practice. Participants must pierce multiple parts of their bodies with needles and skewers and attach hooks to their backs, with which they then drag a cart for more than four hours. After that, they climb the mountain where Murugan’s temple is located. Immediately after each ritual was complete, the worshippers were asked if they would be willing to spend a few minutes answering some questions in a room near the temple. Xygalatas had them rate their experience, their attitude toward others, and their religiosity. Then he asked them a simple question: They would be paid two hundred rupees for their participation (about two days’ wages for an unskilled worker); did they want to anonymously donate any of those earnings to the temple? His goal was to figure out if the pain of the Kavadi led to increased affinity for the temple. For centuries, societies have used pain as a way of creating deep bonds. There are religious rites, such as self-flagellation, solitary pilgrimages, and physical mutilation.
by Bethany Brookshire Rats stink. First there’s the poop smell and the urine. And then there’s just that smell of rat — a kind of dusty, hairy little smell. But it turns out that rats don’t smell quite the same all the time. When they are stressed, they produce a different odor, one that makes other rats anxious. Now, Hideaki Inagaki and colleagues at the University of Tokyo in Japan have isolated the particular stress-related odor and identified the two specific chemicals behind it. The results reveal the first evidence of an isolated anxiety pheromone in rats, and give reason for scientists to look at — or maybe sniff — their behavioral experiments cautiously. And the findings could also offer glimmerings of a new flavor of rat-be-gone. Pheromones are chemicals that give off distinct odors that allow an animal to communicate within its own ranks. In rats, as in many other animals, many pheromones activate the vomeronasal organ, a small patch of cells at the base of the nasal cavity. Other researchers have found evidence of pheromones in maternal behavior and in the response of rat pups to their mothers. In the new study, the pheromones in question are about alarm and anxiety. Study coauthor Yasushi Kiyokawa of The University of Tokyo says he first came across the alarm odor when he was a graduate student. “I noticed the rats released a specific odor when I handled them for the first time, as they were stressed by the novel handling procedure,” he recalls. He went sniffing to find the source. “I found that the intensity of the odor was strongest around the anal region,” he says. Many mammals have glands around the anus that produce oils and odors. Since that first whiff of a clue, Kiyokawa and colleagues at the University of Tokyo have been working with what they called the “alarm pheromone.” While rats may be smelly to some, Kiyokawa says this particular smell isn’t unpleasant. “Like a hay or dried grass,” he says. “At least for me.” © Society for Science & the Public 2000 - 2014
Richard Stephens ‘The curve that sets everything straight” was how comedian Phyllis Diller once described the smile. And it’s true that there’s something charming, trustworthy and disarming about a smile – but this can be misleading. Dig a little deeper and you will understand a much less wholesome side. Because, ladies and gentleman, the smile is one of the biggest fakes going. I know what you’re thinking: we all pull a false smile now and again to appease our fellows and avoid unnecessary conflict. On the other hand, a genuine smile of true enjoyment is something different. Psychologists have named such a smile after the French neurologist Guillaume-Benjamin-Amand Duchenne de Boulogne. The Duchenne smile, utilising the muscles around the eyes that lift the cheeks to produce crow’s feet, has long been held as an inimitable sign of true human emotion. Or at least it was until 2013, when a team of researchers from Northeastern University, Boston, broke that hoodoo. Sarah Gunnery and her colleagues asked one group of volunteers to imitate smiles on photographs, and another group of volunteers to rate them. Some of the photographs depicted mouth-only smiles but others were Duchenne smiles, using mouth and eye muscles together. Surprisingly, a high proportion of individuals – two-thirds – could fake a Duchenne smile – and those that could do this were better able to put on false expressions in their everyday lives. This straightforward study indicates that even the sacrosanct Duchenne smile can be convincingly simulated. So much for smiling being an inimitable sign of true human emotion. So why are we so good at faking smiles? The answer isn’t necessarily sinister – some research shows you can actually smile yourself into a better mood. © 2014 Guardian News and Media Limited
Link ID: 20438 - Posted: 12.23.2014
by Helen Thomson HAVE you read this before? A 23-year-old man from the UK almost certainly feels like he has – he's the first person to report persistent déjà vu stemming from anxiety rather than any obvious neurological disorder. Nobody knows exactly how or why déjà vu happens, but for most of us it is rare. Some people experience it more often, as a side effect associated with epileptic seizures or dementia. Now, researchers have discovered the first person with what they call "psychogenic déjà vu" – where the cause appears to be psychological. The man's episodes began just after he started university, a period when he felt anxious and was also experiencing obsessive compulsions. As time went on, his déjà vu became more and more prolonged, and then fairly continuous after he tried LSD. Now, he avoids television and radio, and finds newspapers distressing as the content feels familiar. There are different theories as to what is going on, says Christine Wells at Sheffield Hallam University in the UK, who has written a paper on the man's experiences. "The general theory is that there's a misfiring of neurons in the temporal lobes – which deal with recollection and familiarity. That misfiring during the process of recollection means we interpret a moment in time as something that has already been experienced," she says. Surprisingly, when Wells gave the man a standard recall test, he scored more similarly to people of his own age without the condition than those with epilepsy-related déjà vu. An MRI and an EEG scan of his brain activity also showed no abnormalities. © Copyright Reed Business Information Ltd.
By David Noonan It was the day before Christmas, and the normally busy MIT laboratory on Vassar Street in Cambridge was quiet. But creatures were definitely stirring, including a mouse that would soon be world famous. Steve Ramirez, a 24-year-old doctoral student at the time, placed the mouse in a small metal box with a black plastic floor. Instead of curiously sniffing around, though, the animal instantly froze in terror, recalling the experience of receiving a foot shock in that same box. It was a textbook fear response, and if anything, the mouse’s posture was more rigid than Ramirez had expected. Its memory of the trauma must have been quite vivid. Which was amazing, because the memory was bogus: The mouse had never received an electric shock in that box. Rather, it was reacting to a false memory that Ramirez and his MIT colleague Xu Liu had planted in its brain. “Merry Freaking Christmas,” read the subject line of the email Ramirez shot off to Liu, who was spending the 2012 holiday in Yosemite National Park. The observation culminated more than two years of a long-shot research effort and supported an extraordinary hypothesis: Not only was it possible to identify brain cells involved in the encoding of a single memory, but those specific cells could be manipulated to create a whole new “memory” of an event that never happened. “It’s a fantastic feat,” says Howard Eichenbaum, a leading memory researcher and director of the Center for Neuroscience at Boston University, where Ramirez did his undergraduate work. “It’s a real breakthrough that shows the power of these techniques to address fundamental questions about how the brain works.” In a neuroscience breakthrough, the duo implanted a false memory in a mouse
|By Bret Stetka When University of Bonn psychologist Monika Eckstein designed her latest published study, the goal was simple: administer a hormone into the noses of 62 men in hopes that their fear would go away. And for the most part, it did. The hormone was oxytocin, often called our “love hormone” due to its crucial role in mother-child relationships, social bonding, and intimacy (levels soar during sex). But it also seems to have a significant antianxiety effect. Give oxytocin to people with certain anxiety disorders, and activity in the amygdala—the primary fear center in human and other mammalian brains, two almond-shaped bits of brain tissue sitting deep beneath our temples—falls. The amygdala normally buzzes with activity in response to potentially threatening stimuli. When an organism repeatedly encounters a stimulus that at first seemed frightening but turns out to be benign—like, say, a balloon popping—a brain region called the prefrontal cortex inhibits amygdala activity. But in cases of repeated presentations of an actual threat, or in people with anxiety who continually perceive a stimulus as threatening, amygdala activity doesn’t subside and fear memories are more easily formed. To study the effects of oxytocin on the development of these fear memories, Eckstein and her colleagues first subjected study participants to Pavlovian fear conditioning, in which neutral stimuli (photographs of faces and houses) were sometimes paired with electric shocks. Subjects were then randomly assigned to receive either a single intranasal dose of oxytocin or a placebo. Thirty minutes later they received functional MRI scans while undergoing simultaneous fear extinction therapy, a standard approach to anxiety disorders in which patients are continually exposed to an anxiety-producing stimulus until they no longer find it stressful. In this case they were again exposed to images of faces and houses, but this time minus the electric shocks. © 2014 Scientific American
by Andy Coghlan How does this make you feel? Simply asking people to think about emotion-laden actions as their brains are scanned could become one of the first evidence-based tests for psychiatric illness. Assessing people in this way would be a step towards a more scientific approach to diagnosis, away from that based on how someone behaves or how they describe their symptoms. The US National Institute of Mental Health has had such a goal in mind since 2013. Marcel Just of Carnegie Mellon University in Pittsburgh, Pennsylvania, and his colleagues developed the brain scanning technique and used it to identify people with autism. "This gives us a whole new perspective to understanding psychiatric illnesses and disorders," says Just. "We've discovered a biological thought-marker for autism." The technique builds on work by the group showing that specific thoughts and emotions are represented in the brain by certain patterns of neural activation. The idea is that deviations from these patterns, what Just refers to as thought-markers, can be used to diagnose different psychiatric conditions. The team asked a group of adults to imagine 16 actions, some of which required emotional involvement, such as "hugging", "persuading" or "adoring", while they lay in an fMRI scanner. © Copyright Reed Business Information Ltd.
By Gabe Bergado It's not news that reading has countless benefits: Poetry stimulates parts of the brain linked to memory and sparks self-reflection; kids who read the Harry Potter books tend to be better people. But what about people who only read newspapers? Or people who scan Twitter all day? Are those readers' brains different from literary junkies who peruse the pages of 19th century fictional classics? Short answer: Yes — reading enhances connectivity in the brain. But readers of fiction? They're a special breed. The study: A 2013 Emory University study looked at the brains of fiction readers. Researchers compared the brains of people after they read to the brains of people who didn't read. The brains of the readers — they read Robert Harris' Pompeii over a nine-day period at night — showed more activity in certain areas than those who didn't read. Specifically, researchers found heightened connectivity in the left temporal cortex, part of the brain typically associated with understanding language. The researchers also found increased connectivity in the central sulcus of the brain, the primary sensory region, which helps the brain visualize movement. When you visualize yourself scoring a touchdown while playing football, you can actually somewhat feel yourself in the action. A similar process happens when you envision yourself as a character in a book: You can take on the emotions they are feeling. It may sound hooey hooey, but it's true: Fiction readers make great friends as they tend to be more aware of others' emotions. Copyright © Mic Network Inc.
By Anna North What is depression? Anyone who has dealt with the condition knows what it can feel like — but what causes it, what sustains it, and what’s the best way to make it subside? Despite the prevalence of the disorder — in one Centers for Disease Control and Prevention study, 9.1 percent of adults met the criteria for depression — experts haven’t fully answered these questions. And to fully do so, some say we need new ways of thinking about depression entirely. For Turhan Canli, a professor of integrative neuroscience at Stony Brook University, that means looking at the possibility that depression could be caused by an infection. “I’ve always been struck by the fact that the treatment options did not seem to have dramatically improved over the course of decades,” Dr. Canli told Op-Talk. “I always had a feeling that somehow we seem to be missing the actual treatment of the disease.” He was intrigued by research showing a connection between depression and inflammation in the body, and he started to think about the known causes of inflammation — among them pathogens like bacteria, viruses and parasites. In a paper published in the journal Biology of Mood and Anxiety Disorders, he lays out his case for rethinking depression as a response to infection. He notes that the symptoms of depression are similar to those of infection: “Patients experience loss of energy; they commonly have difficulty getting out of bed and lose interest in the world around them. Although our Western conceptualization puts affective symptoms front-and-center, non-Western patients who meet DSM criteria for major depression report primarily somatic symptoms.” © 2014 The New York Times Company
by Bethany Brookshire We all experience stress, but some handle it better than others. A lot of research has focused on what makes animals and people susceptible to stress and how that, in turn, can trigger depression. It makes sense to study the condition, not the people that don’t experience it. Depression and susceptibility are the broken state. Resilience seems normal by comparison. But resilience is not just the absence of susceptibility. It turns out that a protein called beta-catenin plays an active role in resilience. A new study, from Eric Nestler’s laboratory at the Mount Sinai School of Medicine in New York City, also identifies a large number of new targets that could help scientists understand why some people are susceptible to stress — and how they might be made more resilient. “When people study stress responses, we often just assume that in an animal that’s stressed, there’s an active process that creates these depression-like behaviors,” says Andre Der-Avakian, a neuroscientist at the University of California, San Diego. “But this study and studies from others have shown that resilience is also an active process.” The nucleus accumbens is an area of the brain most often linked with reward and pleasure from items we enjoy, such as food or drugs. But the area also shows changes in people with depression. “It makes sense — here’s a region important in responding to rewards,” Nestler explains. “One of the symptoms of people with depression is that they don’t derive pleasure from things in life.” © Society for Science & the Public 2000 - 2014
|By Piercarlo Valdesolo Google “successful Thanksgiving” and you will get a lot of different recommendations. Most you’ve probably heard before: plan ahead, get help, follow certain recipes. But according to new research from Florida State University, enjoying your holiday also requires a key ingredient that few guests consider as they wait to dive face first into the turkey: a belief in free will. What does free will have to do with whether or not Aunt Sally leaves the table in a huff? These researchers argue that belief in free will is essential to experiencing the emotional state that makes Thanksgiving actually about giving thanks: gratitude. Previous research has shown that our level of gratitude for an act depends on three things: 1) the cost to the benefactor (in time, effort or money), 2) the value of the act to the beneficiary, and 3) the sincerity of the benefactor’s intentions. For example, last week my 4-year-old daughter gave me a drawing of our family. This act was costly (she spent time and effort), valuable (I love the way she draws herself bigger than everyone else in the family), and sincere (she drew it because she knew I would like it). But what if I thought that she drew it for a different reason? What if I thought that she was being coerced by my wife? Or if I thought that this was just an assignment at her pre-school? In other words, what if I thought she had no choice but to draw it? I wouldn’t have defiantly thrown it back in her face, but I surely would have felt differently about the sincerity of the action. It would have diminished my gratitude. © 2014 Scientific American
By Gary Stix One area of brain science that has drawn intense interest in recent years is the study of what psychologists call reconsolidation—a ponderous technical term that, once translated, means giving yourself a second chance. Memories of our daily experience are formed, often during sleep, by inscribing—or “consolidating”—a record of what happened into neural tissue. Joy at the birth of a child or terror in response to a violent personal assault. A bad memory, once fixed, may replay again and again, turning toxic and all-consuming. For the traumatized, the desire to forget becomes an impossible dream. Reconsolidation allows for a do-over by drawing attention to the emotional and factual content of traumatic experience. In the safety of a therapist’s office, the patient lets demons return and then the goal is to reshape karma to form a new more benign memory. The details remain the same, but the power of the old terror to overwhelm and induce psychic paralysis begins to subside. The clinician would say that the memory has undergone a change in “valence”—from negative to neutral and detached. The trick to undertaking successful reconsolidation requires revival of these memories without provoking panic and chaos that can only makes things worse. Talk therapies and psycho-pharm may not be enough. One new idea just starting to be explored is the toning down of memories while a patient is fast asleep © 2014 Scientific American,
By Chelsea Rice On December 14, 2012, Adam Lanza shot and killed 20 children and six personnel at Sandy Hook Elementary School in Newtown, Connecticut, before turning the gun on himself. Ever since, America has been wondering: Why? Today, after investigating and detailing every available record of the 20-year-old Lanza’s life since birth, the Connecticut Office of the Child Advocate released a report that said: We still don’t know what drove him to commit those terrible acts. But we do know he fell through the cracks of the school system, the health care system, and possibly the awareness of his own parents. Every documented moment of Lanza’s life was evaluated, from mental health records that tracked his social development to school and medical records that outlined his needs—and showed disparities in the services provided to him by the state. The review did not, however, stop at Lanza. It included a review of the laws regarding special education and the confidentiality of personal records in the system, as well as “how these laws implicate professional obligations and practices.” Unredacted state police and law enforcement records were also reviewed alongside interviews and extensive research with members of the Child Fatality Review Panel who led the initial investigation of that day. From “earliest childhood,” according to the report, Lanza had “significant developmental challenges,” such as communication and sensory problems, delays in socialization, and repetitive behaviors. Lanza was seen and evaluated by the New Hampshire “Birth to Three” early intervention program when he was almost 3 years old, and referred to special education preschool services.
By Kate Baggaley WASHINGTON — Being stroked in the right place at the right speed activates specialized nerve fibers. The caresses that people rate most pleasant line up with the probable locations of the fibers on the skin, new research suggests. “Touch is important in terms of our physical health and our psychological well-being,” said Susannah Walker, who presented the research November 17 at the annual meeting of the Society for Neuroscience. “But very little attention has been paid to the neurological basis of that effect.” Sensors in the skin known as C-tactile afferents respond strongly to being stroked at between three and 10 centimeters per second. The sensors send signals to the brain that make touch rewarding, says Walker, a neuroscientist at Liverpool John Moores University in England. Walker and a colleague played videos for 93 participants, showing a hand caressing a person’s palm, back, shoulder or forearm, either at 5 cm/s or 30 cm/s. Participants rated the 5 cm/s stroking — the best speed to get the skin’s sensors firing — as the most pleasant, except on the palm, where there are no stroking sensors. The back got the highest pleasantness ratings, forearms lowest. The spots where people like to be touched may not line up with the areas traditionally considered most sensitive. Though less finely attuned to texture or temperature than the hands or face, the back and shoulders are sensitive to a different, social sort of touch. © Society for Science & the Public 2000 - 2014.
By Tanya Lewis WASHINGTON — From the stroke of a mother's hand to the embrace of a lover, sensations of gentle touch activate a specialized set of nerves in humans. The brain is widely believed to contain a "map" of the body for sensing touch. But humans may also have an emotional body map that corresponds to feelings of gentle touch, according to new research presented here Sunday (Nov. 16) at the 44th annual meeting of the Society for Neuroscience. For humans and all social species, touch plays a fundamental role in the formation and maintenance of social bonds, study researcher Susannah Walker, a behavioral neuroscientist at Liverpool John Moores University in the United KIngdom, said in a news conference. [Top 10 Things That Make Humans Special] "Indeed, a lack of touch can have a detrimental effect on both our physical health and our psychological well-being," Walker said. In a clinical setting, physical contact with premature infants has been shown to boost growth, decrease stress and aid brain development. But not much research has focused on the basis of these effects in the nervous system, Walker said. The human body has a number of different kinds of nerves for perceiving touch. Thicker nerves surrounded by a fatty layer of insulation (called myelin) identify touch and temperature and rapidly send those signals to the brain, whereas thinner nerves that lack this insulation send sensory information more slowly.
By Bethany Brookshire WASHINGTON – Moldy houses are hard on the lungs, and new results in mice suggest that they could also be bad for the brain. Inhaling mold spores made mice anxious and forgetful, researchers reported November 15 at the annual meeting of the Society for Neuroscience. Cheryl Harding, a psychologist at the City University of New York, and colleagues dripped low doses of spores from the toxic mold Stachybotrys into mouse noses three times per week. After three weeks, the mice didn’t look sick. But they had trouble remembering a fearful place. The mice were also more anxious than normal counterparts. The anxiety and memory deficits went along with decreases in new brain cells in the hippocampus — a part of the brain that plays a role in memory — compared with control mice. Harding and colleagues also found that the behaviors linked to increased inflammatory proteins in the hippocampus. Exposure to mold’s toxins and structural proteins may trigger an immune response in the brain. The findings, Harding says, may help explain some of the conditions that people living in moldy buildings complain about, such as anxiety and cognitive problems. C. Harding et al. Mold inhalation, brain inflammation, and behavioral dysfunction. Society for Neuroscience Meeting, Washington, DC, November 15, 2014. © Society for Science & the Public 2000 - 2014.
By John Bohannon If you had the choice between hurting yourself or someone else in exchange for money, how altruistic do you think you’d be? In one infamous experiment, people were quite willing to deliver painful shocks to anonymous victims when asked by a scientist. But a new study that forced people into the dilemma of choosing between pain and profit finds that participants cared more about other people’s well-being than their own. It is hailed as the first hard evidence of altruism for the young field of behavioral economics. Human behavior toward others is hard to predict. On the one hand, we stand out in the animal world for our altruism, often making significant sacrifices to help out a stranger in need. And all but the most antisocial people experience psychological distress at witnessing, let alone causing, pain in others. Yet study after study in the field of behavioral economics has demonstrated that we tend to value our own needs and desires above those of others. For example, researchers have found that just thinking about money makes people behave more selfishly. To try to reconcile the angels and devils of our nature, a team led by Molly Crockett, a psychologist at the University of Oxford in the United Kingdom, combined the classic psychological and economics tools for probing altruism: pain and money. Everyone has their own pain threshold, so the first task was a pain calibration. Researchers administered electric shocks with electrodes attached to the wrists of 160 subjects, starting at an almost imperceptible level and amping up until the subject described the pain as intolerable. (For most people, that threshold for pain is similar to holding your wrist under a stream of 50°C water.) © 2014 American Association for the Advancement of Science.
By Greg Miller This robot causes people to experience the illusory sensation of someone standing behind them. © Alain Herzog/EPFL People who’ve stared death in the face and lived to tell about it—mountain climbers who’ve made a harrowing descent, say, or survivors of the World Trade Center attacks—sometimes report that just when their situation seemed impossible, a ghostly presence appeared. People with schizophrenia and certain types of neurological damage sometimes report similar experiences, which scientists call, aptly, “feeling of presence.” Now a team of neuroscientists says it has identified a set of brain regions that seems to be involved in generating this illusion. Better yet, they’ve built a robot that can cause ordinary people to experience it in the lab. The team was led by Olaf Blanke, a neurologist and neuroscientist at the Swiss Federal Institute of Technology in Lausanne. Blanke has a long-standing interest in creepy illusions of bodily perception. Studying these bizarre phenomena, he says, could point to clues about the biology of mental illness and the mechanisms of human consciousness. In 2006, for example, Blanke and colleagues published a paper in Nature that had one of the best titles you’ll ever see in a scientific journal: “Induction of an illusory shadow person.” In that study, they stimulated the brain of a young woman who was awaiting brain surgery for severe epilepsy. Surgeons had implanted electrodes on the surface of her brain to monitor her seizures, and when the researchers passed a mild current through the electrodes, stimulating a small region at the intersection of the temporal and parietal lobes of her brain, she experienced what she described as a shadowy presence lurking nearby, mimicking her own posture. Colored areas indicate regions of overlap in the lesions of neurological patients who experienced feeling of presence illusions. © 2014 Condé Nast.
by Helen Thomson Scared of the dark? Terrified of heights? Spiders make you scream? For the first time, a person's lifelong phobia has been completely abolished overnight. Unfortunately, it required removing a tiny bit of the man's brain, so for now, most people will have to find another way to dispel their fears. The phobia was abolished by accident. A 44-year-old business man started having seizures out of the blue. Brain scans showed he had an abnormality in his left amygdala – an area in the temporal lobe involved in emotional reactions, among other things. Further tests showed the cause was sarcoidosis, a rare condition that causes damage to the lungs, skin and, occasionally, the brain. Doctors decided it was necessary to remove the man's damaged left amygdala. The surgery went well, but soon after the man noticed a strange turn of events. Not only did he have a peculiar "stomach-lurching" aversion to music – which was particularly noticeable when he heard the song accompanying a certain TV advert – but he also discovered he was no longer afraid of spiders. While his aversion to music waned over time, his arachnophobia never returned. Before the surgery he would throw tennis balls at spiders, or use hairspray to immobilise them before vacuuming them up. Now he is able to touch and observe the little critters at close distance and says he actually finds them fascinating. He hasn't noticed any changes to other kinds of fears or anxieties. For example, he is equally as anxious about public speaking now as he was prior to surgery. © Copyright Reed Business Information Ltd.
Link ID: 20265 - Posted: 11.01.2014
by Dan Jones The way your brain reacts to a single disgusting image can be used to predict whether you lean to the left or the right politically. A number of studies have probed the emotions of people along the political spectrum, and found that disgust in particular is tightly linked to political orientation. People who are highly sensitive to disgusting images – of bodily waste, gore or animal remains – are more likely to sit on the political right and show concern for what they see as bodily and spiritual purity, so tend to oppose abortion and gay marriage, for example. A team led by Read Montague, a neuroscientist at Virginia Tech in Roanoke, recruited 83 volunteers and performed fMRI brain scans on them as they looked at a series of 80 images that were either pleasant, disgusting, threatening or neutral. Participants then rated the images for their emotional impact and completed a series of questionnaires that assessed whether they were liberal, moderate or conservative. The brain-imaging results were then fed to a learning algorithm which compared the whole-brain responses of liberals and conservatives when looking at disgusting images versus neutral ones. For both political groups, the algorithm was able to pick out distinct patterns of brain activity triggered by the disgusting images. And even though liberals and conservatives consciously reported similar emotional reactions to the images, the specific brain regions involved and their patterns of activation differed consistently between the two groups – so much so that they represented a neural signature of political leaning, the team concludes. © Copyright Reed Business Information Ltd
Link ID: 20263 - Posted: 11.01.2014