Links for Keyword: Emotions

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Steve Connor Fear may be felt in the heart as well as the head, according to a study that has found a link between the cycles of a beating heart and the likelihood of someone taking fright. Tests on healthy volunteers found that they were more likely to feel a sense of fear at the moment when their hearts are contracting and pumping blood around their bodies, compared with the point when the heartbeat is relaxed. Scientists say the results suggest that the heart is able to influence how the brain responds to a fearful event, depending on which point it is at in its regular cycle of contraction and relaxation. Sarah Garfinkel, a researcher at the Brighton and Sussex Medical School, said: “We demonstrate for the first time that the way in which we process fear is different dependent on when we see fearful images in relation to our heart.” The study, to be presented today at the British Neuroscience Association Festival in London, tested the fear response of 20 healthy volunteers as they were shown images of fearful faces while connected to heart monitors. “Our results show that if we see a fearful face during systole – when the heart is pumping – then we judge this fearful face as more intense than if we see the very same fearful face during diastole – when the heart is relaxed,” Dr Garfinkel said. “From previous research, we know that if we present images very fast then we have trouble detecting them, but if an image is particularly emotional then it can ‘pop’ out and be seen. © independent.co.uk

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 17999 - Posted: 04.08.2013

By Scicurious Much as we all like to think we’re modest, most of us really aren’t. We might try to be humble and say “we’re just some guy, you know?“, but most often, we actually think we’re better than average. Maybe we think we’re smarter, or better looking, or nicer, or maybe even all of the above. And it turns out that thinking we’re above average (even though, statistically, only half of us CAN be above average) is actually good for us. People who suffer from depression usually show a symptom called “depressive realism”. They actually see themselves MORE REALISTICALLY than other people do. And seeing yourself in the harsh light of reality…well it’s pretty depressing (you don’t really want to know how average you are in a sea of over 6 billion people. You don’t). Thinking that you are better than you actually are is sometimes called the Dunning-Kruger effect (though that usually refers specifically to how competent you think you are…when really you’re not), but in psychology it’s called the Superiority Illusion: the belief that you are better than average in any particular metric. But where does the superiority illusion come from? How do our brains give us this optimism bias? The authors of this study wanted to look at how our brain might give us the idea that we are better than the other guy. They were particularly interested in the connection between two areas of the brain, the frontal cortex, and the striatum. The frontal cortex does a lot of higher processing (things like sense of self), while the striatum is involved in things like feelings of reward. The connection between these two areas is called the fronto-striatal circuit. And the strength of that connection may mean something for how you think of yourself. While people who think well of themselves have relatively low connectivity in this circuit, people with depression have higher levels of connectivity. The two areas are MORE connected. © 2013 Scientific American

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 17976 - Posted: 04.02.2013

by Lizzie Wade Believe it or not, the gelada monkeys (Theropithecus gelada) on the right may be sharing a good laugh—and possibly the emotions that go along with it. Previously, only humans and orangutans had been shown to quickly and involuntarily mimic the facial expressions of their companions, an ability that seems to be linked to empathy. After spending months observing every playful interaction among the gelada population at Germany's NaturZoo, scientists are ready to add another, more distantly related species to that list. Geladas of all ages were more likely to mimic the play faces of their companions within 1 second of seeing them than they were to respond with a different kind of expression, according to a paper published by the team this week in Scientific Reports. What's more, the fastest and most frequent mimicry responses occurred between mothers and their infant offspring, like the pair pictured on the left. More research is required to determine if geladas are sharing emotional states in addition to facial expressions, but the team suggests that studying the quantity and quality of these mother-child interactions could provide a way forward. © 2010 American Association for the Advancement of Science

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 17968 - Posted: 03.30.2013

by Traci Watson You say you want to be alone? Think again. Researchers have found that older people with fewer human contacts are more likely to die—even if they're happy in their solitude—than are people with richer social lives. The study adds to the debate over whether loneliness, social isolation, or some combination of the two leads to higher mortality. Social isolation is an objective condition in which people have little interaction with others. Loneliness, on the other hand, is an emotional state felt by people who are dissatisfied with their social connections. "Someone who's socially isolated is likely to be lonely, and vice versa, but that's not completely the case," says epidemiologist and lead author Andrew Steptoe of University College London. To tease apart the effects of being alone versus just feeling lonely, Steptoe and his colleagues examined data from 6500 Britons aged 50 and up who had filled out questionnaires assessing their levels of loneliness. The researchers also tabulated the subjects' contacts with friends, family, religious groups, and other organizations to gauge their social connections. Then they counted how many subjects died over a 7-year period. The most socially isolated subjects had a 26% greater risk of dying, even when sex, age, and other factors linked to survival were accounted for, the researchers report online today in the Proceedings of the National Academy of Sciences. They then tweaked their model to determine whether the connection to death was due to the fact that isolated people are often lonely. It wasn't. © 2010 American Association for the Advancement of Science

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 17951 - Posted: 03.26.2013

Philip Ball No one with even a passing interest in scientific trends will have failed to notice that the brain is the next big thing. It has been said for at least a decade, but now it’s getting serious — with, for example, the recent award by the European Commission of €500 million (US$646 million) to the Human Brain Project to build a new “infrastructure for future neuroscience” and a $1-billion initiative endorsed by President Obama. Having failed to ‘find ourselves’ in our genome, we’re starting a search in the grey matter. It’s a reasonable objective, but only if we have a clear idea of what we hope and expect to find. Some neuroscientists have grand visions, such as that adduced by Semir Zeki of University College London: “It is only by understanding the neural laws that dictate human activity in all spheres — in law, morality, religion and even economics and politics, no less than in art — that we can ever hope to achieve a more proper understanding of the nature of man.” Zeki heads the UCL Institute of Neuroesthetics. This is one of many fields that attaches ‘neuro’ to some human trait with the implication that the techniques of neuroscience, such as functional magnetic resonance imaging, will explain it. We have neurotheology, neuroethics, neurocriminology and so on. Meanwhile, in popular media, a rash of books and articles proclaim (in a profoundly ugly trope) that “this is your brain on drugs/music/religion/sport”. It seems unlikely that studies of the brain will ever be able to wholly explain how we respond to art. © 2013 Nature Publishing Group

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 7: Vision: From Eye to Brain
Link ID: 17940 - Posted: 03.23.2013

Joshua P. Johansen Anxiety does not arise from a single neural circuit. An interplay between neighbouring, yet opposing, circuits produces anxiety, and outputs from these circuits regulate specific anxiety responses. We all know anxiety. We might have experienced it while waiting to hear about a promotion at work, or on our way to see the doctor because she wants to talk about test results in person. A diffuse uneasiness, sometimes accompanied by perspiration and subtle changes in breathing, anxiety ebbs and flows depending on life's circumstances, and can even occur for no apparent reason. The condition can be healthy and adaptive, but research in the United States1 shows that, for roughly one-third of people, anxiety is a debilitating disorder at some point in their lives. Nevertheless, answers to important questions — such as how different neuronal populations represent anxiety, and how the various components of the anxious state are constructed and represented in neural circuits — remain elusive. In two papers published on Nature's website today, Jennings et al.2 and Kim et al.3 address these questions using optogenetics to manipulate distinct neuronal subpopulations in mice and so dissect out the contribution of intermixed but functionally distinct cell groups. Both teams analysed a large, diffuse brain region called the bed nucleus of the stria terminalis (BNST). Previous studies4, 5, 6, 7 have found that lesions of the BNST reduce anxiety and fear of specific environments. Other work has discovered8, 9 distinct subregions and subpopulations of BNST neurons, and has found that the region has connections with several other brain areas that are involved in motivated behaviour and stress responses. However, the functions of the various BNST subpopulations and subregions, as well as the significance of these connections, have remained unclear. © 2013 Nature Publishing Group,

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 17936 - Posted: 03.23.2013

By Scicurious I think we can all say that we prefer praise. I’d much rather be told that I was peerless and perspicacious than that I was a pathetic peripatetic. But whether we get praise or censure, as social humans we receive a lot of social feedback. People are always telling us, either directly or indirectly, how we are ‘doing’ socially, and how we are perceived. But getting that information, and what you do with it, are very different things indeed. And while we all like to think that we see our own good and bad points for what they are and take in criticism as well as praise….well, it turns out we’re a little biased in our own favor. When most studies want to look at things like social feedback or social processing, they often do fMRI studies with “games” that you play with other “people” (who aren’t real people, just a computer, but you don’t know that). But this has several disadvantages. First, you can’t rate people on various personality traits, you only know if you get socially accepted or rejected. And secondly, you can’t really get good social feedback from a computer. So to look at social feedback, the authors of this study had people meet each other in PERSON. On the first day, a group of five people who had never met before met in the lab to play an hour or so of Monopoly (hopefully if you’re only in the first hour you avoid a lot of the social rancor that I associate with my family’s Monopoly games). © 2013 Scientific American,

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 17903 - Posted: 03.15.2013

by John Bohannon Every day, millions of people click on Facebook "Like" buttons, boldly declaring their preferences for a variety of things, such as books, movies, and cat videos. But those "likes" may reveal more than they intend, such as sexual orientation, drug use, and religious affiliation, according to a study that analyzed the online behavior of thousands of volunteers. Your preferences define you. Researchers have known for decades that people's personal attributes—gender, age, religion, sexual orientation, and personality type—correlate with their choice of products, concepts, and activities. Just consider the different populations at an opera and a NASCAR race. This is why companies are so eager to gather personal information about their consumers: Advertising is far more effective when it is targeted to groups of people who are more likely to be interested in a product. The only aspect that has changed is the increasing proportion of personal information that is available as digital data on the Internet. And Facebook has become a major hub for such data through its like button. A team led by Michal Kosinski, a psychologist at the University of Cambridge in the United Kingdom as well as at Microsoft Research, wondered just how much people's likes reveal about them. The Likes data are public information. The hard part was getting the data on intelligence and other such attributes to compare with the likes. For that, Kosinski and his Cambridge colleague David Stillwell created a Facebook app called myPersonality. After agreeing to volunteer as a research subject, users of the myPersonality app answer survey questions and take a series of psychological tests that measure things such as intelligence, competitiveness, extraversion versus introversion, and general satisfaction with life. Kosinski and Stillwell not only get those data but also data from the user's Facebook profile and friends network. In return, users get a peek at their own information. More than 4 million people have volunteered already. © 2010 American Association for the Advancement of Science.

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 17890 - Posted: 03.12.2013

By Helen Shen When does a monkey turn down a free treat? When it is offered by a selfish person, apparently. Given the choice between accepting goodies from helpful, neutral or unhelpful people, capuchin monkeys (Cebus apella) tend to avoid individuals who refuse aid to others, according to a study published today in Nature Communications. “Humans can build up an impression about somebody just based on what we see,” says author James Anderson, a comparative psychologist at the University of Stirling, UK. The capuchin results suggest that this skill “probably extends to other species”, he says. Anderson chose to study capuchins because of their highly social and cooperative instincts. Monkeys in the study watched as a person either agreed or refused to help another person to open a jar containing a toy. Afterwards, both people offered a food pellet to the animal. The monkey was allowed to accept food from only one. When help was given, the capuchins showed little preference between the person requesting help and the one providing aid. But when help was denied, the seven monkeys tended to accept food less often from the unhelpful person than from the requester. To try to understand the monkeys’ motivations, Anderson and his team tested different scenarios. The animals showed no bias against people who failed to help because they were busy opening their own jar. But they tended to avoid people who were available to help but did not do so. © 2013 Scientific American

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 17871 - Posted: 03.07.2013

By Stephanie Pappas, People infected with HIV, the virus that causes AIDS, have a harder time than healthy individuals recognizing fear in the faces of others. This trouble with emotional recognition may reveal subtle cognitive deficits caused by the disease, researchers wrote today (Feb. 26) in the open-access journal BMC Psychology. Previous studies have found that HIV (human immunodeficiency virus) is linked with abnormalities in the frontostriatal region of the brain, communications corridors that link the frontal lobes to deeper brain structures. "Frontostriatal structures are involved in facial emotion recognition, so we expected that HIV-positive subjects were impaired in facial emotion recognition tasks," said study researcher Eleonora Baldonero of the Catholic University of the Sacred Heart in Rome. Baldonero and her colleagues recruited 49 HIV-positive adults from a clinic, making sure that none of the volunteers had a history of psychiatric or neurological disorders. HIV itself can affect the brain, Baldonero told LiveScience, but better drug therapies have made neurological problems less of an issue. Nevertheless, the team wanted to find out if there were any subtle deficits in the brains of patients. [The 10 Most Stigmatized Health Disorders] For comparison, the researchers also recruited 20 healthy adults chosen to be similar to the 49 HIV patients in age, gender and education. Both groups underwent a battery of neurological tests, including a facial emotion recognition task. In this test, patients saw male and female faces displaying disgust, anger, fear, happiness, surprise and sadness and had to match the name of the emotion to the face. © 2013 Yahoo! Inc

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 17853 - Posted: 02.27.2013

—By Chris Mooney It is still considered highly uncool to ascribe a person's political beliefs, even in part, to that person's biology: hormones, physiological responses, even brain structures and genes. And no wonder: Doing so raises all kinds of thorny, non-PC issues involving free will, determinism, toleration, and much else. There's just one problem: Published scientific research keeps going there, with ever increasing audacity (not to mention growing stacks of data). The past two weeks have seen not one but two studies published in scientific journals on the biological underpinnings of political ideology. And these studies go straight at the role of genes and the brain in shaping our views, and even our votes. First, in the American Journal of Political Science, a team of researchers including Peter Hatemi of Penn State University and Rose McDermott of Brown University studied the relationship between our deep-seated tendencies to experience fear—tendencies that vary from person to person, partly for reasons that seem rooted in our genes—and our political beliefs. What they found is that people who have more fearful disposition also tend to be more politically conservative, and less tolerant of immigrants and people of races different from their own. As McDermott carefully emphasizes, that does not mean that every conservative has a high fear disposition. "It's not that conservative people are more fearful, it's that fearful people are more conservative," as she puts it.

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 17841 - Posted: 02.25.2013

by Emily Underwood BOSTON—Dude, check out these European perch. After swimming in water laced with a common antianxiety medication, the red-finned fish lose their inhibitions and gobble up prey at a much faster rate, according to a new study presented here today at the annual meeting of the American Association for the Advancement of Science (publisher of ScienceNOW). The animals act strangely even after being exposed to low concentrations of the medication found in rivers worldwide, suggesting that the drug and others like it could affect fish behavior and ecology even in small doses. Hundreds of different pharmaceuticals are able to slip past conventional wastewater treatment plants and into our waterways, says Jerker Fick, a toxicologist at Umeå University in Sweden and co-author of the new study. "They don't mysteriously go away after we excrete them." Scientists have known for a long time that many pharmaceuticals can persist in rivers and streams, and have behavioral effects on aquatic species in high doses, he says; however, determining whether more dilute concentrations have an effect is harder to establish. Several years ago, Fick and his colleagues discovered a common psychoactive medication called oxazepam in water samples from the River Fyris, which flows through Uppsala, the fourth largest city in Sweden. Oxazepam belongs to a class of drugs that make neurons less excitable and slower to transmit signals throughout the brain and is an "essential" treatment for panic attacks and other severe anxiety disorders, Fick says. Although the authors describe the concentration of the drug—0.58 micrograms per liter-1—as "unusually high," they also say it is comparable to levels found in rivers in other countries; however, there isn't enough research to know for sure how widespread the drug is. "This is not a particularly Swedish problem," says lead author Tomas Brodin of Umeå University. © 2010 American Association for the Advancement of Science

Related chapters from BP7e: Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 17811 - Posted: 02.16.2013

By Laura Sanders Not all fear is the same. A woman who laughs at horror movies, grabs dangerous snakes and calmly deals with knife-wielding men nonetheless surrenders to terror at a single puff of suffocating carbon dioxide. This woman, known as SM, has a disease that damaged her amygdala, a brain structure implicated in fear. But the new results involving her and two others with the same disease, published online February 3 in Nature Neuroscience, show that a certain kind of danger signal can bypass the amygdala, hitting the panic button in other parts of the brain. The need to breathe is one of the most fundamental requirements for survival. Clinical neuropsychologist Justin Feinstein of the University of Iowa in Iowa City believes that the instinct to get air might tap into a brain system that’s more primal than the amygdala. Feinstein and colleagues work with SM and other patients who suffer from a rare genetic disorder called Urbach-Wiethe disease. In late childhood, this disease destroys the amygdala, a pair of almond-shaped structures deep in the brain. SM shows no fear when confronted with haunted houses, ominous spiders and scary movies (SN: 1/15/11, p/ 14). Now, the scientists have found something that does scare her. A breath of gas that is 35 percent carbon dioxide can immediately provoke a strong, panicky fear. (By contrast, normal air is less than one percent carbon dioxide.) When the gas hits the body, specialized proteins sense that something is amiss and send an urgent “must have air, now” message to the brain. © Society for Science & the Public 2000 - 2013

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 17753 - Posted: 02.04.2013

By Gareth Cook Michael Trimble, a British professor at the Institute of Neurology in London, begins his new book with Gana the gorilla. In the summer of 2009, 11-year-old Gana gave birth to a boy at a Muenster zoo. But one day in August, the baby suddenly and mysteriously died. Gana held up her son in front of her, staring at his limp body. She held him close, stroking him. To onlookers it appeared that Gana was trying to reawaken him, and, as the hours passed, that she was mourning his passing. Some at the zoo that day cried. But Gana did not. Humans, Trimble tells us, are the only creatures who cry for emotional reasons. “Why Humans Like to Cry” is an exploration of why this would be so, a neuroanatomical “where do tears come from.” It’s also a meditation on human psychology. Many distinctions have been offered between humans and the rest of the animal world, and to this list Trimble adds another: the anguished tear, the apprehension that life is tragic. Trimble answered questions from Mind Matters editor Gareth Cook. Cook: How did you first become interested in crying? Trimble: Of course, because I cry, and some things bring tears quite easily, notably music, and opera with the power of the human voice. Crying tears, for emotional reasons, is unique to humans. There has been a game of catch me if you can, which has been played by those interested in finding attributes or behaviours which separate humans from our nearest living relatives – namely the chimpanzees and bonobos. Certainly our propositional language is very special, but primate communities have very sophisticated ways of communicating. Other contenders, such as play, using tools, or having what is called theory of mind (the sense that I know that others have a mind very like mine, with similar inclinations and intentions) have all been argued as unique to our species, but all these have been demonstrated, in some form, to be found in other primates. Emotional crying makes us human. © 2013 Scientific American

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 17737 - Posted: 01.30.2013

By Laura Sanders People with damage to a specific part of the brain entrusted unexpectedly large amounts of money to complete strangers. In an investment game played in the lab, three women with damage to a small part of the brain called the basolateral amygdala handed over nearly twice as much money as healthy people. These women didn’t expect to make a bunch of money back, an international team of researchers reports online the week of January 21 in the Proceedings of the National Academy of Sciences. Nor did they think the person they invested with was particularly trustworthy. When asked why they would invest so generously, the volunteers couldn’t provide an answer. The results suggest that normally, the basolateral amygdala enables selfishness — putting the squeeze on generosity. © Society for Science & the Public 2000 - 2013

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 17702 - Posted: 01.22.2013

By Bruce Bower Chimpanzees often share and share alike when cooperating in pairs, suggesting that these apes come close to a human sense of fairness, a controversial new study finds. Like people, chimps tend to fork over half of a valuable windfall to a comrade in situations where the recipient can choose to accept the deal or turn it down and leave both players with nothing, say psychologist Darby Proctor of Yerkes National Primate Research Center in Lawrenceville, Ga., and her colleagues. And just as people do, chimps turn stingy when supplied with goodies that they can share however they like, the researchers report online January 14 in the Proceedings of the National Academy of Sciences. “Humans and chimpanzees show similar preferences in dividing rewards, suggesting a long evolutionary history to the human sense of fairness,” Proctor says. But psychologist Josep Call of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, considers the new results “far from convincing.” In Proctor’s experiments, pairs of chimps interacted little with each other and showed no signs of understanding that some offers were unfair and could be rejected, Call says. “If anything, Proctor’s study suggests that there is no fairness sensitivity in chimpanzees,” remarks psychologist Keith Jensen of the University of Manchester in England. © Society for Science & the Public 2000 - 2013

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 17680 - Posted: 01.15.2013

By SINDYA N. BHANOO The human brain responds to music in different ways, depending on the listener’s emotional reaction, among other things. Now researchers report that the same holds true for birds listening to birdsong. “The same regions that respond to music in humans, at least the areas that can also be found in the bird brain, responded to song in our sparrows,” said an author of the new report, Donna Maney, a neuroscientist at Emory University. Primed with estrogen to simulate their state during breeding, female white-throated sparrows responded to the songs of male sparrows in the same way as humans listening to pleasant music, she said. Females in a nonbreeding state responded no differently to birdsong than to generic tones of the same frequencies. “So during breeding season, birdsong is received differently by females,” Dr. Maney said. Moreover, male birds treated with testosterone showed a response in the amygdala, the brain’s emotional center, when they heard other males singing. The response is akin to the reaction humans have when they hear the sort of music used in a scary movie scene. “If you’re a male and you hear the song, it means that you’re invading territory or being invaded,” Dr. Maney said. “It’s an aggressive signal.” © 2012 The New York Times Company

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 9: Hearing, Vestibular Perception, Taste, and Smell
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 17646 - Posted: 01.01.2013

Becky Summers Monkeys might not be known for their generosity, but when they do seem to act selflessly, a specific area in their brains keeps track of these kindnesses. The discovery of this neuronal tally chart may help scientists to understand the neural mechanisms underlying normal social behaviour in primates and humans, and might even provide insight into disorders such as autism, in which social processing is disrupted. Steve Chang and his colleagues from Duke University in Durham, North Carolina, used electrodes to directly record neuronal activity in three areas of the brain prefrontal cortex that are known to be involved in social decision-making, while monkeys performed reward-related tasks. When given the option either to drink juice from a tube themselves or to give the juice away to a neighbour, the test monkeys would mostly keep the drink. But when the choice was between giving the juice to the neighbour or neither monkey receiving it, the choosing monkey would frequently opt to give the drink to the other monkey. The researchers found that in two out of the three brain areas being recorded, neurons fired in the presence or absence of the juice reward only. By contrast, the third area — known as the anterior cingulate gyrus — responded only when the monkey allocated the juice to the neighbour and observed it being received. The authors suggest the neurons in the ACG respond to and record the act simultaneously. The study's results are published today in Nature Neuroscience1. © 2012 Nature Publishing Group,

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 17636 - Posted: 12.27.2012

By Joss Fong What do an orgasm, a multiplication problem and a photo of a dead body have in common? Each induces a slight, irrepressible expansion of the pupils in our eyes. For more than a century scientists have known that our eyes' pupils respond to more than changes in light. They also betray mental and emotional commotion. In fact, pupil dilation correlates with arousal so consistently that researchers use pupil size, or pupillometry, to investigate a wide range of psychological phenomena. And they do this without knowing exactly why our eyes behave this way. "Nobody really knows for sure what these changes do," says Stuart Steinhauer, director of the Biometrics Research Lab at the University of Pittsburgh School of Medicine. He views the dilations as a by-product of the nervous system processing important information. The visual cortex in the back of the brain assembles the actual images we see. But a different, older part of the nervous system—the autonomic—manages the continuous tuning of pupil size (along with other involuntary functions such as heart rate and perspiration). Specifically, it dictates the movement of the iris to regulate the amount of light that enters the eye, similar to a camera aperture. The iris is made of two types of muscle: a ring of sphincter muscles that encircle and constrict the pupil down to a couple of millimeters across to prevent too much light from entering; and a set of dilator muscles laid out like bicycle spokes that can expand the pupil up to eight millimeters—approximately the diameter of a chickpea—in low light. © 2012 Scientific American

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 14: Attention and Consciousness
Link ID: 17586 - Posted: 12.10.2012

by Debora Mackenzie The Toxoplasma parasite is an unusually devious operator. When it infects mice, it alters their behaviour so they become fearless enough to seek out cats and get eaten. But exactly how it did this was a mystery. Now it appears that the parasite hijacks its victim's immune system, causing it to produce a chemical normally found in the brain. The discovery suggests that the brain and immune system might have evolved using similar processes to control their behaviour, including electrical and chemical signals now known mainly in nerves. Toxoplasma gondii spends part of its life in a cat's gut, then spreads to mice via cat droppings. It invades their brains and causes them to behave fearlessly towards cats – quickly returning the parasite to a cat's gut and completing its life cycle. The parasite can use other animals as a host, and can spread to humans via infected, uncooked meat as well as cat droppings. Acute infection can harm a fetus, so pregnant women are told to avoid cat litter boxes. A quarter of people have a lifelong Toxoplasma infection and may suffer psychological effects, including increased recklessness. Antonio Barragan of the Karolinska Institute in Stockholm, Sweden, has now discovered that the parasite's mind-bending abilities could be a side effect of the way it hijacks the immune system. Invaders like Toxoplasma normally get engulfed by white blood cells called dendritic cells (DCs), a process that helps other immune cells learn to recognise them. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 17583 - Posted: 12.08.2012