Chapter 11. Emotions, Aggression, and Stress
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by Bruce Bower Thomas Jefferson defended the right to pursue happiness in the Declaration of Independence. But that’s so 237 years ago. Many modern societies champion everyone’s right to be happy pretty much all the time. Good luck with that, says psychologist Joseph Forgas of the University of New South Wales in Sydney. A lack of close friends, unfulfilled financial dreams and other harsh realities leave many people feeling lonely and forlorn a lot of the time. But there’s a mental and social upside to occasional downers that often goes unappreciated. “Bad moods are seen in our happiness-focused culture as representing a problem, but we need to be aware that temporary, mild negative feelings have important benefits,” Forgas says. Growing evidence suggests that gloomy moods improve key types of thinking and behavior, Forgas asserts in a new review paper aptly titled “Don’t worry, be sad!” For good evolutionary reasons, positive and negative moods subtly recruit thinking styles suited to either benign or troubling situations, he says. Each way of dealing with current circumstances generally works well, if imperfectly. New and recent studies described by Forgas in the June Current Directions in Psychological Science illustrate some of the ways in which periods of sadness spontaneously recruit a detail-oriented, analytical thinking style. Morose moods have evolved as early-warning signs of problematic or dangerous situations that demand close attention, these reports suggest. © Society for Science & the Public 2000 - 2013.
By Jason G. Goldman Scientists love yawning. No, that’s not quite right. Scientists love doing research on yawning. It seems to be of interest to folks in fields ranging from primatology to developmental psychology to psychopathology to animal behavior. If the notion of scientifically investigation the purpose of yawning makes you, well, yawn, then you’re missing one of the more interesting debates in the social cognition literature. To understand why yawning is about more than feeling tired or bored, we have to go back a few years. Once upon a time, scientists thought that yawning might be process through which the brain keeps itself cool (PDF). Yawning is associated with increases in blood pressure, and the consequential increase in blood flow might mean that the vascular system acts as a radiator, replacing the warm blood in the brain with cooler blood. It could also be that the deep inhalation of cold air during a yawn can, through convection, alter blood temperature which in turn could cool the brain. Even if it turns out that some yawns can be explained through purely physiological means, yawning is also contagious for humans and other species. If someone watches someone else yawning, they’ll be likely to yawn as well. That means that there is social component to yawning, and it might be related to empathy. It turns out that there’s a correlation between a person’s self-reported empathy and their susceptibility to reacting to a yawn contagion, and those who are more skilled at theory of mind tasks are also more likely (PDF) to yawn contagiously. © 2013 Scientific American
By Sandra G. Boodman, Janet Ruddock was crushed: She had dreamed of greeting her first grandchild, and now that once-in-a-lifetime experience had been marred by the embarrassing problem that had derailed her life for nearly a decade. In June 2010, Ruddock, then 59, and her husband had flown to Vancouver, B.C., from Washington to meet their new grandson. But soon after they arrived, Ruddock’s intractable sweating went into overdrive. As she sat in a rocking chair, perspiration drenched her head and upper body, soaking her shirt and dripping onto the 4-week-old infant. “I burst into tears,” Ruddock recalled. “All I can remember is the feeling that I’m wet, this poor baby’s wet and a moment you should always remember is ruined. You’re never going to get it back. “ For Ruddock, that event precipitated a suicidal depression. For the previous eight years she had undergone tests, taken drugs and endured the bafflement — and skepticism — of a parade of doctors she consulted about the extreme, unpredictable sweating that engulfed her head and upper body. After confiding her despair to a relative, she began seeing a psychiatrist. By chance, a few months later she learned about a woman whose experience mirrored her own and provided her a much-needed road map. “It’s a fascinoma,” said retired Washington internist Charles Abrams, using the medical slang for an unusual — or unusually interesting — case. “You usually hate for patients to come in and say, ‘I found this on the Internet,’ ” said Abrams, who treated Ruddock until his retirement last year. “But every once in a while, something is brought to your attention.” © 1996-2013 The Washington Post
Link ID: 18787 - Posted: 10.15.2013
by Stephanie Pappas, LiveScience Apes orphaned by the African bushmeat trade lack the social savvy of apes raised by their mothers, a new study finds. The study links the emotional development of bonobos (Pan paniscus), one of humans' closest living relatives, with the ability to interact nicely with others, echoing how human emotions develop. Bonobos who are good at soothing themselves out of a bad mood are more likely to comfort other bonobos in distress, researchers report today (Oct. 14) in the journal Proceedings of the National Academy of Sciences. "By measuring the expression of distress and arousal in great apes, and how they cope, we were able to confirm that efficient emotion regulation is an essential part of empathy," study researcher Frans de Waal, of Emory University's National Primate Research Center, said in a statement. PHOTOS: How Santino, the Chimp, Attacks Visitors Though animal emotions "have long been scientifically taboo," de Waal said, he and his colleagues suspected that emotions might have evolved similarly before the bonobo and human lines split about 6 million years ago. The researchers observed juvenile bonobos at a sanctuary near Kinshasa in the Democratic Republic of the Congo. They watched as the young primates fought, threw tantrums and comforted one another by hugging or stroking. (See Video of a Bonobo Hug) In 373 post-distress interactions (318 caused by fights and 55 caused by tantrums), the researchers found that the better a bonobo was at soothing his or her own emotions, the more likely he or she was to rush to aid a friend in need. A similar pattern is seen in human interactions, the researchers reported. © 2013 Discovery Communications, LLC.
By Deborah Kotz / Globe Staff As much as you may hate hearing honking traffic or rumbling trains breaking up the silence while you drift off to sleep, can such irritating noises do serious damage to your health? That’s a question researchers have been trying to answer for years, and they’ve come a bit closer to finding out in a new study looking at the impact of airplane noise in those who live close to airports. Two new studies published in the British Medical Journal this week found that living in a home directly in the flight-path of low-flying planes was associated with an increased risk of being hospitalized for heart disease or a stroke. One study, conducted by Boston-based researchers, examined Medicare records from 6 million seniors living near 89 U.S. airports and found that every 10 decibel level increase in noise from planes that seniors were exposed was linked to a 3.5 percent higher hospitalization rate for heart disease. (About 6 percent of the study population was hospitalized for heart problems during 2009 when the data was collected.) The second study, performed by British researchers, found that folks living near London’s Heathrow airport who were regularly exposed to the greatest levels of noise from planes—greater than 63 decibels which is louder than the sounds of close conversation—were more than 20 percent more likely to be hospitalized for a stroke or for heart disease than those with the least noise exposure. Neither study could prove that the airport noise led to more hospitalizations, but researchers controlled for certain factors like air pollution and road traffic noise which could also raise heart and stroke risks. They couldn’t control for others like smoking habits or diet. © 2013 NY Times Co.
By Stephen L. Macknik and Susana Martinez-Conde Dennis Rogers is an unassuming guy. He's on the short side. And though muscular, he doesn't come across as the kind of towering Venice Beach, muscle-bound Arnold that you might expect from someone billed as the World's Strongest Man. Rather he has the kind of avuncular intensity you find in a great automobile mechanic—a mechanic who happens to be able to lift an engine with one hand while using the fingertips of the other hand to wrench the spark plugs out. Like it's nothing. Rogers, who has been known to keep two U.S. Air Force fighter planes from blasting away in opposite directions by holding them back with his bare hands, performed at the most recent Gathering for Gardner—a conference that celebrates the interests of one of Scientific American's greatest columnists, the late mathemagician Martin Gardner. We asked Rogers about the source of his incredible powers after the show, and we were surprised to learn that he did not know. Bill Amonette of the University of Houston–Clear Lake found that Rogers could recruit an abnormally high number of muscle fibers. But was this ability because of a freak genetic mutation? Another possibility, which Rogers thinks is more likely, is the way he processes pain when he strains those muscles. What if, instead of superpowered muscles, Rogers has a normal—though extremely well exercised—body, and his abilities arise because he can withstand more pain than most mere mortals? He claims that he does feel pain and is actually scared of dentists. In fact, during one stunt in which he held back four souped-up Harley motorbikes with straps, he bit down so hard he split a tooth from top to bottom. Rather than taking his chances at the dentist, he reached into his mouth, clamped his viselike fingertips onto the broken tooth, and extracted it, root and all. Rogers reasons that, unlike in the dentist's office—where he has no control over the pain that is inflicted on him—he has direct executive control over pain that he inflicts on himself. “I know it's coming, I have an idea of what to expect and I can decide to ignore it,” he says. © 2013 Scientific American
by Colin Barras Male marsupial mice just don't know when to stop. For Antechinus stuartii, their debut breeding season is so frenetic and stressful that they drop dead at the end of it from exhaustion or disease. It may be the females of the species that are driving this self-destructive behaviour. Suicidal breeding, known as semelparity, is seen in several marsupials. This is likely linked to short breeding seasons and the fact that the marsupial mice only breed once a year. It is not clear why this is, but it may be that females can only breed when the population of their insect prey reaches its peak. A year is a long and dangerous time for a small animal, so under these circumstances males might do best to pump all their resources into a single breeding season. To test this idea, Diana Fisher of the University of Queensland in St Lucia, Australia, and her colleagues tracked how insect abundance changed with the seasons in the marsupials' home forests. Sure enough, they found that the marsupials' breeding seasons were shortest where insect abundance followed a predictable annual pattern. But the insects are not the whole explanation. It turns out that females do sometimes survive the year and breed again. So why do the males always die? The key factor is that the females are highly promiscuous, says Fisher. Coupled with the short breeding season, this leads to intense competition between males. "Males that exert extreme effort in this short time are at an advantage." © Copyright Reed Business Information Ltd.
By Matthew D. Lieberman The popular conception of human nature emerging from psychology over the last century suggests that we are something of a hybrid, combining reptilian, instinct-driven motivational tendencies with superior higher-level analytic powers. Our motivational tendencies evolved from our reptilian brains eons ago and focus on the four Fs: fighting, fleeing, feeding, and fooling around. In contrast, our intellectual capacities are relatively recent advances. They are what makes us special. One of the things that distinguishes primates from other animals, and humans from other primates, is the size of our brains—in particular, the size of our prefrontal cortex, that is, the front part of the brain sitting right behind the eyes. Our big brains allow us to engage in all sorts of intelligent activities. But that doesn’t mean our brains evolved to do those particular things. Humans are the only animals that can learn to play chess, but no one would argue that the prefrontal cortex evolved specifically so that we could play the game of kings. Rather, the prefrontal cortex is often thought of as an all-purpose computer; we can load it up with almost any software (that is, teach it things). Thus, the prefrontal cortex seems to have evolved for solving novel hard problems, with chess being just one of an endless string of problems it can solve. From this perspective there might not be anything special at all about our ability and tendency to think about the social world. Other people can be thought of as a series of hard problems to be solved because they stand between us and our reptilian desires. Just as our prefrontal cortex can allow us to master the game of chess, the same reasoning suggests that our all-purpose prefrontal cortex can learn to master the social game of chess—that is, the moves that are permissible and advantageous in social life. From this perspective, intelligence is intelligence whether it’s being applied to social life, chess, or studying for a final exam. The creator of one of the most widely used intelligence tests espoused this view, arguing that social intelligence is just “general intelligence applied to social situations.” This view implies social intelligence isn’t special and our interest in the social world is just an accident—a consequence of the particular problems we are confronted with. © 2013 Salon Media Group, Inc
Link ID: 18752 - Posted: 10.07.2013
By R. Douglas Fields Human beings are utterly dependent on a complex social structure for their survival. Since all behavior is controlled by the brain, human beings may have evolved specialized neural circuits that are responsible for compliance with society’s rules. A new study has identified such a region in the human brain, and researchers can increase or decrease a person’s good behavior by electrodes on the scalp that stimulate or inhibit this brain circuit. Individuals must adhere to rules of society, which are ultimately enforced by punishments ranging from peer criticism to severe legal sanctions. “Our findings suggest a neural mechanism that is specialized for social norm compliance,” says Christian Ruff, one of the researchers in this new study published in the October 4, 2013 edition of the journal Science. In addition to illuminating the neurobiological basis for the evolution of social structure in humans, this new finding suggests new therapeutic treatments for people who have problems complying with normal social behavior. “That this mechanism can be upregulated by brain stimulation indeed suggests that targeted influences on these neural processes (by brain stimulation or pharmacology) may help to ameliorate problems with social norm compliance in medical and forensic contexts,” he says. It was already known from fMRI studies that neural activity increased in a specific part of the human cerebral cortex when participants comply with social norms. This region is located in the prefrontal region of the right cerebral hemisphere, called the right lateral prefrontal cortex (rLPFC). However, a correlation between brain activity and behavior does not prove that this neural circuit causes people to comply with social norms. Such proof would require manipulating electrical activity in this brain region to see if people altered their behavior in terms of complying with social expectations. © 2013 Scientific American
Link ID: 18743 - Posted: 10.05.2013
By PAM BELLUCK Say you are getting ready for a blind date or a job interview. What should you do? Besides shower and shave, of course, it turns out you should read — but not just anything. Something by Chekhov or Alice Munro will help you navigate new social territory better than a potboiler by Danielle Steel. That is the conclusion of a study published Thursday in the journal Science. It found that after reading literary fiction, as opposed to popular fiction or serious nonfiction, people performed better on tests measuring empathy, social perception and emotional intelligence — skills that come in especially handy when you are trying to read someone’s body language or gauge what they might be thinking. The researchers say the reason is that literary fiction often leaves more to the imagination, encouraging readers to make inferences about characters and be sensitive to emotional nuance and complexity. “This is why I love science,” Louise Erdrich, whose novel “The Round House” was used in one of the experiments, wrote in an e-mail. The researchers, she said, “found a way to prove true the intangible benefits of literary fiction.” “Thank God the research didn’t find that novels increased tooth decay or blocked up your arteries,” she added. The researchers, social psychologists at the New School for Social Research in New York City, recruited their subjects through that über-purveyor of reading material, Amazon.com. To find a broader pool of participants than the usual college students, they used Amazon’s Mechanical Turk service, where people sign up to earn money for completing small jobs. Copyright 2013 The New York Times Company
Link ID: 18742 - Posted: 10.05.2013
By Travis Riddle Humans like being around other humans. We are extraordinarily social animals. In fact, we are so social, that simply interacting with other people has been shown to be use similar brain areas as those involved with the processing of very basic rewards such as food, suggesting that interacting with people tends to make us feel good. However, it doesn’t take much reflection to notice that the way people interact with each other has radically changed in recent years. Much of our contact happens not face-to-face, but rather while staring at screen-based digital representations of each other, with Facebook being the most prominent example. This raises a very fundamental question – how does online interaction with other people differ from interacting with people in person? One possible way these two interaction styles might differ is through how rewarding we find them to be. Does interacting with Facebook make us feel good as does interacting with people in real life? A recent paper suggests that the answer is “probably not.” In fact, the data from this paper suggest that the more we interact with Facebook, the worse we tend to feel. Researchers recruited participants from around a college campus. The participants initially completed a set of questionnaires, including one measuring their overall satisfaction with life. Following this, participants were sent text messages 5 times a day for two weeks. For each text, participants were asked to respond to several questions, including how good they felt at that moment, as well as how much they had used Facebook, and how much they had experienced direct interaction with others, since the last text. At the end of the two weeks, participants completed a second round of questionnaires. Here, the researchers once again measured participants’ overall satisfaction with life. © 2013 Scientific American
By NICHOLAS BAKALAR Black and Hispanic children who go to an emergency room with stomach pain are less likely than white children to receive pain medication, a new study reports, and more likely to spend long hours in the emergency room. The analysis, published in the October issue of Pediatrics, examined the records of 2,298 emergency room visits by people under 21, a nationally representative sample from a large survey conducted by the Centers for Disease Control and Prevention. About 53 percent were white, 24 percent non-Hispanic black, 21 percent Hispanic, and the rest from other ethnic or racial groups. Over all, 27.1 percent of white children with severe pain received analgesics, but only 15.8 percent of blacks, 18.9 percent of Hispanics and 7.1 percent of children of other races did. Black children were about 68 percent more likely than white children to spend longer than six hours in the emergency room, although there were no statistically significant differences among races in results for any diagnostic test. “This data set will not answer the question of why,” said the lead author, Dr. Tiffani J. Johnson, an instructor at the University of Pennsylvania School of Medicine. “It could be that white parents are more likely to ask for pain meds, or that minority patients are likely to get care in E.R.’s that have longer wait times. And it could be racial bias.” Copyright 2013 The New York Times Company
Mid-life stress may increase a woman's risk of developing dementia, according to researchers. In a study of 800 Swedish women, those who had to cope with events such as divorce or bereavement were more likely to get Alzheimer's decades later. The more stressful events there were, the higher the dementia risk became, BMJ Open reports. The study authors say stress hormones may be to blame, triggering harmful alterations in the brain. Stress hormones can cause a number of changes in the body and affect things such as blood pressure and blood sugar control. And they can remain at high levels many years after experiencing a traumatic event, Dr Lena Johansson and colleagues explain. But they say more work is needed to confirm their findings and ascertain whether the same stress and dementia link might also occur in men. In the study, the women underwent a battery of tests and examinations when they were in either their late 30s, mid-40s or 50s, and then again at regular intervals over the next four decades. At the start of the study, one in four women said they had experienced at least one stressful event, such as widowhood or unemployment. BBC © 2013
By DAVID P. BARASH WAR is in the air. Sad to say, there’s nothing new about this. Nor is there anything new about the claim that war has always been with us, and always will be. What is new, it seems, is the degree to which this claim is wrapped in the apparent acquiescence of science, especially the findings of evolutionary biology with respect to a war-prone “human nature.” This year, an article in The National Interest titled “What Our Primate Relatives Say About War” answered the question “Why war?” with “Because we are human.” In recent years, a piece in New Scientist asserted that warfare has “played an integral part in our evolution” and an article in the journal Science claimed that “death in warfare is so common in hunter-gatherer societies that it was an important evolutionary pressure on early Homo sapiens.” The emerging popular consensus about our biological predisposition to warfare is troubling. It is not just scientifically weak; it is also morally unfortunate, as it fosters an unjustifiably limited vision of human potential. Although there is considerable reason to think that at least some of our hominin ancestors engaged in warlike activities, there is also comparable evidence that others did not. While it is plausible that Homo sapiens owed much of its rapid brain evolution to natural selection’s favoring individuals that were smart enough to defeat their human rivals in violent competition, it is also plausible that we became highly intelligent because selection favored those of our ancestors who were especially adroit at communicating and cooperating. Conflict avoidance, reconciliation and cooperative problem solving could also have been altogether “biological” and positively selected for. © 2013 The New York Times Company
Heather Saul Stress can make the world around us smell unpleasant, the results of a new study are suggesting. Researchers from the University of Wisconsin-Madison used powerful brain imaging technologies to examine how stress and anxiety "re-wire" the brain. A team of psychologists led by Professor Wen Li discovered that when a person experiences stress, emotion systems and olfactory processing in the brain become linked, making inoffensive smells become unpleasant. Although the emotion and olfactory systems within the brain are usually found next to each other, there is rarely 'crosstalk' between the two. Writing in the Journal of Neuroscience, Prof Li said results from their research will now help to uncover the biological mechanisms at work when a person feels stressed. Using functional MRI scans, the team analysed the brain activity of 12 participants after showing them images designed to induce anxiety as they smelled familiar, neutral odours. The subjects were then asked to rate the different smells before being shown the disturbing image and afterwards. The majority showed a more negative response to odours that they had previously considered neutral. This fuels a 'feedback loop' that heightens distress, and can even lead to clinical issues such as depression. Prof Li explained: "After anxiety induction, neutral smells become clearly negative." “In typical odor processing, it is usually just the olfactory system that gets activated,” says Li. “But when a person becomes anxious, the emotional system becomes part of the olfactory processing stream. © independent.co.uk
If you look at the facts and figures on the mental health charity Mind's website, you'll find that around 1 in 4 people will experience some sort of mental health problem each year. About 10% of these people will see their doctor and be diagnosed as having a mental health problem, and of this group, a small proportion will in turn be referred to specialist psychiatric care. Of these people, precisely none resemble the breathtakingly ignorant costumes that have recently been withdrawn from Tesco and Asda. If you want to know what someone with a mental health issue looks like, just look around you. One of the most common types of mental health issue is anxiety – about 9% of people in Britain meet the criteria for mixed anxiety and depression, for example. We all feel anxious from time to time, and that's not necessarily a bad thing. Isaac Marks and Randy Nesse argued in 1994 that anxiety is an important emotion that has been shaped during the course of human evolution. If we are in a potentially dangerous environment, being anxious increases our awareness of our surroundings and puts us in a state of physiological readiness to deal with any threats. However, when an anxiety response kicks in too often, and in situations where it is not needed, it becomes a debilitating problem. In serious cases, anxiety can make it incredibly hard for the person to function. There's now a wealth of research that is trying to tap into the mechanisms involved in both sub-clinical and clinical forms of anxiety. By understanding what happens when we become anxious, we might be able to get a clearer idea of how and why things go wrong in anxiety disorders. For example, a new study published this week in the Journal of Neuroscience has suggested one potential contributing factor – how smells are processed. © 2013 Guardian News and Media Limited
by Megan Gannon, Live Science Deep in the cloud forests of Central America, two species of singing mice put on a high-pitched opera to mark their territory and stave off clashes, researchers discovered. Alston's singing mouse (Scotinomys teguina) and the Chiriqui singing mouse (S. xerampelinus) have overlapping lifestyles in the cloud forests of Costa Rica and Panama. But the tawny cousins seem to establish geographic boundaries so they can avoid competing with each other. "A long-standing question in biology is why some animals are found in particular places and not others," study researcher Bret Pasch, a postdoctoral fellow at the the University of Texas at Austin, said in a statement. "What factors govern the distribution of species across space?" As it turns out, a little communication between individuals affects the spread of both species as a whole. Both species of singing mice produce vocalizations that are barely audible to humans. As video footage of the mouse-y opera from the foggy forest floor shows, the creatures throw their heads back and belt out songs in the form of rapidly repeated notes, known as trills. The Alston's mouse in the clip even looks likes it's taking a bow after its solo. © 2013 Discovery Communications, LLC
By Keith Payne It’s tough to be the boss. A recent Wall Street Journal article described the plight of one CEO who had to drag himself out of bed each morning and muster his game face. It would be a long day of telling other people what to do. It got so bad, we are told, that he had no choice but to take a year off work to sail across the Atlantic Ocean with his family. Forbes agrees: “many CEOs have personal assistants who run their schedules for them, and they go from one meeting straight to another with barely a moment to go to the bathroom.” The indignity! And even worse than the bladder strain is having to fire people: “You may think a CEO can be detached when deciding who to lay off, but generally that couldn’t be farther from the truth. Having to make tough decisions about the people all around you can hit very hard.” Take heart, those of you who have lost your job in these turbulent economic times. At least you didn’t have to fire somebody. This type of silliness usually cites research from the 1950’s on “executive stress syndrome.” The research was not on executives, but rhesus monkeys. In a famous experiment, neuroscientist Joseph Brady subjected one group of monkeys to regular electric shocks every 20 seconds for six hour shifts. Another group of “executive monkeys” had the same schedule, except that they could prevent the shocks by pressing a lever in each 20 second period. The “executive monkeys” quickly learned to prevent the shocks by pressing the levers. This situation sounds awful for both monkeys, but decidedly worse for the monkeys with no escape. And yet, it was the “executive monkeys” with greater responsibility and control who started dropping dead from stomach ulcers. These results seemed to suggest that being responsible for making important decisions was so stressful that it posed a serious health risk. Executive stress syndrome was born. © 2013 Scientific American
By Laura Geggel and SFARI.org Boredom, tiredness, hunger and stress can all set off a yawn. People can even 'catch' a bout of yawning when they see or hear another person in the throes of the involuntary gesture, a phenomenon known as social yawning. Researchers speculate that this shared behavior is a form of empathy that strengthens the bonds of a group: One drowsy person’s yawn that triggers others to do the same could lead to a unanimous call for bedtime, for example. Humans aren't the only species to yawn sympathetically: Dogs yawn in response to human yawns, and chimpanzees and baboons yawn in concert with one another. Children with autism apparently don’t respond to social yawning, however, prompting some researchers to blame their well-chronicled struggle with empathy. A new Japanese study suggests that, instead, children with the disorder miss facial cues, such as closed eyes, that make yawning contagious. The study was published 22 July in Autism Research and Treatment. The researchers say children with autism miss those cues because they avoid looking at people’s faces. But that may not entirely explain it. For example, a small 2009 study found that typically developing children yawn even when they’ve only heard another person do so, but children with autism do not. In the new study, the researchers set up two experiments to determine whether children with autism look at others’ faces enough to catch a social yawn. In the first test, 26 children with autism and 46 controls wore eye-tracking devices while watching video clips of people either yawning or remaining still. The researchers asked the children to count how many people in the clips were wearing glasses to make sure they looked at the people’s eyes. The video showed the person yawning only when the eye tracker verified that the children had fixed their gaze on the eyes. © 2013 Scientific American
By Julianne Chiaet It has taken a century so far for scientists to not figure out the cause of multiple sclerosis (MS). The inflammatory disease, which affects more than 2.1 million people worldwide, has been blamed on toxins, viruses and even food. Most recently, scientists have placed their bets on two major ideas: The first (and far more popular) hypothesis suggests MS begins in white matter, which influences how parts of the brain work together. White matter consists of bundles of axons covered in myelin, a white insulating fatty layer. In people with MS myelin degrades and nerve fibers are left exposed, causing problems in motor coordination and loss of senses. The second hypothesis suggests that MS begins in the gray matter, which affects thinking and learning. The white matter hypothesis overshadows its alternative in part because white matter’s impact is easier to observe. When using a microscope to look at brain tissue, scientists are struck by the degradation in the myelin in samples from patients with MS. And when analyzing MS in the clinic, the overt symptoms experienced by a person with the disease can be attributed to the myelin. Symptoms associated with dysfunctions in gray matter are less obvious, such as the loss of an IQ point. Now, new evidence lends support to the less-favored gray matter hypothesis. Scientists at Rutgers University in Newark tried a new approach to look into the gray matter of MS patients. They analyzed proteins in cerebrospinal fluid (CSF), which can be thought of as the central nervous system’s “blood.” By comparing the quantity of specific CSF proteins in patients who were newly diagnosed or had the relapsing remitting variety of MS with that of healthy patients, the researchers found an uneven distribution of 20 proteins among the three groups. © 2013 Scientific American