Chapter 15. Emotions, Aggression, and Stress
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Daniel Cressey Mirrors are often used to elicit aggression in animal behavioural studies, with the assumption being that creatures unable to recognize themselves will react as if encountering a rival. But research suggests that such work may simply reflect what scientists expect to see, and not actual aggression. For most people, looking in a mirror does not trigger a bout of snarling hostility at the face staring back. But many animals do seem to react aggressively to their mirror image, and for years mirrors have been used to trigger such responses for behavioural research on species ranging from birds to fish. “There’s been a very long history of using a mirror as it’s just so handy,” says Robert Elwood, an animal-behaviour researcher at Queen’s University in Belfast, UK. Using a mirror radically simplifies aggression experiments, cutting down the number of animals required and providing the animal being observed with an ‘opponent’ perfectly matched in terms of size and weight. But in a study just published in Animal Behaviour1, Elwood and his team add to evidence that many mirror studies are flawed. The researchers looked at how convict cichlid fish (Amatitlania nigrofasciata) reacted both to mirrors and to real fish of their own species. This species prefers to display their right side in aggression displays, which means that they end up alongside each other in a head-to-tail configuration. It is impossible for a fish to achieve this with their own reflection, but Elwood reasoned that fish faced with a mirror would attempt it, and flip from side to side as they tried to present an aggressive display. On the other hand, if the reflection did not trigger an aggressive reaction, the fish would not display such behaviour as much or as frequently. © 2014 Nature Publishing Group,
By MOISES VELASQUEZ-MANOFF WHEN Andre H. Lagrange, a neurologist at Vanderbilt University in Nashville, saw the ominous white spots on the patient’s brain scan, he considered infection or lymphoma, a type of cancer. But tests ruled out both. Meanwhile, anti-epilepsy drugs failed to halt the man’s seizures. Stumped, Dr. Lagrange turned to something the mother of the 30-year-old man kept repeating. The fits coincided, she insisted, with spells of constipation and diarrhea. That, along with an odd rash, prompted Dr. Lagrange to think beyond the brain. Antibody tests, followed by an intestinal biopsy, indicated celiac disease, an autoimmune disorder of the gut triggered by the gluten proteins in wheat and other grains. Once on a gluten-free diet, the man’s seizures stopped; those brain lesions gradually disappeared. He made a “nearly complete recovery,” Dr. Lagrange told me. I began encountering case descriptions like this some years ago as I researched autoimmune disease. The first few seemed like random noise in an already nebulous field. But as I amassed more — describing seizures, hallucinations, psychotic breaks and even, in one published case, what looked like regressive autism, all ultimately associated with celiac disease — they began to seem less like anomalies, and more like a frontier in celiac research. They tended to follow a similar plot. What looked like neurological or psychiatric symptoms appeared suddenly. The physician ran through a diagnostic checklist without success. Drugs directed at the brain failed. Some clue suggestive of celiac disease was observed. The diagnosis was made. And the patient recovered on a gluten-free diet. The cases highlighted, in an unusually concrete fashion, the so-called gut-brain axis. The supposed link between the intestinal tract and the central nervous system is much discussed in science journals, often in the context of the microbial community inhabiting the gut. But it’s unclear how, really, we can leverage the link to improve health. © 2014 The New York Times Company
Link ID: 20200 - Posted: 10.13.2014
by Mallory Locklear Do you have an annoying friend who loves bungee jumping or hang-gliding, and is always blathering on about how it never scares them? Rather than being a macho front, their bravado may have a biological basis. Research from Stony Brook University in New York shows that not all risk-takers are cut from the same cloth. Some actually seem to feel no fear – or at least their bodies and brains don't respond to danger in the usual way. The study is the first to attempt to tease apart the differences in the risk-taking population. In order to ensure every participant was a card-carrying risk-taker, the team led by Lilianne Mujica-Parodi, recruited 30 first-time skydivers. "Most studies on sensation-seeking compare people who take risks and people who don't. We were interested in something more subtle – those who take risks adaptively and those who do so maladaptively." In other words, do all risk-takers process potential danger in the same way or do some ignore the risks more than others? To find out, the researchers got their participants to complete several personality questionnaires, including one that asked them to rank how well statements such as, "The greater the risk the more fun the activity," described them. Next, the team used fMRI imaging to observe whether the participants' corticolimbic brain circuit – which is involved in risk assessment - was well-regulated. A well-regulated circuit is one that reacts to a threat and then returns to a normal state afterwards. © Copyright Reed Business Information Ltd
By ALINA TUGEND MANY workers now feel as if they’re doing the job of three people. They are on call 24 hours a day. They rush their children from tests to tournaments to tutoring. The stress is draining, both mentally and physically. At least that is the standard story about stress. It turns out, though, that many of the common beliefs about stress don’t necessarily give the complete picture. MISCONCEPTION NO. 1 Stress is usually caused by having too much work. While being overworked can be overwhelming, research increasingly shows that being underworked can be just as challenging. In essence, boredom is stressful. “We tend to think of stress in the original engineering way, that too much pressure or too much weight on a bridge causes it to collapse,” said Paul E. Spector, a professor of psychology at the University of South Florida. “It’s more complicated than that.” Professor Spector and others say too little to do — or underload, as he calls it — can cause many of the physical discomforts we associate with being overloaded, like muscle tension, stomachaches and headaches. A study published this year in the journal Experimental Brain Research found that measurements of people’s heart rates, hormonal levels and other factors while watching a boring movie — men hanging laundry — showed greater signs of stress than those watching a sad movie. “We tend to think of boredom as someone lazy, as a couch potato,” said James Danckert, a professor of neuroscience at the University of Waterloo in Ontario, Canada, and a co-author of the paper. “It’s actually when someone is motivated to engage with their environment and all attempts to do so fail. It’s aggressively dissatisfying.” © 2014 The New York Times Company
|By Daisy Yuhas Do we live in a holographic universe? How green is your coffee? And could drinking too much water actually kill you? Before you click those links you might consider how your knowledge-hungry brain is preparing for the answers. A new study from the University of California, Davis, suggests that when our curiosity is piqued, changes in the brain ready us to learn not only about the subject at hand, but incidental information, too. Neuroscientist Charan Ranganath and his fellow researchers asked 19 participants to review more than 100 questions, rating each in terms of how curious they were about the answer. Next, each subject revisited 112 of the questions—half of which strongly intrigued them whereas the rest they found uninteresting—while the researchers scanned their brain activity using functional magnetic resonance imaging (fMRI). During the scanning session participants would view a question then wait 14 seconds and view a photograph of a face totally unrelated to the trivia before seeing the answer. Afterward the researchers tested participants to see how well they could recall and retain both the trivia answers and the faces they had seen. Ranganath and his colleagues discovered that greater interest in a question would predict not only better memory for the answer but also for the unrelated face that had preceded it. A follow-up test one day later found the same results—people could better remember a face if it had been preceded by an intriguing question. Somehow curiosity could prepare the brain for learning and long-term memory more broadly. The findings are somewhat reminiscent of the work of U.C. Irvine neuroscientist James McGaugh, who has found that emotional arousal can bolster certain memories. But, as the researchers reveal in the October 2 Neuron, curiosity involves very different pathways. © 2014 Scientific American
Helen Thomson You'll have heard of Pavlov's dogs, conditioned to expect food at the sound of a bell. You might not have heard that a scarier experiment – arguably one of psychology's most unethical – was once performed on a baby. In it, a 9-month-old, at first unfazed by the presence of animals, was conditioned to feel fear at the sight of a rat. The infant was presented with the animal as someone struck a metal pole with a hammer above his head. This was repeated until he cried at merely the sight of any furry object – animate or inanimate. The "Little Albert" experiment, performed in 1919 by John Watson of Johns Hopkins University Hospital in Baltimore, Maryland, was the first to show that a human could be classically conditioned. The fate of Albert B has intrigued researchers ever since. Hall Beck at the Appalachian State University in Boone, North Carolina, has been one of the most tenacious researchers on the case. Watson's papers stated that Albert B was the son of a wet nurse who worked at the hospital. Beck spent seven years exploring potential candidates and used facial analysis to conclude in 2009 that Little Albert was Douglas Merritte, son of hospital employee Arvilla. Douglas was born on the same day as Albert and several other points tallied with Watson's notes. Tragically, medical records showed that Douglas had severe neurological problems and died at an early age of hydrocephalus, or water on the brain. According to his records, this seems to have resulted in vision problems, so much so that at times he was considered blind. © Copyright Reed Business Information Ltd.
By Fredrick Kunkle Here’s something to worry about: A recent study suggests that middle-age women whose personalities tend toward the neurotic run a higher risk of developing Alzheimer’s disease later in life. The study by researchers at the University of Gothenburg in Sweden followed a group of women in their 40s, whose disposition made them prone to anxiety, moodiness and psychological distress, to see how many developed dementia over the next 38 years. In line with other research, the study suggested that women who were the most easily upset by stress — as determined by a commonly used personality test — were two times more likely to develop Alzheimer’s disease than women who were least prone to neuroticism. In other words, personality really is — in some ways — destiny. “Most Alzheimer’s research has been devoted to factors such as education, heart and blood risk factors, head trauma, family history and genetics,” study author Lena Johansson said in a written statement. “Personality may influence the individual’s risk for dementia through its effect on behavior, lifestyle or reactions to stress.” The researchers cautioned that the results cannot be extrapolated to men because they were not included in the study and that further work is needed to determine possible causes for the link. The study, which appeared Wednesday in the American Academy of Neurology’s journal, Neurology, examined 800 women whose average age in 1968 was 46 years to see whether neuroticism — which involves being easily distressed and subject to excessive worry, jealousy or moodiness — might have a bearing on the risk of dementia.
By Linda Carroll The debate over whether violent movies contribute to real-world mayhem may have just developed a wrinkle: New research suggests they might enhance aggression only in those already prone to it. Using PET scanners to peer into the brains of volunteers watching especially bloody movie scenes, researchers determined that the way a viewer’s brain circuitry responds to violent video depends upon whether the individual is aggressive by nature. The study was published Wednesday in PLOS One. “Just as beauty is in the eye of the beholder, environmental stimuli are in the brain of the beholder,” said Nelly Alia-Klein, the study’s lead author and an associate professor at the Friedman Brain Institute and the Icahn School of Medicine at Mount Sinai Hospital in New York City. To test the importance of personality, Alia-Klein and her colleagues rounded up 54 healthy men, some of whom had a history of getting into physical fights, while the others had no history of aggression. The researchers scanned the volunteers three times: doing nothing, watching emotionally charged video and viewing a violent movie. “It wasn’t the whole [violent] movie,” Alia-Klein said, “just the violent scenes, one after another after another.” Along with the brain scans, the researchers monitored blood pressure and asked about the viewers’ moods every 15 minutes.
Link ID: 20132 - Posted: 09.30.2014
By Erik Parens Will advances in neuroscience move reasonable people to abandon the idea that criminals deserve to be punished? Some researchers working at the intersection of psychology, neuroscience and philosophy think the answer is yes. Their reasoning is straightforward: if the idea of deserving punishment depends upon the idea that criminals freely choose their actions, and if neuroscience reveals that free choice is an illusion, then we can see that the idea of deserving punishment is nonsense. As Joshua Greene and Jonathan Cohen speculated in a 2004 essay: “new neuroscience will undermine people’s common sense, libertarian conception of free will and the retributivist thinking that depends on it, both of which have heretofore been shielded by the inaccessibility of sophisticated thinking about the mind and its neural basis.” Just as we need two eyes that integrate slightly different information about one scene to achieve visual depth perception, we need to view ourselves through two lenses to gain a greater depth of understanding of ourselves. This past summer, Greene and several other colleagues did empirical work that appears to confirm that 2004 speculation. The new work finds that when university students learn about “the neural basis of behavior” — quite simply, the brain activity underlying human actions —they become less supportive of the idea that criminals deserve to be punished. According to the study’s authors, once students are led to question the concept of free will — understood as the idea that humans “can generate spontaneous choices and actions not determined by prior events” — they begin to find the idea of “just deserts” untenable. “When genuine choice is deemed impossible, condemnation is less justified,” the authors write. © 2014 The New York Times Company
By Alyssa Abkowitz If you’re wary of investing in a certain stock or exchange-traded fund, it could be because of the your brain’s physical composition. In a recent study, 61 participants from the Northeastern U.S. were asked to choose between monetary options that differed in the level of risk. Questions included: “Would you prefer a 50 percent chance of receiving $5 or would you rather take a 13 percent chance of winning $50?” and “Would you prefer $10 for sure or a 50 percent chance of receiving $50?” Researchers found that individuals with more gray matter in a specific part of their brains tend to tolerate more financial risks, says Agnieszka Tymula, an economist at the University of Sydney and co-author of the findings. Most of the participants answered questions while their brains were being scanned, while others received MRIs afterward (the timing doesn’t make a difference because the researchers were looking at brain structure, not brain function). The study involved measuring the volume of gray matter, or the outer layer of the brain, in the right posterior parietal region of the cortex. Thicker gray matter corresponded to riskier responses. Tymula worked with researchers from Yale University, University College London, New York University, and the University of Pennsylvania. Their findings, published in the Journal of Neuroscience this month, dovetail with previous work in which Tymula found that adults become more risk-averse as they age. Other neuroscience research shows that people’s cortexes become thinner as they get older, meaning there could be a link between a thinning cortex and risk aversion. ©2014 Bloomberg L.P
by Laura Sanders Earlier this month, a star running back for the Minnesota Vikings was indicted for whipping his young son bloody with a switch. Leaked photographs allegedly showed Adrian Peterson’s 4-year-old son with cuts and bruises on his legs, back, buttocks and scrotum. As details about the incident emerged, Peterson took to Twitter to say that he’s not a perfect parent but what he did was not abuse. It was discipline. “My goal is always to teach my son right from wrong and that’s what I tried to do that day,” he wrote. Many people, and I’m one of them, that think Peterson’s actions were disgusting. There’s no way that hitting 4-year-old with a switch until his body is cut and bruised is a good way to impart values and morals. Peterson’s extreme actions, done in the name of corporal punishment, ignited a ferocious, emotionally fraught debate over whether it’s OK to hit your kid. The debate reflects deep divides in our society, chasms that track along political, religious, regional and racial lines. Half of all U.S. parents say they’ve spanked their kid. Spanking doesn’t just happen in the privacy of homes, either. Nineteen states allow teachers or principals to hit children. Opponents often point to scientific studies as proof that spanking is bad. And I confess, I originally thought this post was going to describe those results that we’ve all heard: how children who have been spanked are more aggressive and have more behavioral problems. But despite the headlines, the science behind spanking is actually quite limited, says clinical psychologist Christopher Ferguson of Stetson University in DeLand, Fla. “Because it’s a culture war issue, I think a lot of what we hear has misrepresented what is very nuanced science,” he says. © Society for Science & the Public 2000 - 2014.
|By Corinne Iozzio Albert “Skip” Rizzo of the University of Southern California began studying virtual reality (VR) as psychological treatment in 1993. Since then, dozens of studies, his included, have shown the immersion technique to be effective for everything from post-traumatic stress disorder (PTSD) and anxiety to phobias and addiction. But a lack of practical hardware has kept VR out of reach for clinicians. The requirements for a VR headset seem simple—a high-resolution, fast-reacting screen, a field of vision that is wide enough to convince patients they are in another world and a reasonable price tag— yet such a product has proved elusive. Says Rizzo, “It’s been 20 frustrating years.” In 2013 VR stepped into the consumer spotlight in the form of a prototype head- mounted display called the Oculus Rift. Inventor Palmer Luckey’s goal was to create a platform for immersive video games, but developers from many fields—medicine, aviation, tourism—are running wild with possibilities. The Rift’s reach is so broad that Oculus, now owned by Facebook, hosted a conference for developers in September. The Rift, slated for public release in 2015, is built largely from off- the-shelf parts, such as the screens used in smartphones. A multi- axis motion sensor lets the headset refresh imagery in real time as the wearer’s head moves. The kicker is the price: $350. (Laboratory systems start at $20,000.) Rizzo has been among the first in line. His work focuses on combat PTSD. In a 2010 study, he placed patients into controlled traumatic scenarios, including a simulated battlefield, so they could confront and process emotions triggered in those situations. © 2014 Scientific American
By Maria Konnikova At the turn of the twentieth century, Ivan Pavlov conducted the experiments that turned his last name into an adjective. By playing a sound just before he presented dogs with a snack, he taught them to salivate upon hearing the tone alone, even when no food was offered. That type of learning is now called classical—or Pavlovian—conditioning. Less well known is an experiment that Pavlov was conducting at around the same time: when some unfortunate canines heard the same sound, they were given acid. Just as their luckier counterparts had learned to salivate at the noise, these animals would respond by doing everything in their power to get the imagined acid out of their mouths, each “shaking its head violently, opening its mouth and making movements with its tongue.” For many years, Pavlov’s classical conditioning findings overshadowed the darker version of the same discovery, but, in the nineteen-eighties, the New York University neuroscientist Joseph LeDoux revived the technique to study the fear reflex in rats. LeDoux first taught the rats to associate a certain tone with an electric shock so that they froze upon hearing the tone alone. In essence, the rat had formed a new memory—that the tone signifies pain. He then blunted that memory by playing the tone repeatedly without following it with a shock. After multiple shock-less tones, the animals ceased to be afraid. Now a new generation of researchers is trying to figure out the next logical step: re-creating the same effects within the brain, without deploying a single tone or shock. Is memory formation now understood well enough that memories can be implanted and then removed absent the environmental stimulus?
by Bob Holmes THERE'S something primal in a mother's response to a crying infant. So primal, in fact, that mother deer will rush protectively to the distress calls of other infant mammals, such as fur seals, marmots and even humans. This suggests such calls might share common elements – and perhaps that these animals experience similar emotions. Researchers – and, indeed, all pet owners – know that humans respond emotionally to the distress cries of their domestic animals, and there is some evidence that dogs also respond to human cries. However, most people have assumed this is a by-product of domestication. However, Susan Lingle, a biologist at the University of Winnipeg, Canada, noticed that the infants of many mammal species have similar distress calls: simple sounds with few changes in pitch. She decided to test whether cross-species responses occur more widely across the evolutionary tree. So, Lingle and her colleague Tobias Riede, now at Midwestern University in Glendale, Arizona, recorded the calls made by infants from a variety of mammal species when separated from their mother or otherwise threatened. They then played the recordings through hidden speakers to wild mule deer (Odocoileus hemionus) out on the Canadian prairies. They found that deer mothers quickly moved towards the recordings of infant deer, but also towards those of infant fur seals, dogs, cats and humans, all of which call at roughly the same pitch. Even the ultrasonic calls of infant bats attracted the deer mothers if Lingle used software to lower their pitch to match that of deer calls. In contrast, they found the deer did not respond to non-infant calls such as birdsong or the bark of a coyote (American Naturalist, DOI: 10.1086/677677). © Copyright Reed Business Information Ltd.
By JAMES GORMAN Are chimpanzees naturally violent to one another, or has the intrusion of humans into their environment made them aggressive? A study published Wednesday in Nature is setting off a new round of debate on the issue. The study’s authors argue that a review of all known cases of when chimpanzees or bonobos in Africa killed members of their own species shows that violence is a natural part of chimpanzee behavior and not a result of actions by humans that push chimpanzee aggression to lethal attacks. The researchers say their analysis supports the idea that warlike violence in chimpanzees is a natural behavior that evolved because it could provide more resources or territory to the killers, at little risk. But critics say the data shows no such thing, largely because the measures of human impact on chimpanzees are inadequate. While the study is about chimpanzees, it is also the latest salvo in a long argument about the nature of violence in people. In studying chimpanzee violence, “we’re trying to make inferences about human evolution,” said Michael L. Wilson, an anthropologist at the University of Minnesota and a study organizer. There is no disagreement about whether chimpanzees kill one another, or about some of the claims that Dr. Wilson and his 29 co-authors make. The argument is about why chimpanzees kill. Dr. Wilson and the other authors, who contributed data on killings from groups at their study sites, say the evidence shows no connection between human impact on the chimpanzee sites and the number of killings. He said the Ngogo group of chimpanzees in Uganda “turned out to be the most violent group of chimpanzees there is,” even though the site was little disturbed by humans. They have a pristine habitat, he said, and “they go around and kill their neighbors.” © 2014 The New York Times Company
By John Horgan On this blog, in my book The End of War and elsewhere (see Further Reading and Viewing), I have knocked the deep roots theory of war, which holds that war stems from an instinct deeply embedded in the genes of our male ancestors. Inter-community killings are rare among chimpanzees and non-existent among bonobos, according to a new report in Nature, undercutting the theory that the roots of war extend back to the common ancestor of humans and chimps. Proponents of this theory—notably primatologist Richard Wrangham—claim it is supported by observations of inter-community killings by chimpanzees, Pan troglodytes, our closest genetic relatives. Skeptics, including anthropologists Robert Sussman and Brian Ferguson, have pointed out that chimpanzee violence might be not an adaptation but a response to environmental circumstances, such as human encroachment. This “human impacts” hypothesis is rejected in a new report in Nature by a coalition of 30 primatologists, including Wrangham and lead author Michael Wilson. In “Lethal aggression in Pan is better explained by adaptive strategies than human impacts,” Wilson et al. analyze 152 killings in 18 chimpanzee communities and find “little correlation with human impacts.” Given that the primary interest in chimp violence is its alleged support of the deep-roots theory, it might seem odd, at first, that Wilson et al. do not mention human warfare. Actually, this omission is wise, because the Nature report undermines the deep-roots theory of war, and establishes that the “human impact” issue is a red herring. © 2014 Scientific American,
|By Daniel A. Yudkin If you’re reading this at a desk, do me a favor. Grab a pen or pencil and hold the end between your teeth so it doesn’t touch your lips. As you read on, stay that way—science suggests you’ll find this article more amusing if you do. Why? Notice that holding a pencil in this manner puts your face in the shape of a smile. And research in psychology says that the things we do—smiling at a joke, giving a gift to a friend, or even running from a bear—influence how we feel. This idea—that actions affect feelings—runs counter to how we generally think about our emotions. Ask average folks how emotions work—about the causal relationship between feelings and behavior—and they’ll say we smile because we’re happy, we run because we’re afraid. But work by such psychologists as Fritz Strack, Antonio Damasio, Joe LeDoux shows the truth is often the reverse: what we feel is actually the product, not the cause, of what we do. It’s called “somatic feedback.” Only after we act do we deduce, by seeing what we just did, how we feel. This bodes well, at first blush, for anyone trying to change their emotions for the better. All you’d need to do is act like the kind of person you want to be, and that’s who you’ll become. (Call it the Bobby McFerrin philosophy: “Aren’t happy? Don’t worry. Just smile!”) But new research, published in the Journal of Experimental Social Psychology by Aparna Labroo, Anirban Mukhopadhyay, and Ping Dong suggests there may be limits to our ability to proactively manage our own well-being. The team ran a series of studies examining whether more smiling led to more happiness. One asked people how much smiling they had done that day, and how happy they currently felt. Other studies manipulated the amount of smiling people actually did, either by showing them a series of funny pictures or by replicating a version of the pencil-holding experiment. As expected, across these experiments, the researchers found that the more people smiled, the happier they reported being. © 2014 Scientific American
Link ID: 20085 - Posted: 09.17.2014
By Linda Searing THE QUESTION Benzodiazepines such as Valium, Xanax and Ativan, widely prescribed to relieve anxiety and alleviate insomnia, are known to affect memory and cognition in the short term. Might they also have a more serious, longer-term effect on the brain? THIS STUDY analyzed data on 8,990 adults older than 66, including 1,796 with Alzheimer’s disease. In a five-to-10-year span before the start of the study, 3,767 of the participants (52 percent) had taken benzodiazepines. Overall, those who had taken the drugs were 51 percent more likely to have Alzheimer’s than were those who had never taken benzodiazepines. The longer people took the drugs, the greater their risk for Alzheimer’s. Those who took the drugs for less than 90 days had essentially the same risk as those who never took them. But risk nearly doubled for people who took them for longer than six months. Risk also was greater for longer-acting vs. shorter-acting benzodiazepines. WHO MAY BE AFFECTED? Adults, especially older people, who take benzodiazepines. The drugs have a calming effect on the body and work quickly, unlike antidepressants, which can take weeks to have an effect. The American Geriatrics Society lists benzodiazepines as inappropriate for treating older people for insomnia or agitation because of their negative effect on cognition seen in that age group and an increased likelihood of falls and accidents. However, some recent estimates note that roughly half of older adults take benzodiazepines. CAVEATS Some study participants may have been prescribed benzodiazepines to treat early symptoms of unrecognized dementia, which can include depression, anxiety and sleep disorders; the study authors noted that use of the drugs “might be an early marker of a condition associated with an increased risk of dementia and not the cause.”
by Bethany Brookshire Post-traumatic stress disorder, or PTSD, has many different symptoms. Patients may suffer from anxiety, flashbacks, memory problems and a host of other reactions to a traumatic event. But one symptom is especially common: 70 percent of civilian patients and 90 percent of combat veterans with PTSD just can’t get a decent night’s sleep. Problems with sleep, including rapid-eye movement — or REM — sleep, have long been associated with PTSD. “We know that sleep difficulties in the weeks following trauma predict the development of PTSD, and we know that bad sleep makes PTSD symptoms worse,” says Sean Drummond, a clinical psychologist who studies sleep at the University of California at San Diego. Studies in rats show that exposing the animals to traumatic, fearful experiences such as foot shocks disrupts their REM sleep. Drummond and his research assistant Anisa Marshall wanted to connect those findings to humans. But he soon found out that in humans, it’s not fear that predicts REM sleep. Instead, it’s safety. The scientists tested this in 42 people without PTSD using a measure called fear-potentiated startle. Subjects sit in a comfortable chair with an electrode on their wrists. A screen shows blue squares or yellow squares. If participants see blue squares, they run a high risk of receiving an annoying shock to the wrist. If they see yellow squares, they can relax; no shocks are headed their way. During this time, they will also hear random, loud bursts of white noise. The scientists measure how much the subjects startle in response to the noise by measuring the strength of their eyeblinks in response to the noise. In the presence of the blue squares, the blinks become much stronger, an effect called fear-potentiated startle. With yellow squares, the blinks weaken. © Society for Science & the Public 2000 - 2014.
By Smitha Mundasad Health reporter, BBC News Giving young people Botox treatment may restrict their emotional growth, experts warn. Writing in the Journal of Aesthetic Nursing, clinicians say there is a growing trend for under-25s to seek the wrinkle-smoothing injections. But the research suggests "frozen faces" could stop young people from learning how to express emotions fully. A leading body of UK plastic surgeons says injecting teenagers for cosmetic reasons is "morally wrong". Botox and other versions of the toxin work by temporarily paralysing muscles in the upper face to reduce wrinkling when people frown. Nurse practitioner Helen Collier, who carried out the research, says reality TV shows and celebrity culture are driving young people to idealise the "inexpressive frozen face." But she points to a well-known psychological theory, the facial feedback hypothesis, that suggests adolescents learn how best to relate to people by mimicking their facial expressions. She says: "As a human being our ability to demonstrate a wide range of emotions is very dependent on facial expressions. "Emotions such as empathy and sympathy help us to survive and grow into confident and communicative adults." But she warns that a "growing generation of blank-faced" young people could be harming their ability to correctly convey their feelings. "If you wipe those expressions out, this might stunt their emotional and social development," she says. The research calls for practitioners to use assessment tools to decide whether there are clear clinical reasons for Botox treatment. BBC © 2014
Link ID: 20070 - Posted: 09.13.2014