Chapter 15. Emotions, Aggression, and Stress

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By Laura Sanders Although it’s tricky for us humans to see, mouse feelings are written all over their furry little faces. With machine learning tools, researchers reliably spotted mice’s expressions of joy, fear, pain and other basic emotions. The results, published in the April 3 Science, provide a field guide for scientists seeking to understand how emotions such as joy, regret and empathy work in animals other than humans (SN: 11/10/16; SN: 6/9/14; SN: 12/8/11). Using machine learning to reveal mice’s expressions is “an extraordinarily exciting direction,” says Kay Tye, a neuroscientist at the Salk Institute for Biological Studies in La Jolla, Calif. The findings “lay the foundation for what I expect will be a game changer for neuroscience research on emotional states.” Neuroscientist Nadine Gogolla of the Max Planck Institute of Neurobiology in Martinsried, Germany, and colleagues gave mice experiences designed to elicit distinct emotions. Sugar water evoked pleasure, a shock to the tail triggered pain, bitter quinine water created disgust, an injection of lithium chloride evoked a nauseated malaise, and a place where shocks previously had been delivered sparked fear. For each setup, high-speed video cameras captured subtle movements in the mice’s ears, noses, whiskers and other parts of the face. Observers can generally see that something is happening on the mouse’s face, Gogolla says. But translating those subtle clues into emotions is really hard, “especially for an untrained human being,” she says. © Society for Science & the Public 2000–2020

Keyword: Emotions; Evolution
Link ID: 27168 - Posted: 04.03.2020

By Katherine Rosman The coronavirus outbreak has turned many of us into nervous germophobes, seeking to protect ourselves from infection by washing our hands methodically and frequently, avoiding unnecessary contact with so called high-touch surfaces and methodically sanitizing packages, our homes and our bodies. For people diagnosed with obsessive-compulsive disorder, or O.C.D., the worry created by the threat of coronavirus has the potential for more intense and longer-lasting implications. According to the International OCD Foundation, there are about three million Americans who have been diagnosed with O.C.D. It’s a condition characterized by unwanted thoughts or urges that generate high levels of anxiety and repetitive acts meant to neutralize the obsessional thought. The cleaning and sanitizing practices that help prevent coronavirus infection are bringing people with O.C.D. into closer orbit to behaviors that are a gateway to detrimental patterns that could interfere with their ability to engage meaningfully with the world outside their homes for years to come. Courtenay Patlin, a 28-year-old in Los Angeles, is trying to find balance between appropriate caution and overreaction. Several weeks ago, before the California shelter-in-place order, Ms. Patlin decided to mostly stay indoors. She had read enough about how quickly coronavirus had spread in China, Italy and then Seattle, and how very sick it was making so many. She felt she could rely on only herself and her Clorox to stay healthy. “I keep a very clean apartment, and I feel safe at home,” she said. Ms. Patlin, a graduate student studying clinical psychology, was diagnosed with O.C.D. about five years ago, she said, after years of being afraid of public toilets, refusing to eat off dishes that she hadn’t scrubbed herself or witnessed being sufficiently cleaned by others and being fearful of being hugged by basically anyone. ImageMs. Patlin’s hands. She used to clean her hands and apartment with pure bleach and cleaning solutions until the skin on her fingers started to peel off, which she would take as a sign that she was cleaning the proper amount. © 2020 The New York Times Company

Keyword: OCD - Obsessive Compulsive Disorder
Link ID: 27167 - Posted: 04.03.2020

By Roni Caryn Rabin Neurologists around the world say that a small subset of patients with Covid-19 are developing serious impairments of the brain. Although fever, cough and difficulty breathing are the typical hallmarks of infection with the new coronavirus, some patients exhibit altered mental status, or encephalopathy, a catchall term for brain disease or dysfunction that can have many underlying causes, as well as other serious conditions. These neurological syndromes join other unusual symptoms, such as diminished sense of smell and taste as well as heart ailments. In early March, a 74-year-old man came to the emergency room in Boca Raton, Fla., with a cough and a fever, but an X-ray ruled out pneumonia and he was sent home. The next day, when his fever spiked, family members brought him back. He was short of breath, and could not tell doctors his name or explain what was wrong — he had lost the ability to speak. The patient, who had chronic lung disease and Parkinson’s, was flailing his arms and legs in jerky movements, and appeared to be having a seizure. Doctors suspected he had Covid-19, and were eventually proven right when he was finally tested. On Tuesday, doctors in Detroit reported another disturbing case involving a female airline worker in her late 50s with Covid-19. She was confused, and complained of a headache; she could tell the physicians her name but little else, and became less responsive over time. Brain scans showed abnormal swelling and inflammation in several regions, with smaller areas where some cells had died. Physicians diagnosed a dangerous condition called acute necrotizing encephalopathy, a rare complication of influenza and other viral infections. “The pattern of involvement, and the way that it rapidly progressed over days, is consistent with viral inflammation of the brain,” Dr. Elissa Fory, a neurologist with Henry Ford Health System, said through an email. “This may indicate the virus can invade the brain directly in rare circumstances.” The patient is in critical condition. © 2020 The New York Times Company

Keyword: Neuroimmunology; Stroke
Link ID: 27164 - Posted: 04.03.2020

By Elizabeth Pennisi Males resort to all sorts of desperate measures when fertile females are scarce, including banding together to guard a potential mate. Now, researchers have discovered that such bands of bottlenose dolphins may coordinate their actions with unique “popping” calls—the first evidence that animals other than humans can synchronize themselves using vocal signals. Humans often use vocal signals to coordinate actions, like marching and dancing, that reinforce unity and intimidate outside groups. The synchronized displays of other animals—like fireflies that light up at the same time—are thought to be competitive, showing off which male is the sexiest, rather than cooperative. In Shark Bay, off the coast Western Australia 800 kilometers north of Perth, groups of up to 14 male dolphins form lifelong alliances. Together, subsets of three keep close tabs on potential female mates, swimming, turning, and surfacing in unison to guard and herd them—one female at a time. Scientists watching this behavior noticed these males often emit a unique “popping” call, making series of two to 49 very short sounds, 10 per second, over and over. e dolphins popping The scientists dragged four underwater microphones behind a motorboat and recorded 172 instances in which multiple males were “popping” together (above). When the males pop alone, their timing and tempo varies. But when they pop together, they do it at the same time and at the same rate, suggesting they are using the sounds to enhance their cooperation, the team reports today in the Proceedings of the Royal Society B. This synchronized popping may be a threat, as it tends to make the female dolphin move closer to her male guards. But more importantly, the researchers say, it may help reinforce that the males need to act—and talk—as one to ensure they get their gal. © 2020 American Association for the Advancement of Science

Keyword: Sexual Behavior; Aggression
Link ID: 27156 - Posted: 04.01.2020

By Douglas Starr When Jennifer Eberhardt appeared on The Daily Show with Trevor Noah in April 2019, she had a hard time keeping a straight face. But some of the laughs were painful. Discussing unconscious racial bias, which she has studied for years, the Stanford University psychologist mentioned the “other-race effect,” in which people have trouble recognizing faces of other racial groups. Criminals have learned to exploit the effect, she told Noah. In Oakland, California, a gang of black teenagers caused a mini–crime wave of purse snatchings among middle-aged women in Chinatown. When police asked the teens why they targeted that neighborhood, they said the Asian women, when faced with a lineup, “couldn’t tell the brothers apart.” “That is one of the most horrible, fantastic stories ever!” said Noah, a black South African. But it was true. Eberhardt has written that the phrase “they all look alike,” long the province of the bigot, “is actually a function of biology and exposure.” There’s no doubt plenty of overt bigotry exists, Eberhardt says; but she has found that most of us also harbor bias without knowing it. It stems from our brain’s tendency to categorize things—a useful function in a world of infinite stimuli, but one that can lead to discrimination, baseless assumptions, and worse, particularly in times of hurry or stress. Over the decades, Eberhardt and her Stanford team have explored the roots and ramifications of unconscious bias, from the level of the neuron to that of society. In cleverly designed experiments, she has shown how social conditions can interact with the workings of our brain to determine our responses to other people, especially in the context of race. Eberhardt’s studies are “strong methodologically and also super real-world relevant,” says Dolly Chugh of New York University’s Stern School of Business, a psychologist who studies decision-making. © 2020 American Association for the Advancement of Science.

Keyword: Attention; Emotions
Link ID: 27145 - Posted: 03.27.2020

By Monica Schoch-Spana The novel coronavirus has touched off another stealthy and growing public health crisis that calls for an equally matched emergency response. Like other pandemics and emerging disease outbreaks, COVID-19 is creating immense psychosocial disturbances. The disease involves an unfamiliar threat that is difficult to detect and challenging to distinguish from more benign illnesses. Protracted and dynamic pandemic conditions will draw out the anxiety. Things will get worse before they get better. Absent a vaccine, nonpharmaceutical interventions are the only way to prevent infections, and they dramatically upset everyday bodily habits, social interactions and economic exchanges. Recent grocery store runs are a sign of concern in the community. Personal actions to avoid infection such as stockpiling hand sanitizer also confer a sense of control over an uncertain danger. Improvements to current risk communication can alleviate widespread distress. Top elected officials and health authorities should empathize with people’s fear, normalize stress reactions, provide clear guidance on recommended health behaviors, instruct in concrete protections including those for mental health and share solidarity and resilience messages. Advertisement However, more interventions are essential because specific groups are at a higher risk of both acute and lingering emotional distress. Health care workers on the epidemic front lines face compounding stressors: the prospect of more and longer shifts, the need to improvise childcare coverage, finite supplies of personal protective equipment, fear of bringing infection home, witnessing co-workers becoming ill, and making tough allocation decisions about scarce, lifesaving resources like mechanical ventilators. © 2020 Scientific American

Keyword: Emotions
Link ID: 27131 - Posted: 03.21.2020

Jonathan Kanter and Adam Kuczynski To fight the spread of coronavirus, government officials have asked Americans to swallow a hard pill: Stay away from each other. In times of societal stress, such a demand runs counter to what evolution has hard-wired people to do: Seek out and support each other as families, friends and communities. We yearn to huddle together. The warmth of our breath and bodies, of holding hands and hugging, of talking and listening, is a primary source of soothing. These connections are pivotal for responding to and maximizing our survival in times of stress. Priority number one is to follow the recommended social distancing guidelines to control the virus. The cure is definitely not worse than the disease – experts’ projections of disease spread and mortality without strong intervention make this clear. But as with any pill, there are side effects. As psychological scientists at the University of Washington’s Center for the Science of Social Connection, our lab studies social connectedness, why it is important and how to maximize its benefits. Our clinical and research experiences help us understand the side effects of social distancing and suggest strategies for addressing them. In times of stress and illness, being deprived of social connection can create more stress and illness. People who are lonely have higher levels of the hormone cortisol, an indicator of stress; show weaker immune responses to pathogens; and are at increased risk for premature death. Isolation can lead to depression, suicidal thoughts and other clinical conditions. © 2010–2020, The Conversation US, Inc.

Keyword: Stress
Link ID: 27127 - Posted: 03.17.2020

By Judson A. Brewer, M.D. Anxiety is a strange beast. As a psychiatrist, I have learned that anxiety and its close cousin, panic, are both born from fear. As a behavioral neuroscientist, I know that fear’s main evolutionary function is helping us survive. In fact, fear is the oldest survival mechanism we have. Fear helps us learn to avoid dangerous situations in the future through a process called negative reinforcement. For example, if we step out into a busy street, turn our head and see a car coming right at us, we instinctively jump back onto the safety of the sidewalk. Evolution made this really simple for us. So simple that we only need three elements in situations like this to learn: an environmental cue, a behavior and a result. In this case, walking up to a busy street cues us to look both ways before crossing. The result of not getting killed helps us remember to repeat the action again in the future. Sometime in the last million years, humans evolved a new layer on top of our more primitive survival brain, called the prefrontal cortex. Involved in creativity and planning, the prefrontal cortex helps us think and plan for the future. It predicts what will happen in the future based on past experience. If information is lacking, our prefrontal cortex lays out different scenarios about what might happen, and guesses which will be most likely. It does this by running simulations based on previous events that are most similar. Defined as “a feeling of worry, nervousness or unease, typically about an imminent event or something with an uncertain outcome,” anxiety comes up when our prefrontal cortexes don’t have enough information to accurately predict the future. We see this right now with coronavirus. Without accurate information, it is easy for our brains to spin stories of fear and dread. © 2020 The New York Times Company

Keyword: Emotions; Stress
Link ID: 27117 - Posted: 03.14.2020

By Liz Langley It might be time to reconsider what it means to call someone a “rat.” Previous research has shown the much-maligned rodents assist comrades in need, as well as remember individual rats that have helped them—and return the favor. Now, a new study builds on this evidence of empathy, revealing that domestic rats will avoid harming other rats. In the study, published March 5 in the journal Current Biology, rats were trained to pull levers to get a tasty sugar pellet. If the lever delivered a mild shock to a neighbor, several of the rats stopped pulling that lever and switched to another. Harm aversion, as it's known, is a well-known human trait regulated by a part of the brain called the anterior cingulate cortex (ACC). Further experiments showed the ACC controls this behavior in rats, too. This is the first time scientists have found the ACC is necessary for harm aversion in a non-human species. This likeness between human and rat brains is “super-exciting for two reasons,” says study co-author Christian Keysers, of the Netherlands Institute for Neuroscience. For one, it suggests that preventing harm to others is rooted deep in mammals' evolutionary history. (See what a rat looks like when it’s happy.) What’s more, the finding could have a real impact on people suffering from psychiatric disorders such as psychopathy and sociopathy, whose anterior cingulate cortexes are impaired. “We currently have no effective drugs to reduce violence in antisocial populations,” Keysers says, and figuring out how to increase such patients’ aversion to hurting others could be a powerful tool.

Keyword: Attention; Emotions
Link ID: 27101 - Posted: 03.07.2020

By Michael Price Every Fourth of July, the thunderous crack of my neighbors’ fireworks is quickly followed by the wailing chorus of frightened dogs, including my own two mixed-breed pups. New research suggests Pico’s and Winnie’s sensitivity to noise, especially fireworks, is the most common form of anxiety in pet dogs. The study—the largest ever on canine temperaments—also finds that some breeds are prone to certain anxious behaviors, including aggression, separation anxiety, and fear. The results could help uncover new ways to tackle these traits. Anecdotes on dog behavior abound, but reliable scientific data are lacking, says Hannes Lohi, a canine geneticist at the University of Helsinki. That’s particularly an issue when looking at problem behaviors that can put dogs at higher risk of being euthanized or winding up in shelters. So Lohi and colleagues contacted Finnish dog breed clubs and reached out to dog owners around the world through social media, asking owners to rate their dogs’ behavior on seven different anxiety-related traits: noise sensitivity, general fear, fear of heights and surfaces (like reflective tiles), inattention, compulsive behaviors (like relentless chewing or tail chasing), aggression, and separation anxiety. They received more than 13,700 responses representing 264 breeds. To make reliable comparisons, the researchers limited themselves to the 14 breeds with 200 or more surveyed dogs. © 2020 American Association for the Advancement of Science.

Keyword: Emotions; Genes & Behavior
Link ID: 27099 - Posted: 03.06.2020

Katarina Zimmer Long believed to be simple, pathogen-eating immune cells, macrophages have a far more extensive list of job duties. They appear to have specialized functions across body tissues, help repair damaged tissue, play a key role in regulating inflammation and pain, and participate in other roles scientists are just beginning to reveal. Now, a group of researchers in the Netherlands has identified a mechanism by which macrophages may help resolve inflammatory pain in mice. In a study recently posted as a preprint to bioRxiv, they report that the immune cells shuttle mitochondria to sensory neurons that innervate inflamed tissue, and that this helps resolve pain. The researchers speculate that the mechanism could replenish functional mitochondria in neurons during chronic inflammatory conditions, which is associated with dysfunctional mitochondria. “I think the transfer of mitochondria is quite convincing,” Jan Van den Bossche, an immunologist at Amsterdam University Medical Center who wasn’t involved in the research, writes to The Scientist in an email. If the findings can be replicated, “this could have [implications for] many diseases with chronic inflammation and pain,” he adds. The research is the result of a five-year project that began when Niels Eijkelkamp, a neuroimmunologist at the University Medical Center Utrecht, and his colleagues started investigating how inflammatory pain resolves, “so we could understand what causes chronic pain,” he says. © 1986–2020 The Scientist

Keyword: Glia; Pain & Touch
Link ID: 27097 - Posted: 03.06.2020

By Matthew Cobb We are living through one of the greatest of scientific endeavours – the attempt to understand the most complex object in the universe, the brain. Scientists are accumulating vast amounts of data about structure and function in a huge array of brains, from the tiniest to our own. Tens of thousands of researchers are devoting massive amounts of time and energy to thinking about what brains do, and astonishing new technology is enabling us to both describe and manipulate that activity. A neuroscientist explains: the need for ‘empathetic citizens’ - podcast We can now make a mouse remember something about a smell it has never encountered, turn a bad mouse memory into a good one, and even use a surge of electricity to change how people perceive faces. We are drawing up increasingly detailed and complex functional maps of the brain, human and otherwise. In some species, we can change the brain’s very structure at will, altering the animal’s behaviour as a result. Some of the most profound consequences of our growing mastery can be seen in our ability to enable a paralysed person to control a robotic arm with the power of their mind. Every day, we hear about new discoveries that shed light on how brains work, along with the promise – or threat – of new technology that will enable us to do such far-fetched things as read minds, or detect criminals, or even be uploaded into a computer. Books are repeatedly produced that each claim to explain the brain in different ways. And yet there is a growing conviction among some neuroscientists that our future path is not clear. It is hard to see where we should be going, apart from simply collecting more data or counting on the latest exciting experimental approach. As the German neuroscientist Olaf Sporns has put it: “Neuroscience still largely lacks organising principles or a theoretical framework for converting brain data into fundamental knowledge and understanding.” Despite the vast number of facts being accumulated, our understanding of the brain appears to be approaching an impasse. © 2020 Guardian News & Media Limited

Keyword: Robotics
Link ID: 27084 - Posted: 02.28.2020

Douglas Heaven Human faces pop up on a screen, hundreds of them, one after another. Some have their eyes stretched wide, others show lips clenched. Some have eyes squeezed shut, cheeks lifted and mouths agape. For each one, you must answer this simple question: is this the face of someone having an orgasm or experiencing sudden pain? Psychologist Rachael Jack and her colleagues recruited 80 people to take this test as part of a study1 in 2018. The team, at the University of Glasgow, UK, enlisted participants from Western and East Asian cultures to explore a long-standing and highly charged question: do facial expressions reliably communicate emotions? Researchers have been asking people what emotions they perceive in faces for decades. They have questioned adults and children in different countries and Indigenous populations in remote parts of the world. Influential observations in the 1960s and 1970s by US psychologist Paul Ekman suggested that, around the world, humans could reliably infer emotional states from expressions on faces — implying that emotional expressions are universal2,3. These ideas stood largely unchallenged for a generation. But a new cohort of psychologists and cognitive scientists has been revisiting those data and questioning the conclusions. Many researchers now think that the picture is a lot more complicated, and that facial expressions vary widely between contexts and cultures. Jack’s study, for instance, found that although Westerners and East Asians had similar concepts of how faces display pain, they had different ideas about expressions of pleasure. © 2020 Springer Nature Limited

Keyword: Emotions
Link ID: 27079 - Posted: 02.27.2020

Researchers at the National Institutes of Health found evidence that specific immune cells may play a key role in the devastating effects of cerebral malaria, a severe form of malaria that mainly affects young children. The results, published in the Journal of Clinical Investigation, suggest that drugs targeting T cells may be effective in treating the disease. The study was supported by the NIH Intramural Research Program. “This is the first study showing that T cells target blood vessels in brains of children with cerebral malaria,” said Dorian McGavern, Ph.D., chief of the Viral Immunology and Intravital Imaging Section at the NIH’s National Institute of Neurological Disorders and Stroke (NINDS) who co-directed the study with Susan Pierce, Ph.D., chief of the Laboratory of Immunogenetics at the National Institute of Allergy and Infectious Diseases (NIAID). “These findings build a bridge between mouse and human cerebral malaria studies by implicating T cells in the development of disease pathology in children. It is well established that T cells cause the brain vasculature injury associated with cerebral malaria in mice, but this was not known in humans.” More than 200 million people worldwide are infected annually with mosquito-borne parasites that cause malaria. In a subset of those patients, mainly young children, the parasites accumulate in brain blood vessels causing cerebral malaria, which leads to increased brain pressure from swelling. Even with available treatment, cerebral malaria still kills up to 25% of those affected resulting in nearly 400,000 deaths annually. Children who survive the infection will often have long-lasting neurological problems such as cognitive impairment.

Keyword: Neuroimmunology
Link ID: 27049 - Posted: 02.19.2020

Nicola Davis Parents should not worry about their teenagers’ delinquent behaviour provided they were well behaved in their earlier childhood, according to researchers behind a study that suggests those who offend throughout their life showed antisocial behaviour from a young age and have a markedly different brain structure as adults. According to figures from the Ministry of Justice, 24% of males in England and Wales aged 10–52 in 2006 had a conviction, compared with 6% of females. Previous work has shown that crime rises in adolescence and young adulthood but that most perpetrators go on to become law-abiding adults, with only a minority – under 10% of the general population – continuing to offend throughout their life. Such trends underpin many modern criminal justice strategies, including in the UK where police can use their discretion as to whether to a young offender should enter the formal justice system. Now researchers say they have found that adults with a long history of offences show striking differences in brain structure compared with those who have stuck to the straight and narrow or who transgressed only as adolescents. “These findings underscore prior research that really highlights that there are different types of young offenders – they are not all the same. They should not all be treated the same,” said Prof Essi Viding, a co-author of the study from University College London. Prof Terrie Moffitt, another co-author of the research from Duke University in North Carolina, said the study helped to shed light on what may be behind persistent antisocial behaviour. © 2020 Guardian News & Media Limited

Keyword: Aggression; Brain imaging
Link ID: 27048 - Posted: 02.18.2020

By Laura Sanders SEATTLE — Live bits of brain look like any other piece of meat — pinkish, solid chunks of neural tissue. But unlike other kinds of tissue or organs donated for research, they hold the memories, thoughts and feelings of a person. “It is identified with who we are,” Karen Rommelfanger, a neuroethicist at Emory University in Atlanta, said February 13 in a news conference at the annual meeting of the American Association for the Advancement of Science. That uniqueness raises a whole new set of ethical quandaries when it comes to experimenting with living brain tissue, she explained. Such donations are crucial to emerging research aimed at teasing out answers to what makes us human. For instance, researchers at the Seattle-based Allen Institute for Brain Science conduct experiments on live brain tissue to get clues about how the cells in the human brain operate (SN: 8/7/19). These precious samples, normally discarded as medical waste, are donated by patients undergoing brain surgery and raced to the lab while the nerve cells are still viable. Other experiments rely on systems that are less sophisticated than a human brain, such as brain tissue from other animals and organoids. These clumps of neural tissue, grown from human stem cells, are still a long way from mimicking the complexities of the human brain (SN: 10/24/19). But with major advances, these systems might one day be capable of much more advanced behavior, which might ultimately lead to awareness, a conundrum that raises ethical issues. © Society for Science & the Public 2000–2020

Keyword: Consciousness; Emotions
Link ID: 27047 - Posted: 02.18.2020

By Jade Wu 3 Anxiety-Related Disorders You Might Not Know About Person suffering from trichotillomania, an obsessive compulsive condition where sufferers can't resist pulling their hair out. Credit: Ryan Jackson Getty Images Most people know what it’s like to feel anxious. That tension in your muscles, those butterflies in your stomach, and the drumming of your heart tells you that you’re not calm. And this is totally normal. Where would we be if genuinely dangerous situations like dark alleys at night didn’t give us the heebie-jeebies? And would we take important tasks very seriously if we didn’t get nervous in the spotlight, like when giving a wedding toast? Sometimes, anxiety goes too far and gets in the way of our everyday functioning. It can mess up our health, relationships, work, and fun. It’s not hard to imagine the pain of being plagued by non-stop worries or feeling so shy as to have trouble with dating. But sometimes, anxiety and anxiety-related processes can show up in more unusual ways, even ways that don’t seem at first to have anything to do with emotions. The Diagnostic and Statistics Manual - 5th Edition is the official American Psychiatric Association’s list of psychological disorders. It’s a huge bible detailing everything that’s considered a disorder and how it’s categorized. It takes experts years to update it in response to ongoing scientific findings. Advertisement The Anxiety Disorders section got a big makeover in the last update, which came out in 2013. It’s now split into a few different sections, including Trauma and Stress-Related Disorders and Obsessive-Compulsive Disorders. Some of the less common disorders got shuffled around, some got new names, but experts still agree that the line between categories is blurry at best. Overlapping and related to some of the most common anxiety disorders, such as generalized anxiety disorder and social anxiety disorder, are some that are less well-known.

Keyword: Stress; Emotions
Link ID: 27041 - Posted: 02.14.2020

By Randi Hutter Epstein It was a staple of medical thinking dating to the 1910s that stress was the body’s alarm system, switching on only when terrible things happened, often leaving a person with an either-or choice: fight or flight. The neuroscientist Bruce S. McEwen trailblazed a new way of thinking about stress. Beginning in the 1960s, he redefined it as the body’s way of constantly monitoring daily challenges and adapting to them. Dr. McEwen, who died on Jan. 2 at 81, described three forms of stress: good stress — a response to an immediate challenge with a burst of energy that focuses the mind; transient stress — a response to daily frustrations that resolve quickly; and chronic stress — a response to a toxic, unrelenting barrage of challenges that eventually breaks down the body. It was Dr. McEwen’s research into chronic stress that proved groundbreaking. He and his research team at Rockefeller University in Manhattan discovered in 1968 that stress hormones had a profound effect on the brain. In studies using animals (five rats in the initial one), Dr. McEwen and his colleagues demonstrated that toxic stress atrophied neurons near the hippocampus, the brain’s memory and learning center, while expanding neurons near the amygdala, an area known for vigilance toward threats. Describing the burden of continuing stress, he coined the term “allostatic load” (derived from allostasis, the process by which the body seeks to regain stability, or homeostasis, in response to stressors). Their discoveries, first published in the journal Nature in 1968, ignited a new field of research, one that would reveal how stress hormones and other mediators change the brain, alter behavior and impact health, in some cases accelerating disease. At the time, only a few scientists were asserting that the brain remains malleable throughout life, challenging the dogma that the brain stops changing after adolescence. Dr. McEwen’s studies documenting how hormones alter neurons lent credence to this emerging idea. © 2020 The New York Times Company

Keyword: Stress; Hormones & Behavior
Link ID: 27031 - Posted: 02.11.2020

By Everyday Einstein Sabrina Stierwalt People from all cultures laugh, although we may laugh at different things. (I once interviewed for a job in the Netherlands and none of my jokes landed. I didn’t get that job.) Apes also laugh. We know this because there are scientists whose job it is to tickle animals. I’m not even kidding. What a life! Advertisement Humans start laughing as early as 3 months into life, even before we can speak. This is true even for babies who are deaf or blind. Peekaboo, it turns out, is particularly a global crowd-pleaser. And we know this because studying baby laughter is an actual job, too. So, the ubiquitous nature of laughter suggests that it must serve a purpose, but what? Why do we laugh? Here are a few scientific reasons Laughter clearly serves a social function. It is a way for us to signal to another person that we wish to connect with them. In fact, in a study of thousands of examples of laughter, the speakers in a conversation were found to be 46 percent more likely to laugh than the listeners. We’re also 30 times more likely to laugh in a group. Young children between the ages of 2.5 and 4 were found to be eight times more likely to laugh at a cartoon when they watched it with another child even though they were just as likely to report that the cartoon was funny whether alone or not. Evolutionarily speaking, this signal of connection likely played an important role in survival. Upon meeting a stranger, we want to know: What are your intentions with me? And who else are you aligned with? © 2020 Scientific American

Keyword: Emotions
Link ID: 27029 - Posted: 02.10.2020

By Laura Sanders Immune cells in the brain chew up memories, a new study in mice shows. The finding, published in the Feb. 7 Science, points to a completely new way that the brain forgets, says neuroscientist Paul Frankland of the Hospital for Sick Children Research Institute in Toronto, who wasn’t involved in the study. That may sound like a bad thing, but forgetting is just as important as remembering. “The world constantly changes,” Frankland says, and getting rid of unimportant memories — such as a breakfast menu from two months ago — allows the brain to collect newer, more useful information. Exactly how the brain stores memories is still debated, but many scientists suspect that connections between large groups of nerve cells are important (SN: 1/24/18). Forgetting likely involves destroying or changing these large webs of precise connections, called synapses, other lines of research have suggested. The new result shows that microglia, immune cells that can clear debris from the brain, “do exactly that,” Frankland says. Microglia are master brain gardeners that trim extra synapses away early in life, says Yan Gu, a neuroscientist at Zhejiang University School of Medicine in Hangzhou, China. Because synapses have a big role in memory storage, “we started to wonder whether microglia may induce forgetting by eliminating synapses,” Gu says. Gu’s team first gave mice an unpleasant memory: mild foot shocks, delivered in a particular cage. Five days after the shocks, the mice would still freeze in fear when they were placed in the cage. But 35 days later, they had begun to forget and froze less often in the room. © Society for Science & the Public 2000–2020

Keyword: Learning & Memory; Neuroimmunology
Link ID: 27026 - Posted: 02.07.2020