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By NATALIE ANGIER Tom Vaughan, a photographer then living in Colorado’s Mancos Valley, kept a hummingbird feeder outside his house. One morning, he stepped through the portico door and noticed a black-chinned hummingbird dangling from the side of the red plastic feeder like a stray Christmas ornament. At first, Mr. Vaughan thought he knew what was going on. “I’d previously seen a hummingbird in a state of torpor,” he said, “when it was hanging straight down by its feet, regenerating its batteries, before dropping down and flying off.” On closer inspection, Mr. Vaughan saw that the hummingbird was hanging not by its feet but by its head. And forget about jumping its batteries: the bird was in the grip of a three-inch-long green praying mantis. The mantis was clinging with its back legs to the rim of the feeder, holding its feathered catch in its powerful, seemingly reverent front legs, and methodically chewing through the hummingbird’s skull to get at the nutritious brain tissue within. “It was staring at me as it fed,” Mr. Vaughan said. “Of course, I took a picture of it.” Startled by the clicking shutter, the mantis dropped its partially decapitated meal, crawled under the feeder — and began menacing two hummingbirds on the other side. “Talk about cognitive dissonance,” Mr. Vaughan said. “I always thought of mantises as wonderful things to have in your garden to get rid of bugs, but it turns out they sometimes go for larger prey, too.” “It gave me new respect for mantises,” he added. © 2017 The New York Times Company

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 24101 - Posted: 09.23.2017

Sex and aggression linked in male mouse brains but not in female

By Jessica Hamzelou Aggression and sexual behaviour are controlled by the same brain cells in male mice – but not in females. The finding suggests that males are more likely to become aggressive when they see a potential mate than females. The brain regions that contain these cells look similar in mice and humans, say the researchers behind the study, but they don’t yet know if their finding has relevance to human behaviour. Similar to humans, male mice are, on the whole, more aggressive than females. Because of this, most research into aggression has overlooked females, says Dayu Lin at New York University. “I would say 90 per cent of aggression studies have been done in males,” she says. “We know very little about aggression in females.” But females can be aggressive too. For instance, female mice can be aggressive when protecting their newborn pups. In 2011, Lin and her colleagues studied a region of the brain called the hypothalamus, responsible for regulating many different behaviours. They discovered a set of cells within this region in male mice that controlled both aggressive and sexual behaviours. When the cells were shut off, the mice didn’t mate or show aggression, but both behaviours could be triggered when the cells were stimulated. © Copyright New Scientist Ltd.

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 8: Hormones and Sex
Link ID: 24076 - Posted: 09.19.2017

A researcher reveals the shocking truth about electric eels

Mariah Quintanilla Kenneth Catania knows just how much it hurts to be zapped by an electric eel. For the first time, the biologist at Vanderbilt University in Nashville has measured the strength of a defensive electrical attack on a real-life potential predator — himself. Catania placed his arm in a tank with a 40-centimeter-long electric eel (relatively small as eels go) and determined, in amperes, the electrical current that flowed into him when the eel struck. At its peak, the current reached 40 to 50 milliamperes in his arm, he reports online September 14 in Current Biology. This zap was painful enough to cause him to jerk his hand from the tank during each trial. “If you’ve ever been on a farm and touched an electric fence, it’s pretty similar to that,” he says. This is Catania’s latest study in a body of research analyzing the intricacies of an electric eel’s behavior. The way electric eels have been described by biologists in the past has been fairly primitive, says Jason Gallant, a biologist who heads the Michigan State University Electric Fish Lab in East Lansing who was not involved in the study. Catania’s work reveals that “what the electric eel is doing is taking the electric ability that it has and using that to its absolute advantage in a very sophisticated, deliberate way,” he says. Electric eels use electric current to navigate, communicate and hunt for small prey. But when faced with a large land-based predator, eels will launch themselves from the water and electrify the animal with a touch of the head. |© Society for Science & the Public 2000 - 2017.

Wild Dogs Sneeze When They Are Ready to Hunt

James Gorman African wild dogs sneeze. And that’s a first. No other social animal has been reported to cast a vote, of sorts, by sneezing, although in humans sneezing may once have expressed a negative opinion, as in, “nothing to sneeze at.” Wild dog sneezing is different. For one thing it seems to indicate a positive reaction to a proposal before a group of dogs. When a pack of these dogs is getting ready to hunt, scientists reported Tuesday, the more sneezes, the more likely they are to actually get moving. Just about all social organisms make group decisions that require reaching a consensus. If monkeys or meerkats are looking for a better place to forage, they need to reach a consensus about moving on among a minimum number of animals — called a quorum, just like in Congress. Even some bacteria do this before releasing toxins or lighting up with bioluminescence. Bacteria use chemical signals but larger animals often use sounds as a way of saying, I’m in. However, among grunts, huffs, piping signals and others, the sneeze had not been reported as one of those signals until a group of American, British and Australian researchers published their observations of African dogs in the Proceedings of the Royal Society B. They were studying the dogs where they live in Botswana to see how they decide to go on a hunt. Like most carnivores, the wild dogs sleep a lot. But at some point one of the pack will start what is called a rally, getting all the other members excited and milling around as if they want to play. Sometimes the rallies are successful, and off the pack goes. Sometimes the pack members lie down and go back to sleep. Neil R. Jordan of the University of New South Wales in Sydney, the senior author of the report, noticed that the successful rallies there seemed to have more sneezing. © 2017 The New York Times Company

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 24045 - Posted: 09.07.2017

Low-ranked female monkeys band together against their leaders

By Aylin Woodward If you’re trying to overthrow the boss, you might need a friend to back you up. The same is true for female macaques, who need allies to resist authority and take down more powerful members of the group. Most primates have social hierarchies in which some individuals are dominant over the others. For rhesus macaques, these strict hierarchies are organised around female relationships. Lower-ranked females have little social mobility and must silently bare their teeth to higher-ranked females. The signal means “I want you to know that I know that you out-rank me” and is important in communicating social rank, says Darcy Hannibal at the University of California, Davis. “They are ‘bending the knee’.” But Hannibal and her colleagues have discovered that subordinate females can override the status quo. To do this, female macaques form alliances with family, friends or both. These alliances help females maintain or increase their social rank and compete for resources. A female who wants to challenge those higher up needs this help, says Hannibal. Insubordination events were more likely if the lower-ranked female was older. They were most likely if the subordinate outweighed the dominant female by 7 kilograms and the dominant female had no family allies. The more allies the subordinate female had, and the more days her mother was present in the group, the more often she would exhibit insubordinate behaviour. © Copyright New Scientist Ltd.

Now we men can blame our hormones: testosterone is trouble

Phil Daoust As a man – the sort of thoughtful, Fawcett Society-supporting man who lowers the toilet seat after peeing, even when he has the house to himself – it’s hard to talk about women and their hormones. There’s no doubt that they affect minds and bodies, through puberty, pregnancy and premenstrual syndrome (PMS). The National Association for Premenstrual Syndrome’s list of “common” symptoms includes mood swings, depression, tiredness, anxiety, feeling out of control, irritability, aggression, headaches, sleep disorder, food cravings, breast tenderness, bloating, weight gain and clumsiness. Men can’t and shouldn’t ignore this catalogue of woes. But there’s a fine line between commiserating and condescending. It’s too easy – and tempting – to dismiss a woman’s actions or opinions because it’s “that time of the month”. Mostly it isn’t. Many women are lucky enough to escape PMS. And even when they don’t, sometimes she’s still right and you’re still wrong. For better or worse, however, we males must now face up to our own fluctuating chemistry. We may not routinely bloat and bleed, but a new study makes it clear that we too are at the mercy of our hormones – specifically, the one produced between our legs. After testing hundreds of men, researchers from the California Institute of Technology, Wharton School, Western University and ZRT Laboratory reported (pdf) “a clear and robust causal effect of testosterone on human cognition and decision-making” © 2017 Guardian News and Media Limited

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 5: Hormones and the Brain
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 8: Hormones and Sex
Link ID: 23993 - Posted: 08.25.2017

When Torture Becomes Science

By M. GREGG BLOCHE Was the Central Intelligence Agency’s post-9/11 “enhanced interrogation” program an instance of human experimentation? Recently declassified documents raise this explosive question. The documents were obtained by the American Civil Liberties Union in connection with a federal lawsuit scheduled for trial next month. The case was brought on behalf of three former detainees against two psychologists who developed the C.I.A.’s program. I reviewed some of the documents in a recent article in The Texas Law Review. Internal C.I.A. records indicate that the psychologists, James Mitchell and John Bruce Jessen, anticipated objections that critics would later level against the program, such as that coercion might generate unreliable information, and contracted with the agency to design research tools that addressed some of these concerns. Redactions in the released documents (and the C.I.A.’s withholding of others) make it impossible to know the full extent, if any, of the agency’s data collection efforts or the findings they yielded. At their depositions for the A.C.L.U. lawsuit, each of the psychologists denied having evaluated the program’s effectiveness. But the C.I.A. paid the psychologists to develop a research methodology and instructed physicians and other medical staff members at clandestine detention sites to monitor and chart the health conditions of detainees. In response, the advocacy group Physicians for Human Rights has charged that the program was an unlawful experiment on human beings. It calls the program “one of the gravest breaches of medical ethics by United States health professionals since the Nuremberg Code,” the ethical principles written to protect people from human experimentation after World War II. In its lawsuit, the A.C.L.U. is pressing a similar claim. © 2017 The New York Times Company

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 1: Introduction: Scope and Outlook
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 20:
Link ID: 23956 - Posted: 08.14.2017

These genes may be why dogs are so friendly

Ashley Yeager DNA might reveal how dogs became man’s best friend. A new study shows that some of the same genes linked to the behavior of extremely social people can also make dogs friendlier. The result, published July 19 in Science Advances, suggests that dogs’ domestication may be the result of just a few genetic changes rather than hundreds or thousands of them. “It is great to see initial genetic evidence supporting the self-domestication hypothesis or ‘survival of the friendliest,’” says evolutionary anthropologist Brian Hare of Duke University, who studies how dogs think and learn. “This is another piece of the puzzle suggesting that humans did not create dogs intentionally, but instead wolves that were friendliest toward humans were at an evolutionary advantage as our two species began to interact.” Not much is known about the underlying genetics of how dogs became domesticated. In 2010, evolutionary geneticist Bridgett vonHoldt of Princeton University and colleagues published a study comparing dogs’ and wolves’ DNA. The biggest genetic differences gave clues to why dogs and wolves don’t look the same. But major differences were also found in WBSCR17, a gene linked to Williams-Beuren syndrome in humans. Williams-Beuren syndrome leads to delayed development, impaired thinking ability and hypersociability. VonHoldt and colleagues wondered if changes to the same gene in dogs would make the animals more social than wolves, and whether that might have influenced dogs’ domestication. © Society for Science & the Public 2000 - 2017.

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 23855 - Posted: 07.20.2017

When Is Speech Violence?

By LISA FELDMAN BARRETT Imagine that a bully threatens to punch you in the face. A week later, he walks up to you and breaks your nose with his fist. Which is more harmful: the punch or the threat? The answer might seem obvious: Physical violence is physically damaging; verbal statements aren’t. “Sticks and stones can break my bones, but words will never hurt me.” But scientifically speaking, it’s not that simple. Words can have a powerful effect on your nervous system. Certain types of adversity, even those involving no physical contact, can make you sick, alter your brain — even kill neurons — and shorten your life. Your body’s immune system includes little proteins called proinflammatory cytokines that cause inflammation when you’re physically injured. Under certain conditions, however, these cytokines themselves can cause physical illness. What are those conditions? One of them is chronic stress. Your body also contains little packets of genetic material that sit on the ends of your chromosomes. They’re called telomeres. Each time your cells divide, their telomeres get a little shorter, and when they become too short, you die. This is normal aging. But guess what else shrinks your telomeres? Chronic stress. If words can cause stress, and if prolonged stress can cause physical harm, then it seems that speech — at least certain types of speech — can be a form of violence. But which types? This question has taken on some urgency in the past few years, as professed defenders of social justice have clashed with professed defenders of free speech on college campuses. Student advocates have protested vigorously, even violently, against invited speakers whose views they consider not just offensive but harmful — hence the desire to silence, not debate, the speaker. “Trigger warnings” are based on a similar principle: that discussions of certain topics will trigger, or reproduce, past trauma — as opposed to merely challenging or discomfiting the student. The same goes for “microaggressions.” © 2017 The New York Times Company

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 23846 - Posted: 07.18.2017

Scientists discover brain's neural switch for becoming an alpha male

Hannah Devlin Science correspondent Brash, brawny and keen to impose their will on anyone who enters their sphere of existence: the alpha male in action is unmistakable. Now scientists claim to have pinpointed the biological root of domineering behaviour. New research has located a brain circuit that, when activated in mice, transformed timid individuals into bold alpha mice that almost always prevailed in aggressive social encounters. In some cases, the social ranking of the subordinate mice soared after the scientists’ intervention, hinting that it might be possible to acquire “alphaness” simply by adopting the appropriate mental attitude. Or as Donald Trump might put it: “My whole life is about winning. I almost never lose.” Prof Hailan Hu, a neuroscientist at Zhejiang University in Hangzhou, China, who led the work said: “We stimulate this brain region and we can make lower ranked mice move up the social ladder.” The brain region, called the dorsal medial prefrontal cortex (dmPFC), was already known to light up during social interactions involving decisions about whether to be assertive or submissive with others. But brain imaging alone could not determine whether the circuit was ultimately controlling how people behave. The latest findings answer the question, showing that when the circuit was artificially switched on, low-ranking mice were immediately emboldened. “It’s not aggressiveness per se,” Hu said. “It increases their perseverance, motivational drive, grit.” © 2017 Guardian News and Media Limited

Teaching Machines to Recognize (and Filter) Humanity’s Dark Side

/ By Rod McCullom Facebook has problem — a very significant problem — with the violent and gruesome content which has quickly found its way, in numerous instances, onto the social network and its Facebook Live feature, which was introduced to American users in January 2016. The disturbing litany of murders, suicides and assaults have already become macabre technological milestones. These include Robert Godwin Sr., the 74-year-old father of nine and grandfather of 14 who was selected by a gunman at random and then murdered in a video posted to Facebook in mid-April. One week later, a man in Thailand streamed the murder of his 11-month old daughter on Facebook Live before taking his own life. The beating and torture of an 18-year-old man with intellectual and development disabilities was live-streamed on the service in January, and the tragic shooting death of two-year-old Lavontay White Jr. followed a month later on Valentine’s Day. “At least 45 instances of violence — shootings, rapes, murders, child abuse, torture, suicides, and attempted suicides — have been broadcast via Live [since] December 2015,” Buzzfeed’s Alex Kantrowitz reported this month. “That’s an average rate of about two instances per month.” Copyright 2017 Undark

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 13: Memory and Learning
Link ID: 23778 - Posted: 06.27.2017

Life as a Nonviolent Psychopath

Judith Ohikuare In 2005, James Fallon's life started to resemble the plot of a well-honed joke or big-screen thriller: A neuroscientist is working in his laboratory one day when he thinks he has stumbled upon a big mistake. He is researching Alzheimer's and using his healthy family members' brain scans as a control, while simultaneously reviewing the fMRIs of murderous psychopaths for a side project. It appears, though, that one of the killers' scans has been shuffled into the wrong batch. The scans are anonymously labeled, so the researcher has a technician break the code to identify the individual in his family, and place his or her scan in its proper place. When he sees the results, however, Fallon immediately orders the technician to double check the code. But no mistake has been made: The brain scan that mirrors those of the psychopaths is his own. After discovering that he had the brain of a psychopath, Fallon delved into his family tree and spoke with experts, colleagues, relatives, and friends to see if his behavior matched up with the imaging in front of him. He not only learned that few people were surprised at the outcome, but that the boundary separating him from dangerous criminals was less determinate than he presumed. Fallon wrote about his research and findings in the book The Psychopath Inside: A Neuroscientist's Personal Journey Into the Dark Side of the Brain, and we spoke about the idea of nature versus nurture, and what—if anything—can be done for people whose biology might betray their behavior. © 2017 by The Atlantic Monthly Group.

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 23707 - Posted: 06.05.2017

Cuttlefish really know how to fight for their gals, rare video shows

By Elizabeth Pennisi When, 6 years ago, divers captured on video a cuckolding attempt among squidlike animals called cuttlefish, experts were stunned. “The violence was beyond anything we had ever seen in the laboratory,” says Roger Hanlon, an ecologist at the Marine Biological Laboratory in Woods Hole, Massachusetts, who had been studying captive cuttlefish for years. Now, by carefully analyzing the behavior of the two males involved, he and his colleagues suggest the stepwise escalation of their fight likely required more brainpower than many researchers thought invertebrates had, they report this week in American Naturalist. The video (above) first shows a common European male cuttlefish (Sepia officinalis) mating with a female. While he escorts her to where she will lay her eggs, a second male suddenly appears and chases him away. But the first male doesn’t give up, and as his rival starts to get fresh with the female, the scuffle gets ever more intense. The rivals squirt ink at each other and jet about. Then, their dark markings turn even darker, and they engage in a quick battle of biting, grappling, and cork-screwing that soon sends the intruder scurrying off. Now that the scientists know how such explosive situations come about, they hope to recreate those circumstances in the lab to study male rivalries more systematically. © 2017 American Association for the Advancement of Science. A

The Mind of the Predator

By Gareth Cook The carnivore needs no introduction: fearsome, cold and brutal. But G. A. Bradshaw, known for her psychological work with elephants, asks readers to reconsider. In “Carnivore Minds,” she argues that predators are none of these things. She uses the orca for a case study in the evolution of morals; to explore emotional intelligence, her main example is the crocodile. Through “trans-species psychology,” Bradshaw asks us to consider the many ways that the animals we fear are far more similar to us than we might like to think. She answered questions from Mind Matters editor Gareth Cook. What first lead you to explore the minds of carnivores? Carnivores are a natural counterpoint to the herbivorous elephant, the subject of my previous book, Elephants on the Edge. There certainly are differences between white sharks and elephants, but the similarities are much greater. We know this because of what neuroscience has discovered — mammals, birds, fish, and reptiles (and now, it appears, invertebrates like bees and octopi) share common brain structures and processes that govern thinking and feeling. The scientific model used to explore human minds applies to other animals. This trans-species psychology allows us to see, even experience, the worlds of carnivores as they might — from the inside-out. White sharks, coyotes, and wolves not only have comparable mental and emotional capacities as humans, they are equally vulnerable to psychological trauma. This is what I discovered with the diagnosis of post-traumatic stress disorder (PTSD) in wild elephants. When elephants lose their homes and families, are subjected to mass killing, and are captured and incarcerated in zoos, they breakdown mentally and culturally and exhibit symptoms found in human prisoners and victims of genocide. As a result of hunting and persecution, pumas are showing symptoms of complex PTSD. © 2017 Scientific American

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 23449 - Posted: 04.05.2017

Low-status chimps revealed as trendsetters

Bruce Bower Chimps with little social status influence their comrades’ behavior to a surprising extent, a new study suggests. In groups of captive chimps, a method for snagging food from a box spread among many individuals who saw a low-ranking female peer demonstrate the technique, say primatologist Stuart Watson of the University of St. Andrews in Fife, Scotland, and colleagues. But in other groups where an alpha male introduced the same box-opening technique, relatively few chimps copied the behavior, the researchers report online February 7 in the American Journal of Primatology. “I suspect that even wild chimpanzees are motivated to copy obviously rewarding behaviors of low-ranking individuals, but the limited spread of rewarding behaviors demonstrated by alpha males was quite surprising,” Watson says. Previous research has found that chimps in captivity more often copy rewarding behaviors of dominant versus lower-ranking group mates. The researchers don’t understand why in this case the high-ranking individuals weren’t copied as much. The spread of new behaviors in groups of monkeys and apes depends on a variety of factors — including an innovator’s social status, age and sex — that can interact in unpredictable ways. “That’s why social learning in groups is so interesting to study,” says Elizabeth Lonsdorf, a primatologist at Franklin & Marshall College in Lancaster, Pa., who did not participate in the research. |© Society for Science & the Public 2000 - 2017.

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 15: Language and Lateralization
Link ID: 23269 - Posted: 02.22.2017

Chimps beat up, murder and then cannibalise their former tyrant

By Chelsea Whyte It was a gruesome scene. The body had severe wounds and was still bleeding despite having been lying for a few hours in the hot Senegalese savanna. The murder victim, a West African chimpanzee called Foudouko, had been beaten with rocks and sticks, stomped on and then cannibalised by his own community. This is one of just nine known cases where a group of chimpanzees has killed one of their own adult males, as opposed to killing a member of a neighbouring tribe. These intragroup killings are rare, but Michael Wilson at the University of Minnesota says they are a valuable insight into chimp behaviour such as male coalition building. “Why do these coalitions sometimes succeed, but not very often? It’s at the heart of this tension between conflict and cooperation, which is central to the lives of chimpanzees and even to our own,” he says. Chimps usually live in groups with more adult females than males, but in the group with the murder it was the other way round. “When you reverse that and have almost two males per every female — that really intensifies the competition for reproduction. That seems to be a key factor here,” says Wilson. Jill Pruetz at Iowa State University, who has been studying this group of chimpanzees in south-eastern Senegal since 2001, agrees. She suggests that human influence may have caused this skewed gender ratio that is likely to have been behind this attack. In Senegal, female chimpanzees are poached to provide infants for the pet trade. Fall from power Thirteen years ago, Foudouko reigned over one of the chimp clans at the Fongoli study site, part of the Fongoli Savanna Chimpanzee Project. As alpha male, he was “somewhat of a tyrant”, Pruetz says. © Copyright Reed Business Information Ltd.

Flipping A Switch In The Brain Turns Lab Rodents Into Killer Mice

Jon Hamilton Mice that kill at the flip of a switch may reveal how hunting behavior evolved hundreds of millions of years ago. The mice became aggressive predators when two sets of neurons in the amygdala were activated with laser light, a team reported Thursday in the journal Cell. "The animals become very efficient in hunting," says Ivan de Araujo, an associate professor of psychiatry at Yale University and an associate fellow at The John B. Pierce Laboratory in New Haven. "They pursue the prey [a live cricket] faster and they are more capable of capturing and killing it." Activating the neurons even caused the mice to attack inanimate objects, including sticks, bottle caps and an insectlike toy. "The animals intensively bite the toy and use their forepaws in an attempt to kill it," De Araujo says. But the aggressive behavior is reserved for prey. Mice didn't attack each other, even when both sets of neurons were activated. The results hint at how the brain changed hundreds of millions of years ago when the first animals with jaws began to appear. This new ability to pursue and kill prey "must have influenced the way the brain is wired up in a major way," De Araujo says. Specifically, the brain needed to develop hunting circuits that would precisely coordinate the movements of a predator's jaw and neck. "This is a very complex and demanding task," De Araujo says. © 2017 npr

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 23099 - Posted: 01.13.2017

Oxytocin surge before a fight helps chimps bond with their group

By Andy Coghlan Is the fabled “cuddle hormone” really a “warmone”? Oxytocin levels surge in troops of chimpanzees preparing for conflict with rival groups to defend or expand their territory. The finding is at odds with the prevailing image of oxytocin as something that helps strengthen bonds between parent and infant, or foster friendships. But given its capacity to strengthen loyalty, oxytocin could also be a warmonger hormone that helps chimps galvanise and cooperate against a common enemy. Catherine Crockford of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and her colleagues monitored two rival groups of chimpanzees in the Taï National Park in Ivory Coast, each containing five males and five females, for prolonged periods between October 2013 and May 2015. Thanks to trust built up between the team and the chimps, the team could safely track and video the groups – even during conflict, observing at close quarters what was happening. Crucially, the team was also able to pipette up fresh samples from soil when chimps urinated. The samples revealed that oxytocin levels surge in the mammals whenever the chimps on either side prepared for confrontation, or when either group took the risk of venturing near or into rival-held territories. These surges dwarfed the oxytocin levels seen during activities such as grooming, collaborative hunting for monkey prey or food sharing. © Copyright Reed Business Information Ltd.

Related chapters from BN: Chapter 5: Hormones and the Brain; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 11: Emotions, Aggression, and Stress
Link ID: 23065 - Posted: 01.07.2017

Five Questions for Judith Edersheim

By Chloé Hecketsweiler Can brain science predict when someone will commit a crime, or tell whether a defendant knew right from wrong? In recent decades, scientists and criminal justice experts have been trying to answer tantalizing questions like these — with mixed success. The science of predicting crime using algorithms is still shaky, and while sophisticated tools such as neuroimaging are increasingly being used in courtrooms, they raise a host of tricky questions: What kind of brain defect or brain injury should count when assessing a defendant’s responsibility for a crime? Can brain imaging distinguish truth from falsehood? Can neuroscience predict human behavior? Judith Edersheim, an assistant professor of psychiatry at Harvard Medical School and also a lawyer who specializes in forensic evaluations, focuses her research on these gray areas. In 2009, she co-founded the Center for Law, Brain, and Behavior at Massachusetts General Hospital, with the goal of “translating neuroscience into the legal arena.” And on December 15, at an event at Brigham and Women’s Hospital in Boston, Edersheim will talk about the vulnerability of the aging brain, highlighting the case of a man affected by an undetected brain disease. For this installment of the Undark Five, we asked her what brain imaging can reveal about the “criminal brain,” how relationships between brain functioning and behavior can inform the courtroom, and what controversies this iconoclastic science may raise. Questions and answers have been edited for length and clarity, and Undark has supplied some additional links. UNDARK — Using brain imaging, scientists have identified correlations between certain brain abnormalities and criminal behaviors. Is there a signature for the “criminal brain”? JUDITH EDERSHEIM — There may be no criminal minds; there may be criminal moments. Copyright 2016 Undark

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 2: Functional Neuroanatomy: The Cells and Structure of the Nervous System
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 1: Cells and Structures: The Anatomy of the Nervous System
Link ID: 22978 - Posted: 12.12.2016

Sword-slashing sailfish hint at origins of cooperative hunting

By Brian Owens Cooperation makes it happen. Sailfish that work together in groups to hunt sardines can catch more fish than if they hunt alone, even without a real coordinated strategy. To catch their sardine dinner, a group of sailfish circle a school of sardines – known as a baitball – and break off a small section, driving it to the surface. They then take turns attacking these sardines, slashing at them with their long sword-like bills, which account for a quarter of their total length of up to 3.5 metres. Knocking their prey off-balance makes them easier to grab. These attacks only result in a catch about 25 per cent of the time, but they almost always injure several sardines. As the number of injured fish increases, it becomes ever easier for everyone to snag a meal. “There’s no coordination, no strict turn-taking or specific hunting roles, it’s opportunistic,” says James Herbert-Read, from Uppsala University in Sweden. But Herbert-Reads computer models now show that even this rudimentary form of cooperation is better than going it alone. Sailfish that work in groups capture more sardines than a lone fish would get in the same amount of time. © Copyright Reed Business Information Ltd

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