Chapter 11. Emotions, Aggression, and Stress
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Skepticism about repressed traumatic memories has increased over time, but new research shows that psychology researchers and practitioners still tend to hold different beliefs about whether such memories occur and whether they can be accurately retrieved. The findings are published in Psychological Science, a journal of the Association for Psychological Science. “Whether repressed memories are accurate or not, and whether they should be pursued by therapists, or not, is probably the single most practically important topic in clinical psychology since the days of Freud and the hypnotists who came before him,” says researcher Lawrence Patihis of the University of California, Irvine. According to Patihis, the new findings suggest that there remains a “serious split in the field of psychology in beliefs about how memory works.” Controversy surrounding repressed memory – sometimes referred to as the “memory wars” – came to a head in the 1990s. While some believed that traumatic memories could be repressed for years only to be recovered later in therapy, others questioned the concept, noting that lack of scientific evidence in support of repressed memory. Spurred by impressions that both researchers and clinicians believed the debate had been resolved, Patihis and colleagues wanted to investigate whether and how beliefs about memory may have changed since the 1990s. To find out, the researchers recruited practicing clinicians and psychotherapists, research psychologists, and alternative therapists to complete an online survey. © Association for Psychological Science
by Chelsea Whyte For chameleons, war paint isn't just an accessory, it is a battle flag. The brightness of the colours these lizards display and how rapidly they change are good indicators of which animal will win in a fight. Chameleons are famous for changing colour to hide from predators by blending into their surroundings, but they also use colour for social communication. One of the most diversely coloured species is the veiled chameleon (Chamaeleo calyptratus), which lives in parts of Saudi Arabia and Yemen. "At their brightest, they have vertical yellow stripes, blue-green bellies, black speckles that provide contrast and make their stripes stand out, and orange around the corner of their mouths," says Russell Ligon, a behavioural ecologist at Arizona State University in Tempe. To see if individual variations in these colours and patterns influenced the outcome of a fight, Ligon and his colleague Kevin McGraw staged a round-robin tournament in which 10 male veiled chameleons were pitted against each other. Using a high-speed camera, they were able to capture the brightness and colour changes from 28 points on each animal, taking into account how the colours would look to a chameleon's eye – which sees both visible and ultraviolet light. They found that males with the brightest side stripes were more likely to instigate a fight, whereas those with brighter heads that changed colour most rapidly were more likely to win. This suggests that different colours and patterns may signal different aspects of competitive behaviour – how motivated the chameleon is versus its strength. © Copyright Reed Business Information Ltd.
By JAMES GORMAN Sometimes the scientists who study animal behavior solve puzzles and other times they uncover new ones. The war between mockingbirds and cowbirds is a case in point. Cowbirds are brood parasites, meaning they lay their eggs in the nests of other bird species, thus unloading the messy and demanding business of chick-rearing. They also peck holes in the eggs of the host birds, destroying as many as they can. Mockingbirds are a favorite target of this plan, and it seems to make perfect sense for them to viciously attack cowbirds when they catch them in the nest. But when Ros Gloag, then a doctoral student at Oxford, and her colleagues in Argentina looked closely at the war between chalk-browed mockingbirds and shiny cowbirds, they found something unexpected, as they reported in the November issue of Animal Behaviour. They stationed small video cameras near the nests of 40 pairs of chalk-browed mockingbirds. Over two breeding seasons they recorded more than 200 attacks on intruding cowbirds. They were surprised to find that these attacks, which their videos show to be quite vicious, did not stop the cowbirds from laying eggs. The cowbirds would hunker down and let the much large mockingbirds deliver hammer blows to the head, but in matter of seconds they would lay an egg and flee. How could such a failed strategy persist in evolution? © 2013 The New York Times Company
by Bob Holmes Perseverance in the face of adversity is an admirable character trait – now it turns out you can conjure it up with a quick zap to a tiny spot in the brain. The discovery in two people with epilepsy was accidental but it is the first to show that simple brain stimulation can create rich, complex alterations of consciousness. Josef Parvizi, a neurologist at Stanford University in California, and his colleagues had implanted electrodes in the brains of two people with epilepsy to help identify the source of their seizures. In the course of their work, they noticed that an odd thing happened when they stimulated a region in the anterior midcingulate cortex – a part of the limbic system involved in emotion, processing, learning and memory. Both patients reported feeling a sense of foreboding, coupled with a determination to overcome whatever challenge they were about to face. During the stimulation, one patient reported feeling "worried that something bad is going to happen" but also noted that "it made me stronger". The other said he felt as if he were figuring out how to get through something. He likened it to driving your car when one of the tires bursts. You're only halfway to your destination and you have no option but to keep going forward. "You're like… am I gonna get through this?" he said (see video). He also reported a sense of urgency: "It was more of a positive thing like… push harder, push harder, push harder to try and get through this." One singular sensation In contrast, when the researchers applied a sham stimulation – going through exactly the same procedure, but with the current set to zero – neither volunteer reported feeling any specific sensations. Stimulation of other nearby regions of the brain less than 5 millimetres away also failed to produce the feelings of either foreboding or perseverance. © Copyright Reed Business Information Ltd.
Philip Ball Some animals, like some people, are more aggressive than others: it is just the way they are. But research suggests that for birds at least, it is not always easy to tell which is which. Some birds are inclined to give out exaggerated signs of their aggressiveness, others to underplay it. It is rather like the menacing biker who turns out to be a pussycat, or the geek who will break a bottle over your head. But the analogy with humans goes only so far, because many birds announce their aggression about mating and territory not by appearance but through song and gesture. For example, behavioural ecologist Michael Beecher and his colleagues at the University of Washington in Seattle have observed how the song sparrow (Melospiza melodia) indicates its intention to attack a dummy bird (see video above) or a loudspeaker playing bird songs by either vocalizing distinctive ‘soft songs’ or waving its wings (see video below), both of which are perceived as threatening1. Violent tendencies Both aggressive signalling and the ensuing violent behaviour vary from one bird to another, in a way that correlates with other personality traits such as boldness2. But these attributes also vary for a single individual at different times: birds can have particularly grouchy or placid days. Nonetheless, the degree of aggression implied by the precursory signals generally reflects the actual behaviour, in what evolutionary biologists call an honest signal. But it's not always honest. Earlier this year, Beecher's team showed1 that there is some variability in aggressive signalling that does not match behaviour: a bird might act stroppy but not follow through with an attack. © 2013 Nature Publishing Group
Jo Marchant When Steve Cole was a postdoc, he had an unusual hobby: matching art buyers with artists that they might like. The task made looking at art, something he had always loved, even more enjoyable. “There was an extra layer of purpose. I loved the ability to help artists I thought were great to find an appreciative audience,” he says. At the time, it was nothing more than a quirky sideline. But his latest findings have caused Cole — now a professor at the Cousins Center for Psychoneuroimmunology at the University of California, Los Angeles — to wonder whether the exhilaration and sense of purpose that he felt during that period might have done more than help him to find homes for unloved pieces of art. It might have benefited his immune system too. At one time, most self-respecting molecular biologists would have scoffed at the idea. Today, evidence from many studies suggests that mental states such as stress can influence health. Still, it has proved difficult to explain how this happens at the molecular level — how subjective moods connect with the vastly complex physiology of the nervous and immune systems. The field that searches for these explanations, known as psychoneuroimmunology (PNI), is often criticized as lacking rigour. Cole's stated aim is to fix that, and his tool of choice is genome-wide transcriptional analysis: looking at broad patterns of gene expression in cells. “My job is to be a hard-core tracker,” he says. “How do these mental states get out into the rest of the body?” With his colleagues, Cole has published a string of studies suggesting that negative mental states such as stress and loneliness guide immune responses by driving broad programs of gene expression, shaping our ability to fight disease. If he is right, the way people see the world could affect everything from their risk of chronic illnesses such as diabetes and heart disease to the progression of conditions such as HIV and cancer. Now Cole has switched tack, moving from negative moods into the even more murky territory of happiness. It is a risky strategy; his work has already been criticized as wishful thinking and moralizing. But the pay-off is nothing less than finding a healthier way to live. © 2013 Nature Publishing Group
In the 1970s pop hit “Paradise by the Dashboard Light,” famed rocker Meat Loaf wails to his tired old lover: “[I]f I gotta spend another minute with you I don't think that I can really survive.” Turns out that interactions with the opposite sex really do control life span, at least if you’re an insect or a worm. Sexually frustrated fruit flies perish prematurely, a study has just found. And another experiment reveals that in nematodes—nearly microscopic roundworms—males kill members of the opposite sex by spurring what resembles premature aging. An animal’s environment shapes its longevity, sometimes in surprising ways. For example, placing lab animals on a meager diet that replicates food scarcity in the wild extends survival in many species. And, oddly enough, dulling nematodes’ and flies’ sense of smell or taste stretches their life span. An animal’s environment also includes the other members of its species that it interacts with, such as potential mates and rivals. Researchers have identified some impacts of these interactions on life span. For example, because a male fruit fly’s seminal fluid contains toxins, mating can be fatal for females. Now, Scott Pletcher, a geneticist at the University of Michigan, Ann Arbor, and colleagues have shown that sexually unsatisfied fruit flies give up the ghost faster that usual. The researchers played a dirty trick on some male fruit flies, housing them with other males that had been genetically altered to exude female pheromones, or scent molecules. Normal males woo these she-males but can’t mate with them. Pletcher and colleagues report online today in Science that the sexually thwarted males pined away. Their stored fat dwindled, their ability to endure stress declined, and their life span shrank by more than 10%. The researchers also measured a reduction in female flies’ longevity if they hobnobbed with macho females that released male pheromones. © 2013 American Association for the Advancement of Science.
Regina Nuzzo The gut may know better than the head whether a marriage will be smooth sailing or will hit the rocks after the honeymoon fades, according to research published today in Science1. Researchers have long known that new love can be blind, and that those in the midst of it can harbour positive illusions about their sweetheart and their future. Studies show that new couples rate their partner particularly generously, forgetting his or her bad qualities, and generally view their relationship as more likely to succeed than average2. But newlyweds are also under a lot of conscious pressure to be happy — or, at least, to think they are. Now a four-year study of 135 young couples has found that split-second, 'visceral' reactions about their partner are important, too. The results show that these automatic attitudes, which aren’t nearly as rosy as the more deliberate ones, can predict eventual changes in people’s marital happiness, perhaps even more so than the details that people consciously admit. The researchers, led by psychologist James McNulty of Florida State University in Tallahassee, tapped into these implicit attitudes by seeing how fast newlyweds could correctly classify positively and negatively themed words after being primed by a photo of their spouse for a fraction of a second. If seeing a blink-of-the-eye flash of a partner’s face conjures up immediate, positive gut-level associations, for example, the participant will be quicker to report that 'awesome' is a positive word and slower to report that 'awful' is a negative one. Researchers used the difference between these two reaction times as a measurement of a participant’s automatic reaction. © 2013 Nature Publishing Group
By MARY LOU JEPSEN IN my early 30s, for a few months, I altered my body chemistry and hormones so that I was closer to a man in his early 20s. I was blown away by how dramatically my thoughts changed. I was angry almost all the time, thought about sex constantly, and assumed I was the smartest person in the entire world. Over the years I had met guys rather like this. I was not experimenting with hormone levels out of idle curiosity or in some kind of quirky science experiment. I was on hormone treatments because I’d had a tumor removed along with part of my pituitary gland, which makes key hormones the body needs to function. This long journey may have started as early as 1978, when I was 13. I spent a summer in intensive care with an unknown disease. After that summer, I never thought I would live a long life. So I wanted to live, to do interesting, fascinating work in the limited time I thought I had left. I took on the math-intensive art form of holography, and in my early 20s traveled the world, living on university fellowships to pursue this esoteric craft. I didn’t date much, really — perhaps because I didn’t have many hormones, though I didn’t know that at the time. I worked as an artist, played in a band, met Andy Warhol, Christo, Lou Reed and David Byrne. I had fun. But the gravity of my illness grew in the 1990s. The growth that shut down my pituitary gland’s ability to produce hormones did so insidiously over many years. By my early 20s it was, I suspect in retrospect, causing misdiagnosis of symptoms that were most likely caused by lack of hormones like cortisol. No diagnosis was found, despite the efforts of many doctors. I was a doctoral student in electrical engineering at an Ivy League school, but was growing progressively worse. I routinely slept about 20 hours a day, lived with a constant blistering headache and frequent vomiting, and was periodically wheelchair-bound. Large sections of my skin cycled through a rainbow of colors and sores, half of my face wouldn’t move as if Novocain had been applied. I drooled. Worse: I felt stupid. I couldn’t subtract anymore. I couldn’t make a to-do list, let alone accomplish items on one. I recognized that I wasn’t capable of continuing in graduate school. Utterly defeated, I filled out the paperwork to drop out. © 2013 The New York Times Company
One afternoon in October 2005, neuroscientist James Fallon was looking at brain scans of serial killers. As part of a research project at UC Irvine, he was sifting through thousands of PET scans to find anatomical patterns in the brain that correlated with psychopathic tendencies in the real world. “I was looking at many scans, scans of murderers mixed in with schizophrenics, depressives and other, normal brains,” he says. “Out of serendipity, I was also doing a study on Alzheimer’s and as part of that, had brain scans from me and everyone in my family right on my desk.” “I got to the bottom of the stack, and saw this scan that was obviously pathological,” he says, noting that it showed low activity in certain areas of the frontal and temporal lobes linked to empathy, morality and self-control. Knowing that it belonged to a member of his family, Fallon checked his lab’s PET machine for an error (it was working perfectly fine) and then decided he simply had to break the blinding that prevented him from knowing whose brain was pictured. When he looked up the code, he was greeted by an unsettling revelation: the psychopathic brain pictured in the scan was his own. Many of us would hide this discovery and never tell a soul, out of fear or embarrassment of being labeled a psychopath. Perhaps because boldness and disinhibition are noted psychopathic tendencies, Fallon has gone all in towards the opposite direction, telling the world about his finding in a TED Talk, an NPR interview and now a new book published last month, The Psychopath Inside. In it, Fallon seeks to reconcile how he—a happily married family man—could demonstrate the same anatomical patterns that marked the minds of serial killers. “I’ve never killed anybody, or raped anyone,” he says. “So the first thing I thought was that maybe my hypothesis was wrong, and that these brain areas are not reflective of psychopathy or murderous behavior.”
Robert N. McLay, author of At War with PTSD: Battling Post Traumatic Stress Disorder with Virtual Reality, responds: post-traumatic stress disorder (PTSD) can appear after someone has survived a horrific experience, such as war or sexual assault. A person with PTSD often experiences ongoing nightmares, edginess and extreme emotional changes and may view anything that evokes the traumatic situation as a threat. Although medications and talk therapy can help calm the symptoms of PTSD, the most effective therapies often require confronting the trauma, as with virtual-reality-based treatments. These computer programs, similar to a video game, allow people to feel as if they are in the traumatic scenario. Just as a pilot in a flight simulator might use virtual reality to learn how to safely land a plane without the risk of crashing, a patient with PTSD can learn how to confront painful reminders of trauma without facing any real danger. Virtual-reality programs have been built to simulate driving, the World Trade Center attacks, and combat scenarios in Vietnam and Iraq. The level of the technology varies considerably, from a simple headset that displays rather cartoonish images to Hollywood-quality special effects. A therapist typically observes what patients are seeing while they navigate the virtual experience. They can coach a patient to take on increasingly difficult challenges while making sure that the person does not become overwhelmed. To do so, some therapists may connect the subject to physiological monitoring devices; others may use virtual reality along with talk therapy. In the latter scenario, the patient recites the story of the trauma and reflects on it while passing through the simulation. The idea is to desensitize patients to their trauma and train them not to panic, all in a controlled environment. © 2013 Scientific American
by Simon Makin "The only thing we have to fear is fear itself," said Franklin D. Roosevelt. He might have been onto something: research suggests that the anticipation of pain is actually worse than the pain itself. In other words, people are happy to endure a bit more pain, if it means they spend less time waiting for it. Classical theories of decision-making suppose that people bring rewards forward and postpone punishments, because we give far-off events less weight. This is called "temporal discounting". But this theory seems to go out the window when it comes to pain. One explanation for this is that the anticipation of pain is itself unpleasant, a phenomenon that researchers have appropriately termed "dread". To investigate how dread varies with time, Giles Story at University College London, and his colleagues, hooked up 33 volunteers to a device that gave them mild electric shocks. The researchers also presented people with a series of choices between more or less mildly painful shocks, sooner or later. During every "episode" there was a minimum of two shocks, which could rise to a maximum of 14, but before they were given them, people had to make a choice such as nine extra shocks now or six extra shocks five episodes from now. The number of shocks they received each time was determined by these past choices. Although a few people always chose to experience the minimum pain, 70 per cent of the time, on average, participants chose to receive the extra shocks sooner rather than a smaller number later. By varying the number of shocks and when they occurred, the team was able to figure out that the dread of pain increased exponentially as pain approached in time. Similar results occurred in a test using hypothetical dental appointments. © Copyright Reed Business Information Ltd.
By Gary Stix The emerging academic discipline of neuroethics has been driven, in part, by the recognition that introducing brain scans as legal evidence is fraught with peril. Most neuroscientists think that a brain scan is unable to provide an accurate representation of the state of mind of a defendant or determine whether his frontal lobes predispose to some wanton action. The consensus view holds that studying spots on the wrinkled cerebral cortex that are bigger or smaller in some criminal offenders may hint at overarching insights into the roots of violence, but lack the requisite specificity to be used as evidence in any individual case. “I believe that our behavior is a production of activity in our brain circuits,” Steven E. Hyman of the Broad Institute of Harvard and MIT told a session at the American Association for the Advancement of Science’s annual meeting earlier this year. “But I would never tell a parole board to decide whether to release somebody or hold on to somebody, based on their brain scan as an individual, because I can’t tell what are the causal factors in that individual.” It doesn’t seem to really matter, though, what academic experts believe about the advisability of brain scans as Exhibit One at trial. The entry of neuroscience in the courtroom has already begun, big time. The introduction of a brain scan in a legal case was once enough to generate local headlines. No more. Hundreds of legal opinions each year have begun to invoke the science of mind and brain to bolster legal arguments—references not only to brain scans, but a range of studies that show that the amygdala is implicated in this or the anterior cingulate cortex is at fault for that. The legal establishment, in short, has begun a love affair with all things brain. © 2013 Scientific American
By JOHN TIERNEY How aggressive is the human female? When the anthropologist Sarah B. Hrdy surveyed the research literature three decades ago, she concluded that “the competitive component in the nature of women remains anecdotal, intuitively sensed, but not confirmed by science.” Science has come a long way since then, as Dr. Hrdy notes in her introduction to a recent issue of Philosophical Transactions of the Royal Society devoted entirely to the topic of female aggression. She credits the “stunning” amount of new evidence partly to better research techniques and partly to the entry of so many women into scientific fields once dominated by men. The existence of female competition may seem obvious to anyone who has been in a high-school cafeteria or a singles bar, but analyzing it has been difficult because it tends be more subtle and indirect (and a lot less violent) than the male variety. Now that researchers have been looking more closely, they say that this “intrasexual competition” is the most important factor explaining the pressures that young women feel to meet standards of sexual conduct and physical appearance. The old doubts about female competitiveness derived partly from an evolutionary analysis of the reproductive odds in ancient polygynous societies in which some men were left single because dominant males had multiple wives. So men had to compete to have a chance of reproducing, whereas virtually all women were assured of it. But even in those societies, women were not passive trophies for victorious males. They had their own incentives to compete with one another for more desirable partners and more resources for their children. And now that most people live in monogamous societies, most women face the same odds as men. In fact, they face tougher odds in some places, like the many college campuses with more women than men. © 2013 The New York Times Company
by Erika Engelhaupt When I was in graduate school, I once gassed out my lab with the smell of death. I was studying the products of plant decomposition, and I had placed copious quantities of duckweed into large tubs and let the mix decompose for a few weeks. Duckweed is a small floating aquatic plant; it looks harmless enough. But when I dragged my tubs into the lab and set up a pump and filtration system, all hell broke loose. The filter clogged, the back pressure threw the hose off the pump, and a spray of decomposed mess flew all over a poor professor who had come in to help. For the rest of the day, he smelled like a pile of dead raccoons. That day, I learned about cadaverine and putrescine. These two molecules are produced during the decomposition of proteins, when the amino acids lysine and ornithine break down, and they are largely responsible for the smell of rotting flesh. My mistake in the lab was to think that rotting plants are more innocuous than rotting animals. Duckweed, it turns out, has such high protein levels that it’s used as animal feed, and those proteins, like any proteins, can create a deathly stench. The smells of cadaverine and putrescine tend to provoke a strong reaction (as I learned once the duckweed stench subsided and my labmates were able to return to the lab). But not every animal finds the odors disgusting. Carrion flies, rats and other animals that eat or lay eggs in dead things are attracted to the molecules. So researchers have started to look for exactly how animals tune in to these smells. Pinning down animals' odor detectors gives researchers a way to study aversion or attraction to certain objects. And understanding how these behavioral responses work will, I believe, help researchers clarify why humans feel the distinct emotion known as disgust. © Society for Science & the Public 2000 - 2013.
When President Obama announced his plan to explore the mysteries of the human brain seven months ago, it was long on ambition and short on details. Now some of the details are being sketched in. They will include efforts to restore lost memories in war veterans, create tools that let scientists study individual brain circuits and map the nervous system of the fruit fly. The Defense Advanced Projects Agency, or DARPA, which has committed more than $50 million to the effort, offered the clearest plan. The agency wants to focus on treatments for the sort of brain disorders affecting soldiers who served in Iraq and Afghanistan, according to , deputy director of . "That is our constituency," Ling said at a news conference at the Society for Neuroscience meeting in San Diego. A colored 3-D MRI scan of the brain's white matter pathways traces connections between cells in the cerebrum and the brainstem. So DARPA will be working on problems including PTSD and traumatic brain injuries, Ling says. In particular, the agency wants to help the soldier who has "a terribly damaged brain and has lost a significant amount of declarative memory," Ling said. "We would like to restore that memory." DARPA hopes to do that with an implanted device that will take over some functions of the brain's hippocampus, an area that's important to memory. The agency has already used a device that does this in rodents, Ling said, and the goal is to move on to people quickly. The agency plans to use the same approach that created a better in record time, Ling said. "We went from idea to prototype in 18 months," he says. This undated X-ray image from the Cleveland Clinic shows electrodes implanted in a patient's brain. The method, known as deep brain stimulation, has traditionally been used to treat diseases such as Parkinson's, but new research indicates it could be helpful for patients with obsessive-compulsive disorder. ©2013 NPR
by Jessica Griggs, San Diego Pregnant women may pass on the effects of stress to their fetus by way of bacterial changes in their vagina, suggests a study in mice. It may affect how well their baby's brain is equipped to deal with stress in adulthood. The bacteria in our body outnumber our own cells by about 10 to 1, with most of them found in our gut. Over the last few years, it has become clear that the bacterial ecosystem in our body – our microbiome – is essential for developing and maintaining a healthy immune system. Our gut bugs also help to prevent germs from invading our bodies, and help to absorb nutrients from food. A baby gets its first major dose of bacteria in life as it passes through its mother's birth canal. En route, the baby ingests the mother's vaginal microbes, which begin to colonise the newborn's gut. Chris Howerton, then at the University of Pennsylvania in Philadelphia, and his colleagues wanted to know if this initial population of bacteria is important in shaping a baby's neurological development, and whether that population is influenced by stress during pregnancy. The first step was to figure out what features of the mother's vaginal microbiome might be altered by stress, and then see if any of those changes were transmitted to the offspring's gut. © Copyright Reed Business Information Ltd
by Laura Sanders SAN DIEGO — When stress during pregnancy disrupts a growing baby’s brain, blame bacteria. Microbes take part in an elaborate chain reaction, a new study finds: First, stress changes the populations of bacteria dwelling in a pregnant mouse’s vagina; those changes then affect which bacteria colonize a newborn pup’s gut; and the altered gut bacteria change the newborn’s brain. The research, presented at the annual Society for Neuroscience meeting, may help explain how a stressful environment early in life can make a person more susceptible to disorders such as autism or schizophrenia. The finding also highlights the important and still mysterious ways that the bacteria living in bodies can influence the brain. “This is really fascinating and promising work,” said neuroscientist Cory Burghy of the University of Wisconsin–Madison. “I am excited to take a look at how these systems interact in humans,” she said. Stress during pregnancy dramatically shifts the mix of bacteria that dwell in the vagina, Christopher Howerton of the University of Pennsylvania reported November 11. The alarming odor of foxes, loud noise, physical restraints and other stressful situations during a mouse’s pregnancy changed the composition of its vaginal bacteria, he and his colleagues found. The population of helpful Lactobacillus bacteria, for instance, decreased after stress. And because newborn mouse pups populate their guts with bacteria dwelling in their mother’s birth canal, microbes from mom colonize the baby’s gut. Mice born to moms with lower levels of Lactobacillus in the vagina had lower levels of Lactobacillus in their guts soon after they were born, the team reported. © Society for Science & the Public 2000 - 2013
SAN DIEGO, CALIFORNIA—How do we recognize emotions in the facial expressions of others? A small, almond-shaped structure called the amygdala, located deep within the brain (yellow in image above), plays a key role, but exactly what it responds to is unclear. To learn more, neuroscientists implanted electrodes into the amygdalae of seven epileptic patients who were about to undergo brain surgery for their condition. They recorded the activity of 200 single amygdala neurons and determined how they responded while the patients viewed photographs of happy and fearful faces. The team found a subset of cells that distinguish between what the patients thought to be happy and fearful faces, even when they perceived ambiguous facial expressions incorrectly. (The team carefully manipulated some of the photos of fearful faces, so that some of the subjects perceived them as being neutral.) The findings, presented here yesterday at the 43rd annual meeting of the Society for Neuroscience, suggest that amygdala neurons respond to the subjective judgement of emotions in facial expressions, rather than the visual characteristics of faces that convey emotions. The scientists also found that the cellular responses persisted long after each of the photographs disappeared, further suggesting that the amygdala cooperates with other brain regions to create awareness of the emotional content of faces. Thus, when it comes to recognizing the facial expressions of others, what we think we see seems to be more important than what we actually see. © 2013 American Association for the Advancement of Science.
Ian Sample, science correspondent in San Diego Criminal courts in the United States are facing a surge in the number of defendants arguing that their brains were to blame for their crimes and relying on questionable scans and other controversial, unproven neuroscience, a legal expert who has advised the president has warned. Nita Farahany, a professor of law who sits on Barack Obama's bioethics advisory panel, told a Society for Neuroscience meeting in San Diego that those on trial were mounting ever more sophisticated defences that drew on neurological evidence in an effort to show they were not fully responsible for murderous or other criminal actions. Lawyers typically drew on brain scans and neuropsychological tests to reduce defendants' sentences, but in a substantial number of cases the evidence was used to try to clear defendants of all culpability. "What is novel is the use by criminal defendants to say, essentially, that my brain made me do it," Farahany said following an analysis of more than 1,500 judicial opinions from 2005 to 2012. The rise of so-called neurolaw cases has caused serious concerns in the country where brain science first appeared in murder cases. The supreme court has begun a review of how such evidence can be used in criminal cases. But legal and scientific experts nevertheless foresee the trend spreading to other countries, including the UK, and Farahany said she was expanding her work abroad. The survey even found cases where defendants had used neuroscience to argue that their confessions should be struck out because they were not competent to provide them. "When people introduce this evidence for competency, it has actually been relatively successful," Farahany said. © 2013 Guardian News and Media Limited