Links for Keyword: Emotions
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Lynne Peeples Every heartbeat is choreographed not just by the brain but also by a mysterious nervous system embedded in the heart itself. Now, scientists studying mice have started to unravel how this complex system works to keep the heart beating steadily even at times of extreme stress — findings that challenge the classic view that all cardiac neurons are alike. “The key is to keep the heart functional no matter what happens. Because if the pump function stops, you will die,” says Rui Chang, a neuroscientist at Yale University School of Medicine in New Haven, Connecticut, and co-author of the new paper. The findings, published today in Cell1, could inform better treatments for heart disease. Like the gut’s widely recognized ‘second brain’, the heart contains a mini-brain of its own — known, more formally, as the intrinsic cardiac nervous system. This network of neurons is embedded in the fat pad surrounding the heart. The system’s neurons exchange messages with the brain and with each other, and are the final players in a long chain of neurons that controls cardiac function. But because intrinsic cardiac neurons are exceedingly rare, making up only about 0.01% of the cells in a piece of heart tissue, their precise roles have been hard to pin down, says Chang. Damage from a heart attack comes from brain signals, mouse study suggests To fill that gap, his team genetically engineered mice to label all of the animals’ cardiac neurons. The scientists sequenced genes isolated from these neurons and identified markers for two neuronal subtypes. They then used techniques such as high-resolution imaging to identify the genetically distinct subtypes’ core functions and to map their locations. © 2026 Springer Nature Limited
Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 4: Development of the Brain
Link ID: 30336 - Posted: 07.22.2026
By Jake Currie Humans are social animals, so seeing a fellow human face triggers a cascade of activity in our brains. Information about the age, gender, familiarity, emotional state, and more get processed within milliseconds. Now, new research published in the journal Developmental Cognitive Neuroscience suggests how our brains respond to faces in our youth could impact our social lives later on. “Faces contain a lot of social information, and perceptually or cognitively humans process that information really, really quickly,” study author Myles N. Arrington said in a statement. “That makes it great for neuroscience, because as soon as you show a face to a person it doesn’t take long for their brain to respond.” Arrington and his fellow neuroscientists at the University of California, Davis studied brain activity of almost 6,000 children between the ages of 8 and 11 from the Adolescent Brain Cognitive Development Study. The kids were shown pictures of faces displaying positive, negative, and neutral emotions (which contain loads of social information) and places (which contain none) while their brain activity was monitored on an fMRI machine. Combining the fMRI results with two-year follow-ups, they found that increased activity in the amygdala—the brain’s fight-or-flight center—in response to faces was correlated with changes in their social lives. Interestingly, boys and girls with heightened amygdala activity had much different results later in life. Girls with more active amygdalas tended to have more involvement with peers two years down the road, while boys showed less involvement. According to the researchers, this could be due to differences in how the two genders are socialized. For example, “boys may be socialized to withhold intimacy and distance themselves from their peers,” the team wrote. It’s possible that this socialization can impact how their developing young minds process the social information contained in faces. © Copyright 2026
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: 30324 - Posted: 07.15.2026
By Emily Anthes Humor is deeply personal. A punchline or a pratfall that leaves one person doubled over in delight might elicit blank stares from another. But laughter is universal, an innate instinct shared by humans everywhere. And not just humans. Chimps chuckle, gorillas guffaw, bonobos bust a gut. All the planet’s great apes laugh, and they often do so in the same kind of regular, repeating rhythm that humans do, scientists found in a small new study. The research sheds light on how laughter evolved with and among great apes, becoming faster and more variable in humans than in these other primate species. While nonhuman apes appeared to laugh in ways that were largely fixed, humans were more flexible in their expressions of mirth, changing up the tempo of their chuckles depending on the circumstance, the scientists found. “I think we can say we are the masters of laughter,” said Chiara De Gregorio, a research fellow at the University of Warwick in Britain and an author of the study. “We can have a small, polite laugh in front of the Queen of England, and then we are in the pub with our friends, and we laugh so much in a different way. We can even laugh in a way that communicates to the other person that we actually didn’t find the joke they said funny.” This wide-ranging repertoire requires significant vocal flexibility and control — the same skills that humans would have needed for spoken language. The study demonstrates the “uniqueness of human laughter,” said Greg Bryant, a cognitive scientist at the University of California, Los Angeles, who was not involved in the new research. “It provides a window into human vocal evolution.” In the new study, which was published on Thursday in the journal Communications Biology, the researchers analyzed the recorded laughter of four children and 13 young, captive apes: four orangutans, two gorillas, three bonobos and four chimpanzees. Some of the recordings featured laughter produced during play, while others captured laughter elicited by tickling. © 2026 The New York Times Company
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: 30298 - Posted: 06.27.2026
By Elizabeth Preston To our human eyes, a mouse’s furred face doesn’t betray much emotion. But if you watch the body language of a mouse who’s reunited with one of her sisters after five days in a cage alone, you might suspect you know what she’s feeling. The formerly isolated mouse chatters in squeaks too high for a human to hear. She follows her sister, crawling beneath the other mouse’s body as if trying to get a hug. She looks like she’s feeling what you or I feel when meeting a long-lost friend or a family member — maybe with more sniffing. Loneliness isn’t just for humans, and neither are its harms. Over the past decade or so, some researchers have come to believe that an animal’s craving for the company of others isn’t just a preference, but a basic, deeply held need. When we don’t socialize enough, we feel the lack like hunger or thirst, they say. When we’ve had our fill of togetherness, we feel satisfied or quenched. The amount of socializing a creature needs may be particular to that species, and even to that individual. Scientists have found within-species social differences in birds, monkeys, fish and even cockroaches. Among humans, “you can feel lonely at a party, or you can feel fine alone in your office,” says Kay Tye, a neuroscientist at the Salk Institute for Biological Studies in California. Whatever the ideal degree of togetherness, Tye and others think that an animal’s need to balance time alone and time with others represents a kind of homeostasis: an equilibrium that’s critical for survival. Today, they are on a hunt to find where, in the brain, this equilibrium is controlled — and hoping their work will hold dividends for lonely humans.
Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 14: Attention and Higher Cognition
Link ID: 30269 - Posted: 06.06.2026
By Nicole Rust Anthropic’s artificial intelligence (AI), Claude, like other large language models (LLMs), appears to express emotions ranging from joy to despair when interacting with human users. In a report the company shared in April, researchers examined the model’s inner workings to understand why these emotional expressions happen and what they reflect about how Claude works. They concluded that these emotional displays are nontrivial, reflecting more than simple repetitions of patterns in Claude’s training data (the common pairing of the phrases “rainy day” and “feeling sad,” for example). At the same time, they found no evidence that Claude has genuine feelings like our own. Instead, Claude’s emotion equivalents contribute to its ability to adaptively solve complex problems. Like human emotions, this adaptivity comes at a cost, sometimes leading Claude to make irrational decisions. We should not conflate Claude’s emotions with our own, but studying emotion equivalents in Claude and other AIs can help lay the foundation for understanding the mysterious, multifaceted functions that emotions serve in humans. To understand Anthropic’s claims about Claude, we first need to grapple with its definition of “emotion.” For many, the term implies an inner experience—feelings such as happiness, fear or despair. But that is not the only way to define it. Consider “memory.” Like emotion, memory can refer to an inner experience: When we remember, we experience something. Yet when we talk about the memory of our laptop—having it retrieve an image, for example—we do not think of it as having an inner experience. In this second sense, memory is defined functionally; it is simply the capacity to store information for later recall and use. © 2026 Simons Foundation
Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 30248 - Posted: 05.20.2026
By Richard Stone The wind picks up dust from the unpaved road one afternoon in December as Jack van Honk turns into a ramshackle neighborhood in Lambert’s Bay, on the west coast of South Africa. A stocky woman in a red patterned sundress steps out of a small home painted palest sea green, her ochre-dirt yard crowded with potted plants, many medicinal. She smiles broadly, deep wrinkles creasing a face that is cherubic and yet careworn beyond her 47 years. “Doctor! I missed you,” she beams, her husky voice barely more than a hoarse whisper. Maria carries a rare genetic mutation that is almost unknown outside of southern Africa. Its effects have been to calcify a part of the brain called the basolateral amygdala, and to thicken and scar the vocal cords. A friend of Maria with the same condition lives several hours inland, and sometimes they meet when van Honk brings them to Cape Town for brain scans and other tests. “It helps to know I’m not alone,” Maria says. By every measure of daily life — holding down a job, keeping a household running, raising two teenage sons — Maria is competent and engaged. “You talk to her, and you don’t see anything wrong,” says van Honk, a social neuroscientist at the University of Cape Town. She and others he knows with her condition, Urbach-Wiethe disease, “are kind, sweet people by nature.” In an interview in her kitchen, Maria struggles to recollect even a fleeting moment of unhappiness — before mentioning that she kicked out her partner some years ago because of his drinking. Photograph of a woman in a red dress standing in her yard. Maria lives with a rare genetic disorder that damages part of the amygdala — a brain region increasingly linked not just to fear, but to how humans weigh the needs of others.
Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 30246 - Posted: 05.16.2026
By Hannah Thomasy For nearly a decade, Vincent Bombail has been tickling rats. It’s been a standard technique used in the study of animal happiness. But not all rats particularly enjoy the experience, data show. Female rats prefer gentler, more playful tickling than males, Bombail and his colleagues report April 15 in Biology Letters. The findings suggest that the same physical experience evokes a different emotional response in different individuals, potentially influencing the results of studies on animal happiness. “This research helps us understand these animals as playful but also rich and complex and having opinions,” says Daniel Weary, an animal welfare scientist at the University of British Columbia who was not involved in the study. “Understanding the affective lives of animals is actually one of the coolest and most difficult questions there is in science,” he says. As early as the 1930s, researchers deliberately exposed rats to standardized negative experiences to study the physical effects of stress. Figuring out how to study positive experiences took longer. It wasn’t until the 1990s that researchers developed the standard tickling protocol, where a researcher flips a rat over, pins it on its back and tickles its belly. The protocol is intended to mimic the rough-and-tumble play of young male rats. © Society for Science & the Public 2000–2026.
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: 30242 - Posted: 05.16.2026
By Holly Barker Astrocytes—but not neurons—in the amygdala encode anxiety-like states in mice, according to a paper published today in Neuron. The findings suggest that the cells—which are altered in people with some neuropsychiatric conditions, including autism—contribute to mental health difficulties documented in such groups. “In a very sophisticated way, the [study] shows that astrocytes are these core computational cells for highly complicated behaviors,” says Michael Wheeler, assistant professor of neurology at Harvard University, who did not contribute to the new work. “Astrocytes are understanding and signaling computations in these circuits.” Violent movies and other stressful stimuli activate the amygdala, human imaging studies have shown. And in mice, neurons in the basolateral amygdala are active when the animals are placed in exposed environments, which they find aversive, previous research has found. But that neuronal activity appears to mark shifts between defensive and exploratory behaviors rather than tracking anxiety-related ones, according to a later study. The new findings suggest that astrocytes not only help neurons to regulate anxiety—as previous studies have shown—but “instruct local neurons from the top down,” says study investigator Ciaran Murphy-Royal, associate professor of neuroscience at the University of Montreal. The cells’ activity appears to function as a “safety signal,” that relays danger to other brain regions, he says. Murphy-Royal and his colleagues used calcium imaging to measure astrocytic activity in the mouse basolateral amygdala. Calcium release tracked with freezing, hesitancy and other behaviors reminiscent of anxiety as mice investigated various environments, the team found. In the elevated plus maze, for example, astrocyte activity rose when the rodents explored an open arm of the maze and surged whenever mice peeked over the edge of the suspended setup. © 2026 Simons Foundation
Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 30174 - Posted: 03.25.2026
By Joshua P. Johansen Growing up in the 1980s in Santa Cruz, California, where redwood-covered mountains descend to the rocky edge of the Pacific, might sound idyllic. But in the dark wake of the drug-fueled ’70s, the beach town could also be frightening. There was a bully at my high school who once chased me down the street threatening to hurt me. Unsurprisingly, catching sight of him in the hallways or at the skate park filled me with dread. Just walking past his house would trigger a wave of anxiety. Yet if I saw him in class, with teachers present, I felt more at ease. How did my brain know to fear him only in specific circumstances? More broadly, how did I infer emotional significance from the world around me? The fact that I or anyone can make these judgments suggests that emotion arises from an internal model in the brain that supports inference, abstraction and flexible, context-dependent evaluations of threat or safety. These model-based emotion systems helped me infer danger from otherwise innocuous features of the environment, such as the bully’s house, or to downgrade my alarm, as I did when an adult was present. Understanding the neural basis of emotion is a central question in neuroscience, with profound implications for the treatment of anxiety, trauma and mood disorders. Yet the field remains divided over what emotions are and how they should be defined, limiting progress. On one side are neurobiologists focused on the neural underpinnings of simple learned and innate defensive behaviors. On the other are psychological theorists who view emotions as subjective experiences arising from complex conceptual brain models of the world that are unique to humans. This divide fuels persistent arguments over whether emotion should be defined primarily as a conscious state or not. Though subjective feelings are undeniably important, limiting our definitions to conscious phenomena prevents us from studying the underlying mechanisms in nonhuman species. To move forward, we need to identify the conserved neural processes that support higher-order, internal-model-based emotional experiences across species, regardless of whether they rise to consciousness. © 2026 Simons Foundation
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: 30096 - Posted: 01.28.2026
By Darren Incorvaia Much like his ninja namesake, Naruto the white-lipped peccary was a bit of a loner. Named after the titular character from a popular manga and anime, Naruto was the youngest male and one of the least social in his group of 17 peccaries, all of whom were born and raised in captivity at the Laboratory of Applied Ethology at the State University of Santa Cruz in Ilhéus, Brazil. Destined for reintroduction into Brazil’s Estação Veracel Private Natural Heritage Reserve and the Pau-Brasil Ecological Station, the peccaries were each given a personality test of sorts by lab researchers. The piglike mammals were video recorded as they went about their daily lives, resulting in 17 hours’ worth of behavioral data. Their aggressive actions, friendly touches and moments of exploration were tallied so that the peccaries could be ranked in traits such as boldness and sociability. The goal was to determine whether an individual peccary’s behavioral traits influenced its survival when released into the wild. White-lipped peccaries (Tayassu pecari) are listed as vulnerable by the International Union for Conservation of Nature, or IUCN. In Brazil, the size of the species’ historical range had plunged by 60 percent by 2020, and past efforts to reintroduce them had met limited success. Around the globe, scientists are increasingly recognizing how a reintroduced animal’s personality can impact how both individuals and groups fare in the wild. Such work is part of a growing trend to infuse the study of personality, and how it affects behavior, into conservation. When working with wild animals and tight budgets, personality tests may not always be possible. But understanding animal personality could help conservationists choose which individuals stand the best chance of surviving — helping to restore populations threatened with extinction. © Society for Science & the Public 2000–2026.
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: 30083 - Posted: 01.17.2026
By Natalia Mesa Nestled in the ventromedial nucleus of the hypothalamus lies a cluster of neurons that can make otherwise mild-mannered mice fly into a rage. Stimulating these neurons, as if flipping a switch, prompts male mice to attack their cagemates. The optogenetic manipulation of these and other specialized hypothalamic neurons, starting in the early 2010s, supported the long-standing idea that distinct cell types act as an “on” switch for different innate behaviors. But it has proved challenging to disentangle the neural signals that underlie those innate behaviors from ones that drive an animal’s internal state—such as anger, hunger or sexual arousal. Mounting evidence suggests that the hypothalamus also gives rise to these internal states, which can shape innate perceptions and behaviors. Rather than triggering an innate behavior, a specific pattern of population activity encodes the intensity and duration of anger and sexual arousal, according to four studies published within the past three years. This work is “revolutionary for the hypothalamus community,” says Tatiana Engel, associate professor of computational neuroscience at the Princeton Neuroscience Institute, who was not involved in the studies. It upends the notion that the neurons in the hypothalamus merely act as a simple switchboard, Engel says. Instead, local computations in the hypothalamus keep track of the animal’s internal state and influence its behavior, the studies suggest. The hypothalamic signals that encode the intensity and duration of aggression and sexual arousal can be represented by a mathematical model called a line attractor, the four studies show. © 2026 Simons Foundation
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: 30073 - Posted: 01.10.2026
By Trip Gabriel Paul Ekman, a psychologist who linked thousands of facial expressions to the emotions they often subconsciously conveyed, and who used his research to advise F.B.I. interrogators and screeners for the Transportation Security Administration as well as Hollywood animators, died on Nov. 17 at his home in San Francisco. He was 91. His daughter, Eve Ekman, confirmed the death. Dr. Ekman sought to add scientific exactitude to the human impulse to interpret how others feel through their facial expressions. He recorded 18 types of smiles, for example, distinguishing between a forced smile and a spontaneous one; a genuine smile, he discovered, crinkles the orbicularis oculi muscle — that is, it creates crow’s feet around the eyes. Sometimes described as the world’s most famous face reader, Dr. Ekman was ranked No. 15 in 2015 by the American Psychological Association in its list of 200 eminent psychologists of the modern era. He was influential in reshaping the way facial expressions were understood — as the product of evolution rather than environment — and his findings crossed over to popular culture. The Fox TV drama “Lie to Me,” which ran for three seasons starting in 2009, featured a psychologist modeled on Dr. Ekman (played by Tim Roth) who assists criminal investigations by decoding the hidden meanings of facial expressions and body language. The show was developed by the producer Brian Grazer, who was inspired by a lengthy profile of Dr. Ekman by Malcolm Gladwell in The New Yorker in 2002. “The idea that you could tell a liar by some scientific test and know what they’re feeling just by looking at them was staggering to me,” the show’s writer, Samuel Baum, told The New York Times in 2009. As a young research psychologist in the late 1960s, Dr. Ekman changed the scientific consensus on facial expressions. In the postwar era, the conventional wisdom of eminent anthropologists like Margaret Mead was that human facial expressions were learned and that they varied across cultures. © 2025 The New York Times Company
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: 30031 - Posted: 11.29.2025
Joel Snape All vertebrates yawn, or indulge in a behaviour that’s at least recognisable as yawn-adjacent. Sociable baboons yawn, but so do semi-solitary orangutans. Parakeets, penguins and crocodiles yawn – and so, probably, did the first ever jawed fish. Until relatively recently, the purpose of yawning wasn’t clear, and it’s still contested by researchers and scientists. But this commonality provides a clue to what it’s really all about – and it’s probably not what you’re expecting. “When I poll audiences and ask: ‘Why do you think we yawn?’, most people suggest that it has to do with breathing or respiration and might somehow increase oxygen in the blood,” says Andrew Gallup, a professor in behavioural biology at Johns Hopkins University. “And that’s intuitive because most yawns do have this clear respiratory component, this deep inhalation of air. However, what most people don’t realise is that that hypothesis has been explicitly tested and shown to be false.” To test the idea that we yawn to bring in more oxygen or expel excess carbon dioxide, studies published in the 1980s manipulated the levels of both gases in air inhaled by volunteers – and they found that while changes did significantly affect other respiratory processes, they didn’t influence the regularity of yawns. There also doesn’t seem to be any systematically measurable difference in the yawning behaviour of people suffering from illnesses associated with breathing and lung function – which is what you would expect if yawns were respiration-related. This, more or less, was where Gallup came to the subject. “When I was pursuing my honours thesis, my adviser at the time said, well, why not study yawning, because nobody knows why we do it?” he says. “That was intriguing – we knew it had to serve some underlying physiological function. So I started to examine the motor action pattern it involves – this extended gaping of the jaw that’s accompanied by this deep inhalation of air, followed by a rapid closure of the jaw and a quicker exhalation. And it occurred to me that this likely has important circulatory consequences that are localised to the skull.” © 2025 Guardian News & Media Limited
Related chapters from BN: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 11: Emotions, Aggression, and Stress
Link ID: 29990 - Posted: 10.29.2025
By Lauren Schneider Bad news for mouse poker players: Their facial movements offer “tells” about decision-making variables that the animals track without always acting on them, according to a study published today in Nature Neuroscience. The findings indicate that “cognition is embodied in some surprising ways,” says study investigator Zachary Mainen, a researcher at the Champalimaud Center for the Unknown. And this motor activity holds promise as a noninvasive bellwether of cognitive patterns. The study builds on mounting evidence that mouse facial expressions are not solely the result of a task’s motor demands and provides a “very clear” illustration of how this movement reflects cognitive processes, says Marieke Schölvinck, a researcher at the Ernst Strüngmann Institute for Neuroscience, who was not involved with the work. For years, mouse facial movements have mostly served as a way for researchers to gauge an animal’s pain levels. Now, however, machine-learning technology has made it possible to analyze this fine motor behavior in greater detail, says Schölvinck, who has investigated how facial expressions reflect inner states in mice and macaques. Evidence that mouse facial expressions correspond to emotional states inspired the new analysis, according to Fanny Cazettes, who conducted the experiments as a postdoctoral researcher in Mainen’s lab. She says she wondered what other ways the “internal, private thoughts of animals” might manifest on their faces. Two variables shape most mouse decisions over different foraging sites, the team found: the number of failures at a site (unrewarded licks from a source of sugar water) and the site’s perceived value (the difference between reward and failure). © 2025 Simons Foundation
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: 29950 - Posted: 10.01.2025
By Brandon Keim Should you meet a turtle basking on a log in the sun, you might reasonably conclude that the turtle is in a good mood. Granted, there has been little scientific evidence that reptiles experience such emotional richness — until now, at least. Researchers in England identified what they describe as “mood states” — emotional experiences that are more than momentary — in red-footed tortoises by administering cleverly designed tests that use responses to ambiguity as windows into the psyche. The results of the study, published in the journal Animal Cognition in June, could apply to many more reptiles and have profound implications for how people treat them. “There was an acceptance that reptiles could do these short-term emotions,” said Oliver Burman, who studies animal behavior at the University of Lincoln in England and is an author of the paper. “They could respond to positive things and unpleasant things. But the long-term mood states are really important.” As for why it took so long to show this in reptiles, Dr. Burman said, “maybe we just haven’t asked them correctly.” Reptiles have a longstanding reputation as being unintelligent. Writing in 1892, Charles Henry Turner, the pioneering comparative psychologist, described reptiles as “intellectual dwarfs.” Eight decades later, in 1973, prominent scientists were referring to them as “reflex machines” and (in a paper titled “The Evolutionary Advantages of Being Stupid”) as possessing “a very small brain which does not function vigorously. Dr. Burman is among the scientists responsible for what some have called a “reptilian renaissance.” An array of findings — tortoises learning from one another, snakes with social networks, crocodiles displaying complex communication — indicate that reptiles are no less brainy than mammals and birds. © 2025 The New York Times Company
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: 29938 - Posted: 09.20.2025
By R. Douglas Fields It is late at night. You are alone and wandering empty streets in search of your parked car when you hear footsteps creeping up from behind. Your heart pounds, your blood pressure skyrockets. Goose bumps appear on your arms, sweat on your palms. Your stomach knots and your muscles coil, ready to sprint or fight. Now imagine the same scene, but without any of the body’s innate responses to an external threat. Would you still feel afraid? Experiences like this reveal the tight integration between brain and body in the creation of mind — the collage of thoughts, perceptions, feelings and personality unique to each of us. The capabilities of the brain alone are astonishing. The supreme organ gives most people a vivid sensory perception of the world. It can preserve memories, enable us to learn and speak, generate emotions and consciousness. But those who might attempt to preserve their mind by uploading its data into a computer miss a critical point: The body is essential to the mind. How is this crucial brain-body connection orchestrated? The answer involves the very unusual vagus nerve. The longest nerve in the body, it wends its way from the brain throughout the head and trunk, issuing commands to our organs and receiving sensations from them. Much of the bewildering range of functions it regulates, such as mood, learning, sexual arousal and fear, are automatic and operate without conscious control. These complex responses engage a constellation of cerebral circuits that link brain and body. The vagus nerve is, in one way of thinking, the conduit of the mind. How could stimulating a single nerve potentially have such wide-ranging psychological and cognitive benefits? Nerves are typically named for the specific functions they perform. Optic nerves carry signals from the eyes to the brain for vision. Auditory nerves conduct acoustic information for hearing. The best that early anatomists could do with this nerve, however, was to call it the “vagus,” from the Latin for “wandering.” The wandering nerve was apparent to the first anatomists, notably Galen, the Greek polymath who lived until around the year 216. But centuries of study were required to grasp its complex anatomy and function. This effort is ongoing: Research on the vagus nerve is at the forefront of neuroscience today. © 2025Simons Foundation
Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 29909 - Posted: 08.30.2025
Jon Hamilton Get cut off in rush-hour traffic and you may feel angry for the whole trip, or even snap at a noisy child in the back seat. Get an unexpected smile from that same kid and you may feel like rush hour — and even those other drivers — aren't so bad. "The thing about emotion is it generalizes. It puts the brain into a broader state," says Dr. Karl Deisseroth, a psychiatrist and professor at Stanford University. Deisseroth and a team of researchers have come up with an explanation for how that happens. The process involves a signal that, after a positive or negative experience, lingers in the brain, the team reports in the journal Science. Experiences themselves act a bit like piano notes in the brain. Some are staccato, producing only a brief burst of activity that may result in a reflexive response, like honking at another driver, or smiling back at a child. But more profound experiences can be more like a musical note that is held with the sustain pedal and still audible when the next note is played, or the one after that. "You just need it to be sustained long enough to merge with and interact with other notes," Deisseroth says. "And from our perspective, this is exactly what emotion needs." If the team is right, it could help explain the emotional differences seen in some neuropsychiatric conditions. People on the autism spectrum, for example, often have trouble recognizing emotions in others, and regulating their own emotions. Schizophrenia can cause mood swings and reduced emotional expression. © 2025 npr
Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 13: Memory and Learning
Link ID: 29819 - Posted: 06.04.2025
Konstantina Kilteni Gargalesis, or tickle, is one of the most trivial yet enigmatic human behaviors. We do not know how a touch becomes ticklish or why we respond to other people’s tickles but not our own. No theory satisfactorily explains why touch on some body areas feels more ticklish than on others or why some people are highly sensitive while others remain unresponsive. Gargalesis is likely the earliest trigger for laughter in life, but it is unclear whether we laugh because we enjoy it. Socrates, Aristotle, Bacon, Galileo, Descartes, and Darwin theorized about tickling, but after two millennia of intense philosophical interest, experimentation remains scarce. This review argues that gargalesis is an exhilarating scientific puzzle with far-reaching implications for developmental, sensorimotor, social, affective, clinical, and evolutionary neuroscience. We reflect on the challenges in defining and eliciting ticklish sensations in the lab and unraveling their neural mechanism, discuss five classic yet unanswered questions about tickle, and suggest directions for future research. Gargalesis, commonly known as tickle, is a very familiar sensation that most of us have experienced at least once in life. Whether actively tickling our babies, family, friends, partners, or pets, or being on the receiving end of a tickle attack, humans undoubtedly engage in tickling behaviors. However, despite its triviality, the scientific understanding of gargalesis is extremely poor. Today, we do not know why certain areas of the body are more ticklish than others and why some people enjoy being tickled, while others dislike it but still burst into laughter. We have also not fully understood why we cannot tickle ourselves and why some people are very ticklish, while others are not responsive at all. Furthermore, the primary function of tickling in humans, as well as in other species, remains a big enigma. Are these questions new, and is that why we do not have any scientific answers yet? Definitely not! Inquiries about the epistemological role of gargalesis have persisted throughout human history, from Ancient Greece to the Renaissance and beyond (1). Socrates (in Plato’s “Philebus”), Aristotle (in “Parts of Animals”), Desiderius Erasmus (in “Adagia”), Francis Bacon (in “Sylva Sylvarum”), Galileo Galilei (in “Il Saggiatore”), René Descartes (in “Treatise on Man” and “The Passions of the Soul”), and Charles Darwin (in “The Expression of the Emotions in Man and Animals”) all theorized about different aspects of gargalesis including its nature and underlying mechanism.
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: 29805 - Posted: 05.24.2025
RJ Mackenzie Neuroscientists have identified a brain signal in mice that kick-starts the process of overwriting fearful memories once danger is passed — a process known as fear extinction. The research is at an early stage, but could aid the development of drugs to treat conditions, such as post-traumatic stress disorder (PTSD), that are linked to distressing past experiences. In a study published on 28 April in the Proceedings of the National Academy of Sciences1, the researchers focused on two populations of neurons in a part of the brain called the basolateral amygdala (BLA). These two types of neuron have contrasting effects: one stimulates and the other suppresses fear responses, says co-author Michele Pignatelli, a neuroscientist at Massachusetts Institute of Technology in Cambridge. Until now, scientists didn’t know what activated these neurons during fear extinction, although previous research implicated the neurotransmitter dopamine, released by a specific group of neurons in another part of the brain called the ventral tegmental area (VTA). To investigate this possibility, the authors used fluorescent tracers injected into the brains of mice to show that the VTA sends dopamine signals to the BLA, and that both pro- and anti-fear neurons in the BLA can respond to these signals. They then studied the effects of these circuits on behaviour, using mice that had been genetically modified so that dopamine activity in their brains produced fluorescent light, which allowed the researchers to record the activity of the VTA–BLA connections using fibre optics. They first placed these mice into chambers that delivered mild but unpleasant electrical shocks to their feet, which made them freeze in fear. The next day, they put the mice back in the chambers but did not give them any shocks. Although initially fearful, the mice began to relax after about 15 minutes, and the researchers saw a dopamine current surge through their ‘anti-fear’ BLA neurons. © 2025 Springer Nature Limited
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: 29766 - Posted: 04.30.2025
Hannah Thomasy, PhD In recent decades, scientists have demonstrated that prosocial behaviors are not unique to humans, or even to primates. Rats, in particular, have proved surprisingly sensitive to the distress of conspecifics, and will often come to the aid of a fellow rat in trouble. In 2011, researchers showed that when rats were provided with a clear box containing chocolate chips, they usually opened the box and consumed all the chocolate.1 But when one box contained chocolate and another contained a trapped cagemate, the rats were more likely to open both boxes and share the chocolate. But some rats didn’t play as nicely with others. In versions of the test that did not involve chocolate, only a rat and its trapped cagemate, researchers noticed that while some rats consistently freed their compatriots, others did not. In a new Journal of Neuroscience study, neuroscientists Jocelyn Breton at Northeastern University and Inbal Ben-Ami Bartal at Tel-Aviv University explored the behaviors and neural characteristics of helpers and non-helpers.2 They found that helper rats displayed greater social interactions with their cagemates, greater activity in prosocial neural networks, and greater expression of oxytocin receptors in the nucleus accumbens (NAc), providing clues about the mechanisms that govern prosocial behaviour. “We appear to live in an increasingly polarized society where there is a gap in empathy towards others,” said Bartal in a press release. “This work helps us understand prosocial, or helpful, acts better. We see others in distress all the time but tend to help only certain individuals. The similarity between human and rat brains helps us understand the way our brain mediates prosocial decisions.” To undertake these experiments, the researchers first divided the rats into pairs and allowed them to acclimatize to their cagemates for a few weeks. Then they placed the pair in the testing arena, where they allowed one rat to roam free and restrained the other in a clear box that could only be opened from the outside. While they were not trained to open the box, more than half of the rats figured out how to free their trapped companions and did so during multiple days of consecutive testing. © 1986-2025 The Scientist.
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: 29765 - Posted: 04.30.2025


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