By David Marchese Our memories form the bedrock of who we are. Those recollections, in turn, are built on one very simple assumption: This happened. But things are not quite so simple. “We update our memories through the act of remembering,” says Charan Ranganath, a professor of psychology and neuroscience at the University of California, Davis, and the author of the illuminating new book “Why We Remember.” “So it creates all these weird biases and infiltrates our decision making. It affects our sense of who we are.” Rather than being photo-accurate repositories of past experience, Ranganath argues, our memories function more like active interpreters, working to help us navigate the present and future. The implication is that who we are, and the memories we draw on to determine that, are far less fixed than you might think. “Our identities,” Ranganath says, “are built on shifting sand.” What is the most common misconception about memory? People believe that memory should be effortless, but their expectations for how much they should remember are totally out of whack with how much they’re capable of remembering.1 Another misconception is that memory is supposed to be an archive of the past. We expect that we should be able to replay the past like a movie in our heads. The problem with that assumption is that we don’t replay the past as it happened; we do it through a lens of interpretation and imagination. Semantic memory is the term for the memory of facts and knowledge about the world. standpoint? It’s exceptionally hard to answer the question of how much we can remember. What I’ll say is that we can remember an extraordinary amount of detail that would make you feel at times as if you have a photographic memory. We’re capable of these extraordinary feats. I would argue that we’re all everyday-memory experts, because we have this exceptional semantic memory, which is the scaffold for episodic memory. I know it sounds squirmy to say, “Well, I can’t answer the question of how much we remember,” but I don’t want readers to walk away thinking memory is all made up. © 2024 The New York Times Company

Keyword: Learning & Memory
Link ID: 29134 - Posted: 02.06.2024

By Shruti Ravindran When preparing to become a butterfly, the Eastern Black Swallowtail caterpillar wraps its bright striped body within a leaf. This leaf is its sanctuary, where it will weave its chrysalis. So when the leaf is disturbed by a would-be predator—a bird or insect—the caterpillar stirs into motion, briefly darting out a pair of fleshy, smelly horns. To humans, these horns might appear yellow—a color known to attract birds and many insects—but from a predator’s-eye-view, they appear a livid, almost neon violet, a color of warning and poison for some birds and insects. “It’s like a jump scare,” says Daniel Hanley, an assistant professor of biology at George Mason University. “Startle them enough, and all you need is a second to get away.” Hanley is part of a team that has developed a new technique to depict on video how the natural world looks to non-human species. The method is meant to capture how animals use color in unique—and often fleeting—behaviors like the caterpillar’s anti-predator display. Most animals, birds, and insects possess their own ways of seeing, shaped by the light receptors in their eyes. Human retinas, for example, are sensitive to three wavelengths of light—blue, green, and red—which enables us to see approximately 1 million different hues in our environment. By contrast, many mammals, including dogs, cats, and cows, sense only two wavelengths. But birds, fish, amphibians, and some insects and reptiles typically can sense four—including ultraviolet light. Their worlds are drenched in a kaleidoscope of color—they can often see 100 times as many shades as humans do. Hanley’s team, which includes not just biologists but multiple mathematicians, a physicist, an engineer, and a filmmaker, claims that their method can translate the colors and gradations of light perceived by hundreds of animals to a range of frequencies that human eyes can comprehend with an accuracy of roughly 90 percent. That is, they can simulate the way a scene in a natural environment might look to a particular species of animal, what shifting shapes and objects might stand out most. The team uses commercially available cameras to record video in four color channels—blue, green, red, and ultraviolet—and then applies open source software to translate the picture according to the mix of light receptor sensitivities a given animal may have. © 2024 NautilusNext Inc.,

Keyword: Vision; Evolution
Link ID: 29133 - Posted: 02.06.2024

By Sabrina Malhi Researchers have found a possible link between the common hormone disorder PCOS and cognitive decline later in life. PCOS, which stands for polycystic ovary syndrome, is the most common endocrine disorder among women ages 15 to 44. However, it is often underdiagnosed because many of its symptoms, including abnormal menstrual cycles and excess hair, can be attributed to other causes. The syndrome was first described in 1935 by American gynecologists Irving F. Stein and Michael L. Leventhal. They published a paper documenting a group of women with lack of periods, excess body hair and enlarged ovaries with multiple cysts. Their work helped identify and characterize PCOS as it is known today. Health experts hypothesize that genetic factors could contribute to the development of the condition, but the exact causes are still unknown. Here’s what to know about PCOS and its potential link to cognitive health. PCOS is a chronic hormonal disorder characterized by overproduction of androgens, which are typically considered male hormones. High androgen levels can lead to irregular menstrual cycles and fertility issues when excessively produced in women. In the United States, 6 to 12 percent of people assigned female at birth who are of reproductive age are affected by PCOS, according to data from the Centers for Disease Control and Prevention. The condition is associated with an increased risk of obesity, high blood pressure, high cholesterol and endometrial cancer. PCOS is also often linked to insulin resistance, which can result in elevated blood sugar levels and an escalated risk of Type 2 diabetes. The condition can contribute to various metabolic issues, including high blood pressure, excess abdominal fat, and abnormal cholesterol or triglyceride levels. People with PCOS face an elevated risk of developing cardiovascular problems, such as high blood pressure, high cholesterol levels and an increased risk of heart disease. A recent study in the journal Neurology found that people with PCOS performed lower than normal on a suite of cognitive tests.

Keyword: Hormones & Behavior; Learning & Memory
Link ID: 29132 - Posted: 02.06.2024

By Ashley Juavinett In the 2010 award-winning film “Inception,” Leonardo DiCaprio’s character and others run around multiple layers of someone’s consciousness, trying to implant an idea in the person’s mind. If you can plant something deep enough, the film suggests, you can make them believe it is their own idea. The film was billed as science fiction, but three years later, in 2013, researchers actually did this — in a mouse, at least. The work focused on the hippocampus, along with its closely interconnected structures, long recognized by scientists to hold our dearest memories. If you damage significant portions of just one region of your hippocampus, the dentate gyrus, you’ll lose the ability to form new memories. How these memories are stored, however, is still up for debate. One early but persistent idea posits that enduring changes in our neural circuitry, or “engrams,” may represent the physical traces of specific memories. An engram is sometimes thought of as a group of cells, along with their synaptic weights and connections throughout the brain. In sum, the engram is what DiCaprio’s character would have had to discreetly manipulate in his target. In 2012, a team in Susumu Tonegawa’s lab at the Massachusetts Institute of Technology (MIT) showed that you could mark the cells of a real memory engram and reactivate them later. Taking that work one step further, Steve Ramirez, Xu Liu and others in Tonegawa’s lab demonstrated the following year that you can implant a memory of something that never even happened. In doing so, they turned science fiction into reality, one tiny foot shock at a time. Published in Science, Ramirez and Liu’s study is a breath of fresh air, scientifically speaking. The abstract starts with one of the shortest sentences you’ll ever find in a scientific manuscript: “Memories can be unreliable.” The entire paper is extremely readable, and there is no shortage of related papers and review articles that you could give your students to read for additional context. © 2024 Simons Foundation

Keyword: Learning & Memory
Link ID: 29131 - Posted: 02.06.2024

By Ernesto Londoño Seizures of psychedelic mushrooms across the nation by law enforcement officials have increased significantly in recent years as attitudes regarding their use have grown more permissive, according to a government-funded study released Tuesday. Researchers found that law enforcement officials confiscated 844 kilos of mushrooms containing psilocybin in 2022, an increase of 273 percent from 2017. Psilocybin is the psychoactive component in the fungi commonly known as magic mushrooms. Officials at the National Institute on Drug Abuse, which commissioned the study, said that the increase in seizures of magic mushroom reflected rising use of the drugs, rather than an indication that counternarcotics officials were pursuing the substances more aggressively than before. The marketplace for magic mushrooms, which are illegal under federal law, has boomed in recent years as several clinical studies have shown that they may be effective as therapies to treat depression and other serious conditions. But many medical professionals say they worry that the hype surrounding psychedelics has moved faster than the science. Dr. Nora Volkow, the director of the N.I.D.A, said that preliminary clinical studies had shown that psychedelics might one day become an important tool for the treatment of psychiatric disorders, including addiction to other drugs. But she said she worried that many people were self-medicating with psychedelics. “Psychedelic drugs have been promoted as a potential cure for many health conditions without adequate research to support these claims,” Dr. Volkow said. “There are people who are very desperate for mental health care, and there are businesses that are very eager to make money by marketing substances as treatments or cures.” © 2024 The New York Times Company

Keyword: Drug Abuse; Depression
Link ID: 29130 - Posted: 02.06.2024

Dawn Megli In late 2022, Sarah Gutilla's treatment-resistant depression had grown so severe that she was actively contemplating suicide. Raised in foster care, the 34-year-old's childhood was marked by physical violence, sexual abuse and drug use, leaving her with life-threatening mental scars. Out of desperation, her husband scraped together $600 for the first of six rounds of intravenous ketamine therapy at Ketamine Clinics Los Angeles, which administers the generic anesthetic for off-label uses such as treating depression. When Gutilla got into an Uber for the 75-mile ride to Los Angeles, it was the first time she had left her home in Llano, Calif., in two years. The results, she says, were instant. "The amount of relief I felt after the first treatment was what I think 'normal' is supposed to feel like," she says. "I've never felt so OK and so at peace." For-profit ketamine clinics have proliferated over the past few years, offering infusions for a wide array of mental health issues, including obsessive-compulsive disorder, depression and anxiety. Although the off-label use of ketamine hydrochloride, a Schedule III drug approved by the Food and Drug Administration as an anesthetic in 1970, was considered radical just a decade ago, now between 500 and 750 ketamine clinics have cropped up across the United States. Market analysis firm Grand View Research pegged industry revenues at $3.1 billion in 2022, and it projects them to more than double to $6.9 billion by 2030. Most insurance doesn't cover ketamine for mental health, so patients must pay out-of-pocket. While it's legal for doctors to prescribe ketamine, the FDA hasn't approved it for mental health treatment, which means that individual practitioners develop their own treatment protocols. The result is wide variability among providers, with some favoring gradual, low-dosage treatments while others advocate larger amounts that can induce hallucinations, as the drug is a psychedelic at the right doses. "Ketamine is the Wild West," says Dustin Robinson, the managing principal of Iter Investments, a venture capital firm specializing in hallucinogenic drug treatments. © 2024 npr

Keyword: Depression; Drug Abuse
Link ID: 29129 - Posted: 02.03.2024

By Carolyn Todd Any sleep tracker will show you that slumber is far from a passive affair. And no stage of sleep demonstrates that better than rapid eye movement, or REM, commonly called dream sleep. “It’s also called paradoxical sleep or active sleep, because REM sleep is actually very close to being awake,” said Dr. Rajkumar Dasgupta, a sleep medicine and pulmonary specialist at the Keck School of Medicine of the University of Southern California. Before scientists discovered REM sleep in the 1950s, it wasn’t clear that much of anything was happening in the brain at night. Researchers today, however, understand sleep as a highly active process composed of very different types of rest — including REM, which in some ways doesn’t seem like rest at all. While the body typically remains “off” during REM sleep, the brain is very much “on.” It’s generating vivid dreams, as well as synthesizing memories and knowledge. Scientists are still working to unravel exactly how this strange state of consciousness works. “It is fair to say that there is a lot left to learn about REM sleep,” Dr. Dasgupta said. But from what researchers do understand, REM is critical to our emotional health and brain function — and potentially even our longevity. Where does REM sleep fall in the sleep cycle? Throughout the night, “We’re going in and out of this rhythmic, symphonic pattern of the various stages of sleep: non-REM 1, 2, 3 and REM,” said Rebecca Robbins, an instructor in medicine at Harvard Medical School and an associate scientist in the division of sleep and circadian disorders at Brigham and Women’s Hospital. © 2024 The New York Times Company

Keyword: Sleep; Neuroimmunology
Link ID: 29128 - Posted: 02.03.2024

April Smith Did you know that anorexia is the most lethal mental health condition? One person dies from an eating disorder every hour in the U.S. Many of these deaths are not from health consequences related to starvation, but from suicide. Up to 1 in 5 women and 1 in 7 men in the U.S. will develop an eating disorder by age 40, and 1 in 2 people with an eating disorder will think about ending their life. About 1 in 4 people with anorexia nervosa or bulimia nervosa will attempt to kill themselves, and those with anorexia have a risk of death by suicide 31 times higher than peers without the disorder. In fact, nonsuicidal self-injury, suicidal ideation, suicide attempts and suicide deaths are all more prevalent among those with any type of eating disorder compared to those without an eating disorder. Why might that be? I am a clinical psychologist who studies eating disorders and self-harm, and I have spent the past 15 years researching this question. We still don’t have the answer. But new work on perception of the internal state of the body points to some promising possibilities for treatment. And what we’re learning could help anyone improve their relationship with their body. To understand why people with eating disorders are at risk of dying by suicide, I first want to ask you to do a little thought exercise. I’d like you to really think about your body: Think about your hair, face, arms, stomach, chest and legs. What words and feelings come to mind? Are there any things you wish you could change? Feel free to close your eyes and try this out. © 2010–2024, The Conversation US, Inc.

Keyword: Anorexia & Bulimia
Link ID: 29127 - Posted: 02.03.2024

By Laura Sanders Under extremely rare circumstances, it appears that Alzheimer’s disease can be transmitted between people. Five people who received contaminated injections of a growth hormone as children went on to develop Alzheimer’s unusually early, researchers report January 29 in Nature Medicine. The findings represent “the first time iatrogenic Alzheimer’s disease has been described,” neurologist John Collinge said January 25 in a news briefing, referring to a disease caused by a medical procedure. That sounds alarming, but researchers are quick to emphasize that Alzheimer’s disease is not contagious in everyday life, including caretaking and most medical settings. Support Science Today. Thank you for being a subscriber to Science News! Interested in more ways to support STEM? Consider making a gift to our nonprofit publisher, Society for Science, an organization dedicated to expanding scientific literacy and ensuring that every young person can strive to become an engineer or scientist. Donate Now “We are not suggesting for a moment that you can catch Alzheimer’s disease,” said Collinge, of the University College London’s Institute of Prion Diseases. “This is not transmissible in the sense of a viral or bacterial infection.” The reassurance is echoed by Carlo Condello, a neurobiologist at the University of California, San Francisco who wasn’t involved in the study. “In no way do we believe sporadic Alzheimer’s disease is a communicable disease,” he says. “Only under incredibly artificial, now out-of-date, medical practices is this appearing. It’s no longer an issue.” © Society for Science & the Public 2000–202

Keyword: Alzheimers
Link ID: 29126 - Posted: 01.31.2024

By Ben Guarino Billionaire technologist Elon Musk announced this week that his company Neuralink has implanted its brain-computer interface into a human for the first time. The recipient was “recovering well,” Musk wrote on his social media platform X (formerly Twitter) on Monday evening, adding that initial results showed “promising neuron spike detection”—a reference to brain cells’ electrical activity. Each wireless Neuralink device contains a chip and electrode arrays of more than 1,000 superthin, flexible conductors that a surgical robot threads into the cerebral cortex. There the electrodes are designed to register thoughts related to motion. In Musk’s vision, an app will eventually translate these signals to move a cursor or produce text—in short, it will enable computer control by thinking. “Imagine if Stephen Hawking could communicate faster than a speed typist or auctioneer. That is the goal,” Musk wrote of the first Neuralink product, which he said is named Telepathy. The U.S. Food and Drug Administration had approved human clinical trials for Neuralink in May 2023. And last September the company announced it was opening enrollment in its first study to people with quadriplegia. Monday’s announcement did not take neuroscientists by surprise. Musk, the world’s richest man, “said he was going to do it,” says John Donoghue, an expert in brain-computer interfaces at Brown University. “He had done the preliminary work, built on the shoulders of others, including what we did starting in the early 2000s.” Neuralink’s original ambitions, which Musk outlined when he founded the company in 2016, included meshing human brains with artificial intelligence. Its more immediate aims seem in line with the neural keyboards and other devices that people with paralysis already use to operate computers. The methods and speed with which Neuralink pursued those goals, however, have resulted in federal investigations into dead study animals and the transportation of hazardous material. © 2024 SCIENTIFIC AMERICAN

Keyword: Robotics
Link ID: 29124 - Posted: 01.31.2024

By Ben Guarino Billionaire technologist Elon Musk announced this week that his company Neuralink has implanted its brain-computer interface into a human for the first time. The recipient was “recovering well,” Musk wrote on his social media platform X (formerly Twitter) on Monday evening, adding that initial results showed “promising neuron spike detection”—a reference to brain cells’ electrical activity. Each wireless Neuralink device contains a chip and electrode arrays of more than 1,000 superthin, flexible conductors that a surgical robot threads into the cerebral cortex. There the electrodes are designed to register thoughts related to motion. In Musk’s vision, an app will eventually translate these signals to move a cursor or produce text—in short, it will enable computer control by thinking. “Imagine if Stephen Hawking could communicate faster than a speed typist or auctioneer. That is the goal,” Musk wrote of the first Neuralink product, which he said is named Telepathy. The U.S. Food and Drug Administration had approved human clinical trials for Neuralink in May 2023. And last September the company announced it was opening enrollment in its first study to people with quadriplegia. Monday’s announcement did not take neuroscientists by surprise. Musk, the world’s richest man, “said he was going to do it,” says John Donoghue, an expert in brain-computer interfaces at Brown University. “He had done the preliminary work, built on the shoulders of others, including what we did starting in the early 2000s.” Neuralink’s original ambitions, which Musk outlined when he founded the company in 2016, included meshing human brains with artificial intelligence. Its more immediate aims seem in line with the neural keyboards and other devices that people with paralysis already use to operate computers. The methods and speed with which Neuralink pursued those goals, however, have resulted in federal investigations into dead study animals and the transportation of hazardous material. © 2024 SCIENTIFIC AMERICAN

Keyword: Robotics
Link ID: 29123 - Posted: 01.31.2024

By Laurie McGinley ABINGTON, Pa. — Wrapped in a purple blanket, Robert Williford settles into a quiet corner of a bustling neurology clinic, an IV line delivering a colorless liquid into his left arm. The 67-year-old, who has early Alzheimer’s disease, is getting his initial dose of Leqembi. The drug is the first to clearly slow the fatal neurodegenerative ailment that afflicts 6.7 million older Americans, though the benefits may be modest. The retired social worker, one of the first African Americans to receive the treatment, hopes it will ease his forgetfulness so “I drive my wife less crazy.” But as Williford and his doctors embark on this treatment, they are doing so with scant scientific data about how the medication might work in people of color. In the pivotal clinical trial for the drug, Black patients globally accounted for only 47 of the 1,795 participants — about 2.6 percent. For U.S. trial sites, the percentage was 4.5 percent. The proportion of Black enrollees was similarly low for Eli Lilly Alzheimer’s drug, called donanemab, expected to be cleared by the Food and Drug Administration in coming months. Black people make up more than 13 percent of the U.S. population. The paltry data for the new class of groundbreaking drugs, which strip a sticky substance called amyloid beta from the brain, has ignited an intense debate among researchers and clinicians. Will the medications — the first glimmer of hope after years of failure — be as beneficial for African Americans as for White patients? “Are these drugs going to work in non-Whites? And particularly in Blacks? We just don’t have enough data, I don’t think,” said Suzanne E. Schindler, a clinical neurologist and dementia specialist at Washington University in St. Louis.

Keyword: Alzheimers
Link ID: 29122 - Posted: 01.31.2024

By Jyoti Madhusoodanan On July 12, 2015, Elena Daly was packing for a family vacation when she walked into her 16-year-old son’s room and found him unconscious. Her son, Max, had overdosed on opioids, aspirated vomit, and fallen into a coma. By that point, Max had struggled with addiction for about three years. He had tried medication, therapy, and residential treatment programs in France, where the family lives, as well as in the United States and the United Kingdom. In fact, his July relapse occurred just days after returning home from a six-month stint in an in-patient rehab program. The coma lasted three days and worsened a pre-existing movement disorder to a degree where Max was unable to attend high school. “I couldn’t hold a pen without throwing it across the room or hold a cup of coffee without spilling it on myself,” he recently recalled. Max’s struggles with opioid use are not unusual: An estimated 40 to 60 percent of people who have an addiction experience relapse after treatment. Some researchers have suggested that a substantial portion of those who relapse suffer from what might be considered a “treatment-resistant” form of the disorder, though that condition is not formally recognized as a medical diagnosis. In recent years, scientists have explored treating these intractable cases of opioid dependence with deep brain stimulation, an intervention that entails surgically implanting an electrode into a precisely determined region of the brain, where it delivers regular pulses to control problematic electric signals. The surgery has proven effective for neurological conditions such as Parkinson’s disease and essential tremor, a disorder that can cause a person’s limbs, head, trunk, and voice to quake. But for researchers attempting to study its efficacy for addiction, the procedure’s invasiveness and cost — typically in the hundreds of thousands of dollars — have raised steep hurdles. Work in the field has largely been limited to one-off treatments and small studies with one or a few participants, making it tough to ascertain how many people globally have received the treatment or how successful it has been for them.

Keyword: Drug Abuse
Link ID: 29121 - Posted: 01.31.2024

Ashley Montgomery In December 1963, a military family named the Gardners had just moved to San Diego, Calif. The oldest son, 17-year-old Randy Gardner, was a self-proclaimed "science nerd." His family had moved every two years, and in every town they lived in, Gardner made sure to enter the science fair. He was determined to make a splash in the 10th Annual Greater San Diego Science Fair. When researching potential topics, Gardner heard about a radio deejay in Honolulu, Hawaii, who avoided sleep for 260 hours. So Gardner and his two friends, Bruce McAllister and Joe Marciano, set out to beat this record. Randy Gardner spoke to NPR's Hidden Brain host Shankar Vedantam in 2017. When asked about his interest in breaking a sleep deprivation record, Gardner said, "I'm a very determined person, and when I get things under my craw, I can't let it go until there's some kind of a solution." Of his scientific trio, Randy lost the coin toss: He would be the test subject who would deprive himself of sleep. His two friends would take turns monitoring his mental and physical reaction times as well as making sure Gardner didn't fall asleep. The experiment began during their school's winter break on Dec. 28, 1963. Three days into sleeplessness, Gardner said, he experienced nausea and had trouble remembering things. Speaking to NPR in 2017, Gardner said: "I was really nauseous. And this went on for just about the entire rest of the experiment. And it just kept going downhill. I mean, it was crazy where you couldn't remember things. It was almost like an early Alzheimer's thing brought on by lack of sleep." But Gardner stayed awake. The experiment gained the attention of local reporters, which, in Gardner's opinion, was good for the experiment "because that kept me awake," he said. "You know, you're dealing with these people and their cameras and their questions." The news made its way to Stanford, Calif., where a young Stanford sleep researcher named William C. Dement was so intrigued that he drove to San Diego to meet Gardner. © 2024 npr

Keyword: Sleep
Link ID: 29120 - Posted: 01.31.2024

By Gina Kolata Aissam Dam, an 11-year-old boy, grew up in a world of profound silence. He was born deaf and had never heard anything. While living in a poor community in Morocco, he expressed himself with a sign language he invented and had no schooling. Last year, after moving to Spain, his family took him to a hearing specialist, who made a surprising suggestion: Aissam might be eligible for a clinical trial using gene therapy. On Oct. 4, Aissam was treated at the Children’s Hospital of Philadelphia, becoming the first person to get gene therapy in the United States for congenital deafness. The goal was to provide him with hearing, but the researchers had no idea if the treatment would work or, if it did, how much he would hear. The treatment was a success, introducing a child who had known nothing of sound to a new world. “There’s no sound I don’t like,” Aissam said, with the help of interpreters during an interview last week. “They’re all good.” While hundreds of millions of people in the world live with hearing loss that is defined as disabling, Aissam is among those whose deafness is congenital. His is an extremely rare form, caused by a mutation in a single gene, otoferlin. Otoferlin deafness affects about 200,000 people worldwide. The goal of the gene therapy is to replace the mutated otoferlin gene in patients’ ears with a functional gene. Although it will take years for doctors to sign up many more patients — and younger ones — to further test the therapy, researchers said that success for patients like Aissam could lead to gene therapies that target other forms of congenital deafness. © 2024 The New York Times Company

Keyword: Hearing
Link ID: 29119 - Posted: 01.27.2024

James O’Brien for Quanta Magazine In recent decades, neuroscience has seen some stunning advances, and yet a critical part of the brain remains a mystery. I am referring to the cerebellum, so named for the Latin for “little brain,” which is situated like a bun at the back of the brain. This is no small oversight: The cerebellum contains three-quarters of all the brain’s neurons, which are organized in an almost crystalline arrangement, in contrast to the tangled thicket of neurons found elsewhere. Encyclopedia articles and textbooks underscore the fact that the cerebellum’s function is to control body movement. There is no question that the cerebellum has this function. But scientists now suspect that this long-standing view is myopic. Or so I learned in November in Washington, D.C., while attending the Society for Neuroscience annual meeting, the largest meeting of neuroscientists in the world. There, a pair of neuroscientists organized a symposium on newly discovered functions of the cerebellum unrelated to motor control. New experimental techniques are showing that in addition to controlling movement, the cerebellum regulates complex behaviors, social interactions, aggression, working memory, learning, emotion and more. The connection between the cerebellum and movement has been known since the 19th century. Patients suffering trauma to the brain region had obvious difficulties with balance and movement, leaving no doubt that it was critical for coordinating motion. Over the decades, neuroscientists developed a detailed understanding of how the cerebellum’s unique neural circuitry controls motor function. The explanation of how the cerebellum worked seemed watertight. Then, in 1998, in the journal Brain, neurologists reported on wide-ranging emotional and cognitive disabilities in patients with damage to the cerebellum. For example, in 1991, a 22-year-old female college student had fallen while ice skating; a CT scan revealed a tumor in her cerebellum. After it was removed surgically, she was a completely different person. The bright college student had lost her ability to write with proficiency, do mental arithmetic, name common objects or copy a simple diagram. Her mood flattened. She hid under covers and behaved inappropriately, undressing in the corridors and speaking in baby talk. Her social interactions, including recognizing familiar faces, were also impaired.

Keyword: Emotions; Movement Disorders
Link ID: 29118 - Posted: 01.27.2024

By Erin Garcia de Jesús Bruce the kea is missing his upper beak, giving the olive green parrot a look of perpetual surprise. But scientists are the astonished ones. The typical kea (Nestor notabilis) sports a long, sharp beak, perfect for digging insects out of rotten logs or ripping roots from the ground in New Zealand’s alpine forests. Bruce has been missing the upper part of his beak since at least 2012, when he was rescued as a fledgling and sent to live at the Willowbank Wildlife Reserve in Christchurch. The defect prevents Bruce from foraging on his own. Keeping his feathers clean should also be an impossible task. In 2021, when comparative psychologist Amalia Bastos arrived at the reserve with colleagues to study keas, the zookeepers reported something odd: Bruce had seemingly figured out how to use small stones to preen. “We were like, ‘Well that’s weird,’ ” says Bastos, of Johns Hopkins University. Over nine days, the team kept a close eye on Bruce, quickly taking videos if he started cleaning his feathers. Bruce, it turned out, had indeed invented his own work-around to preen, the researchers reported in 2021 in Scientific Reports. First, Bruce selects the proper tool, rolling pebbles around in his mouth with his tongue and spitting out candidates until he finds one that he likes, usually something pointy. Next, he holds the pebble between his tongue and lower beak. Then, he picks through his feathers. “It’s crazy because the behavior was not there from the wild,” Bastos says. When Bruce arrived at Willowbank, he was too young to have learned how to preen. And no other bird in the aviary uses pebbles in this way. “It seems like he just innovated this tool use for himself,” she says. © Society for Science & the Public 2000–2024.

Keyword: Intelligence; Evolution
Link ID: 29117 - Posted: 01.27.2024

By Christian Guay & Emery Brown What does it mean to be conscious? People have been thinking and writing about this question for millennia. Yet many things about the conscious mind remain a mystery, including how to measure and assess it. What is a unit of consciousness? Are there different levels of consciousness? What happens to consciousness during sleep, coma and general anesthesia? As anesthesiologists, we think about these questions often. We make a promise to patients every day that they will be disconnected from the outside world and their inner thoughts during surgery, retain no memories of the experience and feel no pain. In this way, general anesthesia has enabled tremendous medical advances, from microscopic vascular repairs to solid organ transplants. In addition to their tremendous impact on clinical care, anesthetics have emerged as powerful scientific tools to probe questions about consciousness. They allow us to induce profound and reversible changes in conscious states—and study brain responses during these transitions. But one of the challenges that anesthesiologists face is measuring the transition from one state to another. That’s because many of the approaches that exist interrupt or disrupt what we are trying to study. Essentially, assessing the system affects the system. In studies of human consciousness, determining whether someone is conscious can arouse the person being studied—confounding that very assessment. To address this challenge, we adapted a simple approach we call the breathe-squeeze method. It offers us a way to study changes in conscious state without interrupting those shifts. To understand this approach, it helps to consider some insights from studies of consciousness that have used anesthetics. For decades researchers have used electroencephalography (EEG) to observe electrical activity in the brains of people receiving various anesthetics. They can then analyze that activity with EEG readings to characterize patterns that are specific to various anesthetics, so-called anesthetic signatures. © 2024 SCIENTIFIC AMERICAN

Keyword: Consciousness; Sleep
Link ID: 29116 - Posted: 01.27.2024

By Shaena Montanari Around 2012, Jennifer Groh and her colleagues began a series of experiments investigating the effect of eye movements on auditory signals in the brain. It wasn’t until years later that they noticed something curious in their data: In both an animal model and in people, eye movements coincide with ripples across the eardrum. The finding, published in 2018, seemed “weird,” says Groh, professor of psychology and neuroscience at Duke University — and ripe for further investigation. “You can go your whole career never studying something that is anywhere near as beautifully regular and reproducible,” she says. “Signals that are really robust are unlikely to be just random.” A new experiment from Groh’s lab has now taken her observation a step further and suggests the faint sounds — dubbed “eye movement-related eardrum oscillations,” or EMREOs for short — serve to link two sensory systems. The eardrum oscillations contain “clean and precise” information about the direction of eye movements and, according to Groh’s working hypothesis, help animals connect sound with a visual scene. “The basic problem is that the way we localize visual information and the way we localize sounds leads to two different reference frames,” Groh says. EMREOs, she adds, play a part in relating those frames. The brain, and not the eyes, must generate the oscillations, Groh and her colleagues say, because they happen at the same time as eye movements, or sometimes even before. To learn more about the oscillations, the team placed small microphones in the ears of 10 volunteers, who then performed visual tasks while the researchers tracked their eye movements. The group published their results in Proceedings of the National Academy of Sciences in November. © 2024 Simons Foundation

Keyword: Hearing
Link ID: 29115 - Posted: 01.27.2024

Jon Hamilton Scientists know that Black people are at a greater risk for health problems like heart disease, diabetes and Alzheimer's disease than white people. A growing body of research shows that racism in health care and in daily life contributes to these long-standing health disparities for Black communities. Now, some researchers are asking whether part of the explanation involves how racism, across individual interactions and systems, may physically alter the brain. "That could be behaviors like, let's say, a woman clutching her purse as a black man is walking next to her. Or they could be verbal, like someone saying, like... 'I didn't expect you to be so articulate,'" says Negar Fani, a clinical neuroscientist at Emory University who studies people experiencing Posttraumatic Stress Disorder, or PTSD. Recently, Fani has collaborated with Nate Harnett, an assistant professor of psychiatry at Harvard Medical School, to study how the brain responds to traumatic events and extreme stress, including the events and stress related to racism. So how does one go about measuring the impact of zoomed out, societal-scale issues on the individual? Harnett is the first to admit, it's not the simplest task. "It's very difficult for neuroimaging to look specifically at redlining," notes Harnett. But he can—indirectly. For example, Harnett has used inequities in neighborhood resources as a way of tracking or measuring structural racism. "We're able to look at these sort of proxy measures in these outcomes of structural racism and then correlate those with both brain and behavioral responses to stress or trauma and see how they tie with different psychiatric disorders like PTSD," Harnett says. In other research, Harnett and Fani have looked at correlations between racial discrimination and the response to threat in Black women who had experienced trauma. Fani says patients who experience PTSD tend to be more vigilant or show hyperarousal and be startled easily. Fani says their bodies are in a constant state of fight or flight—even when they're in a safe situation. But in patients who've also experienced racial discrimination, Fani says she sees the opposite effect: They show an increased activation in areas related to emotion regulation. In some ways, Fani says this activation can be adaptive. For example, people may experience microaggressions or discrimination at work and need to regulate their emotional response in order to get through the moment. But when people have to utilize this strategy over long periods of time, Fani and Harnett think it may contribute to the degradation they've seen in other areas in the brain. © 2024 npr

Keyword: Stress; Aggression
Link ID: 29114 - Posted: 01.27.2024