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By Phie Jacobs Is there really such a thing as a “male” or “female” brain? Sex certainly seems to affect a person’s risk of developing various psychiatric and other brain-related conditions—but scientists aren’t entirely sure why. Attention-deficit/hyperactivity disorder for example, is more commonly diagnosed in individuals who were assigned male at birth (AMAB), whereas those assigned female at birth (AFAB) are more likely to exhibit symptoms of anxiety. It’s unclear, however, whether these differences are actually driven by sex, or have more to do with how people are perceived and treated based on their sex or gender. Now, new research suggests sex and gender are associated with distinct brain networks. Published today in Science Advances, the findings draw on brain imaging data from nearly 5000 children to reveal that gender and sex aren’t just distinct from one another in society—they also play unique roles in biology. In science, the term “biological sex” encompasses a variety of genetic, hormonal, and anatomical characteristics. People are typically assigned “male” or “female” as their sex at birth, although the medical establishment in recent years has begun to acknowledge that sex doesn’t always fall neatly into binary categories. Indeed, about 0.05% of children born in the United States are assigned intersex at birth. Gender, by contrast, has more to do with a person’s attitudes, feelings, and behavior—and may not always align with the sex they were assigned at birth. These nuances often go unrecognized in neuroscience, says Sheila Shanmugan, a reproductive psychiatrist at the University of Pennsylvania who wasn’t involved in the new study. Sex and gender-based differences in the brain “have historically been understudied,” she explains, “and terms describing each are often conflated.” © 2024 American Association for the Advancement of Science.

Keyword: Sexual Behavior; Brain imaging
Link ID: 29393 - Posted: 07.13.2024

By Erin Garcia de Jesús In spring 2022, a handful of red foxes in Wisconsin were behaving oddly. Veterinary pathologist Betsy Elsmo learned that a local wildlife rehabilitation center was caring for foxes with neurological symptoms like seizures, tremors, uncoordinated movements and lethargy. But tests for common pathogens like canine distemper virus and rabies that typically cause the symptoms came back negative. Then a red fox kit tested positive for influenza A. This group of viruses includes seasonal flus that cause respiratory disease in people and many other strains that commonly circulate among animals such as waterfowl and other birds. “I was surprised,” says Elsmo, of the University of Wisconsin–Madison. “And to be honest, at first I kind of wrote it off.” That is, until a veterinary technician at the rehab center sent Elsmo a study describing cases of avian influenza in red foxes in the Netherlands. Examinations of the Wisconsin kit’s tissues under the microscope revealed lesions in the brain, lung and heart that matched what had been seen in the Netherlands animals. “And I thought, I think it is [bird flu],” she recalls. Additional testing confirmed the diagnosis in the kit and the other foxes, Elsmo and colleagues reported in the December 2023 Emerging Infectious Diseases. The animals had contracted a lethal strain of H5N1 avian influenza that emerged in late 2020 in Europe and has since spread around the world. At the time infections were discovered in the Wisconsin red foxes, bird flu was expanding its incursion into North America. Since H5N1 arrived on North American shores in December 2021, it has infected animals as wide-ranging as polar bears, skunks, sea lions, bottlenosed dolphins and cows (SN: 7/8/24). And one unwelcome revelation of the ongoing outbreak is the virus’s propensity to invade the brains of myriad mammals. © Society for Science & the Public 2000–2024.

Keyword: Stress
Link ID: 29392 - Posted: 07.13.2024

By Lara Lewington, It's long been known that our lifestyles can help to keep us healthier for longer. Now scientists are asking whether new technology can also help slow down the ageing process of our brains by keeping track of what happens to them as we get older. One sunny morning, 76-year-old Dutch-born Marijke and her husband Tom welcomed me in for breakfast at their home in Loma Linda, an hour east of Los Angeles. Oatmeal, chai seeds, berries, but no processed sugary cereal or coffee were served - a breakfast as pure as Loma Linda’s mission. Loma Linda has been identified as one of the world’s so-called Blue Zones, places where people have lengthier-than-average lifespans. In this case, it is the city’s Seventh-Day Adventist Church community who are living longer. They generally don’t drink alcohol or caffeine, stick to a vegetarian or even vegan diet and consider it a duty of their religion to look after their bodies as best they can. This is their “health message”, as they call it, and it has put them on the map - the city has been the subject of decades of research into why its residents live better for longer. Dr Gary Fraser from the University of Loma Linda told me members of the Seventh-Day Adventist community there can expect not only a longer lifespan, but an increased “healthspan” - that is, time spent in good health - of four to five years extra for women and seven years extra for men. Marijke and Tom had moved to the city later in life, but both were now firmly embedded in the community. Copyright 2024 BBC.

Keyword: Development of the Brain; Learning & Memory
Link ID: 29391 - Posted: 07.13.2024

By Mitch Leslie Millions of people have taken glucagon-like peptide-1 (GLP-1) agonist drugs such as Ozempic to lose weight, despite the fact that the drugs can cause severe nausea and vomiting. But a new mouse study shows distinct groups of neurons in the brain diminish appetite and trigger nausea, a finding that could lead to less stomach-turning treatments that activate one set of cells and not the other. “It’s a very solid paper,” says neuroscientist Chuchu Zhang of the University of California, Los Angeles, who wasn’t connected to the study. “It shows us something new” about the activity of GLP-1 agonists. Scientists haven’t pinned down exactly how GLP-1 agonist drugs work, and previous studies have produced conflicting results on where they exert their effects. Some research suggests the drugs curb appetite by targeting the hypothalamus, a control center for physiological functions such as thirst and hunger that is located in the center of the brain. Other findings point to the rear portion of the brain, known as the hindbrain, and still others implicate the vagus nerve, which carries messages to and from organs such as the stomach and heart. All of these locations contain cells bearing GLP-1 receptors, to which the drugs bind. Another key question is whether the drugs cause weight loss primarily because people feel full or because they feel nauseated—a side effect suffered by more than half of individuals who take the drugs. “Do we need the nausea and aversion [to food] to see the appetite suppression and weight loss?” asks neuroscientist Amber Alhadeff of the Monell Chemical Senses Center. To answer that question, she and her colleagues first tried to pinpoint where GLP-1 agonists act. Using a genetically modified virus containing genes for either of two cell-killing molecules, they selectively eliminated cells bearing GLP-1 receptors in the hypothalamus, the hindbrain, or the vagus nerve. Only destroying the hindbrain cells prevented weight loss when mice received a GLP-1 agonist, suggesting this region curtails appetite. In a follow-up experiment, the researchers stimulated cells in the hindbrain and found that even slender mice lost weight. © 2024 American Association for the Advancement of Science.

Keyword: Obesity
Link ID: 29390 - Posted: 07.11.2024

Anna Bawden The idea that night owls who don’t go to bed until the early hours struggle to get anything done during the day may have to be revised. It turns out that staying up late could be good for our brain power as research suggests that people who identify as night owls could be sharper than those who go to bed early. Researchers led by academics at Imperial College London studied data from the UK Biobank study on more than 26,000 people who had completed intelligence, reasoning, reaction time and memory tests. They then examined how participants’ sleep duration, quality, and chronotype (which determines what time of day we feel most alert and productive) affected brain performance. They found that those who stay up late and those classed as “intermediate” had “superior cognitive function”, while morning larks had the lowest scores. Going to bed late is strongly associated with creative types. Artists, authors and musicians known to be night owls include Henri de Toulouse-Lautrec, James Joyce, Kanye West and Lady Gaga. But while politicians such as Margaret Thatcher, Winston Churchill and Barack Obama famously seemed to thrive on little sleep, the study found that sleep duration is important for brain function, with those getting between seven and nine hours of shut-eye each night performing best in cognitive tests. © 2024 Guardian News & Media Limited

Keyword: Biological Rhythms; Learning & Memory
Link ID: 29389 - Posted: 07.11.2024

By Miryam Naddaf About one-third of people who suffer from migraines experience a phenomenon known as aura before the headache.Credit: Tunatura/Getty For one billion people worldwide, the symptoms can be debilitating: throbbing head pain, nausea, blurred vision and fatigue that can last for days. But how brain activity triggers these severest of headaches — migraines — has long puzzled scientists. A study1 in mice, published in Science on 4 July, now offers clues about the neurological events that spark migraines. It suggests that a brief brain ‘blackout’ — when neuronal activity shuts down — temporarily changes the content of the cerebrospinal fluid, the clear liquid that surrounds the brain and spinal cord. This altered fluid, researchers suggest, travels through a previously unknown gap in anatomy to nerves in the skull where it activates pain and inflammatory receptors, causing headaches. “This work is a shift in how we think the headaches originate,” says Gregory Dussor, a neuroscientist at the University of Texas at Dallas in Richardson. “A headache might just be a general warning sign for lots of things happening inside the brain that aren’t normal.” “Migraine is actually protective in that way. The pain is protective because it’s telling the person to rest and recover and sleep,” says study co-author Maiken Nedergaard, a neuroscientist at the University of Copenhagen. The brain itself has no pain receptors; the sensation of headaches comes from areas outside the brain that are in the peripheral nervous system. But how the brain, which is not directly linked to the peripheral nervous system, triggers nerves to cause headaches is poorly understood, making them difficult to treat. © 2024 Springer Nature Limited

Keyword: Pain & Touch
Link ID: 29388 - Posted: 07.11.2024

Tijl Grootswagers Genevieve L Quek Manuel Varlet You are standing in the cereal aisle, weighing up whether to buy a healthy bran or a sugary chocolate-flavoured alternative. Your hand hovers momentarily before you make the final grab. But did you know that during those last few seconds, while you’re reaching out, your brain is still evaluating the pros and cons – influenced by everything from your last meal, the health star rating, the catchy jingle in the ad, and the colours of the letters on the box? Our recently published research shows our brains do not just think first and then act. Even while you are reaching for a product on a supermarket shelf, your brain is still evaluating whether you are making the right choice. Read news coverage based on evidence, not tweets Further, we found measuring hand movements offers an accurate window into the brain’s ongoing evaluation of the decision – you don’t have to hook people up to expensive brain scanners. What does this say about our decision-making? And what does it mean for consumers and the people marketing to them? There has been debate within neuroscience on whether a person’s movements to enact a decision can be modified once the brain’s “motor plan” has been made. Our research revealed not only that movements can be changed after a decision – “in flight” – but also the changes matched incoming information from a person’s senses. To study how our decisions unfold over time, we tracked people’s hand movements as they reached for different options shown in pictures – for example, in response to the question “is this picture a face or an object?” Put simply, reaching movements are shaped by ongoing thinking and decision-making. © 2010–2024, The Conversation US, Inc.

Keyword: Consciousness
Link ID: 29387 - Posted: 07.11.2024

By Teddy Rosenbluth The process for diagnosing a child with autism heavily relies on a parent's description of their child’s behavior and a professional’s observations. It leaves plenty of room for human error. Parents’ concerns may skew how they answer questionnaires. Providers may hold biases, leading them to underdiagnose certain groups. Children may show widely varying symptoms, depending on factors like culture and gender. A study published Monday in Nature Microbiology bolsters a growing body of research that suggests an unlikely path to more objective autism diagnoses: the gut microbiome. After analyzing more than 1,600 stool samples from children ages 1 to 13, researchers found several distinct biological “markers” in the samples of autistic children. Unique traces of gut bacteria, fungi, viruses and more could one day be the basis of a diagnostic tool, said Qi Su, a researcher at the Chinese University of Hong Kong and a lead author of the study. A tool based on biomarkers could help professionals diagnose autism sooner, giving children access to treatments that are more effective at a younger age, he said. “Too much is left to questionnaires,” said Sarkis Mazmanian, a microbiome researcher at the California Institute of Technology. “If we can get to something we can measure — whatever it is — that’s a huge improvement.” For decades, researchers have scoured the human genome, medical histories and brain scans for a reliable indicator of A.S.D., with limited success. The Food and Drug Administration has approved two diagnostic tests based on eye-tracking software, which Dr. Su said required significant involvement from a psychiatrist. © 2024 The New York Times Company

Keyword: Autism
Link ID: 29386 - Posted: 07.09.2024

By Tyler Sloan If I ask you to picture a group of “neurons firing,” what comes to mind? For most people, it’s a few isolated neurons flashing in synchrony. This type of minimalist representation of neurons is common within neuroscience, inspired in part by Santiago Ramón y Cajal’s elegant depictions of the nervous system. His work left a deep mark on our intuitions, but the method he used—Golgi staining—highlights just 1 to 5 percent of neurons. More than a century later, researchers have mapped out brain connectivity in such detail that it easily becomes overwhelming; I vividly recall an undergraduate neurophysiology lecture in which the professor showed a wiring diagram of the primary visual cortex to make the point that it was too complex to understand. We’ve reached a point where simple wiring diagrams no longer suffice to represent what we’re learning about the brain. Advances in experimental and computational neuroscience techniques have made it possible to map brains in more detail than ever before. The wiring diagram for the whole fly brain, for example, mapped at single-synapse resolution, comprises 2.7 million cell-to-cell connections and roughly 150 million synapses. Building an intuitive understanding of this type of complexity will require new tools for representing neural connectivity in a way that is both meaningful and compact. To do this, we will have to embrace the elaborate and move beyond the single neuron to a more “maximalist” approach to visualizing the nervous system. I spent my Ph.D. studying the spinal cord, where commissural growth cones are depicted as pioneers on a railhead extending through uncharted territory. The watershed moment for me was seeing a scanning electron micrograph of the developing spinal cord for the first time and suddenly understanding the growth cone’s dense environment—its path was more like squeezing through a crowded concert than wandering across an empty field. I realized how poor my own intuitions were, which nudged me toward learning the art of 3D visualization. © 2024 Simons Foundation

Keyword: Brain imaging; Development of the Brain
Link ID: 29385 - Posted: 07.09.2024

By Zachary Siegel Why do people use drugs? It’s one of those neglected questions with answers right in front of our noses. We just refuse to look. Getting high—and overdosing—is after all, as American as apple pie. Over 46 million people in the U.S. have an alcohol- or drug-use disorder. Everyone knows someone who died, or who lost a son or daughter, mother or father, to a drug overdose, one of the 100,000-plus now yearly recorded nationwide. Lost in today’s raging debate over drug policy and how to curb this spiraling mortality is the deep malaise that lies at the root of substance use in America. We are stuck on a loop, veering from “drug war” to legalization to backlash against legalization, without a record of improving lives and setting people on a successful path of recovery. And that’s because we are frankly unwilling to fix the economic cruelty that drives and keep people locked in dangerous drug use. In a 2022 photographic-ethnography published in the journal Criminology, investigators did the obvious thing and asked people using meth in rural Alabama how they made sense of their tumultuous lives. Rather than gathering post-hoc justifications for using meth, the study aimed to hear people who use drugs tell their own stories. The results painted a remarkably vivid portrait of poverty and drug use in 21st-century rural America. Across small towns in the northern tier of Alabama, a state with the sixth lowest median household income and seventh highest poverty rate, the researchers observed lives caught in repetitive and destructive patterns. Women felt trapped in relationships that were volatile and often violent. They would flee but have nowhere to go. People felt a pervasive sense that they lacked freedom and agency to improve their circumstances. If you feel boxed in by the absence of opportunity and mobility, then daily meth use, adding a synthetic buzz and thrill to otherwise boring or dreadful moments, isn’t such a stretch. © 2024 SCIENTIFIC AMERICAN,

Keyword: Drug Abuse
Link ID: 29384 - Posted: 07.09.2024

By Sara Reardon By eavesdropping on the brains of living people, scientists have created the highest-resolution map yet of the neurons that encode the meanings of various words1. The results hint that, across individuals, the brain uses the same standard categories to classify words — helping us to turn sound into sense. The study is based on words only in English. But it’s a step along the way to working out how the brain stores words in its language library, says neurosurgeon Ziv Williams at the Massachusetts Institute of Technology in Cambridge. By mapping the overlapping sets of brain cells that respond to various words, he says, “we can try to start building a thesaurus of meaning”. The brain area called the auditory cortex processes the sound of a word as it enters the ear. But it is the brain’s prefrontal cortex, a region where higher-order brain activity takes place, that works out a word’s ‘semantic meaning’ — its essence or gist. Previous research2 has studied this process by analysing images of blood flow in the brain, which is a proxy for brain activity. This method allowed researchers to map word meaning to small regions of the brain. But Williams and his colleagues found a unique opportunity to look at how individual neurons encode language in real time. His group recruited ten people about to undergo surgery for epilepsy, each of whom had had electrodes implanted in their brains to determine the source of their seizures. The electrodes allowed the researchers to record activity from around 300 neurons in each person’s prefrontal cortex. © 2024 Springer Nature Limited

Keyword: Language; Brain imaging
Link ID: 29383 - Posted: 07.06.2024

By Simon Makin Most of us have an “inner voice,” and we tend to assume everybody does, but recent evidence suggests that people vary widely in the extent to which they experience inner speech, from an almost constant patter to a virtual absence of self-talk. “Until you start asking the right questions you don’t know there’s even variation,” says Gary Lupyan, a cognitive scientist at the University of Wisconsin–Madison. “People are really surprised because they’d assumed everyone is like them.” A new study, from Lupyan and his colleague Johanne Nedergaard, a cognitive scientist at the University of Copenhagen, shows that not only are these differences real but they also have consequences for our cognition. Participants with weak inner voices did worse at psychological tasks that measure, say, verbal memory than did those with strong inner voices. The researchers have even proposed calling a lack of inner speech “anendophasia” and hope that naming it will help facilitate further research. The study adds to growing evidence that our inner mental worlds can be profoundly different. “It speaks to the surprising diversity of our subjective experiences,” Lupyan says. Psychologists think we use inner speech to assist in various mental functions. “Past research suggests inner speech is key in self-regulation and executive functioning, like task-switching, memory and decision-making,” says Famira Racy, an independent scholar who co-founded the Inner Speech Research Lab at Mount Royal University in Calgary. “Some researchers have even suggested that not having an inner voice may impact these and other areas important for a sense of self, although this is not a certainty.” Inner speech researchers know that it varies from person to person, but studies have typically used subjective measures, like questionnaires, and it is difficult to know for sure if what people say goes on in their heads is what really happens. “It’s very difficult to reflect on one’s own inner experiences, and most people aren’t very good at it when they start out,” says Charles Fernyhough, a psychologist at Durham University in England, who was not involved in the study. © 2024 SCIENTIFIC AMERICAN,

Keyword: Consciousness
Link ID: 29382 - Posted: 07.06.2024

By Charles Q. Choi Chimeroids—brain organoids grown from the cells of multiple people—offer scientists a novel way to compare individual differences in response to drugs, infections or pathogenic variants, according to a new study in Nature. “The possibilities are endless,” says lead investigator Paola Arlotta, professor and chair of stem cell and regenerative biology at Harvard University. The approach overcomes a longstanding issue that has plagued any comparison of organoids derived from different people: Disparities between the organoids might reflect genetic dissimilarities between individual people but could also result just from inadvertent variations in how each organoid was grown, says Aparna Bhaduri, assistant professor of biological chemistry at the University of California, Los Angeles, who did not contribute to the new study. Mixing cells from multiple donors into a single organoid makes it possible to grow all the cells under the same conditions and makes it more likely that any differences seen between the cells are rooted in genetic variations between the people, Bhaduri says. Initially, Arlotta’s team tried to produce chimeroids by mixing pluripotent stem cells from multiple donors. But one person’s cells usually outgrew the others to make up most of each organoid. Even small differences in the stem cells’ extremely high growth rates easily led one person’s cells to overshadow the others, the team noted. So instead, the researchers grew the stem cells independently in organoids until they began to proliferate more slowly as neural stem cells or neural progenitor cells. They then broke these organoids apart and mixed them together, producing the chimeroids that developed with balanced numbers of up to five donors’ cells. Each cell line in the chimeroids could produce all the cell types normally found in the cerebral cortex, Arlotta and her colleagues discovered using DNA and RNA sequencing techniques. © 2024 Simons Foundation

Keyword: Development of the Brain; Genes & Behavior
Link ID: 29381 - Posted: 07.06.2024

By Rodrigo Pérez Ortega It starts with blind spots, flashing lights, and blurry vision—a warning of what’s to come. About an hour later, the dreadful headache kicks in. This pairing, a shining visual experience called an aura and then a headache, happens in about one-third of people who live with migraine. But researchers haven’t been able to figure out exactly how the two are linked at the molecular level. Now, a new study in mice, published today in Science, establishes a direct mechanism: molecules traveling in the fluid that bathes the brain. The finding could lead to new targets for much-needed migraine treatments. “It’s exciting,” says Rami Burstein, a translational neuroscientist at Harvard Medical School who was not involved in the new study. “It takes a very large step into understanding how something that happened in the brain can alter sensation or perception,” he says. It may also explain why the pain of migraine is experienced only in the head, he adds. Migraine, a debilitating neurological disorder, affects about 148 million people worldwide. Recently developed medications can help reduce headaches but are not effective for everyone. Although exact causes remain elusive, research has shown migraines most likely start with a pathological burst of neural activity. During an aura before a migraine, researchers have observed a seizurelike phenomenon called cortical spreading depression (CSD), in which a wave of abnormal neural firing slowly travels throughout the brain’s outer layer, or cortex. But because the brain itself contains no pain-sensing neurons, signals from the brain would have to somehow reach the peripheral nervous system—the nerves that communicate between the body parts and the brain—to cause a headache. In particular, they’d have to get to the two lumps of neurons below the brain called the trigeminal ganglia, which innervate the two sides of our face and head. Scientists knew that pain fibers from the trigeminal ganglion were nested in the meninges—the thin, delicate membranes that envelop and protect the brain.

Keyword: Pain & Touch
Link ID: 29380 - Posted: 07.06.2024

By Paula Span About a month ago, Judith Hansen popped awake in the predawn hours, thinking about her father’s brain. Her father, Morrie Markoff, was an unusual man. At 110, he was thought to be the oldest in the United States. His brain was unusual, too, even after he recovered from a stroke at 99. Although he left school after the eighth grade to work, Mr. Markoff became a successful businessman. Later in life, his curiosity and creativity led him to the arts, including photography and sculpture fashioned from scrap metal. He was a healthy centenarian when he exhibited his work at a gallery in Los Angeles, where he lived. At 103, he published a memoir called “Keep Breathing.” He blogged regularly, pored over The Los Angeles Times daily, discussed articles in Scientific American and followed the national news on CNN and “60 Minutes.” Now he was nearing death, enrolled in home hospice care. “In the middle of the night, I thought, ‘Dad’s brain is so great,’” said Ms. Hansen, 82, a retired librarian in Seattle. “I went online and looked up ‘brain donation.’” Her search led to a National Institutes of Health web page explaining that its NeuroBioBank, established in 2013, collected post-mortem human brain tissue to advance neurological research. Through the site, Ms. Hansen contacted the nonprofit Brain Donor Project. It promotes and simplifies donations through a network of university brain banks, which distribute preserved tissue to research teams. Tish Hevel, the founder of the project, responded quickly, putting Ms. Hansen and her brother in touch with the brain bank at the University of California, Los Angeles. Brain donors may have neurological and other diseases, or they may possess healthy brains, like Mr. Markoff’s. “We’re going to learn so much from him,” Ms. Hevel said. “What is it about these superagers that allows them to function at such a high level for so long?” © 2024 The New York Times Company

Keyword: Development of the Brain; Brain imaging
Link ID: 29379 - Posted: 07.06.2024

By Dave Philipps David Metcalf’s last act in life was an attempt to send a message — that years as a Navy SEAL had left his brain so damaged that he could barely recognize himself. He died by suicide in his garage in North Carolina in 2019, after nearly 20 years in the Navy. But just before he died, he arranged a stack of books about brain injury by his side, and taped a note to the door that read, in part, “Gaps in memory, failing recognition, mood swings, headaches, impulsiveness, fatigue, anxiety, and paranoia were not who I was, but have become who I am. Each is worsening.” Then he shot himself in the heart, preserving his brain to be analyzed by a state-of-the-art Defense Department laboratory in Maryland. The lab found an unusual pattern of damage seen only in people exposed repeatedly to blast waves. The vast majority of blast exposure for Navy SEALs comes from firing their own weapons, not from enemy action. The damage pattern suggested that years of training intended to make SEALs exceptional was leaving some barely able to function. But the message Lieutenant Metcalf sent never got through to the Navy. No one at the lab told the SEAL leadership what the analysis had found, and the leadership never asked. It was not the first time, or the last. At least a dozen Navy SEALs have died by suicide in the last 10 years, either while in the military or shortly after leaving. A grass-roots effort by grieving families delivered eight of their brains to the lab, an investigation by The New York Times has found. And after careful analysis, researchers discovered blast damage in every single one. It is a stunning pattern with important implications for how SEALs train and fight. But privacy guidelines at the lab and poor communication in the military bureaucracy kept the test results hidden. Five years after Lieutenant Metcalf’s death, Navy leaders still did not know. Until The Times told the Navy of the lab’s findings about the SEALs who died by suicide, the Navy had not been informed, the service confirmed in a statement. © 2024 The New York Times Company

Keyword: Brain Injury/Concussion; Depression
Link ID: 29378 - Posted: 07.03.2024

By Adolfo Plasencia Recently, a group of Australian researchers demonstrated a “mind-reading” system called BrainGPT. The system can, according to its creators, convert thoughts (recorded with a non-invasive electrode helmet) into words that are displayed on a screen. Essentially, BrainGPT connects a multitasking EEG encoder to a large language model capable of decoding coherent and readable sentences from EEG signals. Is the mind, the last frontier of privacy, still a safe place to think one’s thoughts? I spoke with Harvard-based behavioral neurologist Alvaro Pascual-Leone, a leader in the study of neuroplasticity and noninvasive brain stimulation, about what it means and how we can protect ourselves. The reality is that the ability to read the brain and influence activity is already here. It’s no longer only in the realm of science fiction. Now, the question is, what exactly can we access and manipulate in the brain? Consider this example: If I instruct you to move a hand, I can tell if you are preparing to move, say, your right hand. I can even administer a precise “nudge” to your brain and make you move your right hand faster. And you would then claim, and fully believe, that you moved it yourself. However, I know that, in fact, it was me who moved it for you. I can even force you to move your left hand—which you were not going to move—and lead you to rationalize why you changed your mind when in fact, our intervention led to that action you perceive as your choice. We have done this experiment in our laboratory. In humans, we can modify brain activity by reading and writing in the brain, so to speak, though we can affect only very simple things right now. In animals, we can do much more complex things because we have much more precise control of the neurons and their timing. But the capacity for that modulation of smaller circuits progressively down to individual neurons in humans is going to come, including much more selective modification with optogenetic alternatives—that is, using light to control the activity of neurons. © 2024 NautilusNext Inc.,

Keyword: Brain imaging
Link ID: 29377 - Posted: 07.03.2024

By Carl Zimmer For thousands of years, philosophers have argued about the purpose of language. Plato believed it was essential for thinking. Thought “is a silent inner conversation of the soul with itself,” he wrote. Many modern scholars have advanced similar views. Starting in the 1960s, Noam Chomsky, a linguist at M.I.T., argued that we use language for reasoning and other forms of thought. “If there is a severe deficit of language, there will be severe deficit of thought,” he wrote. As an undergraduate, Evelina Fedorenko took Dr. Chomsky’s class and heard him describe his theory. “I really liked the idea,” she recalled. But she was puzzled by the lack of evidence. “A lot of things he was saying were just stated as if they were facts — the truth,” she said. Dr. Fedorenko went on to become a cognitive neuroscientist at M.I.T., using brain scanning to investigate how the brain produces language. And after 15 years, her research has led her to a startling conclusion: We don’t need language to think. “When you start evaluating it, you just don’t find support for this role of language in thinking,” she said. When Dr. Fedorenko began this work in 2009, studies had found that the same brain regions required for language were also active when people reasoned or carried out arithmetic. But Dr. Fedorenko and other researchers discovered that this overlap was a mirage. Part of the trouble with the early results was that the scanners were relatively crude. Scientists made the most of their fuzzy scans by combining the results from all their volunteers, creating an overall average of brain activity. © 2024 The New York Times Company

Keyword: Language; Consciousness
Link ID: 29376 - Posted: 07.03.2024

By Abdullahi Tsanni Time takes its toll on the eyes. Now a funky, Hitchcockian video of 64 eyeballs, all rolling and blinking in different directions, is providing a novel visual of one way in which eyes age. A video display of 64 eyeballs, captured using eye trackers, helped researchers compare the size of younger and older study participants’ pupils under differing light conditions, confirming aging affects our eyes. Lab studies have previously shown that the eye’s pupil size shrinks as people get older, making the pupil less responsive to light. A new study that rigged volunteers up with eye-trackers and GoPro videos and sent them traipsing around a university campus has confirmed what happens in the lab happens in real life, too. While pupils remain sensitive to changing light conditions, pupil size can decrease up to about 0.4 millimeters per decade, researchers report June 19 in Royal Society Open Science. “We see a big age effect,” says Manuel Spitschan, a neuroscientist at Max Planck Institute for Biological Cybernetics in Tubingen, Germany. The change helps explain why it can be increasingly harder for people to see in dim light as they age. Light travels through the dark pupil in the center of the eye to the retina, a layer of cells in the back of the eyes that converts the light into images. The pupil’s size can vary from 2 to 8 millimeters in diameter depending on light conditions, getting smaller in bright light and larger in dim light. “With a small pupil, less light enters the eye,” Spitschan says. © Society for Science & the Public 2000–2024.

Keyword: Vision; Development of the Brain
Link ID: 29375 - Posted: 07.03.2024

Richard Luscombe Federal health authorities on Tuesday gave approval to an experimental new drug that has shown to delay the onset of Alzheimer’s disease in trials. Donanemab, manufactured by Eli Lilly, is the second medication that has won the blessing of the Food and Drug Administration (FDA) to treat patients showing early symptoms of the disease, most prominently cognitive impairment. Last year, authorities cleared the drug lecanemab, marketed under the brand name Leqembi, after it demonstrated a similar decline in the progression of Alzheimer’s in a control group. The treatments are not a cure, but the first to physically alter the course of the disease rather than just addressing its symptoms, the FDA said. The video player is currently playing an ad. Indianapolis-based Eli Lilly reported the success of its trial a year ago, and subsequently applied for the FDA authorization that was announced today. Experts at the time said it “could be the beginning of the end of Alzheimer’s disease”, which affects almost 7 million people, mostly older Americans, according to the Alzheimer’s Association. “Kisunla demonstrated very meaningful results for people with early symptomatic Alzheimer’s disease, who urgently need effective treatment options,” Anne White, executive vice-president of Eli Lilly said on Tuesday, referring to donanemab by the brand name it will be sold under. © 2024 Guardian News & Media Limited

Keyword: Alzheimers
Link ID: 29374 - Posted: 07.03.2024