By Rachel E. Gross The first thing Debra McVean did when she woke up at the hospital in March 2024 was try to get to the bathroom. But her left arm wouldn’t move; neither would her left leg. She was paralyzed all along her left side. She had suffered a stroke, her doctor soon explained. A few nights before, a blood clot had lodged in an artery in her neck, choking off oxygen to her brain cells. Now an M.R.I. showed a dark spot in her brain, an eerie absence directly behind her right eye. What that meant for her prognosis, however, the doctor couldn’t say. “Something’s missing there, but you don’t know what,” Ms. McVean’s husband, Ian, recalled recently. “And you don’t know how that will affect her recovery. It’s that uncertainty, it eats away at you.” With a brain injury, unlike a broken bone, there is no clear road to recovery. Nor are there medical tools or therapies to help guide the brain toward healing. All doctors can do is encourage patients to work hard in rehab, and hope. That is why, for decades, the medical attitude toward survivors of brain injury has been largely one of neurological “nihilism,” said Dr. Fernando Testai, a neurologist at the University of Illinois, Chicago, and the editor in chief of the Journal of Stroke and Cerebrovascular Diseases. Stroke, he said, “was often seen as a disease of ‘diagnose and adios.’” That may be about to change. A few days after Ms. McVean woke up in the Foothills Medical Center in Calgary, she was told about a clinical trial for a pill that could help the brain recover from a stroke or traumatic injury, called Maraviroc. Given her level of physical disability, she was a good candidate for the study. She hesitated. The pills were large — horse pills, she called them. But she knew the study could help others, and there was a 50 percent chance that she would get a drug that could help her, too. © 2025 The New York Times Company

Keyword: Stroke; Regeneration
Link ID: 29921 - Posted: 09.06.2025

Rachel Fieldhouse An analysis of 56 million people has shown that exposure to air pollution increases the risk of developing a particular form of dementia, the third most common type after Alzheimer’s disease and vascular dementia. The study, published in Science on 4 September1, suggests that there is a clear link between long-term exposure to PM2.5 — airborne particles that are smaller than 2.5 micrometres in diameter — and the development of dementia in people with Lewy body dementia or Parkinson’s disease. The study found that PM2.5 exposure does not necessarily induce Lewy body dementia, but “accelerates the development,” in people who are already genetically predisposed to it, says Hui Chen, a clinician–neuroscientist at the University of Technology Sydney in Australia. PM2.5 exposure Lewy body dementia is an umbrella term for two different types of dementia: Parkinson’s disease with dementia, and dementia with Lewy bodies. In both cases, dementia is caused by the build-up of α-synuclein (αSyn) proteins into clumps, called Lewy bodies, in the brain’s nerve cells, which cause the cells to stop working and eventually die. Studies have suggested that long-term exposure to air pollution from car-exhaust, wildfires and factory fumes, is linked with increased risks of developing neurodegenerative illnesses, including Parkinson's disease with dementia2. Study co-author Xiaobo Mao, who researches neurodegenerative conditions at Johns Hopkins University in Baltimore, Maryland, says he and his colleagues wanted to determine if PM2.5 exposure also influenced the risk of developing Lewy body dementia. They analysed 2000–2014 hospital-admissions data from 56.5 million people with Lewy body dementia and Parkinson’s disease with or without dementia. The data served to identify people with severe neurological diseases. © 2025 Springer Nature Limited

Keyword: Alzheimers; Parkinsons
Link ID: 29920 - Posted: 09.06.2025

Ivana Drobnjak O'Brien An ultrasound “helmet” offers potential new ways for treating neurological conditions without surgery or other invasive procedures, a study has shown. The device can target brain regions 1,000 times smaller than ultrasound can, and could replace existing approaches such as deep brain stimulation (DBS) in treating Parkinson’s disease. It also holds potential for conditions such as depression, Tourette syndrome, chronic pain, Alzheimer’s and addiction. Unlike DBS, which requires a highly invasive procedure in which electrodes are implanted deep in the brain to deliver electrical pulses, using ultrasound sends mechanical pulses into the brain. But no one had managed to create an approach capable of delivering them precisely enough to make a meaningful impact until now. A study published in Nature Communications introduces a breakthrough system that can hit brain regions 30 times smaller than previous deep-brain ultrasound devices could. “It is a head helmet with 256 sources that fits inside an MRI scanner,” said the author and participant Ioana Grigoras, of Oxford University. “It is chunky and claustrophobic putting it on the head at first, but then you get comfortable.” Current DBS methods used on Parkinson’s patients use hard metal frames that are screwed into the head to hold them down. To test the system, the researchers applied it to seven volunteers, directing ultrasound waves to a tiny region the size of a grain of rice in the lateral geniculate nucleus (LGN), the key pathway for visual information that comes from the eyes to the brain. “The waves reached their target with remarkable accuracy,” the senior author Prof Charlotte Stagg of Oxford University said. “That alone was extraordinary, and no one has done it before.” Follow-up experiments showed that modulating the LGN produced lasting effects in the visual cortex, reducing its activity. “The equivalent in patients with Parkinson’s would be targeting a motor control region and seeing tremors disappear,” she added. © 2025 Guardian News & Media Limite

Keyword: Parkinsons; Brain imaging
Link ID: 29919 - Posted: 09.06.2025

By Claudia López Lloreda The process of making a decision engages neurons across the entire brain, according to a new mouse dataset created by an international collaboration. “Many, many areas are recruited even for what are arguably rather simple decisions,” says Anne Churchland, professor of neurobiology at University of California, Los Angeles and one of the founding members of the collaboration, called the International Brain Laboratory (IBL). The canonical model suggests that the activity underlying vision-dependent decisions goes from the visual thalamus to the primary visual cortex and association areas, and then possibly to the frontal cortex, Churchland says. But the new findings suggest that “maybe there’s more parallel processing and less of a straightforward circuit than we thought.” Churchland and other scientists established the IBL in 2017 out of frustration with small-scale studies of decision-making that analyzed only one or two brain regions at a time. The IBL aimed to study how the brain integrates information and makes a decision at scale. “We came together as a large group with the realization that a large team effort could be transformative in these questions that had been kind of stymieing all of us,” Churchland says. After years of standardizing their methods and instrumentation across the 12 participating labs, the IBL team constructed a brain-wide map of neural activity in mice as they complete a decision-making task. That map, published today in Nature, reveals that the activity associated with choices and motor actions shows up widely across the brain. The same is true for the activity underlying decisions based on prior knowledge, according to a companion paper by the same team, also published today in Nature. © 2025 Simons Foundation

Keyword: Attention; Brain imaging
Link ID: 29918 - Posted: 09.06.2025

Jon Hamilton A rigorous new study finds that a single dose of LSD can ease anxiety and depression for months. The study involved 198 adults with generalized anxiety disorder, or GAD, a disabling form of anxiety that affects about 1 in 10 people over the course of a year. Participants who got lower doses of LSD (25 or 50 micrograms) did no better than those who got a placebo. But people who received higher doses (100 or 200 micrograms) responded quickly, a team reports in the Journal of the American Medical Association. "By the next day, they were showing strong improvements," says Dr. David Feifel of Kadima Neuropsychiatry Institute in San Diego, one of the 22 centers that participated in the study. "And those improvements held out all the way to the end of the study, which was 12 weeks." But it's unclear whether some of the improvement was related to non-drug factors like the sensory environment in which people were treated, says Robin Carhart-Harris, a psychedelics researcher at the University of California, San Francisco who was not involved in the study. "The safety looks good, the tolerability looks good," he says, "but where is the depth of information about the way you delivered this product?" Carhart-Harris, like many scientists who study psychedelics, believes that successful treatment is more likely if a person has the right mindset when beginning a trip and if the trip occurs in a place with the right sensory environment. "It's characterized by continuous worry, inability to relax, and all the physical manifestations, racing heart rates and sweatiness," Feifel says. It's also frequently accompanied by depression. Current antidepressant and antianxiety drugs are inadequate for about half of people diagnosed with GAD. © 2025 npr

Keyword: Stress; Drug Abuse
Link ID: 29917 - Posted: 09.06.2025

By Ute Eberle Before weight coach Bella Barnes consults with new clients, she already knows what they’ll say. The women struggle with their weight, naturally. But they don’t want to lose pounds. They want to gain them. Her clients find themselves too thin, and they’re suffering. “Last week, I signed up a client who wears leggings that have bum pads in them,” says Barnes, who lives in Great Britain. “I’ve had another client recently that, in summer, wears three pairs of leggings just to try and make herself look a bit bigger.” These women belong to a demographic group that has been widely overlooked. As the world focuses on its billion-plus obese citizens, there remain people at the other end of the spectrum who are skinny, often painfully so, but don’t want to be. Researchers estimate that around 1.9 percent of the population are “constitutionally thin,” with 6.5 million of these people in the United States alone. YOU MAY ALSO LIKE Conceptual illustration shows three dinner plates, two at night with crescent moons are empty, representing a nightly fast, and a third with a sun theme, full of food and representing the benefits of eating during a limited time during the day. Constitutionally thin individuals often eat as much as their peers and don’t exercise hard. Yet their body mass index is below 18.5 — and sometimes as low as 14, which translates to 72 pounds on a five-foot frame — and they don’t easily gain weight. The condition is “a real enigma,” write the authors of a recent paper in the Annual Review of Nutrition. Constitutional thinness, they say, challenges “basic dogmatic knowledge about energy balance and metabolism.” It is also understudied: Fewer than 50 clinical studies have looked at constitutionally thin people, compared with thousands on unwanted weight gain. © 2025 Annual Reviews

Keyword: Obesity
Link ID: 29916 - Posted: 09.06.2025

By Jeré Longman Dr. A. James Hudspeth, a neuroscientist at the Rockefeller University in Manhattan who was pivotal in discovering how sound waves are converted in the inner ear to electrical signals that the brain can perceive as a whisper, a symphony or a thunderclap, died on Aug. 16 at his home in Manhattan. He was 79. His wife, Dr. Ann Maurine Packard, said the cause was glioblastoma, a brain cancer. Scientists have long understood how sound waves enter the ear canal and cause the eardrum to vibrate. They have also understood how the vibrations travel through the three small bones of the middle ear, then to the cochlea in the inner ear, a tiny organ about the size of a chickpea that is filled with fluid and is shaped like a snail’s shell. And they have long known that microscopic receptor cells in the cochlea play a role in the process of hearing. But by the time Dr. Hudspeth began his research in the 1970s, it was still unclear how these cells — known as hair cells (the name derives from tufts of cylindrical, hairlike rods known as stereocilia) — transformed the mechanical vibrations of sound waves into nerve impulses that the brain could interpret as, say, a child crying or a dog barking. Dr. Hudspeth “provided the major framework” for this understanding, the committee that awarded him and two other scientists (Robert Fettiplace and Christine Petit) the Kavli Prize in Neuroscience for their pioneering work on the processes of hearing wrote in its citation in 2018. Each cochlea contains about 16,000 hair cells. Atop each cell, 20 to 300 of these rods are gathered in a bundle — the shortest to the tallest — in rows that resemble a staircase or a pipe organ. Hair cells line the cochlea, with each tuned to a narrow frequency range that collectively decodes the broad spectrum of tones in every sound. © 2025 The New York Times Compan

Keyword: Hearing
Link ID: 29915 - Posted: 09.06.2025

Ian Sample Science editor A three-minute brainwave test can detect memory problems linked to Alzheimer’s disease long before people are typically diagnosed, raising hopes that the approach could help identify those most likely to benefit from new drugs for the condition. In a small trial, the test flagged specific memory issues in people with mild cognitive impairment, highlighting who was at greater risk of developing Alzheimer’s. Trials in larger groups are under way. The Fastball test is a form of electroencephalogram (EEG) that uses small sensors on the scalp to record the brain’s electrical activity while people watch a stream of images on a screen. The test detects memory problems by analysing the brain’s automatic responses to images the person sees before the test. “This shows us that our new passive measure of memory, which we’ve built specifically for Alzheimer’s disease diagnosis, can be sensitive to those individuals at very high risk but who are not yet diagnosed,” said Dr George Stothart, a cognitive neuroscientist at the University of Bath, where the test was developed. The trial, run with the University of Bristol, involved 54 healthy adults and 52 patients with mild cognitive impairment (MCI). People with MCI have problems with memory, thinking or language, but these are not usually severe enough to prevent them doing their daily activities. Before the test, volunteers were shown eight images and told to name them, but not specifically to remember them or look out for them in the test. The researchers then recorded the participants’ brain activity as they watched hundreds of images flash up on a screen. Each image appeared for a third of a second and every fifth picture was one of the eight they had seen before. © 2025 Guardian News & Media Limited

Keyword: Alzheimers; Attention
Link ID: 29914 - Posted: 09.03.2025

Jon Hamilton People who inherit two copies of a gene variant called APOE4 have a 60% chance of developing Alzheimer's by age 85. Only about 2% to 3% of people in the U.S. have this genetic profile, and most of them don't know it because they've never sought genetic testing. But three scientists are among those who did get tested, and learned that they are in the high-risk group. Now, each is making an effort to protect not only their own brain, but the brains of others with the genotype known as APOE4-4. "I just felt like the end of the world," says June, who asked to use only her first name out of fear that making her genetic status public could affect her job or health insurance. June was 57 when she found out. As someone with a doctorate in biochemistry, she quickly understood what the results meant. New tests of blood and spinal fluid could help doctors quickly identify patients who would most benefit from treatment. "People with our genotype are almost destined to get the disease," she says. "We tend to get symptoms 7 to 10 years earlier than the general population, which means that I had about seven years left before I may get the disease." At first, June spent sleepless nights online, reading academic papers about Alzheimer's and genetics. She even looked into physician-assisted suicide in an effort to make sure she would not become a burden to her adult son. © 2025 npr

Keyword: Alzheimers; Genes & Behavior
Link ID: 29913 - Posted: 09.03.2025

Rachel Fieldhouse A man with partial paralysis was able to operate a robotic arm when he used a non-invasive brain device partially controlled by artificial intelligence (AI), a study reports1. The AI-enabled device also allowed the man to perform screen-based tasks four times better than when he used the device on its own. Brain–computer interfaces (BCIs) capture electrical signals from the brain, then analyse them to determine what the person wants to do and translate the signals into commands. Some BCIs are surgically implanted and record signals directly from the brain, which typically makes them more accurate than non-invasive devices that are attached to the scalp. Jonathan Kao, who studies AI and BCIs at the University of California, Los Angeles, and his colleagues wanted to improve the performance of non-invasive BCIs. The results of their work are published in Nature Machine Intelligence this week. First, the team tested its BCI by tasking four people — one with paralysis and three without — with moving a computer cursor to a particular spot on a screen. All four were able to complete the task the majority of the time. When the authors added an AI co-pilot to the device, the participants completed the task more quickly and had a higher success rate. The device with the co-pilot doesn’t need to decode as much brain activity because the AI can infer what the user wants to do, says Kao. “These co-pilots are essentially collaborating with the BCI user and trying to infer the goals that the BCI user is wishing to achieve, and then helps to complete those actions,” he adds. The researchers also trained an AI co-pilot to control a robotic arm. The participants were required to use the robotic arm to pick up coloured blocks and move them to marked spots on a table. The person with paralysis could not complete the task using the conventional, non-invasive BCI, but was successful 93% of the time using the BCI with an AI co-pilot. Those without paralysis also completed the task more quickly when using the co-pilot. © 2025 Springer Nature Limited

Keyword: Robotics
Link ID: 29912 - Posted: 09.03.2025

By Lauren Schenkman Microglia safeguard the proliferation and survival of young GABAergic interneurons by secreting insulin-like growth factor 1 (IGF-1), according to a new study of human brain tissue and organoids. The finding points to the potential origin of the brain signaling imbalance implicated in autism and other conditions. Microglia contribute to brain development, past findings show, but their exact function has been unclear. Some experiments showed that these cells prune neural circuits, but later work called that idea into question. The new research “identifies microglia as really an important source of IGF, and one that sets the supply of GABAergic interneurons in the developing brain,” says Damon Page, principal investigator at Seattle Children’s Research Institute. Page was not involved in this work but led an earlier investigation that showed IGF-1 prevents microcephaly in a mouse model of autism when administered during a critical window soon after birth. This new study “extends back that window into the embryonic period,” he says, with implications for understanding both typical development and conditions such as autism. The study was published 6 August in Nature. The investigators used staining techniques to pinpoint microglia in the medial ganglionic eminence, where interneurons form, in human brain tissue samples at various developmental stages. At early developmental stages, microglia were sprinkled throughout brain matter, but later on these cells arranged themselves around clusters of GABAergic neuroblasts, with their processes extending into the clusters. Microglia also aligned themselves with radial glia, the precursors to many brain cells. Based on existing data, IGF-1 emerged as the chemical most likely to mediate microglia’s effects on developing cell types, and in organoid models of the developing human brain, the cells secreted IGF-1, they found. © 2025 Simons Foundation

Keyword: Glia; Learning & Memory
Link ID: 29911 - Posted: 09.03.2025

By Joshua Cohen Roughly 40 percent of adult Americans are considered obese, and weight-loss drugs have come to play a central role in medical treatment over the past few years. As of the spring of 2024, one in eight U.S. adults had taken drugs including Wegovy, Zepbound, or Ozempic, among others, for weight loss. These products belong to a class of drugs known as glucagon-like peptide-1 agonists, or GLP-1s, which can be remarkably effective, but when patients go off GLP-1s, weight rebound occurs. And as it turns out, a relatively large portion of patients discontinue these medications within one year. Prime Therapeutics, a company that manages prescription drug coverage benefits for insurers, employers, and government programs, has been documenting this phenomenon. In 2023, the company published research indicating that merely 32 percent of patients remained on their GLP-1 at the end of one year. A follow-up analysis found that by year two, only 15 percent remained on the drug. And in a new review, the company found that only 8 percent of patients remained on the drugs after three years. The main reason for discontinuation — cited by almost half of patients in a large-scale survey — is concern about the medications’ side effects. People may quit their medication after experiencing common side effects, such as uncomfortable gastrointestinal issues. They may also quit out of fear of more serious ones, like certain cancers — although research suggests GLP-1s are associated with a lower risk for many types of cancer. Additionally, some GLP-1 users may also be at risk of nutrient deficiency and muscle or bone loss without a proper diet and exercise regimen. Health and nutrition experts suggest that optimizing the benefits conferred by GLP-1s requires lifestyle interventions aimed at modifying patient behavior. GLP-1 medicines work for weight loss by curbing hunger and slowing digestion, but they don’t replace the need for improved diet and increased physical activity. Rather, these prescription pharmaceuticals and other non-GLP-1 obesity drugs work together with nutrition and exercise to promote optimal health. In an email to Undark, Jody Dushay, an assistant professor at Harvard Medical School, wrote that “nutrition and exercise hugely benefit overall health” and increase the positive effects of the medications.

Keyword: Obesity
Link ID: 29910 - Posted: 09.03.2025

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

Keyword: Emotions
Link ID: 29909 - Posted: 08.30.2025

Mohana Basu People with a psychiatric disorder are more likely to marry someone who has the same condition than to partner with someone who doesn’t, according to a massive study1 suggesting that the pattern persists across cultures and generations. Researchers had previously noted this trend in Nordic countries, but the phenomenon has seldom been investigated outside Europe until now. The latest study, published in Nature Human Behaviour today, used data from more than 14.8 million people in Taiwan, Denmark and Sweden. It examined the proportion of people in those couples who had one of nine psychiatric disorders: schizophrenia, bipolar disorder, depression, anxiety, attention-deficit hyperactivity disorder, autism, obsessive–compulsive disorder (OCD), substance-use disorder and anorexia nervosa. Scientists lack a definitive understanding of what causes people to develop psychiatric disorders — but genetics and environmental factors are both thought to play a part. The team found that when one partner was diagnosed with one of the nine conditions, the other was significantly more likely to be diagnosed with the same or another psychiatric condition. Spouses were more likely to have the same conditions than to have different ones, says co-author Chun Chieh Fan, a population and genetics researcher at the Laureate Institute for Brain Research in Tulsa, Oklahoma. “The main result is that the pattern holds across countries, across cultures, and, of course, generations,” Fan says. Even changes in psychiatric care over the past 50 years have not shifted the trend, he notes. Only OCD, bipolar disorder and anorexia nervosa showed different patterns across countries. For instance, in Taiwan, married couples were more likely to share OCD than were couples in Nordic countries. © 2025 Springer Nature Limited

Keyword: Depression; Schizophrenia
Link ID: 29908 - Posted: 08.30.2025

By Holly Barker When scientists produced the first map of all synaptic connections in the roundworm Caenorhabditis elegans in 1986, many hailed it as a blueprint for the flow of brain signals. As it turned out, though, models of neuronal activity based on this wiring diagram bore little resemblance to the functional maps of brain activity measured in living worms. This disconnect isn’t limited to worms. Mice, for instance, appear to have widespread silent synapses—wired connections that don’t send signals—and the actual responses of some cells in the fruit fly’s visual system do not match the responses the connectome predicts. A new preprint helps to explain why: Most network features, in C. elegans at least, are not conserved between the anatomical and functional connectomes. Yet the anatomical connectome can still forecast—albeit in a complex way—observed neuronal activity in the worms, according to a second preprint by the same team, because “most signaling is happening along the wires,” says Andrew Leifer, associate professor of physics and neuroscience at Princeton University and principal investigator on both preprints. The findings begin to address the long-standing challenge of reconciling structure and function, and show that “we weren’t entirely wrong” about the importance of synaptic connectivity, says Jihong Bai, professor of basic sciences at the Fred Hutchinson Cancer Center, who was not involved in the work. The debut of a color-coded map of cell types in the worm brain in 2021 split the neuroscience community. It made it possible to identify individual neurons in whole-brain recordings and compare annotated recordings with the connectome—an exercise that revealed no correlation between the two. © 2025 Simons Foundation

Keyword: Brain imaging
Link ID: 29907 - Posted: 08.30.2025

By Carl Zimmer Charles Darwin unveiled his theory of evolution in 1859, in “On the Origin of Species.” But it took him another 12 years to work up the courage to declare that humans evolved, too. In “The Descent of Man,” published in 1871, Darwin argued that humans arose from apes. And one of the most profound changes they underwent was turning into upright walkers. “Man alone has become a biped,” Darwin wrote. Bipedalism, he declared, was one of humanity’s “most conspicuous characters.” Scientists have now discovered some of the crucial molecular steps that led to that conspicuous character millions of years ago. A study published in the journal Nature on Wednesday suggests that our early ancestors became bipeds, as old genes started doing new things. Some genes became active in novel places in the human embryo, while others turned on and off at different times. Scientists have long recognized that a key feature for walking upright is a bone called the ilium. It’s the biggest bone in the pelvis; when you put your hand on your hip, that’s the ilium you feel. The left and right ilium are both fused to the base of the spine. Each ilium sweeps around the waist to the front of the belly, creating a bowllike shape. Many of the leg muscles we use in walking are anchored to the ilium. The bone also supports the pelvic floor, a network of muscles that acts like a basket for our inner organs when we stand up. As vital as the ilium is to everyday life, the bone can also be a source of suffering. The ilium can flare up with arthritis, grow brittle in old age, especially in women, and fracture from a fall. Genetic disorders can deform it, making walking difficult. The ilium also forms much of the birth canal — where babies can sometimes get stuck, endangering the mother’s life. © 2025 The New York Times Company

Keyword: Evolution
Link ID: 29906 - Posted: 08.30.2025

Helen Pearson On 16 April, Robert F. Kennedy Jr held a press conference about rising diagnoses of autism. The US Health and Human Services (HHS) secretary pointed to new data showing that autism prevalence in the United States had risen steeply from one in 150 eight-year-olds in 2000 to one in 31 in 2022. He called it an “epidemic” caused by “an environmental toxin” — and said he would soon be announcing a study to find the responsible agent. The next month, the US National Institutes of Health (NIH), part of the department that Kennedy leads, announced the Autism Data Science Initiative (ADSI). The initiative offered up to US$50 million to fund studies on the causes of autism. The winning applications are expected to be announced in September. Usually, big investments in research are welcomed by scientists — but not this time. Many were dismayed that these developments seemed to ignore decades of work on the well-documented rise in autism diagnoses and on causes of the developmental condition. Although Kennedy said that environmental factors are the main cause of autism, research has shown that genetics plays a bigger part. Population studies1 have linked a handful of environmental factors — mostly encountered during pregnancy — to increased chances of autism, but their precise role has been hard to pin down. More than anything, research has shown that the drivers of autism are fiendishly complicated. “There will never be a sound-bite answer to what causes autism,” says Helen Tager-Flusberg, a psychologist who studies neurodevelopmental conditions at Boston University, Massachusetts. The rise in prevalence, many researchers say, is predominantly caused by an increase in diagnoses rather than a true rise in the underlying symptoms and traits. “We don’t see an epidemic of autism, but we see an ‘epidemic’ of diagnoses,” says Sven Bölte, a specialist in child and adolescent psychiatric science at the Karolinska Institute in Stockholm. Researchers are concerned that Kennedy, an anti-vaccine advocate, will use the ADSI to promote the disproven idea that vaccines are linked to autism. © 2025 Springer Nature Limited

Keyword: Autism
Link ID: 29905 - Posted: 08.27.2025

Welcome to Entanglements. In this episode, hosts Brooke Borel and Anna Rothschild ask: Should we try to prevent autism? It’s a question that has divided the autistic community, and the answer has significant implications on how to focus scientific research and funding. Their guests this week are Jill Escher, a philanthropist, president of the National Council on Severe Autism, and parent of two young adults with severe nonverbal autism, and Eric García, the Washington bureau chief at The Independent and the author of “We’re Not Broken: Changing the Autism Conversation,” who is himself autistic. Robert F. Kennedy Jr: These are kids who will never pay taxes, they’ll never hold a job, they’ll never play baseball, they’ll never write a poem, they’ll never go out on a date. Many of them will never use a toilet unassisted. And we have to recognize we are doing this to our children. Anna Rothschild: That was Health and Human Services Secretary Robert F. Kennedy Jr., talking about autism back in April of 2025. And he promised to find some answers about the cause of the condition, which he called an epidemic. Robert F. Kennedy Jr: This is a preventable disease. We know it’s an environmental exposure. It has to be. Genes do not cause epidemics. Anna Rothschild: On that note, welcome to Entanglements, the show where we wade into the murkiest scientific controversies and search for common ground. I’m science journalist Anna Rothschild. Brooke Borel: And I’m Brooke Borel, articles editor at Undark Magazine. And that was a dramatic cold open. Anna, what’s happening here? Are you about to do an episode on whether vaccines cause autism? Anna Rothschild: No, that is not a murky controversy. That has been rigorously disproven. Brooke Borel: Yeah. Anna Rothschild: No, today we are asking the question: Should we try to prevent autism?

Keyword: Autism
Link ID: 29904 - Posted: 08.27.2025

By Claudia López Lloreda fMRI researchers have long faced a conundrum: Given finite resources and time to spend on scanning, is it better to scan lots of participants for a short time each, or a smaller number of people for a longer time? A new study quantifies this tradeoff for brain-wide association studies (BWAS), which aim to link brain differences to physical and cognitive traits. Using large-scale public fMRI datasets, the team found that their ability to accurately predict cognitive features from functional connectivity data increased with sample size and with scan length, up to 20 minutes. But accuracy began to plateau for longer scans, and beyond 30 minutes, the added length (and cost) provided diminishing returns. A half-hour seems to be the optimal scanning time, says Thomas Yeo, associate professor of electrical and computer engineering at the National University of Singapore and principal investigator of the study. Scan duration is “essentially providing a different knob for people to tune” to meet power requirements in their fMRI experiments, he says. Although the neuroimaging community already knew that scan time is important and five minutes is insufficient, “this is one of the first major studies in the past few years to really quantitatively map that out” for BWAS studies, says Brenden Tervo-Clemmens, assistant professor of psychiatry and behavioral sciences at the University of Minnesota, who was not involved with the study. Tervo-Clemmens and his colleagues had previously shown in a 2022 study the importance of sample size in BWAS, calculating that these analyses need thousands of participants to get meaningful associations. This new study adds another part of the equation, he says. Yeo’s team developed the Optimal Scan Time Calculator to help other neuroscientists design their own studies. “Democratizing these complex methodological issues into a usable package is really, really useful,” Tervo-Clemmens says. © 2025 Simons Foundation

Keyword: Brain imaging
Link ID: 29903 - Posted: 08.27.2025

Nicola Davis Science correspondent Big hands might mean big feet, but it seems long thumbs are linked to large brains – at least in primates. Researchers say the results suggest the brain co-evolved with manual dexterity in such mammals. “We imagine an evolutionary scenario in which a primate or human has become more intelligent, and with that comes the ability to think about action planning, think about what you are doing with your hands, and realise that actually you are more efficient at doing it one way or another,” said Dr Joanna Baker, lead author of the research from the University of Reading. “And those that have longer thumbs or more ability to manipulate the objects in the way that the mind can see were likely to be more successful.” Large brains and manual dexterity are both thought to have played an important role in human evolution, with opposable thumbs a key feature that enabled a greater ability to grip and manipulate items – including tools. However, with some other primates having partly opposable thumbs, questions have remained over whether other changes in the hand – such as thumb length – could also be important in the evolution of tool use. “In general terms, you can say that the longer the thumb you have, the more motion you have to pick up and control small objects,” said Baker. To explore the issue Baker and colleagues studied the estimated brain mass and thumb length of 94 primate species, from five of our ancient hominin relatives to lemurs. The results, published in the journal Communications Biology, reveal humans and most other hominins have thumbs that are significantly longer than would be predicted based on the hand proportions of primates as a while. However, further analysis revealed an intriguing pattern. “When you have longer thumbs relative to your overall hand, that tends to come in conjunction with overall increased brain size,” said Baker. © 2025 Guardian News & Media Limited

Keyword: Evolution
Link ID: 29902 - Posted: 08.27.2025