By Elie Dolgin Two U.S. states and more than a dozen cities and counties have moved in the past year to stop adding fluoride to community drinking water, citing research suggesting the mineral could harm children’s brain development. But a new analysis of cognitive outcomes tracked over decades finds no evidence that water fluoridation is associated with lower adolescent IQ or diminished mental abilities later in life, researchers report April 13 in the Proceedings of the National Academy of Sciences. The results, based on standardized intelligence testing of more than 10,000 people in Wisconsin followed since their senior year of high school in 1957, challenge the idea that typical fluoridation levels in public drinking water pose a neurodevelopmental risk, a central point of contention in ongoing policy debates. “It’s very strong data,” says Steven Levy, a dentist and public health researcher at the University of Iowa in Iowa City who was not involved in the research. “There’s no strong signal at all coming through that should give us concern.” However, given the politically charged nature of water fluoridation and continued differences in how researchers interpret the available evidence, the findings are unlikely to be the last word on the issue. © Society for Science & the Public 2000–2026

Keyword: Intelligence; Neurotoxins
Link ID: 30200 - Posted: 04.15.2026

By Angie Voyles Askham The idea that some neural representations can “drift,” or change over time, even in the seeming absence of learning, is broadly accepted. But characterizing the phenomenon across the brain has proved challenging. “The interesting part is what exactly seems to be stable and what exactly seems to be drifting. That’s not an easy question,” says Tobias Rose, a group leader at the University of Bonn Medical Center, who presented findings on drift in the mouse primary visual cortex earlier this month at the Computational and Systems Neuroscience (COSYNE) annual meeting. Other new research adds nuance to the discussion: Neurons that code for head direction in the mouse post-subiculum show little drift, retaining their tuning for multiple weeks, according to a study published last month in Nature. And they differ from hippocampal place cells, which are also part of the spatial navigation system but have highly variable responses, as reported in previous research. The new findings raise questions about how stable and flexible representations interact in the brain, given that signals from the post-subiculum ultimately feed into the hippocampus, says Rose, who was not involved in the work. “It’s a rather important study,” he says. The relative stability of head direction cell tuning does not invalidate previous reports of drift elsewhere in the brain, says Adrien Peyrache, associate professor at the Montreal Neurological Institute, who led the head direction study. Instead, it may be that these invariant responses act as a “rigid backbone” onto which more flexible sensory and cognitive responses can be mapped, he says. “I find it reassuring.” Still, the low drift reported in the new work may be partially due to the study’s methods, which eliminated cells that lost their response from one day to the next, says Timothy O’Leary, professor of information engineering and neuroscience at the University of Cambridge, who was not involved in the work. © 2026 Simons Foundation

Keyword: Learning & Memory
Link ID: 30181 - Posted: 03.28.2026

David Adam When neuroscientists gather in the Spanish city of Seville in May for the annual Dopamine Society meeting, one discussion could be unusually lively. Session 31 will feature a debate between researchers who fundamentally disagree about the role dopamine has in the brain. Dopamine is one of the most extensively studied neurotransmitters, chemicals that convey signals from cell to cell. It’s the one with the highest profile outside neuroscience: often known as the ‘pleasure chemical’, it’s depicted as the hit of reward that people get from recreational drugs or scrolling through social media. That’s a gross simplification of what dopamine does; on that, researchers agree. But beyond that, where once there was a simple model that explained how dopamine works in the brain, now there are challenges that seek to amend the theory — or even to overturn it. This could have implications not only for basic neuroscience, but also for clinicians trying to explain and treat conditions such as attention deficit hyperactivity disorder (ADHD) and addiction. If the model is wrong or needs modification, then so might some of the assumptions about what drives these disorders and the best way to treat them. The classic idea, known as the reward prediction error (RPE) hypothesis, is that bursts of dopamine in the brain link stimuli to rewards, helping to reinforce associations that fulfil a need for an animal or a person. The model has dominated and guided research in the field for decades, offering a mathematical framework to interpret data from animal experiments, and it does a good job of explaining behaviour. This was a valuable rarity for researchers struggling to overlay simple theories onto the intense complexity of the brain. “Dopamine was the one field of neuroscience where we had a computational model that explained what the signal was and what it was computing,” says Mark Humphries, a neuroscientist at the University of Nottingham, UK. People in the field knew that some of the assumptions involved in the RPE model were simplistic. But as a working understanding of part of the brain, it was seen as a major step forwards. © 2026 Springer Nature Limited

Keyword: Learning & Memory; Drug Abuse
Link ID: 30166 - Posted: 03.19.2026

By Catherine Offord Scientists have plenty of ideas about why aging impairs memory. Reductions in blood flow in the brain, shrinking brain volume, and malfunctioning neural repair systems have all been blamed. Now, new research in mice points to another possible culprit: microbes in the gut. In a study published today in Nature, scientists show how a bacterium that is particularly common in older animals can drive memory loss. This microbe makes compounds that impair signaling along neurons connecting the gut with the brain, dampening activity in brain regions associated with learning and memory, the team found. “This is a tour de force,” says Haijiang Cai, a neuroscientist at the University of Arizona who studies gut-brain communication and was not involved in the work. “They define the pathway all the way from aging and bacteria … to cognitive function—it’s really impressive.” However, he and others emphasize it remains to be seen whether a similar mechanism exists in humans—and if so, how important it is compared with other drivers of cognitive decline. Research on the so-called gut-brain axis has exploded in recent decades. Multiple studies have identified differences in microbiome composition between healthy people and those with cognitive disorders such as Alzheimer’s disease. This kind of research can’t establish cause and effect, though, and the literature is rife with conflicting results. Some groups have used animal experiments to probe the microbe-memory link. In the new study, Stanford University researchers Christoph Thaiss and Maayan Levy tinkered with the microbiomes of young mice—either by housing them with older animals or feeding them these animals’ poop—and then gave them memory tests. For example, one such test rates animals higher if they spend more time exploring new objects than those they’ve seen before. © 2026 American Association for the Advancement of Science.

Keyword: Learning & Memory; Obesity
Link ID: 30162 - Posted: 03.14.2026

By Catherine Offord Scientists have plenty of ideas about why aging impairs memory. Reductions in blood flow in the brain, shrinking brain volume, and malfunctioning neural repair systems have all been blamed. Now, new research in mice points to another possible culprit: microbes in the gut. In a study published today in Nature, scientists show how a bacterium that is particularly common in older animals can drive memory loss. This microbe makes compounds that impair signaling along neurons connecting the gut with the brain, dampening activity in brain regions associated with learning and memory, the team found. “This is a tour de force,” says Haijiang Cai, a neuroscientist at the University of Arizona who studies gut-brain communication and was not involved in the work. “They define the pathway all the way from aging and bacteria … to cognitive function—it’s really impressive.” However, he and others emphasize it remains to be seen whether a similar mechanism exists in humans—and if so, how important it is compared with other drivers of cognitive decline. Research on the so-called gut-brain axis has exploded in recent decades. Multiple studies have identified differences in microbiome composition between healthy people and those with cognitive disorders such as Alzheimer’s disease. This kind of research can’t establish cause and effect, though, and the literature is rife with conflicting results. Some groups have used animal experiments to probe the microbe-memory link. In the new study, Stanford University researchers Christoph Thaiss and Maayan Levy tinkered with the microbiomes of young mice—either by housing them with older animals or feeding them these animals’ poop—and then gave them memory tests. For example, one such test rates animals higher if they spend more time exploring new objects than those they’ve seen before. © 2026 American Association for the Advancement of Science.

Keyword: Learning & Memory; Obesity
Link ID: 30161 - Posted: 03.14.2026

By Natalia Mesa Experience kindles most of our learning throughout life, without any explicit instruction or reward. Thanks to this process, called statistical learning, people unconsciously recognize patterns in their surroundings, and infants soak up language. The hippocampus, it turns out, may be essential for this capability, according to a new preprint, beginning to resolve a long-standing debate. Numerous functional MRI studies have suggested that the structure is involved in statistical learning, but lesion studies have produced mixed results. “This is a tour-de-force study,” says Anna Schapiro, associate professor of psychology at the University of Pennsylvania, who was not involved in the work. “It makes me feel more confident that, yes, the hippocampus is involved in statistical learning, but it’s also necessary for that learning across species.” In the study, people and mice learned to respond—by pressing a key or licking a waterspout, respectively—to a particular sound. As they performed this “cover” task, they also heard an irrelevant four-note sequence at random times, interspersed with the other sound. After repeating this cover task 100 times, both people and rodents showed strong pupil dilation, a sign of surprise, whenever the sequence of notes changed slightly, with more similar sequences evoking a smaller response—indicating that they had passively learned the original musical motif and abstract rules about its structure. Neuronal populations in the hippocampus encoded not only the original and altered tone sequences but also how frequently each occurred. Pharmacologically or optogenetically shutting down hippocampal neurons in the mice prevented them from passively learning the auditory pattern and making generalizations about how often it played, but it didn’t disrupt their performance on the cover task. © 2026 Simons Foundation

Keyword: Learning & Memory
Link ID: 30154 - Posted: 03.11.2026

By Jake Currie Struggling to remember a forgotten memory is an all-too-common frustration—one that unfortunately becomes more common as we age. We realize that there’s something we can’t recall, but we simply can’t raise it from the depths of our brains. So where did it go? New research published in the Journal of Neuroscience suggests these memories are still lurking in our minds, even though we think they’re long gone. Subscribe to skip ads Featured Video Psychologists from the University of Nottingham led by Benjamin Griffiths strapped participants into a magnetoencephalography machine to measure the magnetic fields surrounding the electrical activity in their brains. Participants were asked to vividly associate a short video clip with a word, and when they were later shown that word, they were asked to recall the video clip while psychologists monitored the magnetic activity of their brains. They found that the brain reactivated memories whether they were consciously recalled or not, meaning the memories were there. When memories were successfully recalled, the reactivated memory signal fluctuated rhythmically in the alpha band. Alpha brain waves, research has shown, are associated with the memorization of visual information, but it was the rhythmicity of the waves that proved key to conscious recall. “What we showed is that even when the brain can reactivate the right memory, it doesn’t guarantee you’ll become aware of it,” Griffiths explained. “Instead, what seems to matter is that the memory rhythmically pulses so that it can be detected above and beyond other neural activity.”

Keyword: Learning & Memory; Brain imaging
Link ID: 30151 - Posted: 03.07.2026

Jon Hamilton A human brain consumes less power than a light bulb, while artificial intelligence systems guzzle electricity to do the same tasks. Now, scientists have created a highly efficient AI model that hints at how living brains are able to do so much with so little, a team reports in the journal Nature. Light enters the compound eye of the fly, causing the photoreceptors to send electrical signals through a complex neural network, enabling the fly to detect motion The model, which mimics a part of the brain's visual system, started out using 60 million variables. But the team was able to compress it into a version that performed nearly as well using just 10,000 variables. "That is incredibly small," says Ben Cowley, an author of the study and an assistant professor at Cold Spring Harbor Laboratory. "This is something we could send in a tweet or an email." The compact model also appears to work more like a living brain, which could help scientists study what goes wrong in diseases like Alzheimer's, Cowley says. More broadly, if the AI model really does replicate strategies found in nature, it could help scientists understand the inner workings of human brains, says Mitya Chklovskii, a group leader at the Simons Foundation's Flatiron Institute, who was not involved in the study. Compact, biology-inspired models of the brain could also lead to "more powerful and more humanlike artificial intelligence," says Chklovskii, who is also on the faculty at NYU. © 2026 npr

Keyword: Robotics; Vision
Link ID: 30147 - Posted: 03.04.2026

By Bethany Brookshire When solving a puzzle, the answer could lie in your dreams. In a study of lucid dreamers, playing soundtracks linked with unsolved puzzles helped the sleepers solve the problems the next day, researchers report February 5 in Neuroscience of Consciousness. Stories of brilliant insights after a nap or daydream abound, but scientists have struggled to successfully influence people’s dreams and rigorously test the idea. “This study provides one of the first experimentally grounded demonstrations of such a link,” says Giulio Bernardi, a cognitive neuroscientist at IMT School for Advanced Studies Lucca, in Italy, who was not involved with the work. Whether we remember our dreams or not, we have countless dreams in our sleep, according to Karen Konkoly, a cognitive neuroscientist who performed the study at Northwestern University in Evanston, Ill. “Your dreams are such a big part of your inner life,” she says. And in the right circumstances, manipulating those dreams could help people think of problems in new ways. While some scientists have shown that sleeping on a problem increases the odds of solving it the next day, others have shown no benefit. Of course, it might help only if you actually think about the problem in your sleep. Konkoly and her colleagues were especially interested in helping sleepers think about specific topics using targeted memory reactivation, or TMR. “It’s this research technique where you have a sensory stimuli that’s associated with a memory,” Konkoly says. “It could be a very soft sound or a smell that’s presented to a sleeper, and it functions to remind the sleeping brain of the full memory.” While people dream in every stage of sleep, the effects of TMR have been strongest in deep, slow-wave sleep, she says. Konkoly wanted to look at the effects of TMR at a different sleep stage — rapid eye movement sleep, which could be helpful for creative thinking. © Society for Science & the Public 2000–2026.

Keyword: Sleep; Learning & Memory
Link ID: 30145 - Posted: 03.04.2026

By Dana G. Smith Many people’s brains deteriorate as they age, becoming riddled with malfunctioning proteins that result in cell death and the loss of memory and cognition. But other people’s brains remain almost perfectly intact, their thinking as sharp at 80 as it was in their 50s. A paper published Wednesday in the journal Nature provides a new potential explanation for this discrepancy, and it taps into one of the hottest debates in neuroscience: whether human brains can grow new neurons in adulthood, a phenomenon called neurogenesis. The study found that so-called super-agers — people 80 and up who have the memory ability of someone 30 years younger — had roughly twice as many new neurons as older adults with normal memory for their age, and 2.5 times more than people with Alzheimer’s disease. The research focused on an area of the brain called the hippocampus, which is important for learning and memory and is thought to be the primary birthplace of new neurons. “This paper shows biological proof that the aging brain is plastic,” even into a person’s 80s, said Tamar Gefen, an associate professor of psychiatry and behavioral sciences at the Northwestern University Feinberg School of Medicine, who contributed to the research. To look for neurogenesis in older adults, the scientists first tried to detect signs of it in the autopsied brains of young adults, age 20 to 40, who died with normal cognition. They identified genetic markers for three key types of cells: neural stem cells, neuroblasts and immature neurons. © 2026 The New York Times Company

Keyword: Neurogenesis; Alzheimers
Link ID: 30144 - Posted: 02.28.2026

Mariana Lenharo Adults whose brains still have strong neuron production seem to have better memory and cognitive function than do those in whom the ability wanes, finds a study published today in Nature1. The authors examined brain samples from deceased donors ranging from young adults to ‘super agers’ — people older than 80 with exceptional memory. She lived to 117: what her genes and lifestyle tell us about longevity They found that young and old adults with healthy cognition generated neurons, a process called neurogenesis, at high levels for their age. The team estimated that the new neurons made up only a small fraction — 0.01% — of those in the hippocampus, a brain region that’s essential for memory. By contrast, in people experiencing cognitive decline, including individuals with Alzheimer’s disease, neurogenesis seems to falter: the researchers spotted fewer developing, or immature, neurons in those brain samples. Surprisingly, a group of ‘super agers’ had an even higher number of immature neurons than did other groups, and significantly more than did those with Alzheimer’s. However, the group sizes were small, so the findings were not all statistically significant. Maura Boldrini Dupont, a neuroscientist and psychiatrist at Columbia University in New York City, says that the small size of the groups — each had ten or fewer individuals — is a reason to take the results with a grain of salt. Understanding the tools that the brain uses to generate neurons and maintain cognitive function in old age could help researchers to develop drugs that induce neurogenesis in people with cognitive decline, says co-author Orly Lazarov, a neuroscientist at the University of Illinois Chicago. © 2026 Springer Nature Limited

Keyword: Neurogenesis; Alzheimers
Link ID: 30143 - Posted: 02.28.2026

By Justin O’Hare For decades, two complementary but often siloed approaches have guided neuroscience: cellular neuroscience, which seeks to understand how individual neurons work; and systems neuroscience, which aims to uncover how networks of neurons coordinate to produce thoughts, movements and behaviors. One studies the tree; the other studies the forest. Each approach has produced tremendous advances. For instance, cellular neuroscientists have revealed how ion channels shape the electrical language of the brain, how synapses strengthen or weaken with experience and how gene expression governs neuronal function. Meanwhile, systems neuroscientists have mapped entire circuits, recorded the activity of tens of thousands of neurons during behavior and identified patterns of activity that correlate with memory, decision-making and emotion. But for all these advances, a question lingers: Are we actually any closer to understanding how the brain works? The jaw-dropping datasets produced by systems-level studies are seldom reconciled with biology, and the exquisite detail uncovered by cellular-level studies is rarely extrapolated from circuits to behavior. These disconnects don’t reflect failures of either approach. Rather, they reflect the vast intellectual and material resources that each requires. Nevertheless, the brain is a multiscale organ. It is organized across multiple hierarchical levels operating in concert, not in parallel. To unravel the brain’s deepest complexities, we need to bridge cellular and systems neuroscience. Because of recent technological advances in high-density electrical probes, genetically encoded fluorescent sensors, multiphoton imaging and high-performance computing, we are better suited to do this now than ever before. © 2026 Simons Foundation

Keyword: Learning & Memory; Brain imaging
Link ID: 30140 - Posted: 02.28.2026

Jon Hamilton A little brain training today may help stave off Alzheimer's disease and other forms of dementia for at least 20 years. That's the conclusion of a study of older adults who participated in a cognitive exercise experiment in the 1990s that was designed to increase the brain's processing speed. The federally funded study of 2,802 people found that those who did eight to 10 roughly hourlong sessions of cognitive speed training, as well as at least one booster session, were about 25% less likely to be diagnosed with dementia over the next two decades. "We now have a gold-standard study that tells us that there is something we can do to reduce our risk for dementia," says Marilyn Albert, an author of the study and a professor of neurology at Johns Hopkins University School of Medicine. "It's super-exciting to see that these effects are still holding 20 years out," says Jennifer O'Brien, an associate professor of psychology at the University of South Florida who was not involved in the research. The study appears in the journal Alzheimer's & Dementia: Translational Research & Clinical Interventions. The result is good news for people like George Kovach, 74, who started doing cognitive speed training a decade ago. This illustration shows a pink human brain with stick legs and stick arms. The pink stick arms are holding up a black barbell with black disk-shaped weights on each end. © 2026 npr

Keyword: Alzheimers; Learning & Memory
Link ID: 30127 - Posted: 02.18.2026

Andrew Gregory Health editor Reading, writing and learning a language or two can lower your risk of dementia by almost 40%, according to a study that suggests millions of people could prevent or delay the condition. Dementia is one of the world’s biggest health threats. The number of people living with the condition is forecast to triple to more than 150 million globally by 2050, and experts say it presents a big and rapidly growing threat to future health and social care systems in every community, country and continent. US researchers found that engaging in intellectually stimulating activities throughout life, such as reading, writing or learning a new language, was associated with a lower risk of Alzheimer’s disease, the most common form of dementia, and slower cognitive decline. The study author Andrea Zammit, of Rush University Medical Center in Chicago, said the discovery suggested cognitive health in later life was “strongly influenced” by lifelong exposure to intellectually stimulating environments. “Our findings are encouraging, suggesting that consistently engaging in a variety of mentally stimulating activities throughout life may make a difference in cognition. Public investments that expand access to enriching environments, like libraries and early education programs designed to spark a lifelong love of learning, may help reduce the incidence of dementia.” Researchers tracked 1,939 people with an average age of 80 who did not have dementia at the start of the study. They were followed for an average of eight years. Participants completed surveys about cognitive activities and learning resources during three stages. © 2026 Guardian News & Media Limited

Keyword: Alzheimers; Learning & Memory
Link ID: 30121 - Posted: 02.14.2026

Peter Lukacs Popular wisdom holds we can ‘rewire’ our brains: after a stroke, after trauma, after learning a new skill, even with 10 minutes a day on the right app. The phrase is everywhere, offering something most of us want to believe: that when the brain suffers an assault, it can be restored with mechanical precision. But ‘rewiring’ is a risky metaphor. It borrows its confidence from engineering, where a faulty system can be repaired by swapping out the right component; it also smuggles that confidence into biology, where change is slower, messier and often incomplete. The phrase has become a cultural mantra that is easier to comprehend than the scientific term, neuroplasticity – the brain’s ability to change and form new neural connections throughout life. But what does it really mean to ‘rewire’ the brain? Is it a helpful shorthand for describing the remarkable plasticity of our nervous system or has it become a misleading oversimplification that distorts our grasp of science? After all, ‘rewiring your brain’ sounds like more than metaphor. It implies an engineering project: a system whose parts can be removed, replaced and optimised. The promise is both alluring and oddly mechanical. The metaphor actually did come from engineering. To an engineer, rewiring means replacing old and faulty circuits with new ones. As the vocabulary of technology crept into everyday life, it brought with it a new way of thinking about the human mind. Medical roots of the phrase trace back to 1912, when the British surgeon W Deane Butcher compared the body’s neural system to a house’s electrical wiring, describing how nerves connect to muscles much like wires connect appliances to a power source. By the 1920s, the Harvard psychologist Leonard Troland was referring to the visual system as ‘an extremely intricate telegraphic system’, reinforcing the comparison between brain function and electrical networks. © Aeon Media Group Ltd. 2012-2026.

Keyword: Learning & Memory; Development of the Brain
Link ID: 30108 - Posted: 02.04.2026

By Ingrid Wickelgren The human brain is a vast network of billions of neurons. By exchanging signals to depress or excite each other, they generate patterns that ripple across the brain up to 1,000 times per second. For more than a century, that dizzyingly complex neuronal code was thought to be the sole arbiter of perception, thought, emotion, and behavior, as well as related health conditions. If you wanted to understand the brain, you turned to the study of neurons: neuroscience. But a recent body of work from several labs, published as a trio of papers in Science in 2025, provides the strongest evidence yet that a narrow focus on neurons is woefully insufficient for understanding how the brain works. The experiments, in mice, zebra fish, and fruit flies, reveal that the large brain cells called astrocytes serve as supervisors. Once viewed as mere support cells for neurons, astrocytes are now thought to help tune brain circuits and thereby control overall brain state or mood — say, our level of alertness, anxiousness, or apathy. Astrocytes, which outnumber neurons in many brain regions, have complex and varied shapes, and sometimes tendrils, that can envelop hundreds of thousands or millions of synapses, the junctions where neurons exchange molecular signals. This anatomical arrangement perfectly positions astrocytes to affect information flow, though whether or how they alter activity at synapses has long been controversial, in part because the mechanisms of potential interactions weren’t fully understood. In revealing how astrocytes temper synaptic conversations, the new studies make astrocytes’ influence impossible to ignore. “We live in the age of connectomics, where everyone loves to say [that] if you understand the connections [between neurons], we can understand how the brain works. That’s not true,” said Marc Freeman (opens a new tab), the director of the Vollum Institute, an independent neuroscience research center at Oregon Health and Science University, who led one of the new studies. “You can get dramatic changes in firing patterns of neurons with zero changes in [neuronal] connectivity.” © 2026 Simons Foundation

Keyword: Glia; Learning & Memory
Link ID: 30103 - Posted: 01.31.2026

By Yasemin Saplakoglu On a remote island in the Indian Ocean, six closely watched bats took to the star-draped skies. As they flew across the seven-acre speck of land, devices implanted in their brains pinged data back to a group of sleepy-eyed neuroscientists monitoring them from below. The researchers were working to understand how these flying mammals, who have brains not unlike our own, develop a sense of direction while navigating a new environment. The research, published in Science, reported that the bats used a network of brain cells (opens a new tab) that informed their sense of direction around the island. Their “internal compass” was tuned by neither the Earth’s magnetic field nor the stars in the sky, but rather by landmarks that informed a mental map of the animal’s environment. These first-ever wild experiments in mammalian mapmaking confirm decades of lab results and support one of two competing theories about how an internal neural compass anchors itself to the environment. “Now we’re understanding a basic principle about how the mammalian brain works” under natural, real-world conditions, said the behavioral neuroscientist Paul Dudchenko (opens a new tab), who studies spatial navigation at the University of Stirling in the United Kingdom and was not involved in the study. “It will be a paper people will be talking about for 50 years.” Follow-up experiments that haven’t yet been published show that other cells critical to navigation encode much more information in the wild than they do in the lab, emphasizing the need to test neurobiological theories in the real world. Neuroscientists believe that a similar internal compass, composed of neurons known as “head direction cells,” might also exist in the human brain — though they haven’t yet been located. If they are someday found, the mechanism could shed light on common sensations such as getting “turned around” and quickly reorienting oneself. It might even explain why some of us are so bad at finding our way. © 2026 Simons Foundation

Keyword: Learning & Memory
Link ID: 30094 - Posted: 01.24.2026

By Pria Anand I loved literature before I loved medicine, and as a medical student, I often found that my textbooks left me cold, their medical jargon somehow missing the point of profound diseases able to rewrite a person’s life and identity. I was born, I decided, a century too late: I found the stories I craved, not in contemporary textbooks, but in outdated case reports, 18th- and 19-century descriptions of how the diseases I was studying might shape the life of a single patient. These reports were alive with vivid details: how someone’s vision loss affected their golf game or their smoking habit, their work or their love life. They were all tragedies: Each ended with an autopsy, a patient’s brain dissected to discover where, exactly, the problem lay, to inch closer to an understanding of the geography of the soul. To write these case studies, neurologists awaited the deaths and brains of living patients, robbing their subjects of the ability to choose what would become of their own bodies—the ability to write the endings of their own stories—after they had already been sapped of agency by their illnesses. Among these case reports was one from a forbidding state hospital in the north of Moscow: the story of a 19th-century Russian journalist referred to simply as “a learned man.” The journalist suffered a type of alcoholic dementia because of the brandy he often drank to cure his writer’s block and he developed a profound amnesia. He could not remember where he was or why. He could win a game of checkers but would forget that he had even played the minute the game ended. In the place of these lost memories, the journalist’s imagination spun elaborate narratives; he believed he had written an article when in fact he had barely begun to conceive it before he became sick, would describe the prior day’s visit to a far-off place when in actuality he had been too weak to get out of bed, and maintained that some of his possessions—kept in a hospital safe—had been taken from him as part of an elaborate heist. Sacks’ journals suggest he injected his own experiences into the stories of his patients. © 2026 NautilusNext Inc.,

Keyword: Attention; Learning & Memory
Link ID: 30089 - Posted: 01.21.2026

By Erin Garcia de Jesús A deck brush can be a good tool for the right task. Just ask Veronika, the Brown Swiss cow. Veronika uses both ends of a deck brush to scratch various parts of her body, researchers report January 19 in Current Biology. It’s the first reported tool use in a cow, a species that is often “cognitively underestimated,” the researchers say. Cows usually rub against trees, rocks or wooden planks to scratch, but Veronika’s handy tool allows her to reach parts of her body that she couldn’t otherwise, says Antonio Osuna-Mascaró, a cognitive biologist at the Messerli Research Institute of the University of Veterinary Medicine, Vienna. It’s unclear how the cow figured it out, but “somehow Veronika learned to use tools, and she’s doing something that other cows simply can’t.” Veronika, a pet cow that lives in a pasture on a small Austrian farm, picks up the brush by its handle with her tongue and twists her neck to place the brush where she needs it. Setting the brush in front of her in different orientations showed that she uses the hard, bristled end to target most areas, including the tough, thick skin on her back. She also uses the nonbristled end, slowly moving the handle over softer body parts such as her belly button and udder. Veronika uses different parts of a deck brush to reach various parts of her body. She uses the brush end to scratch large areas such as her thigh (top left) and back (top right). She uses the handle to scratch more delicate areas such as her navel flap (bottom left) and anus (bottom right). © Society for Science & the Public 2000–2026.

Keyword: Learning & Memory; Evolution
Link ID: 30088 - Posted: 01.21.2026

Lynne Peeples Sometimes the hardest part of doing an unpleasant task is simply getting started — typing the first word of a long report, lifting a dirty dish on the top of an overfilled sink or removing clothes from an unused exercise machine. The obstacle isn’t necessarily a lack of interest in completing a task, but the brain’s resistance to taking the first step. Now, scientists might have identified the neural circuit behind this resistance, and a way to ease it. In a study1 published today in Current Biology, researchers describe a pathway in the brain that seems to act as a ‘motivation brake’, dampening the drive to begin a task. When the team selectively suppressed this circuit in macaque monkeys, goal-directed behaviour rebounded. “The change after this modulation was dramatic,” says study co-author Ken-ichi Amemori, a neuroscientist at Kyoto University in Japan. The motivation brake, which can be particularly stubborn for people with certain psychiatric conditions, such as schizophrenia and major depressive disorder, is distinct from the avoidance of tasks driven by risk aversion in anxiety disorders. Pearl Chiu, a computational psychiatrist at Virginia Tech in Roanoke, who was not involved in the study, says that understanding this difference is essential for developing new treatments and refining current ones. “Being able to restore motivation, that’s especially exciting,” she says. Motivated macaques Previous work on task initiation has implicated a neural circuit connecting two parts of the brain known as the ventral striatum and ventral pallidum, both of which are involved in processing motivation and reward2,3,4. But attempts to isolate the circuit’s role have fallen short. Electrical stimulation, for example, inadvertently activates downstream regions, affecting motivation, but also anxiety. © 2026 Springer Nature Limited

Keyword: Learning & Memory; Emotions
Link ID: 30079 - Posted: 01.14.2026