fjo3 shares a report from France 24: Too many lines of code to analyze, armies of AI assistants to wrangle, and lengthy prompts to draft are among the laments by hard-core AI adopters. Consultants at Boston Consulting Group (BCG) have dubbed the phenomenon "AI brain fry," a state of mental exhaustion stemming "from the excessive use or supervision of artificial intelligence tools, pushed beyond our cognitive limits."

The rise of AI agents that tend to computer tasks on demand has put users in the position of managing smart, fast digital workers rather than having to grind through jobs themselves. "It's a brand-new kind of cognitive load," said Ben Wigler, co-founder of the start-up LoveMind AI. "You have to really babysit these models." [...] "There is a unique kind of reward hacking that can go on when you have productivity at the scale that encourages even later hours," Wigler said.

[Adam Mackintosh, a programmer for a Canadian company] recalled spending 15 consecutive hours fine-tuning around 25,000 lines of code in an application. "At the end, I felt like I couldn't code anymore," he recalled. "I could tell my dopamine was shot because I was irritable and didn't want to answer basic questions about my day."

BCG recommends in a recently published study that company leaders establish clear limits regarding employee use and supervision of AI. However, "That self-care piece is not really an America workplace value," Wigler said. "So, I am very skeptical as to whether or not its going to be healthy or even high quality in the long term." Notably, the report says everyone interviewed for the article "expressed overall positive views of AI despite the downsides." In fact, a recent BCG study actually found a decline in burnout rates when AI took over repetitive work tasks.

If you think your daily doses of espresso or Earl Grey sharpen your mind, you just might be right, new science suggests. The New York Times: A large new study provides evidence of cognitive benefits from coffee and tea -- if it's caffeinated and consumed in moderation: two to three cups of coffee or one to two cups of tea daily.

People who drank that amount for decades had lower chances of developing dementia than people who drank little or no caffeine, the researchers reported. They followed 131,821 participants for up to 43 years. "This is a very large, rigorous study conducted long term among men and women that shows that drinking two or three cups of coffee per day is associated with reduced risk of dementia," said Aladdin Shadyab, an associate professor of public health and medicine at the University of California, San Diego, who wasn't involved in the study.

The findings, published Monday in JAMA, don't prove caffeine causes these beneficial effects, and it's possible other attributes protected caffeine drinkers' brain health. But independent experts said the study adjusted for many other factors, including health conditions, medication, diet, education, socioeconomic status, family history of dementia, body mass index, smoking and mental illness.

For decades, researchers have noted that cancer and Alzheimer's disease are rarely found in the same person, fuelling speculation that one condition might offer some degree of protection from the other. Nature: Now, a study in mice provides a possible molecular solution to the medical mystery: a protein produced by cancer cells seems to infiltrate the brain, where it helps to break apart clumps of misfolded proteins that are often associated with Alzheimer's disease. The study, which was 15 years in the making, was published on 22 January in Cell and could help researchers to design drugs to treat Alzheimer's disease.

"They have a piece of the puzzle," says Donald Weaver, a neurologist and chemist at the Krembil Research Institute at the University of Toronto in Canada, who was not involved in the study. "It's not the full picture by any stretch of the imagination. But it's an interesting piece." [...] A 2020 meta-analysis of data from more than 9.6 million people found that cancer diagnosis was associated with an 11% decreased incidence of Alzheimer's disease. It has been a difficult relationship to unpick: researchers must control for a variety of external factors. For example, people might die of cancer before they are old enough to develop symptoms of Alzheimer's disease, and some cancer treatments can cause cognitive difficulties, which could obscure an Alzheimer's diagnosis.

This month saw results from a yearlong global study of "potential negative risks that generative AI poses to student". The study (by the Brookings Institution's Center for Universal Education) also suggests how to prevent risks and maximize benefits: After interviews, focus groups, and consultations with over 500 students, teachers, parents, education leaders, and technologists across 50 countries, a close review of over 400 studies, and a Delphi panel, we find that at this point in its trajectory, the risks of utilizing generative AI in children's education overshadow its benefits.
"At the top of Brookings' list of risks is the negative effect AI can have on children's cognitive growth," reports NPR — "how they learn new skills and perceive and solve problems." The report describes a kind of doom loop of AI dependence, where students increasingly off-load their own thinking onto the technology, leading to the kind of cognitive decline or atrophy more commonly associated with aging brains... As one student told the researchers, "It's easy. You don't need to (use) your brain." The report offers a surfeit of evidence to suggest that students who use generative AI are already seeing declines in content knowledge, critical thinking and even creativity. And this could have enormous consequences if these young people grow into adults without learning to think critically...

Survey responses revealed deep concern that use of AI, particularly chatbots, "is undermining students' emotional well-being, including their ability to form relationships, recover from setbacks, and maintain mental health," the report says. One of the many problems with kids' overuse of AI is that the technology is inherently sycophantic — it has been designed to reinforce users' beliefs... Winthrop offers an example of a child interacting with a chatbot, "complaining about your parents and saying, 'They want me to wash the dishes — this is so annoying. I hate my parents.' The chatbot will likely say, 'You're right. You're misunderstood. I'm so sorry. I understand you.' Versus a friend who would say, 'Dude, I wash the dishes all the time in my house. I don't know what you're complaining about. That's normal.' That right there is the problem."
AI did have some advantages, the article points out: The report says another benefit of AI is that it allows teachers to automate some tasks: "generating parent emails ... translating materials, creating worksheets, rubrics, quizzes, and lesson plans" — and more. The report cites multiple research studies that found important time-saving benefits for teachers, including one U.S. study that found that teachers who use AI save an average of nearly six hours a week and about six weeks over the course of a full school year...

AI can also help make classrooms more accessible for students with a wide range of learning disabilities, including dyslexia. But "AI can massively increase existing divides" too, [warns Rebecca Winthrop, one of the report's authors and a senior fellow at Brookings]. That's because the free AI tools that are most accessible to students and schools can also be the least reliable and least factually accurate... "[T]his is the first time in ed-tech history that schools will have to pay more for more accurate information. And that really hurts schools without a lot of resources."
The report calls for more research — and make several recommendations (including "holistic" learning and "AI tools that teach, not tell.") But this may be their most important recommendation. "Provide a clear vision for ethical AI use that centers human agency..."

"We find that AI has the potential to benefit or hinder students, depending on how it is used."

alternative_right shares a report from ScienceAlert: A systematic review of 85 studies has now found good reason to differentiate between 'active' sitting, like playing cards or reading, and 'passive' sitting, like watching TV. [...] "Total sitting time has been shown to be related to brain health; however, sitting is often treated as a single entity, without considering the specific type of activity," explains public health researcher Paul Gardiner from the University of Queensland in Australia. "Most people spend many hours sitting each day, so the type of sitting really matters ... These findings show that small everyday choices -- like reading instead of watching television -- may help keep your brain healthier as you age."

Across numerous studies, Gardiner and colleagues found that active sitting activities, like reading, playing card games, and using a computer, showed "overwhelmingly positive associations with cognitive health, enhancing cognitive functions such as executive function, situational memory, and working memory." Meanwhile, passive sitting was most consistently associated with negative cognitive outcomes, including increased risk of dementia. The study was published in the Journal of Alzheimer's Disease.

The growing enthusiasm among Gen Z for ditching smartphones in favor of basic "dumbphones" may be overlooking a significant cognitive reality, according to a WIRED essay that draws on the 1998 "extended mind hypothesis" by philosophers Andy Clark and David Chalmers. The hypothesis argues that external tools can extend the biological brain in an all but physical way, meaning your phone isn't just a device -- it's part of a single cognitive system composed of both the tool and your brain.

"Interference with my phone is like giving me some brain damage," Clark told Wired. He expressed concern about the dumbphone movement, calling it "generally a retrograde step" and warning that as smartphone enmeshment becomes the societal norm, those who opt out risk becoming "effectively disabled within that society." Clark described this as "the creation of a disempowered class."

98% of Americans between 18 and 29 own a smartphone, dropping only to 97% for those aged 30 to 49. Even committed dumbphone users struggle. One user profiled in the piece still carries an "emergency iPhone" for work requirements and admits long-distance friendships have become "nearly impossible to maintain."

This week Noema magazine published a 7,000-word exploration of our modern "Mythology Of Conscious AI" written by a neuroscience professor who directs the University of Sussex Centre for Consciousness Science: The very idea of conscious AI rests on the assumption that consciousness is a matter of computation. More specifically, that implementing the right kind of computation, or information processing, is sufficient for consciousness to arise. This assumption, which philosophers call computational functionalism, is so deeply ingrained that it can be difficult to recognize it as an assumption at all. But that is what it is. And if it's wrong, as I think it may be, then real artificial consciousness is fully off the table, at least for the kinds of AI we're familiar with.
He makes detailed arguments against a computation-based consciousness (including "Simulation is not instantiation... If we simulate a living creature, we have not created life.") While a computer may seem like the perfect metaphor for a brain, the cognitive science of "dynamical systems" (and other approaches) reject the idea that minds can be entirely accounted for algorithmically. And maybe actual life needs to be present before something can be declared conscious.

He also warns that "Many social and psychological factors, including some well-understood cognitive biases, predispose us to overattribute consciousness to machines."

But then his essay reaches a surprising conclusion: As redundant as it may sound, nobody should be deliberately setting out to create conscious AI, whether in the service of some poorly thought-through techno-rapture, or for any other reason. Creating conscious machines would be an ethical disaster. We would be introducing into the world new moral subjects, and with them the potential for new forms of suffering, at (potentially) an exponential pace. And if we give these systems rights, as arguably we should if they really are conscious, we will hamper our ability to control them, or to shut them down if we need to. Even if I'm right that standard digital computers aren't up to the job, other emerging technologies might yet be, whether alternative forms of computation (analogue, neuromorphic, biological and so on) or rapidly developing methods in synthetic biology. For my money, we ought to be more worried about the accidental emergence of consciousness in cerebral organoids (brain-like structures typically grown from human embryonic stem cells) than in any new wave of LLM.

But our worries don't stop there. When it comes to the impact of AI in society, it is essential to draw a distinction between AI systems that are actually conscious and those that persuasively seem to be conscious but are, in fact, not. While there is inevitable uncertainty about the former, conscious-seeming systems are much, much closer... Machines that seem conscious pose serious ethical issues distinct from those posed by actually conscious machines. For example, we might give AI systems "rights" that they don't actually need, since they would not actually be conscious, restricting our ability to control them for no good reason. More generally, either we decide to care about conscious-seeming AI, distorting our circles of moral concern, or we decide not to, and risk brutalizing our minds. As Immanuel Kant argued long ago in his lectures on ethics, treating conscious-seeming things as if they lack consciousness is a psychologically unhealthy place to be...

One overlooked factor here is that even if we know, or believe, that an AI is not conscious, we still might be unable to resist feeling that it is. Illusions of artificial consciousness might be as impenetrable to our minds as some visual illusions... What's more, because there's no consensus over the necessary or sufficient conditions for consciousness, there aren't any definitive tests for deciding whether an AI is actually conscious....

Illusions of conscious AI are dangerous in their own distinctive ways, especially if we are constantly distracted and fascinated by the lure of truly sentient machines... If we conflate the richness of biological brains and human experience with the information-processing machinations of deepfake-boosted chatbots, or whatever the latest AI wizardry might be, we do our minds, brains and bodies a grave injustice. If we sell ourselves too cheaply to our machine creations, we overestimate them, and we underestimate ourselves...

The sociologist Sherry Turkle once said that technology can make us forget what we know about life. It's about time we started to remember.

A study by a Singapore government agency has found that children exposed to high levels of screen time before age two showed brain development changes linked to slower decision-making and higher anxiety in adolescence, adding to concerns about early digital exposure. From a report: The study was conducted by a team within the country's Agency for Science, Technology and Research and the National University of Singapore, and published in The Lancet's eBioMedicine open access journal. It tracked 168 children for more than a decade, and conducted brain scans on them at three time points. Heavier screen exposure among very young children was associated with "accelerated maturation of brain networks" responsible for vision and cognitive control, the study found.

The researchers suggested this may have been the result of "intense sensory stimulation that screens provide." They found that screen time measured at ages three and four, however, did not show the same effects. Those children with "altered brain networks" took longer to make decisions when they were 8.5, and also had higher anxiety symptoms at age 13, the study said.

A new study from the University of Pennsylvania finds that preteens who own smartphones by age 12 have significantly higher odds of depression, obesity, and poor sleep compared to their peers. Axios reports: Kids who owned a smartphone at age 12 were found to have about 31% higher odds of depression, 40% higher odds of obesity and 62% higher odds of insufficient sleep than their peers who didn't have one. The researchers analyzed data from the National Institutes of Health-supported Adolescent Brain Cognitive Development Study assessments conducted between 2016 and 2022. The study included responses from 10,588 youths. Kids who had smartphones were more likely to be female, Black or Hispanic, and from lower-income households. The study has been published in the journal Pediatrics.

Test scores across OECD countries peaked around 2012 and have declined since. IQ scores in many developed countries appear to be falling after rising throughout the twentieth century. Nataliya Kosmyna at MIT's Media Lab began noticing changes around two years ago when strangers started emailing her to ask if using ChatGPT could alter their brains. She posted a study in June tracking brain activity in 54 students writing essays. Those using ChatGPT showed significantly less activity in networks tied to cognitive processing and attention compared to students who wrote without digital help or used only internet search engines. Almost none could recall what they had written immediately after submitting their work.

She received more than 4,000 emails afterward. Many came from teachers who reported students producing passable assignments without understanding the material. A British survey found that 92% of university students now use AI and roughly 20% have used it to write all or part of an assignment. Independent research has found that more screen time in schools correlates with worse results. Technology companies have designed products to be frictionless, removing the cognitive challenges brains need to learn. AI now allows users to outsource thinking itself.

Scientists from Spain and China have successfully repaired the blood-brain barrier in Alzheimer's-model mice, enabling the brain to naturally clear amyloid-beta plaques and reverse cognitive decline. "After just three drug injections, mice with certain genes that mimic Alzheimer's showed a reversal of several key pathological features," adds ScienceAlert. From the report: Within hours of the first injection, the animal brains showed a nearly 45 percent reduction in clumps of amyloid-beta plaques, a hallmark of Alzheimer's disease. The mice had previously shown signs of cognitive decline, but after all three doses, the animals performed on par with their healthy peers in spatial learning and memory tasks. The benefits lasted at least six months.

These preclinical results don't guarantee success in humans, but they're an encouraging start, which the authors say "heralds a new era" in drug research. "The therapeutic implications are profound," claim the international team of researchers, co-led by scientists at the Institute for Bioengineering of Catalonia (IBEC) and the West China Hospital Sichuan University (WCHSU). The findings have been published in Signal Transduction and Targeted Therapy.

Doug Whitney carries a genetic mutation that guaranteed he would develop Alzheimer's disease in his late forties or early fifties. His mother and nine of her thirteen siblings died from the disease. His oldest brother died at 45. The mutation has decimated his family for generations. Whitney is now 76 and remains cognitively healthy. The New York Times has a fascinating long read on Whitney and things happening around him.

Scientists at Washington University School of Medicine in St. Louis have studied Whitney for 14 years. They extract his cerebrospinal fluid and conduct brain scans during his periodic visits from Washington State. His brain contains heavy amyloid deposits but almost no tau tangles in regions associated with dementia. Tau accumulation correlates directly with cognitive decline. Whitney accumulated tau only in his left occipital lobe, an area that does not play a major role in Alzheimer's.

Researchers identified several possibly protective factors in Whitney's biology. His immune system produces a lower inflammatory response than other mutation carriers. He has unusually high levels of heat shock proteins, which prevent proteins from misfolding. Scientists believe his decade working in Navy engine rooms at temperatures reaching 110 degrees may have driven this accumulation. He also carries three gene variants his afflicted relatives lack. His son Brian inherited the mutation and remains asymptomatic at 43. Brian received anti-amyloid drugs in clinical trials. Researchers published their findings on Whitney in Nature Medicine. They described the study as a call for other scientists to help solve the case.

Micro- and nanoplastic particles "infiltrate all systems of the body, including the brain," notes the University of Rhode Island, "where they can accumulate and trigger Alzheimer's-like conditions, according to a new study by researchers in the University of Rhode Island College of Pharmacy."

ScienceDaily shares the announcement: After a previous study that showed how microplastics can infiltrate all systems of the body — including the blood-brain barrier, which protects the brain from harmful substances as small as viruses and bacteria — University of Rhode Island pharmacy assistant professor Jaime Ross expanded the study to determine the brain health impacts of the plastic toxins. Her findings indicate that the accumulation of micro- and nanoplastics in the brain can lead to cognitive decline and even Alzheimer's disease, especially in those who carry genetic risk factors.

Ross' latest study, published recently in the journal Environmental Research Communications, examined mice that had been genetically modified to include the naturally occurring gene APOE4, a strong indicator of Alzheimer's risk making people 3.5 times more likely to develop the disease than those who carry the APOE3 variant of the gene that is passed from parents to offspring... Ross and her team exposed two groups of mice — one with the APOE4 variant and one with APOE3 — to micro- and nanoplastics in their drinking water over a period of three weeks. The tiny particles from polystyrene — among the most abundant plastics in the world, found in Styrofoam take-out containers, plastic cups and more — infiltrated the mice' organs, including the brain, as expected...

Ross' team then ran the mice through a series of tests to examine their cognitive ability, beginning with an open-field test, in which researchers put a mouse in a chamber and allow it to explore at will for 90 minutes. Ordinarily, a mouse will hug the walls, naturally attempting to hide from potential predators. However, after microplastic exposure, the APOE4 mice — especially the male mice — tended to wander more in the middle of the chamber and spend time in open space, leaving themselves vulnerable to predators...

The results are concerning enough to warrant further study into the cognitive decline caused by exposure to micro- and nanoplastics, which are among the most prominent environmental toxins to which people are routinely exposed... Ross is continuing to expand her research into the topic and encourages others to do so, in the hope of leading to better regulation of the toxins.

A research team just discovered older mice have more of the protein FTL1 in their hippocampus, reports ScienceAlert. The hippocampus is the region of the brain involved in memory and learning. And the researchers' paper says their new data raises "the exciting possibility that the beneficial effects of targeting neuronal ferritin light chain 1 (FTL1) at old age may extend more broadly, beyond cognitive aging, to neurodegenerative disease conditions in older people." FTL1 is known to be related to storing iron in the body, but hasn't come up in relation to brain aging before... To test its involvement after their initial findings, the researchers used genetic editing to overexpress the protein in young mice, and reduce its level in old mice. The results were clear: the younger mice showed signs of impaired memory and learning abilities, as if they were getting old before their time, while in the older mice there were signs of restored cognitive function — some of the brain aging was effectively reversed...

"It is truly a reversal of impairments," says biomedical scientist Saul Villeda, from the University of California, San Francisco. "It's much more than merely delaying or preventing symptoms." Further tests on cells in petri dishes showed how FTL1 stopped neurons from growing properly, with neural wires lacking the branching structures that typically provide links between nerve cells and improve brain connectivity...

"We're seeing more opportunities to alleviate the worst consequences of old age," says Villeda. "It's a hopeful time to be working on the biology of aging."
The research was led by a team from the University of California, San Francisco — and published in Nature Aging..

An anonymous reader quotes a report from The Guardian: Fine-particulate air pollution can drive devastating forms of dementia by triggering the formation of toxic clumps of protein that destroy nerve cells as they spread through the brain, research suggests. Exposure to the airborne particles causes proteins in the brain to misfold into the clumps, which are hallmarks of Lewy body dementia, the second most common form of dementia after Alzheimer's disease. The finding has "profound implications" for preventing the neurodegenerative disorder, which affects millions worldwide, with scientists calling for a concerted effort to improve air quality by cutting emissions from industrial activity and vehicle exhausts, improving wildfire management and reducing wood burning in homes.

The researchers began by analyzing hospital records of the 56.5 million US Medicare patients. They looked at those who were admitted for the first time between 2000 and 2014 with the protein damage. Armed with the patients' zip codes, the scientists estimated their long-term exposure to PM2.5 pollution, airborne particles that are smaller than 2.5 thousandths of a millimeter. These can be inhaled deep into the lungs and are found in the bloodstream, brain and other organs. They found that long-term exposure to PM2.5 raised the risk of Lewy body dementia, but had less of an impact on rates of another neurodegenerative brain disease that is not driven by the toxic proteins. Lewy bodies are made from a protein called alpha-synuclein. The protein is crucial for healthy brain functioning, but can misfold in various ways to produce different kinds of harmful Lewy bodies. These can kill nerve cells and cause devastating disease by spreading through the brain.

To see if air pollution could trigger Lewy bodies, the team exposed mice to PM2.5 pollution every other day for 10 months. Some were normal mice, but others were genetically modified to prevent them making alpha-synuclein. The results were striking: in normal mice, nerve cells died off, leading to brain shrinkage and cognitive decline. The genetically modified mice were largely unaffected. Further work in mice showed that PM2.5 pollution drove the formation of aggressive, resilient and toxic clumps of alpha-synuclein clumps that looked very similar to Lewy bodies in humans. Although the work is in mice, the findings are considered compelling evidence. The work has been published in the journal Science.

In a landmark collaboration across 22 labs, neuroscientists have created the first brain-wide map of decision-making in mice, tracking over 620,000 neurons across nearly 280 brain regions. They found that decision-making is distributed much more broadly than previously thought, involving not just "cognitive" centers but also regions linked to movement. From a report: The task was deceptively simple task. Mice sat in front of a screen that intermittently displayed a black-and-white striped circle for a brief amount of time on either the left or right side. A mouse could earn a sip of sugar water if they quickly moved the circle toward the center of the screen by operating a tiny steering wheel in the same direction, often doing so within one second. On some trials, the circle was faint, requiring the animal to rely on past experience to make a guess, which allowed researchers to study how expectations influence future decisions. While the mice performed the task, researchers recorded brain activity using high-density electrodes that allowed them to monitor hundreds of neurons across many regions simultaneously. The work was divided across the participating labs, so that each lab mapped a particular region of the mouse brain. The pooled dataset covers 620,000 neurons recorded from 139 mice in 12 labs, encompassing nearly the entire brain. The resulting map revealed that decision-making activity is distributed across the brain, including in areas traditionally associated with movement rather than cognition. The findings have been published in two papers in the journal Nature.

alternative_right shares a report from ScienceAlert: The insecticide chlorpyrifos is a powerful tool for controlling various pests, making it one of the most widely used pesticides during the latter half of the 20th century. Like many pesticides, however, chlorpyrifos lacks precision. In addition to harming non-target insects like bees, it has also been linked to health risks for much larger animals -- including us. Now, a new US study suggests those risks may begin before birth. Humans exposed to chlorpyrifos prenatally are more likely to exhibit structural brain abnormalities and reduced motor functions in childhood and adolescence.

Progressively higher prenatal exposure to chlorpyrifos was associated with incrementally greater deviations in brain structure, function, and metabolism in children and teens, the researchers found, along with poorer measures of motor speed and motor programming. [...] This supports previous research linking chlorpyrifos with impaired cognitive function and brain development, but these findings are the first evidence of widespread and long-lasting molecular, cellular, and metabolic effects in the brain. "The disturbances in brain tissue and metabolism that we observed with prenatal exposure to this one pesticide were remarkably widespread throughout the brain," says first author Bradley Peterson, a developmental neuroscientist at the University of Southern California's Keck School of Medicine. Senior author Virginia Rauh added: "It is vitally important that we continue to monitor the levels of exposure in potentially vulnerable populations, especially in pregnant women in agricultural communities, as their infants continue to be at risk."

The report notes that the EPA banned residential use of chlorpyrifos in 2001 but the pesticide is still used in agriculture around the world.

The findings have been published in the journal JAMA Neurology.

"According to a new study, wearing the right kind of perfume or cologne can enlarge your brain's gray matter," writes ScienceAlert Researchers from Kyoto University and the University of Tsukuba in Japan asked 28 women to wear a specific rose scent oil on their clothing for a month, with another 22 volunteers enlisted as controls who put on plain water instead. Magnetic resonance imaging ( MRI) scans showed boosts in the gray matter volume of the rose scent participants.

While an increase in brain volume doesn't necessarily translate into more thinking power, the findings could have implications for neurodegenerative conditions such as dementia. "This study is the first to show that continuous scent inhalation changes brain structure," write the researchers in their published paper. We've seen scents like this improve memory and cognitive performance, but here the team wanted to try a longer-term experiment to see how triggering our sense of smell might lead to measurable changes in brain structure...

It's difficult to pin down exactly what's causing this boost in gray matter. Another possibility raised by the researchers is that the rose scent is actually labeled as unpleasant by the brain, with the subsequent emotional regulation responsible for the PCC working harder and increasing in size. The researchers hope that the findings could be useful in the development of aromatherapies that boost mental health and brain plasticity...

The research was published in the Brain Research Bulletin.

"The truly universal properties of languages are not independent of our physiology and cognition," argues the co-author of a new study. Instead he says their research "strengthens the idea that intonation units are a universal feature of language."

Phys.org explains: Have you ever noticed that a natural conversation flows like a dance — pauses, emphases, and turns arriving just in time? A new study has discovered that this isn't just intuition; there is a biological rhythm embedded in our speech...

According to the study, led by Dr. Maya Inbar, alongside Professors Eitan Grossman and Ayelet N. Landau, human speech across the world pulses to the beat of what are called intonation units, short prosodic phrases that occur at a consistent rate of one every 1.6 seconds. The research analyzed over 650 recordings in 48 languages spanning every continent and 27 language families. Using a novel algorithm, the team was able to automatically identify intonation units in spontaneous speech, revealing that regardless of the language spoken, from English and Russian to endangered languages in remote regions, people naturally break their speech into these rhythmic chunks. "These findings suggest that the way we pace our speech isn't just a cultural artifact, it's deeply rooted in human cognition and biology," says Dr. Inbar.

"We also show that the rhythm of intonation units is unrelated to faster rhythms in speech, such as the rhythm of syllables, and thus likely serves a different cognitive role...." Most intriguingly, the low-frequency rhythm they follow mirrors patterns in brain activity linked to memory, attention, and volitional action, illuminating the profound connection between how we speak and how we think.
The work is published in the journal Proceedings of the National Academy of Sciences.

An anonymous reader quotes a report from New Scientist: People withAlzheimer's disease have lower levels of lithium in their brains, and giving lithium to mice with symptoms of the condition reverses cognitive decline. Together, the findings suggest that lithium deficiency could be a driver of Alzheimer's disease and that low-dose lithium medications could help treat it. [...] [Bruce Yanknerat Harvard University] and his colleagues analyzed levels of 27 metals in the brains of 285 people after they died, 94 of whom were diagnosed with Alzheimer's disease and 58 of whom had mild cognitive impairment, a precursor of the condition. The other participants showed no signs of cognitive decline at the time of their death.

Lithium levels in the prefrontal cortex -- a brain region crucial for memory and decision-making -- were about 36 percent lower, on average, in people with Alzheimer's disease than in those without any cognitive decline. For those with mild cognitive impairment, lithium levels were about 23 percent lower. "We suspect that's due to a number of environmental factors: dietary intake, genetics and so forth," says Yankner. Yet there seemed to be another reason, too. In those with Alzheimer's disease, clumps of proteins called amyloid plaques contained nearly three times the amount of lithium as plaque-free regions of their brain. "Lithium becomes sequestered in these plaques," says Yankner. "We have two things going on. There is impaired uptake of lithium [in the brain] very early on and then, as the disease progresses, the lithium that is in the brain is further diminished by being bound to amyloid."

To understand how this influences cognition, the team genetically engineered 22 mice to develop Alzheimer's-like symptoms and reduced their lithium intake by 92 percent. After about eight months, the animals performed significantly worse on multiple memory tests compared with 16 mice on a standard diet. It took lithium-deficient mice around 10 seconds longer to find a hidden platform in a water maze, for example, even after six days of training. Their brains also contained nearly two and a half times as many amyloid plaques. Genetic analysis of brain cells from the lithium-deficient mice showed increased activity in genes related to neurodegeneration and Alzheimer's. They also had more brain inflammation and their immune cells were less able to clear away amyloid plaques, changes also seen in people with Alzheimer's disease.

The team then screened different lithium compounds for their ability to bind to amyloid and found that lithium orotate -- a naturally occurring compound in the body formed by combining lithium with orotic acid -- appeared to be the least likely to get trapped within plaques. Nine months of treatment with this compound significantly reduced plaques in mice with Alzheimer's-like symptoms, and they also performed as well on memory tests as normal mice. These results suggest lithium orotate could be a promising treatment for Alzheimer's. The findings have been published in the journal Nature.