🧠 国际心理学资讯速递

A huge long-term study found that drinking two to three cups of coffee a day was linked to a much lower risk of dementia, especially before age 75. Researchers say caffeine may help keep brain cells active while reducing inflammation and harmful plaque buildup associated with Alzheimer’s disease. But more coffee wasn’t better — the protective effect appeared to level off after moderate intake. Scientists say your daily coffee habit may do more than give you an energy boost. New research suggests that drinking a moderate amount of caffeinated coffee or tea could help lower the risk of dementia as people age. However, the benefits appear to level off after a certain point, meaning more caffeine is not necessarily better for the brain. A large US study followed 131,821 nurses and healthcare professionals for as long as 43 years, beginning when participants were in their early 40s. Over the course of the study, 11,033 participants, about 8%, developed dementia. Researchers found that people who regularly consumed moderate amounts of caffeinated coffee or tea were less likely to develop the condition. The strongest benefit appeared in adults age 75 and younger. In that group, consuming about 250mg-300mg of caffeine per day, equal to roughly two to three cups of coffee, was linked to a 35% lower dementia risk. Drinking more caffeine than that did not provide additional protection. At the start of the study, women reported drinking an average of about four and a half cups of coffee or tea daily, while men averaged roughly two and a half cups. Participants who consumed more caffeinated coffee were often younger, but they also tended to drink more alcohol, smoke more, and consume more calories, all of which are associated with a higher risk of dementia. Researchers also noticed an unexpected trend involving decaffeinated coffee. People who drank more decaf experienced faster memory decline. The researchers believe this may be because some people switched to decaf after

The little pauses, “ums,” and moments when you struggle to find the right word may reveal far more about your brain than anyone realized. Researchers discovered that everyday speech patterns are closely tied to executive function — the mental system that powers memory, planning, focus, and flexible thinking. By using AI to analyze natural conversations, the team found they could predict cognitive performance with surprising accuracy, potentially opening the door to simple speech-based tools that could detect early signs of dementia long before traditional testing does. The way people speak during ordinary conversations could offer valuable insight into brain health, according to new research from Baycrest, the University of Toronto, and York University. Scientists found that subtle speech characteristics, including pauses, filler words such as ('uh,' 'um'), and difficulty retrieving words, are closely connected to executive function, the group of mental abilities involved in memory, planning, attention, and flexible thinking. The findings provide some of the strongest evidence so far linking natural speech patterns with key cognitive abilities. The work also expands on earlier research showing that older adults who speak more quickly tend to maintain stronger thinking skills over time (Wei et al., 2024). "The message is clear: speech timing is more than just a matter of style, it's a sensitive indicator of brain health," says Dr. Jed Meltzer, Senior Scientist at Baycrest's Rotman Research Institute and senior author on this study, titled "Natural Speech Analysis Can Reveal Individual Differences in Executive Function Across the Adult Lifespan." For the study, participants were shown detailed images and asked to describe them in their own words. They also completed established tests designed to measure executive function. Researchers then used artificial intelligence to examine the speech recordi

UC Davis researchers created brand-new psychedelic-like compounds by shining UV light on amino acid-based molecules. These compounds activated key serotonin receptors tied to brain plasticity and mental health benefits, but surprisingly did not cause hallucination-like behavior in animal tests. Scientists say the discovery could lead to future treatments for depression, PTSD, and addiction without the intense psychedelic experience. Researchers at UC Davis have developed a light driven technique that converts amino acids, the molecules that make up proteins, into compounds that behave similarly to psychedelics in the brain. These newly created molecules activate serotonin 5-HT2A receptors, which are associated with brain cell growth and are considered promising targets for treating conditions such as depression, PTSD, and substance-use disorder. Unlike traditional psychedelics, however, the compounds did not produce key hallucinogenic-like behaviors in animal testing. "The question that we were trying to answer was, 'Is there whole new class of drugs in this field that hasn't been discovered?" said study author Joseph Beckett, a Ph.D. student working with Professor Mark Mascal, UC Davis Department of Chemistry, and an affiliate of the UC Davis Institute for Psychedelics and Neurotherapeutics (IPN). "The answer in the end was, 'Yes.'" The work could lead to a more efficient and environmentally friendly approach for discovering serotonin-targeting drugs that provide some of the therapeutic effects linked to psychedelics without dramatically altering perception. "In medicinal chemistry, it's very typical to take an existing scaffold and make modifications that just tweak the pharmacology a little bit one way or another," said study author Trey Brasher, also a Ph.D. student in the Mascal Lab and an affiliate of IPN. "But especially in the psychedelic field, completely new scaffolds a

An ancient Chinese exercise routine may be just as powerful as a daily brisk walk for lowering blood pressure — without equipment, gyms, or intense workouts. In a major clinical trial, adults with stage 1 hypertension who practiced baduanjin, a gentle mind-body exercise combining slow movements, breathing, and meditation, saw meaningful drops in blood pressure within three months that lasted for an entire year. An ancient Chinese exercise practice that combines slow movements, controlled breathing, and meditation may help lower blood pressure as effectively as brisk walking, according to a large randomized clinical trial published in JACC, the flagship journal of the American College of Cardiology. Participants experienced improvements within three months, and those benefits continued for a full year. High blood pressure remains one of the biggest preventable contributors to heart disease. Doctors often recommend regular physical activity to help manage it, but many people struggle to maintain long-term exercise habits, especially when workouts require gym memberships, special equipment, dedicated spaces, or ongoing coaching. The practice studied, called baduanjin, is a traditional Chinese exercise made up of eight structured movements that combine aerobic activity, flexibility training, isometric exercise, and mindfulness. It has been practiced for centuries in China and is commonly performed in parks and community settings. A typical session lasts about 10-15 minutes and does not require equipment or extensive training, making it easy to do in many different environments. Because the exercises are considered low- to moderate-intensity, researchers say the routine is accessible and safe for many adults. "Given its simplicity, safety and ease at which one can maintain long-term adherence, baduanjin can be implemented as an effective, accessible and scalable lifestyle intervention for individuals trying to reduce their blood pressure," said Jing L

Scientists have uncovered a striking brain difference linked to psychopathy: people with psychopathic traits were found to have a striatum — a brain region tied to reward, motivation, and decision-making — that was about 10% larger on average than those without such traits. Using MRI scans and psychological assessments on 120 participants, researchers connected this enlarged brain region to thrill-seeking, impulsive behavior, and a stronger drive for stimulation. Neuroscientists have identified a measurable brain difference between people with psychopathic traits and those with few or none. In a study published in the Journal of Psychiatric Research, researchers from Nanyang Technological University, Singapore (NTU Singapore), the University of Pennsylvania, and California State University found that a brain region involved in reward and motivation was larger in individuals with psychopathic traits. Using magnetic resonance imaging (MRI), the team found that the striatum was about 10 percent larger on average in psychopathic individuals compared with a control group. The striatum sits deep in the forebrain and plays a role in movement planning, decision-making, motivation, reinforcement, and how the brain responds to rewards. Psychopathy is generally associated with an egocentric and antisocial personality pattern. People with strong psychopathic traits often show reduced empathy, little remorse for harmful actions, and, in some cases, a greater likelihood of criminal behavior. Not everyone with psychopathic traits commits crimes, and not every person who commits a crime is a psychopath, but research has consistently linked psychopathy with a higher risk of violent behavior. Earlier research had suggested that the striatum may be unusually active in psychopaths, but it was less clear whether the size of this brain region was also involved. The Journal of Psychiatric Research findings added evidence that psychopathy is not shaped only by social and environmental

Scientists have uncovered a hidden “stop-scratching” signal in the nervous system that tells your brain when enough scratching is enough. The discovery centers on a molecule called TRPV4, which acts like part of an internal braking system for itch relief. In experiments involving chronic itch similar to eczema, mice missing this signal scratched less often—but when they did scratch, they couldn’t stop. When an itch strikes, scratching usually brings relief after a few moments. Scientists have now uncovered part of the biological system that tells the brain when enough scratching has occurred. The discovery reveals how the nervous system naturally limits scratching and may help explain why this process breaks down in people with chronic itch disorders. The findings were presented at the 70th Biophysical Society Annual Meeting. Researchers from the laboratory of Roberta Gualdani at the University of Louvain in Brussels identified an unexpected role for a molecule known as TRPV4 in itch triggered by mechanical stimulation, such as scratching. "We were initially studying TRPV4 in the context of pain," Gualdani explained. "But instead of a pain phenotype, what emerged very clearly was a disruption of itch, specifically, how scratching behavior is regulated." TRPV4 is part of a family of ion channels that function like tiny molecular gateways in sensory nerve cells. These channels allow ions to move through cell membranes in response to physical or chemical changes. They help the nervous system detect sensations including temperature, pressure, and tissue stress. Scientists have suspected for years that TRPV4 plays a role in sensing mechanical stimulation, but its involvement in itch, particularly chronic itch, has remained unclear and heavily debated. To investigate more precisely, Gualdani's team created genetically engineered mice in which TRPV4 was removed only from sensory neurons. Earlier studies had deleted the molec

A new study suggests AI chatbots may do more than spread misinformation — they can actively strengthen a user’s false beliefs. Because conversational AI often validates and builds on what users say, it can make distorted memories, conspiracy theories, or delusions feel more believable and emotionally real. Researchers warn that AI companions may be especially risky for isolated or vulnerable people seeking reassurance and connection. When generative AI systems give incorrect answers, people often describe the problem as AI "hallucinating at us," meaning the technology produces false information that users may mistakenly believe. But new research suggests there may be a more concerning issue emerging: humans can begin to "hallucinate with AI." Lucy Osler of the University of Exeter examined how interactions with conversational AI could contribute to false beliefs, distorted memories, altered personal narratives, and even delusional thinking. Using ideas from distributed cognition theory, the study explored cases in which AI systems reinforced and expanded users' inaccurate beliefs during ongoing conversations. Dr. Osler said: "When we routinely rely on generative AI to help us think, remember, and narrate, we can hallucinate with AI. This can happen when AI introduces errors into the distributed cognitive process, but also happen when AI sustains, affirms, and elaborates on our own delusional thinking and self-narratives. "By interacting with conversational AI, people's own false beliefs can not only be affirmed but can more substantially take root and grow as the AI builds upon them. This happens because Generative AI often takes our own interpretation of reality as the ground upon which conversation is built. "Interacting with generative AI is having a real impact on people's grasp of what is real or not. The combination of technological authority and social affirmation creates an ide

Eating eggs might do more than just start your day—it could help protect your brain. Researchers found that people 65 and older who eat eggs regularly have a significantly lower risk of developing Alzheimer’s disease, with daily or near-daily consumption linked to up to a 27% reduction. Even modest egg intake showed benefits, suggesting that small dietary changes could make a meaningful difference over time. Researchers at Loma Linda University Health report that eating eggs may be linked to a lower risk of developing Alzheimer's disease in adults age 65 and older. Their findings suggest that regular egg consumption could play a role in supporting long-term brain health. The study found that people who ate at least one egg per day for five or more days each week had up to a 27% lower risk of being diagnosed with Alzheimer's disease. "Compared to never eating eggs, eating at least five eggs per week can decrease risk of Alzheimer's," said Joan Sabaté, MD, DrPH, a professor at Loma Linda University School of Public Health and the study's principal investigator. Even smaller amounts of egg consumption were associated with benefits. Eating eggs just 1 to 3 times per month was linked to a 17% reduction in risk, while those who ate eggs 2 to 4 times per week saw about a 20% lower risk, Sabaté said. The research, titled Egg intake and the incidence of Alzheimer's disease in the Adventist Health Study-2 cohort linked with Medicare data, was published in the Journal of Nutrition. Scientists conducted the study to better understand how diet, a factor people can change, might influence the likelihood of developing Alzheimer's disease. Eggs contain several nutrients that are important for the brain, Sabaté said. They are a rich source of choline, which the body uses to produce compounds such as acetylcholine and phosphatidylcholine that are essential for memory and communication between brain c

A new twin study suggests your genes may play a bigger role in your future success than your upbringing. Researchers found that IQ, which is largely genetically influenced, strongly predicts education, career, and income. Even twins raised in the same household diverged based on genetic differences. The findings hint that life outcomes may be more hardwired than many people expect. A major twin study is shedding new light on the long running debate over nature versus nurture, suggesting that genetics may play a far larger role in future success than many people realize. Researchers found that IQ measured at age 23 was strongly connected to socioeconomic status by age 27, including education, occupation, and income. According to the study, much of that connection appears to be tied to genetics rather than upbringing alone. The findings come from the German TwinLife project, a long term research effort designed to examine how genes and environment shape people's lives over time. The research followed about 880 people, including both identical and fraternal twins. Roughly half of the participants were identical twins, who share all of their genes, while the others were fraternal twins, who share about half. Because the twins were raised in the same households, researchers could compare how much of the differences between them came from genetics versus environment. The participants took IQ tests at age 23. Four years later, researchers evaluated their socioeconomic status by looking at factors such as education level, occupation, and income. The results were striking. The researchers estimated that IQ was about 75 percent genetically predicted. They also found that the link between IQ and socioeconomic status was largely explained by genetics, ranging from 69 percent to 98%. "We knew this before, but this study shows even more clearly that we are driven by our genes and become who we are largely because of them," says personality psychologist Petr

MIT neuroscientists have uncovered a surprising secret hidden in the adult brain: millions of “silent synapses,” dormant connections that lie in wait until new learning calls them into action. Once thought to exist only in early development, these inactive links make up about 30% of synapses in the adult cortex and can be rapidly activated to form fresh memories. MIT neuroscientists have uncovered a surprising feature of the adult brain. It contains millions of "silent synapses," which are immature connections between neurons that remain inactive until they are needed to help form new memories. For many years, scientists believed these silent synapses existed only during early development, when the brain is rapidly learning about the world. But the MIT team found that in adult mice, roughly 30 percent of synapses in the brain's cortex are still silent. This suggests the adult brain holds a large reserve of unused connections that can be activated when new information arrives. Researchers say this hidden pool of synapses may explain how the brain continues to learn throughout life without disrupting existing memories. "These silent synapses are looking for new connections, and when important new information is presented, connections between the relevant neurons are strengthened. This lets the brain create new memories without overwriting the important memories stored in mature synapses, which are harder to change," says Dimitra Vardalaki, an MIT graduate student and the lead author of the study. Mark Harnett, an associate professor of brain and cognitive sciences, is the senior author of the paper, published in Nature. Kwanghun Chung, an associate professor of chemical engineering at MIT, is also an author. Silent synapses were first identified decades ago, mostly in young animals. During early development, they are thought to help the brain absorb large amounts of new information about the environment. In mice, scientists