Most Recent Links

Follow us on Facebook or subscribe to our mailing list, to receive news updates. Learn more.


Links 2161 - 2180 of 29517

By John Horgan In my 20s, I had a friend who was brilliant, charming, Ivy-educated and rich, heir to a family fortune. I’ll call him Gallagher. He could do anything he wanted. He experimented, dabbling in neuroscience, law, philosophy and other fields. But he was so critical, so picky, that he never settled on a career. Nothing was good enough for him. He never found love for the same reason. He also disparaged his friends’ choices, so much so that he alienated us. He ended up bitter and alone. At least that’s my guess. I haven’t spoken to Gallagher in decades. There is such a thing as being too picky, especially when it comes to things like work, love and nourishment (even the pickiest eater has to eat something). That’s the lesson I gleaned from Gallagher. But when it comes to answers to big mysteries, most of us aren’t picky enough. We settle on answers for bad reasons, for example, because our parents, priests or professors believe it. We think we need to believe something, but actually we don’t. We can, and should, decide that no answers are good enough. We should be agnostics. Some people confuse agnosticism (not knowing) with apathy (not caring). Take Francis Collins, a geneticist who directs the National Institutes of Health. He is a devout Christian, who believes that Jesus performed miracles, died for our sins and rose from the dead. In his 2006 bestseller The Language of God, Collins calls agnosticism a “cop-out.” When I interviewed him, I told him I am an agnostic and objected to “cop-out.” © 2021 Scientific American

Keyword: Consciousness
Link ID: 27952 - Posted: 08.18.2021

Natalie Grover Cuttlefish have one of the largest brains among invertebrates and can remember what, where, and when specific things happened right up to their final days of life, according to new research. The cephalopods – which have three hearts, eight arms, blue-green blood, regenerating limbs, and the ability to camouflage and exert self-control – only live for roughly two years. As they get older, they show signs of declining muscle function and appetite, but it appears that no matter their age they can remember what they ate, where and when, and use this to guide their future feeding decisions, said the lead study author, Dr Alexandra Schnell from the University of Cambridge. This is in contrast to humans, who gradually lose the ability to remember experiences that occurred at a particular time and place with age – for instance, what you ate for lunch last Wednesday. This “episodic memory” and its deterioration is linked to the hippocampus, a seahorse-shaped organ in the part of the brain near our ears. Cuttlefish, meanwhile, do not have a hippocampus, but a “vertical lobe” associated with learning and memory. In the study, Schnell and her colleagues conducted memory tests in 24 cuttlefish. Half were 10-12 months old (not quite adults) while the rest were 22-24 months old (the equivalent of a human in their 90s), according to the paper, published in the journal Proceedings of the Royal Society B. In one experiment, both groups of cuttlefish were first trained to approach a specific location in their tank, marked with a flag, and learn that two different foods would be provided at different times. At one spot, the flag was waved and the less-preferred king prawn was provided every hour. Grass shrimp, which they like more, was provided at a different spot where another flag was waved – but only every three hours. This was done for about four weeks, until they learned that waiting for longer meant that they could get their preferred food. © 2021 Guardian News & Media Limited

Keyword: Learning & Memory; Evolution
Link ID: 27951 - Posted: 08.18.2021

Ruth Williams In the days before a newborn mouse opens its peepers, nerve impulses that have been sweeping randomly across the retina since birth start flowing consistently in one direction, according to a paper published in Science today (July 22). This specific pattern has a critical purpose, the authors say, helping to establish the brain circuitry to be used later in motion detection. “I love this paper. It blew my mind,” says David Berson, who studies the visual system at Brown University and was not involved in the research. “What it implies is that evolution has built a visual system that can simulate the patterns of activity that it will see later when it’s fully mature and the eyes are open, and that [the simulated pattern] in turn shapes the development of the nervous system in a way that makes it better adapted to seeing those patterns. . . . That’s staggering.” The thread of this concept may be looped, but to unravel it, Berson says, it helps to think of the mammalian visual system, or really any neuronal circuitry, as being formed by a combination of evolution and life experiences—in short, nature and nurture. We might expect that life’s visual experiences, the nurture part, would begin when the eyes open. But, much like a human baby in the womb practices breathing and sucking without ever having experienced air or breastfeeding, the eyes of newborn mice appear to practice seeing before they can actually see. Motion detection is important enough to mouse survival that evolution has selected for gene variants that set up this prevision training, says Berson. © 1986–2021 The Scientist.

Keyword: Vision; Development of the Brain
Link ID: 27950 - Posted: 08.18.2021

By Gina Kolata Everyone knows conventional wisdom about metabolism: People put pounds on year after year from their 20s onward because their metabolisms slow down, especially around middle age. Women have slower metabolisms than men. That’s why they have a harder time controlling their weight. Menopause only makes things worse, slowing women’s metabolisms even more. All wrong, according to a paper published Thursday in Science. Using data from nearly 6,500 people, ranging in age from 8 days to 95 years, researchers discovered that there are four distinct periods of life, as far as metabolism goes. They also found that there are no real differences between the metabolic rates of men and women after controlling for other factors. The findings from the research are likely to reshape the science of human physiology and could also have implications for some medical practices, like determining appropriate drug doses for children and older people. “It will be in textbooks,” predicted Leanne Redman, an energy balance physiologist at Pennington Biomedical Research Institute in Baton Rouge, La., who also called it “a pivotal paper.” Rozalyn Anderson, a professor of medicine at the University of Wisconsin-Madison, who studies aging, wrote a perspective accompanying the paper. In an interview, she said she was “blown away” by its findings. “We will have to revise some of our ideas,” she added. But the findings’ implications for public health, diet and nutrition are limited for the moment because the study gives “a 30,000-foot view of energy metabolism,” said Dr. Samuel Klein, who was not involved in the study and is director of the Center for Human Nutrition at the Washington University School of Medicine in St. Louis. He added, “I don’t think you can make any new clinical statements” for an individual. When it comes to weight gain, he says, the issue is the same as it has always been: People are eating more calories than they are burning. Metabolic research is expensive, and so most published studies have had very few participants. But the new study’s principal investigator, Herman Pontzer, an evolutionary anthropologist at Duke University, said that the project’s participating researchers agreed to share their data. There are more than 80 co-authors on the study. By combining efforts from a half dozen labs collected over 40 years, they had sufficient information to ask general questions about changes in metabolism over a lifetime. © 2021 The New York Times Company

Keyword: Obesity
Link ID: 27949 - Posted: 08.14.2021

By Teresa Carr In the fall of 2016, sex therapist and researcher Leonore Tiefer shuttered the New View Campaign, an organization she had founded to combat what she refers to as “the medicalization of sex” — essentially, the pharmaceutical industry’s efforts to define variations in sexuality and sexual problems as medical issues requiring a drug fix. For 16 years, the group had fought against industry’s involvement in sex research, including its push for a drug to boost women’s sex drives. New View hosted conferences and its members penned papers and testified before the United States Food and Drug Administration. The campaign was prominently featured in an 80-minute documentary called Orgasm Inc, and promoted a clever (if off-pitch) video advising women to “throw that pink pill away,” a reference to the female-libido drug flibanserin (Addyi), which was seeking FDA approval at the time. New View counted some successes: The FDA didn’t approve an allegedly libido-boosting testosterone patch for women, on the grounds that the patch’s slim benefits didn’t outweigh its risks, and the FDA twice rejected flibanserin for the same reason. But in August 2015, the agency reversed itself and approved the so-called pink Viagra. “I felt we’d said everything we had to say,” said Tiefer of ending the campaign. Advocates predicted FDA approval would be sought for additional women’s libido drugs, but the group felt there was nothing they could do to stop it. “However many more drugs were going to come down the pike,” said Tiefer, “it was just going to be more of the same.”

Keyword: Sexual Behavior
Link ID: 27948 - Posted: 08.14.2021

By Virginia Hughes In the 1960s, the drug was given to women during childbirth to dampen their consciousness. In the 1990s, an illicit version made headlines as a “date rape” drug, linked to dozens of deaths and sexual assaults. And for the last two decades, a pharmaceutical-grade slurry of gamma-hydroxybutyrate, or GHB, has been tightly regulated as a treatment for narcolepsy, a disorder known for its sudden sleep attacks. Now, the Food and Drug Administration has approved the drug for a new use: treating “idiopathic hypersomnia,” a mysterious condition in which people sleep nine or more hours a day, yet never feel rested. Branded as Xywav, the medication is thought to work by giving some patients restorative sleep at night, allowing their brains to be more alert when they wake up. It is the first approved treatment for the illness. But some experts say the publicly available evidence to support the new approval is weak. And they worry about the dangers of the medication, which acts so swiftly that its label advises users to take it while in bed. Xywav and an older, high-salt version called Xyrem have a host of serious side effects, including breathing problems, anxiety, depression, sleepwalking, hallucinations and suicidal thoughts. GHB “has serious safety concerns, both in terms of its abuse liability and its addictive potential,” said Dr. Lewis S. Nelson, the director of medical toxicology at Rutgers New Jersey Medical School. An estimated 40,000 people in the United States have been diagnosed with idiopathic hypersomnia, but Dr. Nelson said that many more people with daytime drowsiness might wind up with this diagnosis now that it has an F.D.A.-approved treatment. The disorder’s hallmark symptoms — sleep cravings, long naps and brain fog — overlap with many other conditions. The more people who take the drug, the more opportunity for abuse. “The potential for the scope of use to expand is very real,” Dr. Nelson said. “So that is concerning to me.” © 2021 The New York Times Company

Keyword: Sleep; Drug Abuse
Link ID: 27947 - Posted: 08.14.2021

By Katherine Ellison ADHD — the most common psychiatric disorder of childhood —  lasts longer for more people than has been widely assumed, according to new research. “Only 10 percent of people really appear to grow out of ADHD,” says the lead author, psychologist Margaret Sibley, associate professor of psychiatry and behavioral sciences at the University of Washington School of Medicine. “Ninety percent still struggle with at least mild symptoms as adults — even if they have periods when they are symptom free.” The study challenges a widely persistent perception of a time-limited condition occurring mostly in childhood. Indeed, one of the earliest names for attention deficit/hyperactivity disorder was “a hyperkinetic disease of infancy,” while its most common poster child has long been a young, White, disruptive male. Previous research has suggested the condition essentially vanishes in about half of those who receive diagnoses. But in recent years, increasing numbers of women, people of color and especially adults have been seeking help in managing the hallmark symptoms of distraction, forgetfulness and impulsivity. By the most recent estimates, 9.6 percent of children ages 3 to 17 have been diagnosed with ADHD. Yet researchers report that only 4.4 percent of young adults ages 18 to 44 have the disorder, suggesting that if the new estimates are valid, there may be some catching up to do. Sibley’s paper paints a picture of an on-again, off-again condition, with symptoms fluctuating depending on life circumstances. © 1996-2021 The Washington Post

Keyword: ADHD
Link ID: 27946 - Posted: 08.14.2021

By Cara Giaimo Giraffes seem above it all. They float over the savanna like two-story ascetics, peering down at the fray from behind those long lashes. For decades, many biologists thought giraffes extended this treatment to their peers as well, with one popular wildlife guide calling them “aloof” and capable of only “the most casual” associations. Sign up for Science Times Get stories that capture the wonders of nature, the cosmos and the human body. Get it sent to your inbox. But more recently, as experts have paid closer attention to these lanky icons, a different social picture has begun to emerge. Female giraffes are now known to enjoy yearslong bonds. They have lunch buddies, stand guard over dead calves and stay close with their mothers and grandmothers. Females even form shared day care-like arrangements, called crèches, in which they take turns babysitting and feeding each others young. Observations like these have reached a critical mass, said Zoe Muller, a wildlife biologist who completed her Ph.D. at the University of Bristol in England. She and Stephen Harris, also at Bristol, recently reviewed hundreds of giraffe studies to look for broader patterns. Their analysis, published on Tuesday in the journal Mammal Review, suggests that giraffes are not loners, but socially complex creatures, akin to elephants or chimpanzees. They’re just a little more subtle about it. Dr. Muller’s sense of giraffes as secret socialites began in 2005, when she was researching her master’s thesis in Laikipia, Kenya. There to collect data on antelopes, she found herself drawn to the ganglier ungulates. “They are so weird to look at,” she said. “If somebody described them to you, you wouldn’t believe they even really existed.” After noticing that the same giraffes tended to spend time together — they looked “like teenagers hanging out,” she said — Dr. Muller started to read up on their lifestyles. “I was really surprised to see that all the scientific books said that they were completely non-sociable,” she said. “I thought, ‘Well, hang on. That’s not what I see at all.’” © 2021 The New York Times Company

Keyword: Evolution; Emotions
Link ID: 27945 - Posted: 08.11.2021

Jordana Cepelewicz An understanding of numbers is often viewed as a distinctly human faculty — a hallmark of our intelligence that, along with language, sets us apart from all other animals. But that couldn’t be further from the truth. Honeybees count landmarks when navigating toward sources of nectar. Lionesses tally the number of roars they hear from an intruding pride before deciding whether to attack or retreat. Some ants keep track of their steps; some spiders keep track of how many prey are caught in their web. One species of frog bases its entire mating ritual on number: If a male calls out — a whining pew followed by a brief pulsing note called a chuck — his rival responds by placing two chucks at the end of his own call. The first frog then responds with three, the other with four, and so on up to around six, when they run out of breath. Practically every animal that scientists have studied — insects and cephalopods, amphibians and reptiles, birds and mammals — can distinguish between different numbers of objects in a set or sounds in a sequence. They don’t just have a sense of “greater than” or “less than,” but an approximate sense of quantity: that two is distinct from three, that 15 is distinct from 20. This mental representation of set size, called numerosity, seems to be “a general ability,” and an ancient one, said Giorgio Vallortigara, a neuroscientist at the University of Trento in Italy. Now, researchers are uncovering increasingly more complex numerical abilities in their animal subjects. Many species have displayed a capacity for abstraction that extends to performing simple arithmetic, while a select few have even demonstrated a grasp of the quantitative concept of “zero” — an idea so paradoxical that very young children sometimes struggle with it. All Rights Reserved © 2021

Keyword: Intelligence; Evolution
Link ID: 27944 - Posted: 08.11.2021

Max G. Levy Agony is contagious. If you drop a thick textbook on your toes, circuits in your brain’s pain center come alive. If you pick it up and accidentally drop it on my toes, hurting me, an overlapping neural neighborhood will light up in your brain again. “There's a physiological mechanism for emotional contagion of negative responses like stress and pain and fear,” says Inbal Ben-Ami Bartal, a neuroscientist at Tel-Aviv University in Israel. That's empathy. Researchers debate to this day whether empathy is a uniquely human ability. But more scientists are finding evidence suggesting it exists widely, particularly in social mammals like rats. For the past decade, Bartal has studied whether—and why—lab rodents might act on that commiseration to help pals in need. Picture two rats in a cage. One roams freely, while the other is constrained in a vented plexiglass tunnel with a small door that only opens from the outside. Bartal, along with teams at UC Berkeley and the University of Chicago, has shown that the free rat may feel their trapped fellow’s distress and learn to open the door. This empathic pull is so strong that rats will rescue their roommates instead of feasting on piles of chocolate chips. (Disclosure: I have three pet rats. My sources confirm that chocolate chips are borderline irresistible.) But there's been a catch: Bartal’s experiments over the years have shown that rats only help others they perceive as members of their social group—specific pals or entire genetic strains they recognize. So does this mean they can't empathize with strangers? In new results appearing in the journal eLife in July, Bartal and her adviser from Berkeley, Daniela Kaufer, uncovered a surprise. Rats do show the neural signatures of empathy for trapped strangers, but that alone isn’t enough to make them help. While seeing a trapped stranger lights up parts of the brain associated with empathy, only seeing a familiar rat or breed elicits a rush of activity in the brain’s so-called reward center, the nucleus accumbens—so only those rats get rescued. © 2021 Condé Nast

Keyword: Emotions; Evolution
Link ID: 27943 - Posted: 08.11.2021

Lydia Denworth Lee Reeves always wanted to be a veterinarian. When he was in high school in the Washington, D.C., suburbs, he went to an animal hospital near his house on a busy Saturday morning to apply for a job. The receptionist said the doctor was too busy to talk. But Reeves was determined and waited. Three and a half hours later, after all the dogs and cats had been seen, the veterinarian emerged and asked Reeves what he could do for him. Reeves, who has stuttered since he was three years old, had trouble answering. “I somehow struggled out the fact that I wanted the job and he asked me what my name was,” he says. “I couldn’t get my name out to save my life.” The vet finally reached for a piece of paper and had Reeves write down his name and add his phone number, but he said there was no job available. “I remember walking out of that clinic that morning thinking that essentially my life was over,” Reeves says. “Not only was I never going to become a veterinarian, but I couldn’t even get a job cleaning cages.” More than 50 years have passed. Reeves, who is now 72, has gone on to become an effective national advocate for people with speech impairments, but the frustration and embarrassment of that day are still vivid. They are also emblematic of the complicated experience that is stuttering. Technically, stuttering is a disruption in the easy flow of speech, but the physical struggle and the emotional effects that often go with it have led observers to wrongly attribute the condition to defects of the tongue or voice box, problems with cognition, emotional trauma or nervousness, forcing left-handed children to become right-handed, and, most unfortunately, poor parenting. Freudian psychiatrists thought stuttering represented “oral-sadistic conflict,” whereas the behavioralists argued that labeling a child a stutterer would exacerbate the problem. Reeves’s parents were told to call no attention to his stutter—wait it out, and it would go away. © 2021 Scientific American,

Keyword: Language
Link ID: 27942 - Posted: 08.11.2021

Nicola Davis Science correspondent It’s been used to detect eye diseases, make medical diagnoses, and spot early signs of oesophageal cancer. Now it has been claimed artificial intelligence may be able to diagnose dementia from just one brain scan, with researchers starting a trial to test the approach. The team behind the AI tool say the hope is that it will lead to earlier diagnoses, which could improve outcomes for patients, while it may also help to shed light on their prognoses. Dr Timothy Rittman, a senior clinical research associate and consultant neurologist at the University of Cambridge, who is leading the study, told the BBC the AI system is a “fantastic development”. “These set of diseases are really devastating for people,” he said. “So when I am delivering this information to a patient, anything I can do to be more confident about the diagnosis, to give them more information about the likely progression of the disease to help them plan their lives is a great thing to be able to do.” It is expected that in the first year of the trial the AI system, which uses algorithms to detect patterns in brain scans, will be tested in a “real-world” clinical setting on about 500 patients at Addenbrooke’s hospital in Cambridge and other memory clinics across the country. “If we intervene early, the treatments can kick in early and slow down the progression of the disease and at the same time avoid more damage,” Prof Zoe Kourtzi, of Cambridge University and a fellow of national centre for AI and data science the Alan Turing Institute, told the BBC. “And it’s likely that symptoms occur much later in life or may never occur.” © 2021 Guardian News & Media Limited

Keyword: Alzheimers; Development of the Brain
Link ID: 27941 - Posted: 08.11.2021

Jon Hamilton Scientists are working to develop new treatments for Alzheimer's disease by looking beyond amyloid plaques, which have been the focus of most Alzheimer's drug development in the past 20 years. Science Photo Library — ZEPHYR./Getty Images Immune cells, toxic protein tangles and brain waves are among the targets of future Alzheimer's treatments, scientists say. These approaches are noteworthy because they do not directly attack the sticky amyloid plaques in the brain that are a hallmark of Alzheimer's. The plaques have been the focus of most Alzheimer's drug development in the past 20 years. And the drug Aduhelm was given conditional approval by the Food and Drug Administration in June based primarily on the medication's ability to remove amyloid from the brain. But many researchers believe amyloid drugs alone can't stop Alzheimer's. "The field has been moving beyond amyloid for many years now," says Malú Gámez Tansey, co-director of the Center for Translational Research in Neurodegenerative Disease at the University of Florida. Tansey and a number of other researchers offered a wide range of alternative strategies at the Alzheimer's Association International Conference in Denver last month. Here are three of the most promising: © 2021 npr

Keyword: Alzheimers; Development of the Brain
Link ID: 27940 - Posted: 08.11.2021

By Rachel Fritts As you age, your brain slows down. You may forget where you left your glasses or have trouble picking up a new skill. Now there’s hope from rodent experiments that some of these declines could be reversed—but it takes guts. New research shows a transplant of gut microbes, in the form of feces, from young mice to old ones can turn back the clock on the aging brain. The study is “a tour de force” for the scope of data it collected, says Sean Gibbons, a gut microbe researcher at the Institute for Systems Biology. Still, he says, more work must be done before anyone considers doing anything similar with humans. The bacteria in our intestines influence everything from our daily moods to our overall health. This “gut microbiome” also changes over the course of our lives. But whereas some studies have shown young blood can have rejuvenating effects on old mice, the microbiome’s impact on age-related declines hasn’t been clear. To test whether a young microbiome could reverse signs of aging, researchers took fecal samples from 3- to 4-month-old mice, the equivalent of young adults, and transplanted them into 20-month-old animals—ancient by mouse standards. The scientists fed a slurry of feces to the old mice using a feeding tube twice a week for 8 weeks. As controls, old mice received transplants from fellow old mice, and young from young. The first thing the team noticed was that the gut microbiomes of the old mice given young mouse microbes began to resemble those of the younger ones. The common gut microbe Enterococcus became much more abundant in old mice, just as it is in young mice, for example. © 2021 American Association for the Advancement of Science

Keyword: Obesity; Development of the Brain
Link ID: 27939 - Posted: 08.11.2021

By Lisa Sanders, M.D. The burning started as soon as the 59-year-old woman put the drops into her eye. She blinked to try to rinse away the medication with her tears. She leaned forward to the mirror. Her left eye was red and angry-looking. She’d been using these eye drops for nearly a year to treat her newly diagnosed glaucoma, adding artificial tears for the dry eyes that appeared a few months later. And while she’d had plenty of problems with her eyes since all this started, this fiery pain was new. The vision in her left eye had been bad for a few years by then, but with an operation nearly two years earlier to remove an abnormal membrane on her retina and more recent cataract surgery, she had hoped she would have her old vision back by now. She was a physician-researcher and spent much of her time reading and writing, so her vision was very important to her livelihood. But despite the efforts of her eye doctors — and at this point she had many — she still couldn’t see well. It was when she was getting ready for the cataract surgery that the patient learned she had glaucoma. After her initial exam, her new eye surgeon told her that the pressure inside her left eye was abnormally high, and she was already showing signs of damage from it. He wanted her to see one of his colleagues, Dr. Amanda Bicket, a glaucoma specialist who was then at the Wilmer Eye Institute at Johns Hopkins. A quick phone call later, she had an appointment to see the doctor that day. It was urgent that this be evaluated and treated before her upcoming surgery. © 2021 The New York Times Company

Keyword: Vision
Link ID: 27938 - Posted: 08.11.2021

By Annie Roth As anyone who has ever tried to eat french fries on a beach will attest, stealing is not an uncommon behavior among birds. In fact, many birds are quite skilled at bold and brazen theft. Scientists have documented several species of birds, including magpies, bowerbirds, and black kites, looting everything from discarded plastic to expensive jewelry to decorate their nests. And then there are birds who want hair, and will go to great lengths to get their beaks on it. Hair from dogs, raccoons and even humans has been found in the nests of birds, which scientists believe makes the nests better insulated. For a long time, scientists assumed that birds had to collect hair that had been shed or scavenge it from mammal carcasses. However, a new study, published last week in the journal Ecology, shows that several species of bird, including chickadees and titmice, don’t just scavenge hair, they steal it. The study, based largely on analysis of YouTube videos, shows numerous examples of birds pulling tufts of hair from living mammals, including humans. This phenomenon, which the study’s authors have dubbed “kleptotrichy,” has been well-documented by birders on the web, but this is the first time scientists have formally recognized it. “This is just another example of something that was overlooked in the scientific literature but was common knowledge in the bird watching and bird feeding community,” said Henry Pollock, a postdoctoral researcher in ornithology at the University of Illinois and co-author of the new study. Last spring, Dr. Pollock was participating in his university’s annual spring bird count when a tufted titmouse caught his eye. It was flitting near a raccoon sleeping soundly on a tree branch, inching closer and closer to it. Then, to Dr. Pollock’s amusement, the tiny bird began plucking tufts of the raccoon’s fur. The titmouse managed to steal over 20 beak-fulls of the raccoon’s fur without waking it. © 2021 The New York Times Company

Keyword: Learning & Memory; Evolution
Link ID: 27937 - Posted: 08.07.2021

By Pamela Feliciano As social beings, when thinking about autism we tend to focus on its social challenges, such as difficulty communicating, making friends and showing empathy. I am a geneticist and the mother of a teenage boy with autism. I too worry most about whether he’ll have the conversational skills to do basic things like grocery shopping or whether he will ever have a real friend. But I assure you that the nonsocial features of autism are also front and center in our lives: intense insistence on sameness, atypical responses to sensory stimuli and a remarkable ability to detect small details. Many attempts have been made to explain all the symptoms of autism holistically, but no one theory has yet explained all the condition’s puzzling and diverse features. Now, a growing number of neurocognitive scientists think that many traits found in people with autism spectrum disorder (ASD) may be explained centrally by impairments in predictive skills—and have begun testing this hypothesis. Generally, the human brain determines what’s coming next based on the status quo, plus what we recall from previous experiences. Scientists theorize that people with ASD have differences that disturb their ability to predict. It’s not that people with autism can’t make predictions; it’s that their predictions are flawed because they perceive the world “too accurately.” Their predictions are less influenced by prior experiences and more influenced by what they are experiencing in the moment. They overemphasize the “now.” © 2021 Scientific American

Keyword: Autism
Link ID: 27936 - Posted: 08.07.2021

By Jane E. Brody No one with debilitating symptoms likes to be told “it’s all in your head.” Yet, this is often what distressed patients with irritable bowel syndrome hear, implicitly or explicitly, when a medical work-up reveals no apparent explanation for their repeated bouts of abdominal pain, bloating, diarrhea or constipation. In fact, irritable bowel syndrome, or I.B.S., is a real problem causing real symptoms, no matter how hard its sufferers may wish it gone. But unlike an infection or tumor, I.B.S. is what medicine calls a functional disorder: a condition with no identifiable cause. Patients have no visible signs of damage or disease in their digestive tracts. Rather, the prevailing theory holds that overly sensitive nerves in the patient’s gastrointestinal tract send distress signals to the brain that result in pain and malfunction. However, as medical science progresses, experts are beginning to find physical explanations for disorders that previously had no known biological cause. For example, conditions like epilepsy, Alzheimer’s disease and migraine were once considered functional disorders, but are now known to have measurable physical or biochemical underpinnings. And recent research has revealed at least one likely explanation for the symptoms of I.B.S.: an infection in the digestive tract that triggers a localized allergic reaction in the gut. As Dr. Marc E. Rothenberg wrote in The New England Journal of Medicine in June, “Patients with I.B.S. often report that their symptoms started at the time of a gastrointestinal infection.” Dr. Rothenberg, who is the director of the division of allergy and immunology at Cincinnati Children’s Hospital Medical Center, explained in an interview that the infection can temporarily disrupt the layer of cells that normally lines the bowel. These cells form a barrier that prevents allergy-inducing proteins in foods from being absorbed. When that barrier is penetrated, people can become intolerant to foods that previously caused them no issue. Sign up for the Well Newsletter Get the best of Well, with the latest on health, fitness and nutrition. Get it sent to your inbox. © 2021 The New York Times Company

Keyword: Stress
Link ID: 27935 - Posted: 08.07.2021

Jake Buehler As the midday sun hangs over the Scandinavian spruce forest, a swarm of hopeful suitors takes to the air. They are dance flies, and it is time to attract a mate. Zigzagging and twirling, the flies show off their wide, darkened wings and feathery leg scales. They inflate their abdomens like balloons, making themselves look bigger and more appealing to a potential partner. Suddenly, the swarm electrifies with excitement at the arrival of a new fly, the one they have all been waiting for: a male. It’s time for the preening flock of females to shine. The flies are flipping the classic drama reenacted across the animal kingdom, in which eager males with dazzling plumage, snarls of antlers or other extraordinary traits compete for a chance to woo a reluctant female. Such competitions between males for the favor of choosy females are enshrined in evolutionary theory as “sexual selection,” with the females’ choices molding the evolution of the males’ instruments of seduction over generations. Yet it’s becoming clear that this traditional picture of sexual selection is woefully incomplete. Dramatic and obvious reversals of the selection scenario, like that of the dance flies, aren’t often observed in nature, but recent research suggests that throughout the tree of animal life, females jockey for the attention of males far more than was believed. A new study hosted on the preprint server biorxiv.org has found that in animals as diverse as sea urchins and salamanders, females are subject to sexual selection — not as harshly as males are, but enough to make biologists rethink the balance of evolutionary forces shaping species in their accounts of the history of life. All Rights Reserved © 2021

Keyword: Sexual Behavior; Evolution
Link ID: 27934 - Posted: 08.07.2021

By Christina Caron Q: How common is adult A.D.H.D.? What are the symptoms and is it possible for someone who was not diagnosed with it as a child to be diagnosed as an adult? A: Attention deficit hyperactivity disorder, or A.D.H.D., is a neurodevelopmental disorder often characterized by inattention, disorganization, hyperactivity and impulsivity. It is one of the most common mental health disorders. According to the World Federation of A.D.H.D., it is thought to occur in nearly 6 percent of children and 2.5 percent of adults. In the United States, 5.4 million children, or about 8 percent of all U.S. children ages 3 to 17, were estimated to have A.D.H.D. in 2016, the Centers for Disease Control and Prevention reported. For decades, experts believed that A.D.H.D. occurred only among children and ended after adolescence. But a number of studies in the ’90s showed that A.D.H.D. can continue into adulthood. Experts now say that at least 60 percent of children with A.D.H.D. will also have symptoms as adults. It’s not surprising that so many people are now wondering whether they might have the disorder, especially if their symptoms were exacerbated by the pandemic. The Attention Deficit Disorder Association, an organization founded in 1990 for adults with A.D.H.D, saw its membership nearly double between 2019 and 2021. In addition, Children and Adults With Attention-Deficit/Hyperactivity Disorder, or CHADD, reported that the highest proportion of people who call their A.D.H.D. help line are adults seeking guidance and resources for themselves. © 2021 The New York Times Company

Keyword: ADHD
Link ID: 27933 - Posted: 08.07.2021