By Yasemin Saplakoglu Around 2,500 years ago, Babylonian traders in Mesopotamia impressed two slanted wedges into clay tablets. The shapes represented a placeholder digit, squeezed between others, to distinguish numbers such as 50, 505 and 5,005. An elementary version of the concept of zero was born. Hundreds of years later, in seventh-century India, zero took on a new identity. No longer a placeholder, the digit acquired a value and found its place on the number line, before 1. Its invention went on to spark historic advances in science and technology. From zero sprang the laws of the universe, number theory and modern mathematics. “Zero is, by many mathematicians, definitely considered one of the greatest — or maybe the greatest — achievement of mankind,” said the neuroscientist Andreas Nieder (opens a new tab), who studies animal and human intelligence at the University of Tübingen in Germany. “It took an eternity until mathematicians finally invented zero as a number.” Perhaps that’s no surprise given that the concept can be difficult for the brain to grasp. It takes children longer to understand and use zero than other numbers, and it takes adults longer to read it than other small numbers. That’s because to understand zero, our mind must create something out of nothing. It must recognize absence as a mathematical object. “It’s like an extra level of abstraction away from the world around you,” said Benjy Barnett (opens a new tab), who is completing graduate work on consciousness at University College London. Nonzero numbers map onto countable objects in the environment: three chairs, each with four legs, at one table. With zero, he said, “we have to go one step further and say, ‘OK, there wasn’t anything there. Therefore, there must be zero of them.’” © 2024 Simons Foundation

Keyword: Attention
Link ID: 29523 - Posted: 10.19.2024

By Phil Plait I remember watching the full moon rise one early evening a while back. It was when I still lived in Colorado, and I was standing outside in my yard. I first noticed a glow to the east lighting up the flat horizon in the darkening sky, and within moments the moon was cresting above it, yellow and swollen—like, really swollen As it cleared the horizon, the moon looked huge! It also seemed so close that I could reach out and touch it; it was so “in my face” that I felt I could fall in. I gawped at it for a moment and then smiled. I knew what I was actually seeing: the moon illusion. Anyone who is capable of seeing the moon (or the sun) near the horizon has experienced this effect. The moon looks enormous there, far larger than it does when it’s overhead. I’m an astronomer, and I know the moon is no bigger on the horizon than at the zenith, yet I can’t not see it that way. It’s an overwhelming effect. But it’s not real. Simple measurements of the moon show it’s essentially the same size on the horizon as when it’s overhead. This really is an illusion. It’s been around awhile, too: the illusion is shown in cuneiform on a clay tablet from the ancient Assyrian city Nineveh that has been dated to the seventh century B.C.E. Attempts to explain it are as old as the illusion itself, and most come up short. Aristotle wrote about it, for example, attributing it to the effects of mist. This isn’t correct, obviously; the illusion manifests even in perfectly clear weather. A related idea, still common today, is that Earth’s air acts like a lens, refracting (bending) the light from the moon and magnifying it. But we know that’s not right because the moon is measurably the same size no matter where it is in the sky. Also, examining the physics of that explanation shows that it falls short as well. In fact, while the air near the horizon does indeed act like a lens, its actual effect is to make the sun and moon look squished, like flat ovals, not to simply magnify them. So that can’t be the cause either.

Keyword: Vision; Attention
Link ID: 29522 - Posted: 10.19.2024

By Giorgia Guglielmi As the famed tale “Hansel and Gretel” makes clear, hunger can change behavior. The two lost and starving siblings give in to the temptation of a gingerbread cottage and ignore the danger lurking within—a wicked witch who has created the delicious house as a trap. Hunger is such a powerful driver that animals often pursue food at the expense of other survival needs, such as avoiding predators or recovering from injury. Hungry vicuñas, for example, will sometimes increase their risk of predation by pumas to get something to eat, behavioral ecologists have shown. Scientists know many of the key cells and circuits behind these competing drives—such as the hypothalamic “hunger neurons” that regulate food intake. But how the brain juggles the need to eat amidst other urges has remained mysterious, says Henning Fenselau, who leads the Synaptic Transmission in Energy Homeostasis group at the Max Planck Institute for Metabolism Research in Köln, Germany. “This is still a huge question [in neuroscience],” he says. In recent years, however, new clues about where and how hunger collides with rival motivations have come from technology to manipulate and monitor individual neurons across multiple brain regions at once. Those findings suggest that hunger neuron activity can override some brain signals, such as fear and pain. Exploring the brain’s ability to handle multiple needs simultaneously may offer insights into decision-making, anxiety and other neuropsychiatric conditions—helping to explain why people sometimes make maladaptive choices, says Nicholas Betley, associate professor of biology at the University of Pennsylvania. © 2024 Simons Foundation

Keyword: Obesity; Attention
Link ID: 29515 - Posted: 10.12.2024

By Miryam Naddaf Neurons in the hippocampus help to pick out patterns in the flood of information pouring through the brain.Credit: Arthur Chien/Science Photo Library The human brain is constantly picking up patterns in everyday experiences — and can do so without conscious thought, finds a study1 of neuronal activity in people who had electrodes implanted in their brain tissue for medical reasons. The study shows that neurons in key brain regions combine information on what occurs and when, allowing the brain to pick out the patterns in events as they unfold over time. That helps the brain to predict coming events, the authors say. The work was published today in Nature. “The brain does a lot of things that we are not consciously aware of,” says Edvard Moser, a neuroscientist at the Norwegian University of Science and Technology in Trondheim. “This is no exception.” To make sense of the world around us, the brain must process an onslaught of information on what happens, where it happens and when it happens. The study’s authors wanted to explore how the brain organizes this information over time — a crucial step in learning and memory. The team studied 17 people who had epilepsy and had electrodes implanted in their brains in preparation for surgical treatment. These electrodes allowed the authors to directly capture the activity of individual neurons in multiple brain regions. Among those regions were the hippocampus and entorhinal cortex, which are involved in memory and navigation. These areas contain time and place cells that act as the body’s internal clock and GPS system, encoding time and locations. “All the external world coming into our brain has to be filtered through that system,” says study co-author Itzhak Fried, a neurosurgeon and neuroscientist at the University of California, Los Angeles. © 2024 Springer Nature Limited

Keyword: Attention; Learning & Memory
Link ID: 29497 - Posted: 09.28.2024

By Angie Voyles Askham Most people visit the Minnesota State Fair for a fun-filled day of fried food, farm animals and carnival rides. Not Ka Ip. He saw the annual event as the perfect setting for a new experiment. Ip, assistant professor of child development at the University of Minnesota, is particularly interested in executive function: the set of skills, such as organization and impulse control, people need to plan and achieve goals. Children from lower socioeconomic backgrounds tend to perform worse on tests of these skills than do their more privileged peers, past research shows. But that gap may reflect where those skills are typically tested: a quiet lab, in which some children may feel out of their element, Ip says. “That may not actually mimic their actual day-to-day environment.” Which is why Ip started to devise a series of experiments to conduct at the less-than-serene state fair. “We really want to understand how, for example, unpredictability in the home environment is related to executive function development,” he says. The fair also offered a way to recruit children from a wider swath of society than researchers can often find at a university, he adds. Last month, after a year of planning, Ip and his team lugged a trolley full of equipment to the fairgrounds outside Minneapolis. There, they collected functional near-infrared spectroscopy (fNIRS) data on 75 children aged 3 to 7 as they played a computer game that tests impulse control. The team aims to evaluate whether the bustling surroundings affect participants’ performances and neural activity differently based on their background. © 2024 Simons Foundation

Keyword: Brain imaging; Attention
Link ID: 29490 - Posted: 09.25.2024

By Angie Voyles Askham Nathaniel Daw has never touched a mouse. As professor of computational and theoretical neuroscience at Princeton University, he mainly works with other people’s data to construct models of the brain’s decision-making process. So when a collaborator came to him a few years ago with confusing data from mice that had performed a complex decision-making task in the lab, Daw says his best advice was just to fit the findings to the tried-and-true model of reward prediction error (RPE). That model relies on the idea that dopaminergic activity in the midbrain reflects discrepancies between expected and received rewards. Daw’s collaborator, Ben Engelhard, had measured the activity of dopamine neurons in the ventral tegmental area (VTA) of mice as they were deciding how to navigate a virtual environment. And although the virtual environment was more complex than what a mouse usually experiences in the real world, an RPE-based model should have held, Daw assumed. “It was obvious to me that there was this very simple story that was going to explain his data,” Daw says. But it didn’t. The neurons exhibited a wide range of responses, with some activated by visual cues and others by movement or cognitive tasks. The classic RPE model, it turned out, could not explain such heterogeneity. Daw, Engelhard and their colleagues published the findings in 2019. That was a wake-up call, Daw says, particularly after he watched videos of what the mice actually experienced in the maze. “It’s just so much more complicated, and high dimensional, and richer” than expected, he says. The idea that this richness could be reduced to such a simple model seems ludicrous now, he adds. “I was just so blinded.” © 2024 Simons Foundation

Keyword: Attention; Drug Abuse
Link ID: 29479 - Posted: 09.14.2024

By Christina Caron Julianna McLeod, 26, had her first psychotic episode while taking Vyvanse for attention deficit hyperactivity disorder last year. Ms. McLeod, who lives in Ontario, Canada, had taken the drug before but paused while pregnant with her first child and didn’t start taking it again until six months postpartum. Although the dose was 40 milligrams, she often forgot when she had last taken a pill. So she took one whenever she remembered — and may have ended up taking more than her prescribed daily dose. The delusions that she experienced made her feel euphoric and highly energetic. “I felt like my brain was exploding with connections,” she said. In her mind, she was a “super detective” who was uncovering the people and organizations that were secretly engaging in child sex trafficking. She even began to believe that someone was drugging her and her baby. Psychosis and mania are each known side effects of stimulant medications, and the Food and Drug Administration has added warnings to the medications’ labels saying that they may cause symptoms like hallucinations, delusional thinking or mania. But these side effects are considered rare — experienced by an estimated 1 in 1,000 patients — and have not been extensively researched. It can take months for someone to fully recover. A new study published on Thursday in The American Journal of Psychiatry suggests that dosage may play a role. It found that among people who took high doses of prescription amphetamines such as Vyvanse and Adderall, there was a fivefold increased risk of developing psychosis or mania for the first time compared with those who weren’t taking stimulants. The researchers defined a high dose as more than 40 milligrams of Adderall, 100 milligrams of Vyvanse or 30 milligrams of dextroamphetamine. The medium dosage (20 to 40 milligrams of Adderall, 50 to 100 milligrams of Vyvanse or 16 to 30 milligrams of dextroamphetamine) was associated with a 3.5 times higher risk of psychosis or mania. There was no increased risk of psychosis or mania among those who used methylphenidate drugs, like Concerta or Ritalin, regardless of the dose. © 2024 The New York Times Company

Keyword: ADHD; Schizophrenia
Link ID: 29478 - Posted: 09.14.2024

By Christina Caron Patients and caregivers have struggled for two years to find stimulant medications like Adderall, Vyvanse and Concerta to treat attention deficit hyperactivity disorder. Some spend hours each month going from pharmacy to pharmacy to find a drug, while others are forced to switch to a different brand or formulation, or go without medication for weeks. This week the Drug Enforcement Administration announced a potential solution: It is raising the amount of lisdexamfetamine (Vyvanse) that can be produced by U.S. manufacturers this year by nearly 24 percent to meet demand in the United States and abroad. Vyvanse is an amphetamine that has been approved for use in children and adults with A.D.H.D. and has become commonly prescribed after the generic version was introduced last year. According to the D.E.A., the latest data shows that demand for the drug has been rising globally. But right now every manufacturer of generic Vyvanse listed on the Food and Drug Administration website is experiencing a shortage. Many health care providers who specialize in treating patients with A.D.H.D. said that the D.E.A.’s decision was a positive development but that it was unclear just how much of an effect it might have on the shortage. “Obviously it’s not going to solve the problem completely,” said Ami Norris-Brilliant, clinical director of the Division of A.D.H.D., Learning Disorders, and Related Disorders at the Icahn School of Medicine at Mount Sinai in New York City. “But I think anything that helps increase drug availability is a good thing.” It is not the first time that the D.E.A. has increased production quotas for A.D.H.D. drugs. Last year it announced a new 2023 limit for methylphenidate, which is used to make drugs like Ritalin and Concerta, raising the allotted amount by 27 percent for 2023. The drug remains in shortage, however, in the extended release formulation. © 2024 The New York Times Company

Keyword: ADHD
Link ID: 29473 - Posted: 09.11.2024

By Steve Paulson Oliver Sacks wasn’t always the beloved neurologist we remember today, sleuthing around the backwaters of the mind in search of mysterious mental disorders. For a few years in the 1960s, he was a committed psychonaut, often spending entire weekends blitzed out of his mind on weed, LSD, morning glory seeds, or mescaline. Once, after injecting himself with a large dose of morphine, he found himself hovering over an enormous battlefield, watching the armies of England and France drawn up for battle, and then realized he was witnessing the 1415 Battle of Agincourt. “I completely lost the sense that I was lying on my bed stoned,” he told me in 2012, a few years before he died. “I felt like a historian, seeing Agincourt from a celestial viewpoint. This was not ordinary imagination. It was absolutely real.” The vision seemed to last only a few minutes, but later, he discovered he’d been tripping for 13 hours. These early experiences with hallucinogens gave Sacks an appreciation for the strange turns the mind can take. He had a craving for direct experience of the numinous, but he believed his visions were nothing more than hallucinations. “At the physiological level, everything is electricity and chemistry, but it was a wonderful feeling,” he said. When I asked if he ever thought he’d crossed over into some transpersonal dimension of reality, he said, “I’m an old Jewish atheist. I have no belief in heaven or anything supernatural or paranormal, but there’s a mystical feeling of oneness and of beauty, which is not explicitly religious, but goes far beyond the aesthetic.” I’ve often thought about this conversation as I’ve watched today’s psychedelic renaissance. Clinical trials with psychedelic-assisted therapy show great promise for treating depression, addiction, and PTSD, and a handful of leading universities have recently created their own heavily endowed psychedelic centers. © 2024 NautilusNext Inc.,

Keyword: Drug Abuse; Consciousness
Link ID: 29453 - Posted: 08.28.2024

By Rachel Nuwer One person felt a sensation of “slowly floating into the air” as images flashed around. Another recalled “the most profound sense of love and peace,” unlike anything experienced before. Consciousness became a “foreign entity” to another whose “whole sense of reality disappeared.” These were some of the firsthand accounts shared in a small survey of people who belonged to an unusual cohort: They had all undergone a near-death experience and tried psychedelic drugs. The survey participants described their near-death and psychedelic experiences as being distinct, yet they also reported significant overlap. In a paper published on Thursday, researchers used these accounts to provide a comparison of the two phenomena. “For the first time, we have a quantitative study with personal testimony from people who have had both of these experiences,” said Charlotte Martial, a neuroscientist at the University of Liège in Belgium and an author of the findings, which were published in the journal Neuroscience of Consciousness. “Now we can say for sure that psychedelics can be a kind of window through which people can enter a rich, subjective state resembling a near-death experience.” Near-death experiences are surprisingly common — an estimated 5 to 10 percent of the general population has reported having one. For decades, scientists largely dismissed the fantastical stories of people who returned from the brink of death. But some researchers have started to take these accounts seriously. “In recent times, the science of consciousness has become interested in nonordinary states,” said Christopher Timmermann, a research fellow at the Center for Psychedelic Research at Imperial College London and an author of the article. “To get a comprehensive account of what it means to be a human being requires incorporating these experiences.” © 2024 The New York Times Company

Keyword: Consciousness; Drug Abuse
Link ID: 29450 - Posted: 08.22.2024

By Carl Zimmer When people suffer severe brain damage — as a result of car crashes, for example, or falls or aneurysms — they may slip into a coma for weeks, their eyes closed, their bodies unresponsive. Some recover, but others enter a mysterious state: eyes open, yet without clear signs of consciousness. Hundreds of thousands of such patients in the United States alone are diagnosed in a vegetative state or as minimally conscious. They may survive for decades without regaining a connection to the outside world. These patients pose an agonizing mystery both for their families and for the medical professionals who care for them. Even if they can’t communicate, might they still be aware? A large study published on Wednesday suggests that a quarter of them are. Teams of neurologists at six research centers asked 241 unresponsive patients to spend several minutes at a time doing complex cognitive tasks, such as imagining themselves playing tennis. Twenty-five percent of them responded with the same patterns of brain activity seen in healthy people, suggesting that they were able to think and were at least somewhat aware. Dr. Nicholas Schiff, a neurologist at Weill Cornell Medicine and an author of the study, said the study shows that up to 100,000 patients in the United States alone might have some level of consciousness despite their devastating injuries. The results should lead to more sophisticated exams of people with so-called disorders of consciousness, and to more research into how these patients might communicate with the outside world, he said: “It’s not OK to know this and to do nothing.” When people lose consciousness after a brain injury, neurologists traditionally diagnose them with a bedside exam. They may ask patients to say something, to look to their left or right, or to give a thumbs-up. © 2024 The New York Times Company

Keyword: Consciousness
Link ID: 29436 - Posted: 08.15.2024

By Greg Donahue In late 2018, after an otherwise-normal Christmas holiday, Laurie Beatty started acting strange. An 81-year-old retired contractor, he grew unnaturally quiet and began poring over old accounting logs from a construction business he sold decades earlier, convinced that he had been bilked in the deal. Listen to this article, read by Robert Petkoff Over the course of several days, Beatty slipped further into unreality. He told his wife the year was 1992 and wondered aloud why his hair had turned white. Then he started having seizures. His arms began to move in uncontrollable jerks and twitches. By the end of May, he was dead. Doctors at the Georges-L.-Dumont University Hospital Center in Moncton, the largest city in the province of New Brunswick, Canada, zeroed in on an exceedingly rare condition — Creutzfeldt-Jakob disease, caused by prions, misfolding proteins in the brain — as the most likely culprit. The doctors explained this to Beatty’s children, Tim and Jill, and said they would run additional tests to confirm the post-mortem diagnosis. Three months later, when the siblings returned to the office of their father’s neurologist, Dr. Alier Marrero, that’s what they were expecting to hear. Instead, Marrero told them that Laurie’s Creutzfeldt-Jakob test had come back negative. “We were all looking at one another,” Tim says, “because we were all very confused.” If Creutzfeldt-Jakob hadn’t killed their father, then what had? What Marrero said next was even more unsettling. “There’s something going on,” they recall him saying. “And I don’t know what it is.” It turned out that Laurie Beatty was just one of many local residents who had gone to Marrero’s office exhibiting similar, inexplicable symptoms of neurological decline — more than 20 in the previous four years. The first signs were often behavioral. One patient fell asleep for nearly 20 hours straight before a friend took her to the hospital; another found himself afraid to disturb the stranger who had sat down in his living room, only to realize hours later that the stranger was his wife. © 2024 The New York Times Company

Keyword: Alzheimers; Learning & Memory
Link ID: 29434 - Posted: 08.15.2024

By Sneha Khedkar About 10 years ago, when Michael Yartsev set up the NeuroBat Lab, he built a new windowless cave of sorts: a fully automated bat flight room. Equipped with cameras and other recording devices, the remote-controlled space has enabled his team to study the neuronal basis of navigation, acoustic and social behavior in Egyptian fruit bats without having any direct interaction with the animals. “In our lab, there’s never a human involved in the experiments,” says Yartsev, associate professor of bioengineering at the University of California, Berkeley. The impetus to create the space was clear. The setup, paired with wireless electrodes inserted in the bats’ hippocampus, has helped the team demonstrate, for example, that place cells encode a flying bat’s current, past and future locations. Also, a mountain of evidence suggests that the identity, sex and stress levels of human experimenters can influence the behavior of and brain circuit activity in other lab animals, such as mice and rats. Now Yartsev and his team have proved that “experimenter effects” hold true for bats, too, according to a new study published last month in Nature Neuroscience. The presence of human experimenters changed hippocampal neuronal activity in bats both at rest and during flight—and exerted an even stronger influence than another fruit bat, the study shows. The team expected that humans would influence neural activity, Yartsev says, “but we did not expect it to be so profound.” © 2024 Simons Foundation

Keyword: Attention; Hearing
Link ID: 29430 - Posted: 08.13.2024

By Hartmut Neven & Christof Koch The brain is a mere piece of furniture in the vastness of the cosmos, subject to the same physical laws as asteroids, electrons or photons. On the surface, its three pounds of neural tissue seem to have little to do with quantum mechanics, the textbook theory that underlies all physical systems, since quantum effects are most pronounced on microscopic scales. Newly proposed experiments, however, promise to bridge this gap between microscopic and macroscopic systems, like the brain, and offer answers to the mystery of consciousness. Quantum mechanics explains a range of phenomena that cannot be understood using the intuitions formed by everyday experience. Recall the Schrödinger’s cat thought experiment, in which a cat exists in a superposition of states, both dead and alive. In our daily lives there seems to be no such uncertainty—a cat is either dead or alive. But the equations of quantum mechanics tell us that at any moment the world is composed of many such coexisting states, a tension that has long troubled physicists. Taking the bull by its horns, the cosmologist Roger Penrose in 1989 made the radical suggestion that a conscious moment occurs whenever a superimposed quantum state collapses. The idea that two fundamental scientific mysteries—the origin of consciousness and the collapse of what is called the wave function in quantum mechanics—are related, triggered enormous excitement. Penrose’s theory can be grounded in the intricacies of quantum computation. Consider a quantum bit, a qubit, the unit of information in quantum information theory that exists in a superposition of a logical 0 with a logical 1. According to Penrose, when this system collapses into either 0 or 1, a flicker of conscious experience is created, described by a single classical bit. © 2024 SCIENTIFIC AMERICAN,

Keyword: Consciousness
Link ID: 29427 - Posted: 08.11.2024

By Maya L. Kapoor Six years ago, while shopping at a supermarket, Sadie Dingfelder spied her husband selecting a store-branded peanut butter jar. “Since when do you buy generic?” she asked, grabbing the jar from the cart. To her surprise, the frightened man turned out to be a total stranger. As usual, Dingfelder quickly began rewriting the unsettling interaction in her mind as a funny story, but a stark thought struck her this time: “Other people do not make this kind of mistake.” Dingfelder, a freelance science journalist, has prosopagnosia, or face blindness. It’s extremely difficult for her to recognize faces: She has gotten into cars with the wrong people; she has made plans with friends and then been surprised by who came. She once had to ask filmmaker John Waters, who met her at a museum for an interview, to help identify the museum staffer who had just introduced them — she couldn’t pick her out from a crowd of his fans. In “Do I Know You? A Faceblind Reporter’s Journey Into the Science of Sight, Memory, and Imagination,” Dingfelder begins coming to terms with her neurodivergence, weaving together science reporting — including brain scans, computerized tests, and assessments by medical researchers — and personal memoir in order to understand herself better. Ultimately, “Do I Know You?” is a question Dingfelder seems to be asking herself. By the end of the book, the answer feels like a firm yes. The term prosopagnosia, a portmanteau of the Greek words for “face” and “not knowing,” was coined by Joachim Bodamer, a psychiatrist and neurologist in Nazi Germany. Bodamer had encountered German soldiers with head traumas who had lost the ability to recognize people, including one soldier who blithely passed by his own mother at a train station.

Keyword: Attention
Link ID: 29423 - Posted: 08.11.2024

By Yasemin Saplakoglu Two years ago, Sarah Shomstein realized she didn’t have a mind’s eye. The vision scientist was sitting in a seminar room, listening to a scientific talk, when the presenter asked the audience to imagine an apple. Shomstein closed her eyes and did so. Then, the presenter asked the crowd to open their eyes and rate how vividly they saw the apple in their mind. Saw the apple? Shomstein was confused. She didn’t actually see an apple. She could think about an apple: its taste, its shape, its color, the way light might hit it. But she didn’t see it. Behind her eyes, “it was completely black,” Shomstein recalled. And yet, “I imagined an apple.” Most of her colleagues reacted differently. They reported actually seeing an apple, some vividly and some faintly, floating like a hologram in front of them. In that moment, Shomstein, who’s spent years researching perception at George Washington University, realized she experienced the world differently than others. She is part of a subset of people — thought to be about 1% to 4% of the general population — who lack mental imagery, a phenomenon known as aphantasia. Though it was described more than 140 years ago, the term “aphantasia” was coined only in 2015. It immediately drew the attention of anyone interested in how the imagination works. That included neuroscientists. So far, they’re finding that aphantasia is not a disorder — it’s a different way of experiencing the world. Early studies have suggested that differences in the connections between brain regions involved in vision, memory and decision-making could explain variations in people’s ability to form mental images. Because many people with aphantasia dream in images and can recognize objects and faces, it seems likely that their minds store visual information — they just can’t access it voluntarily or can’t use it to generate the experience of imagery. That’s just one explanation for aphantasia. In reality, people’s subjective experiences vary dramatically, and it’s possible that different subsets of aphantasics have their own neural explanations. Aphantasia and hyperphantasia, the opposite phenomenon in which people report mental imagery as vivid as reality, are in fact two ends of a spectrum, sandwiching an infinite range of internal experiences between them. © 2024 the Simons Foundation.

Keyword: Attention; Vision
Link ID: 29417 - Posted: 08.02.2024

Jake Rogers Nature Reviews Neuroscience (2024)Cite this article To better understand the therapeutic potential of the psychedelic drug psilocybin, we need a fuller understanding of its short-term and long-term effects on the human brain. In this study, Siegel et al. reveal individual-specific psilocybin-induced acute and persistent brain network changes in neurotypical young adults. The authors used longitudinal precision functional mapping — involving ~18 sessions of fMRI per individual — to capture individual-specific functional brain networks. Through this approach, acute (during) and persistent (between or after) intervention-induced changes to individual-specific network organization could be detected in young adult participants who received either high-dose psilocybin or dose-matched methylphenidate (a non-psychedelic stimulant chosen as an active control for psilocybin-induced cardiovascular and arousal effects) and who then, 1–2 weeks later, received the compound not administered first. Acutely, psilocybin caused not only widespread cortical functional connectivity (FC) changes (most prominently in association areas), but also disruption in subcortical regions connected with the default mode network (DMN), including the thalamus, basal ganglia, cerebellum and hippocampus. Furthermore, FC changes correlated with the intensity of the subjective experience documented using the 30-item mystical experience questionnaire (MEQ30). Several participants also received a second high dose of psilocybin and repeated an acute fMRI session six months later. Despite it being entirely plausible in a second acute session that individuals might experience the same effect, this repeated session revealed that individuals had substantially reduced or increased MEQ30 scores compared to their first acute session, and that the degree of the widespread brain changes and intensity of subjective experience correlated across and within individuals. By contrast, acute methylphenidate was associated with substantially less whole-brain FC disruption and most FC changes localized to sensorimotor systems. © 2024 Springer Nature Limited

Keyword: Drug Abuse; Depression
Link ID: 29415 - Posted: 08.02.2024

By Christina Caron The 6-year-old boy sitting across from Douglas Tynan, a child and adolescent clinical psychologist based in Delaware, clearly did not have attention deficit hyperactivity disorder. Dr. Tynan was sure of that. But the boy’s first-grade teacher disagreed. He could be inattentive in class, but at home his behavior wasn’t out of the ordinary for a child his age. A voracious reader, he told Dr. Tynan that he liked to bring his own books to school because the ones in class were too easy. What his teacher had not considered was that the child was most likely academically gifted, as his mother had been as a child, Dr. Tynan said. (Studies have shown that Black children, like the boy in his office, are less likely to be identified for gifted programs.) Further testing revealed that Dr. Tynan was correct. The child wasn’t inattentive in school because of A.D.H.D. It was because he was bored. A.D.H.D. is a neurodevelopmental disorder that begins in childhood and typically involves inattention, disorganization, hyperactivity and impulsivity that cause trouble in two or more settings, like at home and at school. But those symptoms — for children and adults alike — can overlap with a multitude of other traits and disorders. In fact, difficulty concentrating is one of the most common symptoms listed in the American Psychiatric Association’s diagnostic manual, and it’s associated with 17 diagnoses, according to a study published in April. Patients need a careful evaluation to avoid either being misdiagnosed with A.D.H.D. or having a missed A.D.H.D. diagnosis. Here’s a look at some common problems that can mimic A.D.H.D. Mental health conditions like anxiety, depression or oppositional defiant disorder can show up as A.D.H.D.-like symptoms. © 2024 The New York Times Company

Keyword: ADHD; Development of the Brain
Link ID: 29404 - Posted: 07.27.2024

By Brandon Keim 1 How We Think About Animals Has a Long, Complicated History Back when I first started writing about scientific research on animal minds, I had internalized a straightforward historical narrative: The western intellectual tradition held animals to be unintelligent, but thanks to recent advances in the science, we were learning otherwise. The actual history is so much more complicated. The denial of animal intelligence does have deep roots, of course. You can trace a direct line from Aristotle, who considered animals capable of feeling only pain and hunger, to medieval Christian theologians fixated on their supposed lack of rationality, to Enlightenment intellectuals who likened the cries of beaten dogs to the squeaking of springs. But along the way, a great many thinkers, from early Greek philosopher Plutarch on through to Voltaire, pushed back. They saw animals as intelligent and therefore deserving of ethical regard, too. Those have always been the stakes of this debate: If animals are mindless then we owe them nothing. Through that lens it’s no surprise that societies founded on exploitation—of other human beings, of animals, of the whole natural world—would yield knowledge systems that formally regarded animals as dumb. The Plutarchs and Voltaires of the world were cast to the side. The scientific pendulum did swing briefly in the other direction, thanks in no small part to the popularity of Charles Darwin. He saw humans as related to other animals not only in body but in mind, and recognized rich forms of consciousness even in earthworms. But the backlash to that way of thinking was fierce, culminating in a principle articulated in the 1890s and later enshrined as Morgan’s Canon: An animal’s behavior should not be interpreted as evidence of a higher psychological faculty until all other explanations could be ruled out. Stupidity by default. © 2024 NautilusNext Inc.,

Keyword: Evolution; Attention
Link ID: 29399 - Posted: 07.23.2024

By Andrew Jacobs July 17, 2024 If you had to come up with a groovy visualization of the human brain on psychedelic drugs, it might look something like this. The image, as it happens, comes from dozens of brain scans produced by researchers at Washington University School of Medicine in St. Louis who gave psilocybin, the compound in “magic mushrooms,” to participants in a study before sending them into a functional M.R.I. scanner. The kaleidoscopic whirl of colors they recorded is essentially a heat map of brain changes, with the red, orange and yellow hues reflecting a significant departure from normal activity patterns. The blues and greens reflect normal brain activity that occurs in the so-called functional networks, the neural communication pathways that connect different regions of the brain. The scans, published Wednesday in the journal Nature, offer a rare glimpse into the wild neural storm associated with mind-altering drugs. Researchers say they could provide a potential road map for understanding how psychedelic compounds like psilocybin, LSD and MDMA can lead to lasting relief from depression, anxiety and other mental health disorders. “Psilocybin, in contrast to any other drug we’ve tested, has this massive effect on the whole brain that was pretty unexpected,” said Dr. Nico Dosenbach, a professor of neurology at Washington University and a senior author of the study. “It was quite shocking when we saw the effect size.” The study included seven healthy adults who were given either a single dose of psilocybin or a placebo in the form of methylphenidate, the generic version of the amphetamine Ritalin. Each participant underwent a total of 18 brain scans, taken before, during and after the initial dosing. © 2024 The New York Times Company

Keyword: Drug Abuse; Depression
Link ID: 29398 - Posted: 07.18.2024