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By Nora Bradford Whenever you’re actively performing a task — say, lifting weights at the gym or taking a hard exam — the parts of your brain required to carry it out become “active” when neurons step up their electrical activity. But is your brain active even when you’re zoning out on the couch? The answer, researchers have found, is yes. Over the past two decades they’ve defined what’s known as the default mode network, a collection of seemingly unrelated areas of the brain that activate when you’re not doing much at all. Its discovery has offered insights into how the brain functions outside of well-defined tasks and has also prompted research into the role of brain networks — not just brain regions — in managing our internal experience. In the late 20th century, neuroscientists began using new techniques to take images of people’s brains as they performed tasks in scanning machines. As expected, activity in certain brain areas increased during tasks — and to the researchers’ surprise, activity in other brain areas declined simultaneously. The neuroscientists were intrigued that during a wide variety of tasks, the very same brain areas consistently dialed back their activity. It was as if these areas had been active when the person wasn’t doing anything, and then turned off when the mind had to concentrate on something external. Researchers called these areas “task negative.” When they were first identified, Marcus Raichle, a neurologist at the Washington University School of Medicine in St. Louis, suspected that these task-negative areas play an important role in the resting mind. “This raised the question of ‘What’s baseline brain activity?’” Raichle recalled. In an experiment, he asked people in scanners to close their eyes and simply let their minds wander while he measured their brain activity. All Rights Reserved © 2024

Related chapters from BN: Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 14: Attention and Higher Cognition
Link ID: 29135 - Posted: 02.06.2024

By Conor Feehly A decade ago, when I was starting my first year of university in New Zealand, I attended a stage hypnosis. It was one of a number of events the university offered to incoming students during orientation week. From the stage of a campus auditorium, the hypnotist-for-hire asked an audience of some 200 students to close their eyes and listen to his voice. Then he directed us to clasp our hands tightly together, and to imagine an invisible thread wrapping around them—over and under, over and under—until it was impossible to pull them apart. After a few minutes of this, he told us to try to separate our hands. Those who could not, he said, should come on down to the stage. I instantly pulled my hands apart, but to my surprise, a close friend sitting next to me made his way to the front of the auditorium with roughly 20 others from the audience. Once on stage, the hypnotist tried to bring them deeper into a hypnotic trance, directing them to focus on his calm, authoritative voice. He then asked a few of them to role-play scenarios for our entertainment: a supermarket checkout clerk ringing up shopping items, a lifeguard scanning for lives to save. After a short time, I saw the hypnotist whisper something into the ear of my friend. He sheepishly made his way back to the seat next to me. “What did he say to you?” I asked. He replied, “I can tell you’re acting, mate, get off the stage.” In the more than 200 years since the practice of contemporary hypnosis was described by German physician Franz Mesmer, public perception of it has see-sawed between skepticism and credulity. Today hypnotherapy is used to provide therapeutic remedy for depression, pain, substance use disorders, and certain traumas, uses that are supported to a certain extent by research evidence. But many still consider hypnosis more of a cheap magician’s trick than legitimate clinical medicine. © 2024 NautilusNext Inc.,

Related chapters from BN: Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 14: Attention and Higher Cognition
Link ID: 29094 - Posted: 01.13.2024

By Regina G. Barber Human brains aren't built to comprehend large numbers, like the national debt or how much to save for retirement. But with a few tools — analogies, metaphors and visualizations — we can get better at it. erhui1979/Getty Images Imagine a horizontal line. The very left is marked one thousand and the very right is marked one billion. On this line, where would you add a marker to represent one million? If you said somewhere in the middle, you answered the same as the roughly 50 percent of people who have done this exercise in a number line study. But the answer is actually much closer to one thousand since there are one thousand millions in one billion. This error makes sense because "our human brains are pretty bad at comprehending large numbers," says Elizabeth Toomarian, an educational neuroscientist at Stanford University. She studies how the brain makes sense of numbers. Or doesn't. "Our brains are evolutionarily very old and we are pushing them to do things that we've only just recently conceptualized," says Toomarian. Instead, the human brain is built to understand how much of something is in its environment. For example, which bush has more berries or how many predators are in that clearing? But comprehending the national debt or imagining the size of our universe? "We certainly can use our brains in that way, but we're recycling these sort of evolutionarily old brain architectures to do something really new," she says. In other words, it's not our fault that we have trouble wrapping our heads around big numbers. © 2024 npr

Related chapters from BN: Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 14: Attention and Higher Cognition
Link ID: 29074 - Posted: 01.03.2024

By Ann Gibbons Louise hadn’t seen her sister or nephew for 26 years. Yet the moment she spotted them on a computer screen, she recognized them, staring hard at their faces. The feat might have been impressive enough for a human, but Louise is a bonobo—one who had spent most of her life at a separate sanctuary from these relatives. The discovery, published today in the Proceedings of the National Academy of Sciences, reveals that our closest primate cousins can remember the faces of friends and family for years, and sometimes even decades. The study, experts say, shows that the capability for long-term social memory is not unique to people, as was long believed. “It’s a remarkable finding,” says Frans de Waal, a primatologist at Emory University who was not involved with the work. “I’m not even sure we humans remember most individuals we haven’t seen for 2 decades.” The research, he says, raises the possibility that other animals can also do this and may remember far more than we give them credit for. Trying to figure out whether nonhuman primates remember a face isn’t simple. You can’t just ask them. So in the new study, comparative psychologist Christopher Krupenye at Johns Hopkins University and colleagues used eye trackers, infrared cameras that noninvasively map a subject’s gaze as they look at images of people or objects. The scientists worked with 26 chimpanzees and bonobos living in three zoos or sanctuaries in Europe and Japan. The team showed the animals photos of the faces of two apes placed side by side on the screen at the same time for 3 seconds. Some images were of complete strangers; some were of close friends, foes, or family members who had once lived in their same social groups, but whom they hadn’t seen in years.

Related chapters from BN: Chapter 18: Attention and Higher Cognition; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 14: Attention and Higher Cognition
Link ID: 29058 - Posted: 12.19.2023

By Jaimie Seaton It’s not uncommon for Veronica Smith to be looking at her partner’s face when suddenly she sees his features changing—his eyes moving closer together and then farther apart, his jawline getting wider and narrower, and his skin moving and shimmering. Smith, age 32, has experienced this phenomenon when looking at faces since she was four or five years old, and while it’s intermittent when she’s viewing another person’s face, it’s more constant when she views her own. “I almost always experience it when I look at my own face in the mirror, which makes it really hard to get ready because I’ll think that I look weird,” Smith explains. “I can more easily tell that I’m experiencing distortions when I’m looking at other people because I know what they look like.” Smith has a rare condition called prosopometamorphopsia (PMO), in which faces appear distorted in shape, texture, position or color. (PMO is related to Alice in Wonderland syndrome, or AIWS, which distorts the size perception of objects or one’s own body.) PMO has fascinated many scientists. The late neurologist and writer Oliver Sacks co-wrote a paper on the condition that was published in 2014, the year before he died. Brad Duchaine, a professor of psychological and brain sciences at Dartmouth College, explains that some people with it see distortions that affect the whole face (bilateral PMO) while others see only the left or right half of a face as distorted (hemi-PMO). “Not surprisingly, people with PMO find the distortions extremely distressing. Over the last century, approximately 75 cases have been reported in the literature. However, little is known about the condition because cases with face distortions have usually been documented by neurologists who don’t have expertise in visual neuroscience or the time to study the cases in depth,” Duchaine says. For 25 years Duchaine’s work has focused on prosopagnosia (face blindness), but after co-authoring a study on hemi-PMO that was published in 2020, Duchaine shifted much of his lab’s work to PMO. © 2023 SCIENTIFIC AMERICAN,

Related chapters from BN: Chapter 18: Attention and Higher Cognition; Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 14: Attention and Higher Cognition; Chapter 7: Vision: From Eye to Brain
Link ID: 29051 - Posted: 12.16.2023

By Francesca Paris There are more Americans who say they have serious cognitive problems — with remembering, concentrating or making decisions — than at any time in the last 15 years, data from the Census Bureau shows. The increase started with the pandemic: The number of working-age adults reporting “serious difficulty” thinking has climbed by an estimated one million people. About as many adults ages 18 to 64 now report severe cognitive issues as report trouble walking or taking the stairs, for the first time since the bureau started asking the questions each month in the 2000s. The sharp increase captures the effects of long Covid for a small but significant portion of younger adults, researchers say, most likely in addition to other effects of the pandemic, including psychological distress. But they also say it’s not yet possible to fully dissect all the reasons behind the increase. Richard Deitz, an economist at the Federal Reserve Bank of New York, analyzed the data and attributed much of the increase to long Covid. “These numbers don’t do this — they don’t just start suddenly increasing sharply like this,” he said. In its monthly Current Population Survey, the census asks a sample of Americans whether they have serious problems with their memory and concentration. It defines them as disabled if they answer yes to that question or one of five others about limitations on their daily activities. The questions are unrelated to disability applications, so respondents don’t have a financial incentive to answer one way or another. At the start of 2020, the survey estimated there were fewer than 15 million Americans ages 18 to 64 with any kind of disability. That rose to about 16.5 million by September 2023. Nearly two-thirds of that increase was made up of people who had newly reported limitations on their thinking. There were also increases in census estimates of the number of adults with a vision disability or serious difficulty doing basic errands. For older working-age Americans, the pandemic ended a yearslong decline in reported rates of disability. © 2023 The New York Times Company

Related chapters from BN: Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 14: Attention and Higher Cognition
Link ID: 29003 - Posted: 11.13.2023

By Yasemin Saplakoglu More than 150 years ago, the economist and philosopher William Stanley Jevons discovered something curious about the number 4. While musing about how the mind conceives of numbers, he tossed a handful of black beans into a cardboard box. Then, after a fleeting glance, he guessed how many there were, before counting them to record the true value. After more than 1,000 trials, he saw a clear pattern. When there were four or fewer beans in the box, he always guessed the right number. But for five beans or more, his quick estimations were often incorrect. Jevons’ description of his self-experiment, published in Nature in 1871, set the “foundation of how we think about numbers,” said Steven Piantadosi, a professor of psychology and neuroscience at the University of California, Berkeley. It sparked a long-lasting and ongoing debate about why there seems to be a limit on the number of items we can accurately judge to be present in a set. Now, a new study in Nature Human Behaviour has edged closer to an answer by taking an unprecedented look at how human brain cells fire when presented with certain quantities. Its findings suggest that the brain uses a combination of two mechanisms to judge how many objects it sees. One estimates quantities. The second sharpens the accuracy of those estimates — but only for small numbers. It’s “very exciting” that the findings connect long-debated ideas to their neural underpinnings, said Piantadosi, who was not involved in the study. “There’s not many things in cognition where people have been able to pinpoint very plausible biological foundations.” Although the new study does not end the debate, the findings start to untangle the biological basis for how the brain judges quantities, which could inform bigger questions about memory, attention and even mathematics. All Rights Reserved © 2023

Related chapters from BN: Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 14: Attention and Higher Cognition
Link ID: 29000 - Posted: 11.11.2023

By Caren Chesler In 2019, Debra Halsch was diagnosed with smoldering multiple myeloma, a rare blood and bone marrow disorder that can develop into a type of blood cancer. Her doctors recommended chemotherapy, she said, but she feared the taxing side effects the drugs might wreak on her body. Instead, the life coach from Piermont, New York tried meditation. A friend had told Halsch, now 57, about Joe Dispenza, who holds week-long meditation retreats that regularly attract thousands of people and carry a $2,299 price tag. Halsch signed up for one in Cancun, Mexico and soon became a devotee. She now meditates for at least two hours a day and says her health has improved as a result. Goop, the health and lifestyle brand launched by actor and entrepreneur Gwyneth Paltrow in 2008, will have its own series on Netflix beginning January 24. Dispenza, a chiropractor who has written various self-help books, has said he believes the mind can heal the body. After all, he says he healed himself back in 1986, when a truck hit him while he was bicycling, breaking six vertebrae. Instead of surgery, Dispenza says he spent hours each day recreating his spine in his mind, visualizing it healthy and healed. After 11 weeks, the story goes, he was back on his feet. Halsch said she believes she can do the same for her illness. “If our thoughts and emotions can make our bodies sick, they can make us well, too,” she said. In an email to Undark, Rhadell Hovda, chief operating officer for Dispenza’s parent company, Encephalon, Inc., emphasized that Dispenza does not claim meditation can treat or cure cancer. However, he does “follow the evidence when it is presented,” and has encountered people at workshops and retreats “who claimed to have healed from many conditions.” For more than two decades, various studies have suggested that meditation and mindfulness — that is, being aware of the present moment — can help reduce and improve pain management, lending some credence to the notion that the brain can affect the body. Such results have helped the field grow into a multibillion-dollar industry, populated by meditation apps, guided workshops, and upscale retreats.

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 14: Attention and Higher Cognition
Link ID: 28990 - Posted: 11.08.2023

By Laura Sanders Like tiny, hairy Yodas raising X-wings from a swamp, rats can lift digital cubes and drop them near a target. But these rats aren’t using the Force. Instead, they are using their imagination. This telekinetic trick, described in the Nov. 3 Science, provides hints about how brains imagine new scenarios and remember past ones. “This is fantastic research,” says Mayank Mehta, a neurophysicist at UCLA. “It opens up a lot of exciting possibilities.” A deeper scientific understanding of the brain area involved in the feat could, for instance, help researchers diagnose and treat memory disorders, he says. Neuroscientist Albert Lee and his colleagues study how brains can go back in time by revisiting memories and jump ahead to imagine future scenarios. Those processes, sometimes called “mental time travel,” are “part of what makes our inner mental lives quite rich and interesting,” says Lee, who did the new study while at Howard Hughes Medical Institute’s Janelia Research Campus in Ashburn, Va. To dip into these complex questions, the researchers began with a simpler one: “Can you be in one place and think about another place?” says Lee, who is now an HHMI investigator at Beth Israel Deaconess Medical Center in Boston. “The rat isn’t doing anything fancier than that. We’re not asking them to recall their summer vacation.” Neuroscientist and engineer Chongxi Lai, also now at Beth Israel Deaconess, Lee and colleagues trained rats to move on a spherical treadmill in the midst of a 3-D virtual world projected onto a surrounding screen. While the rats poked around their virtual world, electrodes recorded signals from nerve cells in the rats’ hippocampi, brain structures known to hold complex spatial information, among other things (SN: 10/6/14). In this way, researchers matched patterns of brain activity with spots in the virtual world. © Society for Science & the Public 2000–2023.

Related chapters from BN: Chapter 11: Motor Control and Plasticity; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 14: Attention and Higher Cognition
Link ID: 28988 - Posted: 11.04.2023

Linda Geddes Science correspondent The former Premier League goalkeeper Brad Friedel once said that to be able to work well in the box, you have to be able to think outside the box. Now scientific data supports the idea that goalies’ brains really do perceive the world differently – their brains appear able to merge signals from the different senses more quickly, possibly underpinning their unique abilities on the football pitch. Goalkeeping is the most specialised position in football, with the primary objective of stopping the opposition from scoring. But while previous studies have highlighted differences in physiological and performance profiles between goalkeepers and other players, far less was known about whether they have different perceptual or cognitive abilities. “Unlike other football players, goalkeepers are required to make thousands of very fast decisions based on limited or incomplete sensory information,” said Michael Quinn, a former goalkeeper in the Irish Premiership, who is now studying for a master’s degree in behavioural neuroscience at University College Dublin. Suspecting that this ability might hinge on an enhanced capacity to combine information from different senses, Quinn and researchers at Dublin City University and University College Dublin recruited 60 professional goalkeepers, outfield players and age-matched non-players to do a series of tests, looking for differences in their ability to distinguish sounds and flashes as separate from one another. Doing so enabled them to estimate volunteers’ temporal binding windows – the timeframe in which different sensory signals are fused together in the brain. The study, published in Current Biology, found that goalkeepers had a narrower temporal binding window relative to outfielders and non-soccer players. © 2023 Guardian News & Media Limited

Related chapters from BN: Chapter 18: Attention and Higher Cognition; Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 14: Attention and Higher Cognition; Chapter 5: The Sensorimotor System
Link ID: 28954 - Posted: 10.10.2023

Mariana Lenharo For more than a century, researchers have known that people are generally very good at eyeballing quantities of four or fewer items. But performance at sizing up numbers drops markedly — becoming slower and more prone to error — in the face of larger numbers. Now scientists have discovered why: the human brain uses one mechanism to assess four or fewer items and a different one for when there are five or more. The findings, obtained by recording the neuron activity of 17 human participants, settle a long-standing debate on how the brain estimates how many objects a person sees. The results were published in Nature Human Behaviour1 on 2 October. The finding is relevant to the understanding of the nature of thinking, says psychologist Lisa Feigenson, the co-director of the Johns Hopkins University Laboratory for Child Development in Baltimore, Maryland. “Fundamentally, the question is one of mental architecture: what are the building blocks that give rise to human thought?” The limits of the human ability to estimate large quantities have puzzled many generations of scientists. In an 1871 Nature article2, economist and logician William Stanley Jevons described his investigations into his own counting skills and concluded “that the number five is beyond the limit of perfect discrimination, by some persons at least”. Some researchers have argued that the brain uses a single estimation system, one that is simply less precise for higher numbers. Others hypothesize that the performance discrepancy arises from there being two separate neuronal systems to quantify objects. But experiments have failed to determine which model is correct. Then, a team of researchers had a rare opportunity to record the activity of individual neurons inside the brains of people who were awake. All were being treated for seizures at the University Hospital Bonn in Germany, and had microelectrodes inserted in their brains in preparation for surgery. © 2023 Springer Nature Limited

Related chapters from BN: Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 14: Attention and Higher Cognition
Link ID: 28953 - Posted: 10.10.2023

By Jim Davies Think of what you want to eat for dinner this weekend. What popped into mind? Pizza? Sushi? Clam chowder? Why did those foods (or whatever foods you imagined) appear in your consciousness and not something else? Psychologists have long held that when we are making a decision about a particular category of thing, we tend to bring to mind items that are typical or common in our culture or everyday lives, or ones we value the most. On this view, whatever foods you conjured up are likely ones that you eat often, or love to eat. Sounds intuitive. But a recent paper published in Cognition suggests it’s more complicated than that. Tracey Mills, a research assistant working at MIT, led the study along with Jonathan Phillips, a cognitive scientist and philosopher at Dartmouth College. They put over 2,000 subjects, recruited online, through a series of seven experiments that allowed them to test a novel approach for understanding which ideas within a category will pop into our consciousness—and which won’t. In this case, they had subjects think about zoo animals, holidays, jobs, kitchen appliances, chain restaurants, sports, and vegetables. What they found is that what makes a particular thing come to mind—such as a lion when one is considering zoo animals—is determined not by how valuable or familiar it is, but by where it lies in a multidimensional idea grid that could be said to resemble a kind of word cloud. “Under the hypothesis we argue for,” Mills and Phillips write, “the process of calling members of a category to mind might be modeled as a search through feature space, weighted toward certain features that are relevant for that category.” Historical “value” just happens to be one dimension that is particularly relevant when one is talking about dinner, but is less relevant for categories such as zoo animals or, say, crimes, they write. © 2023 NautilusNext Inc., All rights reserved.

Related chapters from BN: Chapter 18: Attention and Higher Cognition; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 14: Attention and Higher Cognition; Chapter 13: Memory and Learning
Link ID: 28910 - Posted: 09.16.2023

Jon Hamilton Dr. Josef Parvizi remembers meeting a man with epilepsy whose seizures were causing some very unusual symptoms. "He came to my clinic and said, 'My sense of self is changing,'" says Parvizi, a professor of neurology at Stanford University. The man told Parvizi that he felt "like an observer to conversations that are happening in my mind" and that "I just feel like I'm floating in space." Parvizi and a team of researchers would eventually trace the man's symptoms to a "sausage-looking piece of brain" called the anterior precuneus. This area, nestled between the brain's two hemispheres, appears critical to a person's sense of inhabiting their own body, or bodily self, the team recently reported in the journal Neuron. The finding could help researchers develop forms of anesthesia that use electrical stimulation instead of drugs. It could also help explain the antidepressant effects of mind-altering drugs like ketamine. It took Parvizi's team years of research to discover the importance of this obscure bit of brain tissue. In 2019, when the man first came to Stanford's Comprehensive Epilepsy Program, Parvizi thought his symptoms were caused by seizures in the posteromedial cortex, an area toward the back of the brain. This area includes a brain network involved in the narrative self, a sort of internal autobiography that helps us define who we are. Parvizi's team figured that the same network must be responsible for the bodily self too. "Everybody thought, 'Well, maybe all kinds of selves are being decoded by the same system,'" he says. © 2023 npr

Related chapters from BN: Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 14: Attention and Higher Cognition
Link ID: 28846 - Posted: 07.06.2023

By Jordan Kinard Long the fixation of religions, philosophy and literature the world over, the conscious experience of dying has recently received increasingly significant attention from science. This comes as medical advances extend the ability to keep the body alive, steadily prying open a window into the ultimate locked room: the last living moments of a human mind. “Around 1959 humans discovered a method to restart the heart in people who would have died, and we called this CPR,” says Sam Parnia, a critical care physician at NYU Langone Health. Parnia has studied people’s recollections after being revived from cardiac arrest—phenomena that he refers to as “recalled experiences surrounding death.” Before CPR techniques were developed, cardiac arrest was basically synonymous with death. But now doctors can revive some people up to 20 minutes or more after their heart has stopped beating. Furthermore, Parnia says, many brain cells remain somewhat intact for hours to days postmortem—challenging our notions of a rigid boundary between life and death. Advancements in medical technology and neuroscience, as well as shifts in researchers’ perspectives, are revolutionizing our understanding of the dying process. Research over the past decade has demonstrated a surge in brain activity in human and animal subjects undergoing cardiac arrest. Meanwhile large surveys are documenting the seemingly inexplicable periods of lucidity that hospice workers and grieving families often report witnessing in people with dementia who are dying. Poet Dylan Thomas famously admonished his readers, “Do not go gentle into that good night. Rage, rage against the dying of the light.” But as more resources are devoted to the study of death, it is becoming increasingly clear that dying is not the simple dimming of one’s internal light of awareness but rather an incredibly active process in the brain. © 2023 Scientific American,

Related chapters from BN: Chapter 18: Attention and Higher Cognition; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 14: Attention and Higher Cognition; Chapter 13: Memory and Learning
Link ID: 28820 - Posted: 06.14.2023

By Yasemin Saplakoglu Is this the real life? Is this just fantasy? Those aren’t just lyrics from the Queen song “Bohemian Rhapsody.” They’re also the questions that the brain must constantly answer while processing streams of visual signals from the eyes and purely mental pictures bubbling out of the imagination. Brain scan studies have repeatedly found that seeing something and imagining it evoke highly similar patterns of neural activity. Yet for most of us, the subjective experiences they produce are very different. “I can look outside my window right now, and if I want to, I can imagine a unicorn walking down the street,” said Thomas Naselaris, an associate professor at the University of Minnesota. The street would seem real and the unicorn would not. “It’s very clear to me,” he said. The knowledge that unicorns are mythical barely plays into that: A simple imaginary white horse would seem just as unreal. So “why are we not constantly hallucinating?” asked Nadine Dijkstra, a postdoctoral fellow at University College London. A study she led, recently published in Nature Communications, provides an intriguing answer: The brain evaluates the images it is processing against a “reality threshold.” If the signal passes the threshold, the brain thinks it’s real; if it doesn’t, the brain thinks it’s imagined. They’ve done a great job, in my opinion, of taking an issue that philosophers have been debating about for centuries and defining models with predictable outcomes and testing them. Such a system works well most of the time because imagined signals are typically weak. But if an imagined signal is strong enough to cross the threshold, the brain takes it for reality. All Rights Reserved © 2023

Related chapters from BN: Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 14: Attention and Higher Cognition
Link ID: 28803 - Posted: 05.27.2023

By Sara Reardon Many people who have come close to death or have been resuscitated report a similar experience: Their lives flash before their eyes, memorable moments replay, and they may undergo an out-of-body experience, sensing they’re looking at themselves from elsewhere in the room. Now, a small study mapping the brain activity of four people while they were dying shows a burst of activity in their brains after their hearts stop. The authors say the finding, published today in the Proceedings of the National Academy of Sciences, may explain how a person’s brain could replay conscious memories even after the heart has stopped. It “suggests we are identifying a marker of lucid consciousness,” says Sam Parnia, a pulmonologist at New York University Langone Medical Center who was not involved in the study. Although death has historically been medically defined as the moment when the heart irreversibly stops beating, recent studies have suggested brain activity in many animals and humans can continue for seconds to hours. In 2013, for instance, University of Michigan neurologist Jimo Borjigin and team found that rats’ brains showed signs of consciousness up to 30 seconds after their hearts had stopped beating. “We have this binary concept of life and death that is ancient and outdated,” Parnia says. Still, despite the numerous reports over hundreds of years from people who have been resuscitated following clinical death or nearly died, “I was shocked to realize we know almost nothing” about brain activity during the dying process, Borjigin says. For the current study, she and her team looked at the medical records of four people who were in comas and on life support on whom physicians had placed electroencephalography caps. None of the patients had any chance of survival.

Related chapters from BN: Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 14: Attention and Higher Cognition
Link ID: 28765 - Posted: 05.03.2023

Ruth Ogden A year and half alone in a cave might sound like a nightmare to a lot of people, but Spanish athlete Beatriz Flamini emerged with a cheerful grin and said she thought she had more time to finish her book. She had almost no contact with the outside world during her impressive feat of human endurance. For 500 days, she documented her experiences to help scientists understand the effects of extreme isolation. One of the first things that became apparent on April 12 2023 when she emerged from the cave was how fluid time is, shaped more by your personality traits and the people around you than a ticking clock. When talking to reporters about her experiences, Flamini explained she rapidly lost her sense of time. The loss of time was so profound that, when her support team came to retrieve her, she was surprised that her time was up, instead believing she had only been there for 160-170 days. Our actions, emotions and changes in our environment can have powerful effects on the way in which our minds process time. For most people, the rising and setting of the sun mark the passing of days, and work and social routines mark the passing of hours. In the darkness of an underground cave, without the company of others, many signals of passing of time will have disappeared. So Flamini may have become more reliant on psychological processes to monitor time. One way in which we keep track of the passage of time is memory. If we don’t know how long we have been doing something for, we use the number of memories formed during the event as an index to the amount of time that has passed. The more memories we form in an event or era, the longer we perceive it to have lasted. © 2010–2023, The Conversation US, Inc.

Related chapters from BN: Chapter 18: Attention and Higher Cognition; Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 14: Attention and Higher Cognition; Chapter 10: Biological Rhythms and Sleep
Link ID: 28755 - Posted: 04.26.2023

By Ellen Barry It is a truism that time seems to expand or contract depending on our circumstances: In a state of terror, seconds can stretch. A day spent in solitude can drag. When we’re trying to meet a deadline, hours race by. A study published this month in the journal Psychophysiology by psychologists at Cornell University found that, when observed at the level of microseconds, some of these distortions could be driven by heartbeats, whose length is variable from moment to moment. The psychologists fitted undergraduates with electrocardiograms to measure the length of each heartbeat precisely, and then asked them to estimate the length of brief audio tones. The psychologists discovered that after a longer heartbeat interval, subjects tended to perceive the tone as longer; shorter intervals led subjects to assess the tone as shorter. Subsequent to each tone, the subjects’ heartbeat intervals lengthened. A lower heart rate appeared to assist with perception, said Saeedeh Sadeghi, a doctoral candidate at Cornell and the study’s lead author. “When we need to perceive things from the outside world, the beats of the heart are noise to the cortex,” she said. “You can sample the world more — it’s easier to get things in — when the heart is silent.” The study provides more evidence, after an era of research focusing on the brain, that “there is no single part of the brain or body that keeps time — it’s all a network,” she said, adding, “The brain controls the heart, and the heart, in turn, impacts the brain.” Interest in the perception of time has exploded since the Covid pandemic, when activity outside the home came to an abrupt halt for many and people around the world found themselves facing stretches of undifferentiated time. A study of time perception conducted during the first year of the lockdown in Britain found that 80 percent of participants reported distortions in time, in different directions. On average, older, more socially isolated people reported that time slowed, and younger, more active people reported that it sped up. © 2023 The New York Times Company

Related chapters from BN: Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 14: Attention and Higher Cognition
Link ID: 28704 - Posted: 03.15.2023

By Stephani Sutherland Tara Ghormley has always been an overachiever. She finished at the top of her class in high school, graduated summa cum laude from college and earned top honors in veterinary school. She went on to complete a rigorous training program and build a successful career as a veterinary internal medicine specialist. But in March 2020 she got infected with the SARS-CoV-2 virus—just the 24th case in the small, coastal central California town she lived in at the time, near the site of an early outbreak in the COVID pandemic. “I could have done without being first at this,” she says. Almost three years after apparently clearing the virus from her body, Ghormley is still suffering. She gets exhausted quickly, her heartbeat suddenly races, and she goes through periods where she can't concentrate or think clearly. Ghormley and her husband, who have relocated to a Los Angeles suburb, once spent their free time visiting their “happiest place on Earth”—Disneyland—but her health prevented that for more than a year. She still spends most of her days off resting in the dark or going to her many doctors' appointments. Her early infection and ongoing symptoms make her one of the first people in the country with “long COVID,” a condition where symptoms persist for at least three months after the infection and can last for years. The syndrome is known by medical professionals as postacute sequelae of COVID-19, or PASC. People with long COVID have symptoms such as pain, extreme fatigue and “brain fog,” or difficulty concentrating or remembering things. As of February 2022, the syndrome was estimated to affect about 16 million adults in the U.S. and had forced between two million and four million Americans out of the workforce, many of whom have yet to return. Long COVID often arises in otherwise healthy young people, and it can follow even a mild initial infection. The risk appears at least slightly higher in people who were hospitalized for COVID and in older adults (who end up in the hospital more often). Women and those at socioeconomic disadvantage also face higher risk, as do people who smoke, are obese, or have any of an array of health conditions, particularly autoimmune disease. Vaccination appears to reduce the danger but does not entirely prevent long COVID.

Related chapters from BN: Chapter 17: Learning and Memory; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 14: Attention and Higher Cognition
Link ID: 28667 - Posted: 02.15.2023

By Betsy Mason Some fish can recognize their own faces in photos and mirrors, an ability usually attributed to humans and other animals considered particularly brainy, such as chimpanzees, scientists report. Finding the ability in fish suggests that self-awareness may be far more widespread among animals than scientists once thought. “It is believed widely that the animals that have larger brains will be more intelligent than animals of the small brain,” such as fish, says animal sociologist Masanori Kohda of Osaka Metropolitan University in Japan. It may be time to rethink that assumption, Kohda says. Kohda’s previous research showed that bluestreak cleaner wrasses can pass the mirror test, a controversial cognitive assessment that purportedly reveals self-awareness, or the ability to be the object of one’s own thoughts. The test involves exposing an animal to a mirror and then surreptitiously putting a mark on the animal’s face or body to see if they will notice it on their reflection and try to touch it on their body. Previously only a handful of large-brained species, including chimpanzees and other great apes, dolphins, elephants and magpies, have passed the test. In a new study, cleaner fish that passed the mirror test were then able to distinguish their own faces from those of other cleaner fish in still photographs. This suggests that the fish identify themselves the same way humans are thought to — by forming a mental image of one’s face, Kohda and colleagues report February 6 in the Proceedings of the National Academy of Sciences. “I think it’s truly remarkable that they can do this,” says primatologist Frans de Waal of Emory University in Atlanta who was not involved in the research. “I think it’s an incredible study.” © Society for Science & the Public 2000–2023.

Related chapters from BN: Chapter 18: Attention and Higher Cognition; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 14: Attention and Higher Cognition
Link ID: 28659 - Posted: 02.08.2023