By Laura Sanders A honeybee that’s been promoted to forager has upgrades in her nerve cells, too. Vibration-sensing nerve cells, or neurons, are more specialized in bees tasked with finding food compared with younger, inexperienced adult bees, researchers report August 26 in eNeuro. This neural refinement may help forager bees better sense specific air vibrations produced by their fellow foragers during waggle dances — elaborate routines that share information about food location, distance and quality (SN Online: 1/24/14). Researchers compared certain neurons in adult bees that had emerged from their cells one to three days earlier to neurons of forager bees, which were older than 10 days. In the foragers, these neurons had more refined shapes, the team found. These vibration-detecting cells, called DL-INT-1 neurons, appear sparser in certain areas, with fewer message-receiving tendrils called dendrites. Refined dendrites may be a sign that these cells are more selective in their connections. And in foragers, these neurons also appear to handle information more efficiently than their counterparts in the young adult bees, experiments with electrodes reveal. These changes in shape and behavior suggest that in foragers, neurons become adept at decoding vibrations produced by other foragers’ waggle dances, say computational neuroscientist Ajayrama Kumaraswamy of the Ludwig-Maximilians-Universität München in Germany and colleagues. But it’s not clear whether foraging experience in the fields or the passage of time itself prompts these refinements. © Society for Science & the Public 2000–2019

Related chapters from BN: Chapter 17: Learning and Memory; Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 15: Language and Lateralization
Link ID: 26543 - Posted: 08.27.2019

Laura Sanders Seconds before a memory pops up, certain nerve cells jolt into collective action. The discovery of this signal, described in the Aug. 16 Science, sheds light on the mysterious brain processes that store and recall information. Electrodes implanted in the brains of epilepsy patients picked up neural signals in the hippocampus, a key memory center, while the patients were shown images of familiar people and places, including former President Barack Obama and the Eiffel Tower in Paris. As the participants took in this new information, electrodes detected a kind of brain activity called sharp-wave ripples, created by the coordinated activity of many nerve cells in the hippocampus. Later blindfolded, the patients were asked to remember the pictures. One to two seconds before the participants began describing each picture, researchers noticed an uptick in sharp-wave ripples, echoing the ripples detected when the subjects had first seen the images. That echo suggests that these ripples are important for learning new information and for recalling it later, Yitzhak Norman of the Weizmann Institute of Science in Rehovot, Israel, and colleagues write in the study. Earlier studies suggested that these ripples in the hippocampus were important for forming memories. But it wasn’t clear if the ripples also had a role in bringing memories to mind. In another recent study, scientists also linked synchronized ripples in two parts of the brain to better memories of word pairs (SN Online: 3/5/19). |© Society for Science & the Public 2000 - 2019

Related chapters from BN: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 26512 - Posted: 08.19.2019

By Gretchen Reynolds Weight training may have benefits for brain health, at least in rats. When rats lift weights, they gain strength and also change the cellular environment inside their brains, improving their ability to think, according to a notable new study of resistance training, rodents and the workings of their minds. The study finds that weight training, accomplished in rodents with ladders and tiny, taped-on weights, can reduce or even reverse aspects of age-related memory loss. The finding may have important brain-health implications for those of us who are not literal gym rats. Most of us discover in middle age, to our chagrin, that brains change with age and thinking skills dip. Familiar names, words and the current location of our house keys begin to elude us. But a wealth of helpful past research indicates that regular aerobic exercise, such as walking or jogging, can prop up memory and cognition. In these studies, which have involved people and animals, aerobic exercise generally increases the number of new neurons created in the brain’s memory center and also reduces inflammation. Unchecked, inflammation in the brain may contribute to the development of dementia and other neurodegenerative conditions. Far less has been known, though, about whether and how resistance training affects the brain. A few studies with older people have linked weight training to improved cognition, but the studies have been small and the linkages tenuous. While researchers know that lifting weights builds muscle, it is not yet clear how, at a molecular level, it would affect the cells and functions of the brain. © 2019 The New York Times Company

Related chapters from BN: Chapter 17: Learning and Memory; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 4: Development of the Brain; Chapter 4: Development of the Brain
Link ID: 26447 - Posted: 07.24.2019

By Simon Makin Better Memory through Electrical Brain Ripples Hippocampus Neuron, computer illustration Credit: Kateryna Kon Getty Images Specific patterns of brain activity are thought to underlie specific processes or computations important for various mental faculties, such as memory. One such “brain signal” that has received a lot of attention recently is known as a “sharp wave ripple”—a short, wave-shaped burst of high-frequency oscillations. Researchers originally identified ripples in the hippocampus, a region crucially involved in memory and navigation, as central to diverting recollections to long-term memory during sleep. Then a 2012 study by neuroscientists at the University of California, San Francisco, led by Loren Frank and Shantanu Jadhav, the latter now at Brandeis University, showed that the ripples also play a role in memory while awake. The researchers used electrical pulses to disrupt ripples in rodents’ brains, and showed that, by doing so, performance in a memory task was reduced. However, nobody had manipulated ripples to enhance memory—until now, that is. Researchers at NYU School of Medicine led by neuroscientist György Buzsáki have now done exactly that. In a June 14 study in Science, the team showed that prolonging sharp wave ripples in the hippocampus of rats significantly improved their performance in a maze task that taxes working memory—the brain’s “scratch pad” for combining and manipulating information on the fly. “This is a very novel and impactful study,” says Jadhav, who was not involved in the research. “It’s very hard to do ‘gain-of-function’ studies with physiological processes in such a precise way.” As well as revealing new details about how ripples contribute to specific memory processes, the work could ultimately have implications for efforts to develop interventions for disorders of memory and learning. © 2019 Scientific American

Related chapters from BN: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 26330 - Posted: 06.15.2019

Nell Greenfieldboyce At the Marine Biological Laboratory in Woods Hole, Mass., there's a room filled with burbling aquariums. A lot of them have lids weighed down with big rocks. "Octopuses are notorious for being able to, kind of, escape out of their enclosures," says Bret Grasse, whose official title at MBL is "manager of cephalopod operations" — cephalopods being squid, cuttlefish and octopuses. He's part of a team that's trying to figure out the best ways to raise these sea creatures in captivity, so that scientists can investigate their genes and learn the secrets of their strange, almost alien ways. For decades, much of the basic research in biology has focused on just a few, well-studied model organisms like mice, fruit flies, worms and zebrafish. That's because these critters are easy to keep in the laboratory, and scientists have worked out how to routinely alter their genes, leading to all kinds of insights into behavior, diseases and possible treatments. "With these organisms, you could understand what genes did by manipulating them," says Josh Rosenthal, another biologist at MBL. "And that really became an indispensable part of biology." But it's also meant that basic biology has ignored much of the animal kingdom, especially its more exotic denizens. "We're really missing out on, I would say, the diversity of biology's solutions to problems," Rosenthal notes. © 2019 npr

Related chapters from BN: Chapter 17: Learning and Memory; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 26295 - Posted: 06.04.2019

By Benedict Carey The research on brain stimulation is advancing so quickly, and the findings are so puzzling, that a reader might feel tempted to simply pre-order a genius cap from Amazon, to make sense of it all later. In just the past month, scientists reported enhancing the working memory of older people, using electric current passed through a skullcap, and restoring some cognitive function in a brain-damaged woman, using implanted electrodes. Most recently, the Food and Drug Administration approved a smartphone-size stimulator intended to alleviate attention-deficit problems by delivering electric current through a patch placed on the forehead. Last year, another group of scientists announced that they, too, had created a brain implant that boosts memory storage. All the while, a do-it-yourself subculture continues to grow, of people who are experimenting with placing electrodes in their skulls or foreheads for brain “tuning.” Predicting where all these efforts are headed, and how and when they might converge in a grand methodology, is an exercise in rank speculation. Neuro-stimulation covers too many different techniques, for various applications and of varying quality. About the only certainties are the usual ones: that a genius cap won’t arrive anytime soon, and that any brain-zapping gizmo that provides real benefit also is likely to come with risk. Nevertheless, the field is worth watching because it hints at some elementary properties of brain function. Unlike psychiatric drugs, or psychotherapy, pulses of current can change people’s behavior very quickly, and reliably. Turn the current on and things happen; turn it off and the effect stops or tapers. © 2019 The New York Times Company

Related chapters from BN: Chapter 17: Learning and Memory; Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 2: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 26232 - Posted: 05.14.2019

By David Grimm CORVALLIS, OREGON—Carl the cat was born to beat the odds. Abandoned on the side of the road in a Rubbermaid container, the scrawny black kitten—with white paws, white chest, and a white, skunklike stripe down his nose—was rescued by Kristyn Vitale, a postdoc at Oregon State University here who just happens to study the feline mind. Now, Vitale hopes Carl will pull off another coup, by performing a feat of social smarts researchers once thought was impossible. In a stark white laboratory room, Vitale sits against the back wall, flanked by two overturned cardboard bowls. An undergraduate research assistant kneels a couple of meters away, holding Carl firmly. "Carl!" Vitale calls, and then points to one of the bowls. The assistant lets go. Toddlers pass this test easily. They know that when we point at something, we're telling them to look at it—an insight into the intentions of others that will become essential as children learn to interact with people around them. Most other animals, including our closest living relative, chimpanzees, fail the experiment. But about 20 years ago, researchers discovered something surprising: Dogs pass the test with flying colors. The finding shook the scientific community and led to an explosion of studies into the canine mind. Cats like Carl were supposed to be a contrast. Like dogs, cats have lived with us in close quarters for thousands of years. But unlike our canine pals, cats descend from antisocial ancestors, and humans have spent far less time aggressively molding them into companions. So researchers thought cats couldn't possibly share our brain waves the way dogs do. © 2019 American Association for the Advancement of Science

Related chapters from BN: Chapter 19: Language and Lateralization; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 15: Language and Lateralization
Link ID: 26226 - Posted: 05.10.2019

By Dana G. Smith Training software that emulates brain networks to identify dog breeds or sports equipment is by now old news. But getting such an AI network to learn a process on its own that is innate to early child development is truly novel. In a paper published Wednesday in Science Advances, a neural network distinguished between different quantities of things, even though it was never taught what a number is. The neural net reprised a cognitive skill innate to human babies, monkeys and crows, among others. Without any training, it suddenly could tell the difference between larger and smaller amounts—a skill called numerosity, or number sense. Many believe number sense is an essential precursor to our ability to count and do more complex mathematics. But questions have persisted about how this ability spontaneously comes about in the young brain. To research its development, scientists from the University of Tübingen in Germany used a deep-learning system designed to mimic the human brain to see if numerosity would emerge without having to train the software. “We were trying to simulate the workings of the visual system of our brain by building a deep-learning network, an artificial neural network,” says Andreas Nieder, a professor in the Institute of Neurobiology at Tübingen and senior author on the new paper. “The big question was, how is it possible that our brain and the brain of animals can spontaneously represent the number of items in a visual scene?” © 2019 Scientific American

Related chapters from BN: Chapter 17: Learning and Memory; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 4: Development of the Brain; Chapter 4: Development of the Brain
Link ID: 26218 - Posted: 05.09.2019

By Veronique Greenwood You’re holed up with colleagues in a meeting room for two hours, hashing out a plan. Risks are weighed, decisions are made. Then, as you emerge, you realize it was much, much warmer and stuffier in there than in the rest of the office. Small rooms can build up heat and carbon dioxide from our breath — as well as other substances — to an extent that might surprise you. And as it happens, a small body of evidence suggests that when it comes to decision making, indoor air may matter more than we have realized. At least eight studies in the last seven years have looked at what happens specifically in a room accumulating carbon dioxide, a main ingredient in our exhalations. While the results are inconsistent, they are also intriguing. They suggest that while the kinds of air pollution known to cause cancer and asthma remain much more pressing as public health concerns, there may also be pollutants whose most detrimental effects are on the mind, rather than the body. So can you trust the decisions made in small rooms? How much does the quality of air indoors affect your cognitive abilities? And as our knowledge of indoor air’s effects grows, do we need to revise how we design and use our buildings? Buildings in the United States have grown better sealed in the last 50 years, helping reduce energy used in heating and cooling. That’s also made it easier for gasses and other substances released by humans and our belongings to build up inside. Although indoor air quality is not as well monitored as the air outdoors, scientists and ventilation professionals have extensively monitored carbon dioxide indoors. © 2019 The New York Times Company

Related chapters from BN: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 26216 - Posted: 05.07.2019

/ By Elizabeth Svoboda As he neared his 50s, Anthony Andrews realized that living inside his own head felt different than it used to. The signs were subtle at first. “My wife started noticing that I wasn’t getting through things,” Andrews says. Every so often, he’d experience what he calls “cognitive voids,” where he’d get dizzy and blank out for a few seconds. It wasn’t just that he would lose track of things, as if the thought bubble over his head had popped. Over time, Andrews’ issues became more pronounced. It wasn’t just that he would lose track of things, as if the thought bubble over his head had popped. A dense calm had descended on him like a weighted blanket. “I felt like I was walking through the swamp,” says Andrews, now 54. He had to play internet chess each morning to penetrate the mental murk. In 2016, Anthony Andrews and his wife Mona were told he likely had CTE, a neurodegenerative disorder caused by repeated head impacts. With his wife, Mona, by his side, Andrews went to doctor after doctor racking up psychiatric diagnoses. One told him he had ADHD. Another thought he was depressed, and another said he had bipolar disorder. But the drugs and therapies they prescribed didn’t seem to help. “After a month,” Andrews recalls of these treatments, “I knew it’s not for me.” Copyright 2019 Undark

Related chapters from BN: Chapter 17: Learning and Memory; Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 15: Language and Lateralization
Link ID: 26215 - Posted: 05.07.2019

By Gretchen Reynolds A single, moderate workout may immediately change how our brains function and how well we recognize common names and similar information, according to a promising new study of exercise, memory and aging. The study adds to growing evidence that exercise can have rapid effects on brain function and also that these effects could accumulate and lead to long-term improvements in how our brains operate and we remember. Until recently, scientists thought that by adulthood, human brains were relatively fixed in their structure and function, especially compared to malleable tissues, like muscle, that continually grow and shrivel in direct response to how we live our lives. But multiple, newer experiments have shown that adult brains, in fact, can be quite plastic, rewiring and reshaping themselves in various ways, depending on our lifestyles. Exercise, for instance, is known to affect our brains. In animal experiments, exercise increases the production of neurochemicals and the numbers of newborn neurons in mature brains and improves the animals’ thinking abilities. Similarly, in people, studies show that regular exercise over time increases the volume of the hippocampus, a key part of the brain’s memory networks. It also improves many aspects of people’s thinking. But substantial questions remain about exercise and the brain, including the time course of any changes and whether they are short-term or, with continued training, become lasting. That particular issue intrigued scientists at the University of Maryland. They already had published a study in 2013 with older adults looking at the long-term effects of exercise on portions of the brain involved in semantic-memory processing. © 2019 The New York Times Company

Related chapters from BN: Chapter 17: Learning and Memory; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 4: Development of the Brain; Chapter 4: Development of the Brain
Link ID: 26199 - Posted: 05.02.2019

In a study of healthy volunteers, National Institutes of Health researchers found that our brains may solidify the memories of new skills we just practiced a few seconds earlier by taking a short rest. The results highlight the critically important role rest may play in learning. “Everyone thinks you need to ‘practice, practice, practice’ when learning something new. Instead, we found that resting, early and often, may be just as critical to learning as practice,” said Leonardo G. Cohen, M.D., Ph.D., senior investigator at NIH’s National Institute of Neurological Disorders and Stroke and a senior author of the paper published in the journal Current Biology. “Our ultimate hope is that the results of our experiments will help patients recover from the paralyzing effects caused by strokes and other neurological injuries by informing the strategies they use to ‘relearn’ lost skills.” The study was led by Marlene Bönstrup, M.D., a postdoctoral fellow in Dr. Cohen’s lab. Like many scientists, she held the general belief that our brains needed long periods of rest, such as a good night’s sleep, to strengthen the memories formed while practicing a newly learned skill. But after looking at brain waves recorded from healthy volunteers in learning and memory experiments at the NIH Clinical Center, she started to question the idea. The waves were recorded from right-handed volunteers with a highly sensitive scanning technique called magnetoencephalography. The subjects sat in a chair facing a computer screen and under a long cone-shaped brain scanning cap. The experiment began when they were shown a series of numbers on a screen and asked to type the numbers as many times as possible with their left hands for 10 seconds; take a 10 second break; and then repeat this trial cycle of alternating practice and rest 35 more times. This strategy is typically used to reduce any complications that could arise from fatigue or other factors.

Related chapters from BN: Chapter 17: Learning and Memory; Chapter 2: Functional Neuroanatomy: The Cells and Structure of the Nervous System
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 1: Cells and Structures: The Anatomy of the Nervous System
Link ID: 26137 - Posted: 04.13.2019

By Benedict Carey Anyone above a certain age who has drawn a blank on the name of a favorite uncle, a friend’s phone number or the location of a house key understands how fragile memory is. Its speed and accuracy begin to slip in one’s 20s and keep slipping. This is particularly true for working memory, the mental sketch pad that holds numbers, names and other facts temporarily in mind, allowing decisions to be made throughout the day. On Monday, scientists reported that brief sessions of specialized brain stimulation could reverse this steady decline in working memory, at least temporarily. The stimulation targeted key regions in the brain and synchronized neural circuits in those areas, effectively tuning them to one another, as an orchestra conductor might tune the wind section to the strings. The findings, reported in the journal Nature Neuroscience, provide the strongest support yet for a method called transcranial alternating current stimulation, or tACS, as a potential therapy for memory deficits, whether from age-related decline, brain injury or, perhaps, creeping dementia. In recent years, neuroscientists have shown that memory calls on a widely distributed network in the brain, and it coordinates those interactions through slow-frequency, thrumming rhythms called theta waves, akin to the pulsing songs shared among humpback whales. The tACS technology is thought to enable clearer communication by tuning distant circuits to one another. The tACS approach is appealing for several reasons, perhaps most of all because it is noninvasive; unlike other forms of memory support, it involves no implant, which requires brain surgery. The stimulation passes through the skull with little sensation. Still, a widely available therapy is likely years away, as the risks and benefits are not fully understood, experts said. © 2019 The New York Times Company

Related chapters from BN: Chapter 17: Learning and Memory; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 4: Development of the Brain; Chapter 4: Development of the Brain
Link ID: 26123 - Posted: 04.09.2019

Laura Sanders Brains have long been star subjects for neuroscientists. But the typical “brain in a jar” experiments that focus on one subject in isolation may be missing a huge part of what makes us human — our social ties. “There’s this assumption that we can understand how the mind works by just looking at individual minds, and not looking at them in interactions,” says social neuroscientist Thalia Wheatley of Dartmouth College. “I think that’s wrong.” To answer some of the thorniest questions about the human brain, scientists will have to study the mind as it actually exists: steeped in social connections that involve rich interplay among family, friends and strangers, Wheatley argues. To illustrate her point, she asked the audience at a symposium in San Francisco on March 26, during the annual meeting of the Cognitive Neuroscience Society, how many had talked to another person that morning. Nearly everybody in the crowd of about 100 raised a hand. Everyday social interactions may seem inconsequential. But recent work on those who have been isolated, such as elderly people and prisoners in solitary confinement, suggests otherwise: Brains deprived of social interaction stop working well (SN: 12/8/18, p. 11). “That’s a hint that it’s not just that we like interaction,” Wheatley says. “It’s important to keep us healthy and sane.” |© Society for Science & the Public 2000 - 2019

Related chapters from BN: Chapter 17: Learning and Memory; Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 15: Language and Lateralization
Link ID: 26122 - Posted: 04.09.2019

By Carl Zimmer In 2011, Dr. Dena Dubal was hired by the University of California, San Francisco, as an assistant professor of neurology. She set up a new lab with one chief goal: to understand a mysterious hormone called Klotho. Dr. Dubal wondered if it might be the key to finding effective treatments for dementia and other disorders of the aging brain. At the time, scientists only knew enough about Klotho to be fascinated by it. Mice bred to make extra Klotho lived 30 percent longer, for instance. But scientists also had found Klotho in the brain, and so Dr. Dubal launched experiments to see whether it had any effect on how mice learn and remember. The results were startling. In one study, she and her colleagues found that extra Klotho protects mice with symptoms of Alzheimer’s disease from cognitive decline. “Their thinking, in every way that we could measure them, was preserved,” said Dr. Dubal. She and her colleagues also bred healthy mice to make extra Klotho. They did better than their fellow rodents on learning mazes and other cognitive tests. Klotho didn’t just protect their brains, the researchers concluded — it enhanced them. Experiments on more mice turned up similar results. “I just couldn’t believe it — was it true, or was it just a false positive?” Dr. Dubal recalled. “But here it is. It enhances of cognition even in a young mouse. It makes them smarter.” Five years have passed since Dr. Dubal and her colleagues began publishing these extraordinary results. Other researchers have discovered tantalizing findings of their own, suggesting that Klotho may protect against other neurological disorders, including multiple sclerosis and Parkinson’s disease. © 2019 The New York Times Company

Related chapters from BN: Chapter 17: Learning and Memory; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 4: Development of the Brain; Chapter 4: Development of the Brain
Link ID: 26105 - Posted: 04.02.2019

Emma Yasinski In the 1970s, scientists discovered that certain neurons in the hippocampus—an area of the brain involved in learned and memory—would fire in response to particular locations. They were called “place cells,” explains Charlotte Boccara, a researcher at the University of Oslo. “They were deemed important for spatial representation . . . a bit like the ‘You Are Here’ signal’ on a map.” But it wasn’t until 2005 that researchers discovered the brain’s grid cells, which they believed function as that map. These cells, found adjacent to the hippocampus in the medial entorhinal cortex (MEC), self-organize into a pattern of hexagons that serve as coordinates to help animals make sense of their surroundings and the signals from our place cells. A pair of studies published today (March 28) in Science suggests that this map may not be as rigid as once thought. The experiments demonstrated that, in rats at least, the cellular activity within these grids changes as the animals learn and remember where they can find food rewards. “These are wonderful studies,” says György Buzsáki, a neuroscientist at New York University who was not involved in either of them. “When ideas converge from multiple, different directions, and they converge and come to the same conclusion, the result is always stronger.” In the first study, Boccara, then a researcher at the Institute of Science and Technology Austria, and her team placed rats one by one in a cheeseboard maze, a flat board drilled full of holes. They hid three food rewards in different holes then scattered food dust over the entire surface so the rats would not be able to sniff their ways to the reward. The rats explored the maze until they found the prizes and repeated the task until they learned to go straight to the food instead of foraging. The next day, the researchers conducted the same experiment but changed the locations of the rewards. © 1986 - 2019 The Scientist.

Related chapters from BN: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 26094 - Posted: 03.30.2019

By Benedict Carey Whatever its other properties, memory is a reliable troublemaker, especially when navigating its stockpile of embarrassments and moral stumbles. Ten minutes into an important job interview and here come screenshots from a past disaster: the spilled latte, the painful attempt at humor. Two dates into a warming relationship and up come flashbacks of an earlier, abusive partner. The bad timing is one thing. But why can’t those events be somehow submerged amid the brain’s many other dimming bad memories? Emotions play a role. Scenes, sounds and sensations leave a deeper neural trace if they stir a strong emotional response; this helps you avoid those same experiences in the future. Memory is protective, holding on to red flags so they can be waved at you later, to guide your future behavior. But forgetting is protective too. Most people find a way to bury, or at least reshape, the vast majority of their worst moments. Could that process be harnessed or somehow optimized? Perhaps. In the past decade or so, brain scientists have begun to piece together how memory degrades and forgetting happens. A new study, published this month in the Journal of Neuroscience, suggests that some things can be intentionally relegated to oblivion, although the method for doing so is slightly counterintuitive. For the longest time, forgetting was seen as a passive process of decay and the enemy of learning. But as it turns out, forgetting is a dynamic ability, crucial to memory retrieval, mental stability and maintaining one’s sense of identity. © 2019 The New York Times Company

Related chapters from BN: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 26070 - Posted: 03.23.2019

Liam Drew A mouse scurries down a hallway, past walls lined with shifting monochrome stripes and checks. But the hallway isn’t real. It’s part of a simulation that the mouse is driving as it runs on a foam wheel, mounted inside a domed projection screen. While the mouse explores its virtual world, neuroscientist Aman Saleem watches its brain cells at work. Light striking the mouse’s retinas triggers electrical pulses that travel to neurons in its primary visual cortex, where Saleem has implanted electrodes. Textbooks say that these neurons each respond to a specific stimulus, such as a horizontal or vertical line, so that identical patterns of inputs should induce an identical response. But that’s not what happens. When the mouse encounters a repeat of an earlier scene, its neurons fire in a different pattern. “Five years ago, if you’d told me that, I’d have been like, ‘No, that’s not true. That’s not possible’,” says Saleem, in whose laboratory at University College London we are standing. His results, published last September1, show that cells in the hippocampus that track where the mouse has run along the hallway are somehow changing how cells in the visual cortex fire. In other words, the mouse’s neural representation of two identical scenes differs, depending on where it perceives itself to be. It’s no surprise that an animal’s experiences change how it sees the world: all brains learn from experience and combine multiple streams of information to construct perceptions of reality. But researchers once thought that at least some areas in the brain — those that are the first to process inputs from the sense organs — create relatively faithful representations of the outside world. According to this model, these representations then travel to ‘association’ areas, where they combine with memories and expectations to produce perceptions.

Related chapters from BN: Chapter 17: Learning and Memory; Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 7: Vision: From Eye to Brain
Link ID: 26039 - Posted: 03.15.2019

Laura Sanders Fast waves of activity ripple in the brain a half second before a person calls up a memory. The finding, published in the March 1 Science, hint that these brain waves might be a key part of a person’s ability to remember. The results come from a study of 14 people with epilepsy who had electrodes placed on their brains as part of their treatment. Those electrodes also allowed scientists to monitor neural activity while the people learned pairs of words. One to three minutes after learning the pairs, people were given one word and asked to name its partner. As participants remembered the missing word, neuroscientist and neurosurgeon Kareem Zaghloul and his colleagues caught glimpses of fast brain waves rippling across parts of the brain at a rate of around 100 per second. These ripples appeared nearly simultaneously in two brain regions — the medial temporal lobe, which is known to be important for memory, and the temporal association cortex, which has a role in language. When a person got the answer wrong, or didn’t answer at all, these coordinated ripples were less likely to be present, the researchers found. “We see this happening, and then we see people remember,” says Zaghloul, of the National Institutes of Health in Bethesda, Md. While recalling a memory, “you mentally jump back in time and re-experience it,” Zaghloul says. Just after the ripples, the researchers saw telltale signs of that mental time travel — an echo of brain activity similar to the brain activity when the memory of the word pair was first formed. |© Society for Science & the Public 2000 - 201

Related chapters from BN: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 26003 - Posted: 03.05.2019

Laura Sanders People often fret about television time for children. A new study examines the habit at the other end of life. The more television older people watched, the worse they recalled a list of words, researchers report online February 28 in Scientific Reports. But the study describes only a correlation; it can’t say that lots of TV time actually causes the memory slips. Researchers examined data on 3,590 people collected as part of the English Longitudinal Study of Aging, a long-running study of English people aged 50 and older. In 2008 and 2009, participants reported how many hours a day, on average, they spent watching television. In addition to the surveys, participants listened to a recording of 10 common words, one word every two seconds. Then, people tried to remember as many words as they could, both immediately after hearing the words and after a short delay. Six years later, people took the same tests. People who watched more than 3.5 hours of TV daily back in 2008 or 2009 were more likely to have worse verbal memory scores six years later, the researchers found. Television “dose” seemed to matter: Beyond that 3.5-hour threshold, the more TV people watched, the bigger their later verbal memory scores declined. It’s not known whether television time actually causes verbal memory problems. The reverse could be true: People who have worse memories might be more likely to watch more television. Still, the researchers suggest that TV might cause a certain kind of mental stress that might contribute to memory trouble. |© Society for Science & the Public 2000 - 2019

Related chapters from BN: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 26000 - Posted: 03.02.2019