By Erin Garcia de Jesús Forget screwdrivers or drills. A stick and a straw make for a great cockatoo tool kit. Some Goffin’s cockatoos (Cacatua goffiniana) know whether they need to have more than one tool in claw to topple an out-of-reach cashew, researchers report February 10 in Current Biology. By recognizing that two items are necessary to access the snack, the birds join chimpanzees as the only nonhuman animals known to use tools as a set. The study is a fascinating example of what cockatoos are capable of, says Anne Clark, a behavioral ecologist at Binghamton University in New York, who was not involved in the study. A mental awareness that people often attribute to our close primate relatives can also pop up elsewhere in the animal kingdom. A variety of animals including crows and otters use tools but don’t deploy multiple objects together as a kit (SN: 9/14/16; SN: 3/21/17). Chimpanzees from the Republic of Congo’s Noubalé-Ndoki National Park, on the other hand, recognize the need for both a sharp stick to break into termite mounds and a fishing stick to scoop up an insect feast (SN: 10/19/04). Researchers knew wild cockatoos could use three different sticks to break open fruit in their native range of Indonesia. But it was unclear whether the birds might recognize the sticks as a set or instead as a chain of single tools that became necessary as new problems arose, says evolutionary biologist Antonio Osuna Mascaró of the University of Veterinary Medicine Vienna. © Society for Science & the Public 2000–2023.

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: 28663 - Posted: 02.11.2023

By Claudia López Lloreda Learning lots of new information as a baby requires a pool of ready-to-go, immature connections between nerve cells to form memories quickly. Called silent synapses, these connections are inactive until summoned to help create memories, and were thought to be present mainly in the developing brain and die off with time. But a new study reveals that there are many silent synapses in the adult mouse brain, researchers report November 30 in Nature. Neuroscientists have long puzzled over how the adult human brain can have stable, long-term memories, while at the same time maintaining a certain flexibility to be able to make new memories, a concept known as plasticity (SN: 7/27/12). These silent synapses may be part of the answer, says Jesper Sjöström, a neuroscientist at McGill University in Montreal who was not involved with the study. “The silent synapses are ready to hook up,” he says, possibly making it easier to store new memories as an adult by using these connections instead of having to override or destabilize mature synapses already connected to memories. “That means that there’s much more room for plasticity in the mature brain than we previously thought.” In a previous study, neuroscientist Mark Harnett of MIT and his colleagues had spotted many long, rod-shaped structures called filopodia in adult mouse brains. That surprised Harnett because these protrusions are mostly found on nerve cells in the developing brain. “Here they were in adult animals, and we could see them crystal clearly,” Harnett says. So he and his team decided to examine the filopodia to see what role they play, and if they were possibly silent synapses. The researchers used a technique to expand the brains of adult mice combined with high-resolution microscopy. Since nerve cell connections and the molecules called receptors that allow for communication between connected cells are so small, these methods revealed synapses that past research missed. © Society for Science & the Public 2000–2022.

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 3: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 28602 - Posted: 12.17.2022

Heidi Ledford Hundreds of thousands of human neurons growing in a dish coated with electrodes have been taught to play a version of the classic computer game Pong1. In doing so, the cells join a growing pantheon of Pong players, including pigs taught to manipulate joysticks with their snout2 and monkeys wired to control the game with their minds. (Google’s DeepMind artificial-intelligence (AI) algorithms mastered Pong many years ago3 and have moved on to more-sophisticated computer games such as StarCraft II4.) The gamer cells respond not to visual cues on a screen but to electrical signals from the electrodes in the dish. These electrodes both stimulate the cells and record changes in neuronal activity. Researchers then converted the stimulation signals and the cellular responses into a visual depiction of the game. The results are reported today in Neuron. The work is a proof of principle that neurons in a dish can learn and exhibit basic signs of intelligence, says lead author Brett Kagan, chief scientific officer at Cortical Labs in Melbourne, Australia. “In current textbooks, neurons are thought of predominantly in terms of their implication for human or animal biology,” he says. “They’re not thought about as an information processor, but a neuron is this amazing system that can process information in real time with very low power consumption.” Although the company calls its system DishBrain, the neurons are a far cry from an actual brain, Kagan says, and show no signs of consciousness. The definition of intelligence is also hotly debated; Kagan defines it as the ability to collate information and apply it in an adaptive behaviour in a given environment. Cortical Labs’ work follows on work by neuroengineer Steve Potter, now at the Georgia Institute of Technology in Atlanta, and his colleagues. In 2008, the team reported that neurons cultured from rats can exhibit learning and goal-directed behaviour5,6. Animated gif of 4 different microscopy images of different Dishbrain neural cells with different coloured fluorescent markers. © 2022 Springer Nature Limited

Related chapters from BN: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 28511 - Posted: 10.13.2022

By Erin Garcia de Jesús Human trash can be a cockatoo’s treasure. In Sydney, the birds have learned how to open garbage bins and toss trash around in the streets as they hunt for food scraps. People are now fighting back. Bricks, pool noodles, spikes, shoes and sticks are just some of the tools Sydney residents use to keep sulphur-crested cockatoos (Cacatua galerita) from opening trash bins, researchers report September 12 in Current Biology. The goal is to stop the birds from lifting the lid while the container is upright but still allowing the lid to flop open when a trash bin is tilted to empty its contents. This interspecies battle could be a case of what’s called an innovation arms race, says Barbara Klump, a behavioral ecologist at the Max Planck Institute of Animal Behavior in Radolfzell, Germany. When cockatoos learn how to flip trash can lids, people change their behavior, using things like bricks to weigh down lids, to protect their trash from being flung about (SN Explores: 10/26/21). “That’s usually a low-level protection and then the cockatoos figure out how to defeat that,” Klump says. That’s when people beef up their efforts, and the cycle continues. Researchers are closely watching this escalation to see what the birds — and humans — do next. With the right method, the cockatoos might fly by and keep hunting for a different target. Or they might learn how to get around it. In the study, Klump and colleagues inspected more than 3,000 bins across four Sydney suburbs where cockatoos invade trash to note whether and how people were protecting their garbage. Observations coupled with an online survey showed that people living on the same street are more likely to use similar deterrents, and those efforts escalate over time. © Society for Science & the Public 2000–2022.

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: 28476 - Posted: 09.14.2022

Yasemin Saplakoglu You’re on the vacation of a lifetime in Kenya, traversing the savanna on safari, with the tour guide pointing out elephants to your right and lions to your left. Years later, you walk into a florist’s shop in your hometown and smell something like the flowers on the jackalberry trees that dotted the landscape. When you close your eyes, the store disappears and you’re back in the Land Rover. Inhaling deeply, you smile at the happy memory. Now let’s rewind. You’re on the vacation of a lifetime in Kenya, traversing the savanna on safari, with the tour guide pointing out elephants to your right and lions to your left. From the corner of your eye, you notice a rhino trailing the vehicle. Suddenly, it sprints toward you, and the tour guide is yelling to the driver to hit the gas. With your adrenaline spiking, you think, “This is how I am going to die.” Years later, when you walk into a florist’s shop, the sweet floral scent makes you shudder. “Your brain is essentially associating the smell with positive or negative” feelings, said Hao Li, a postdoctoral researcher at the Salk Institute for Biological Studies in California. Those feelings aren’t just linked to the memory; they are part of it: The brain assigns an emotional “valence” to information as it encodes it, locking in experiences as good or bad memories. And now we know how the brain does it. As Li and his team reported recently in Nature, the difference between memories that conjure up a smile and those that elicit a shudder is established by a small peptide molecule known as neurotensin. They found that as the brain judges new experiences in the moment, neurons adjust their release of neurotensin, and that shift sends the incoming information down different neural pathways to be encoded as either positive or negative memories. To be able to question whether to approach or to avoid a stimulus or an object, you have to know whether the thing is good or bad. All Rights Reserved © 2022

Related chapters from BN: Chapter 17: Learning and Memory; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 11: Emotions, Aggression, and Stress
Link ID: 28471 - Posted: 09.10.2022

Diana Kwon People’s ability to remember fades with age — but one day, researchers might be able to use a simple, drug-free method to buck this trend. In a study published on 22 August in Nature Neuroscience1, Robert Reinhart, a cognitive neuroscientist at Boston University in Massachusetts, and his colleagues demonstrate that zapping the brains of adults aged over 65 with weak electrical currents repeatedly over several days led to memory improvements that persisted for up to a month. Previous studies have suggested that long-term memory and ‘working’ memory, which allows the brain to store information temporarily, are controlled by distinct mechanisms and parts of the brain. Drawing on this research, the team showed that stimulating the dorsolateral prefrontal cortex — a region near the front of the brain — with high-frequency electrical currents improved long-term memory, whereas stimulating the inferior parietal lobe, which is further back in the brain, with low-frequency electrical currents boosted working memory. “Their results look very promising,” says Ines Violante, a neuroscientist at the University of Surrey in Guildford, UK. “They really took advantage of the cumulative knowledge within the field.” Using a non-invasive method of stimulating the brain known as transcranial alternating current stimulation (tACS), which delivers electrical currents through electrodes on the surface of the scalp, Reinhart’s team conducted a series of experiments on 150 people aged between 65 and 88. Participants carried out a memory task in which they were asked to recall lists of 20 words that were read aloud by an experimenter. The participants underwent tACS for the entire duration of the task, which took 20 minutes. © 2022 Springer Nature Limited

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 3: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 28445 - Posted: 08.24.2022

By Ingrid Wickelgren For as long as she can remember, Kay Tye has wondered why she feels the way she does. Rather than just dabble in theories of the mind, however, Tye has long wanted to know what was happening in the brain. In college in the early 2000s, she could not find a class that spelled out how electrical impulses coursing through the brain’s trillions of connections could give rise to feelings. “There wasn’t the neuroscience course I wanted to take,” says Tye, who now heads a lab at the Salk Institute for Biological Studies in La Jolla, Calif. “It didn’t exist.” When she dedicated a chapter of her Ph.D. thesis to emotion, she was criticized for it, she recalls. The study of feelings had no place in behavioral neuroscience, she was told. Tye disagreed at the time, and she still does. “Where do we think emotions are being implemented—somewhere other than the brain?” Since then, Tye’s research team has taken a step toward deciphering the biological underpinnings of such ineffable experiences as loneliness and competitiveness. In a recent Nature study, she and her colleagues uncovered something fundamental: a molecular “switch” in the brain that flags an experience as positive or negative. Tye is no longer an outlier in pursuing these questions. Other researchers are thinking along the same lines. “If you have a brain response to anything that is important, how does it differentiate whether it is good or bad?” says Daniela Schiller, a neuroscientist at the Icahn School of Medicine at Mount Sinai in New York City, who wasn’t involved in the Nature paper. “It’s a central problem in the field.” The switch was found in mice in Tye’s study. If it works similarly in humans, it might help a person activate a different track in the brain when hearing an ice cream truck rather than a bear’s growl. This toggling mechanism is essential to survival because animals need to act differently in the contrasting scenarios. “This is at the hub of where we translate sensory information into motivational significance,” Tye says. “In evolution, it’s going to dictate whether you survive. In our modern-day society, it will dictate your mental health and your quality of life.” © 2022 Scientific American,

Related chapters from BN: Chapter 17: Learning and Memory; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 11: Emotions, Aggression, and Stress
Link ID: 28436 - Posted: 08.13.2022

Helena Horton Environment reporter Otters are able to learn from each other – but still prefer to solve some puzzles on their own, scientists have found. The semi-aquatic mammals are known to be very social and intelligent creatures, but a study by the University of Exeter has given new insight into their intellect. Researchers gave otters “puzzle boxes”, some of which contained familiar food, while others held unfamiliar natural prey – shore crab and blue mussels, which are protected by hard outer shells. For the familiar food – meatballs, a favourite with the Asian short-clawed otters in the study – the scientists had five different types of boxes, and the method to extract the food changed in each version, for example pulling a tab or opening a flap. The unfamiliar food presented additional problems because the otters did not know if the crab and mussels were safe to eat and had no experience of getting them out of their shells. In order to decide whether food was safe and desirable to eat, the otters, which live at Newquay zoo and the Tamar Otter and Wildlife Centre, watched intently as their companions inspected what was in the boxes and copied if the other otters sampled the treats. However, they spent more time trying to figure out how to remove the meat from the shells on their own and relied less on the actions of their companions. Of the 20 otters in the study, 11 managed to extract the meat from all three types of natural prey. © 2022 Guardian News & Media Limited

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: 28360 - Posted: 06.09.2022

Jon Hamilton An HIV drug — known as maraviroc — may have another, unexpected, use. The medication appears to restore a type of memory that allows us to link an event, like a wedding, with the people we saw there, a team reports in this week's issue of the journal Nature. Maraviroc's ability to improve this sort of memory was demonstrated in mice, but the drug acts on a brain system that's also found in humans and plays a role in a range of problems with the brain and nervous system. "You might have an effect in Alzheimer's disease, in stroke, in Parkinson's and also in spinal cord injuries," says Dr. S. Thomas Carmichael, chair of neurology at the University of California, Los Angeles, who was not involved in the study. The ability to link memories that occur around the same time is known as relational memory. It typically declines with age, and may be severely impaired in people with Alzheimer's disease. Problems with relational memory can appear in people who have no difficulty forming new memories, says Alcino Silva, an author of the new study and director of the Integrative Center for Learning and Memory at UCLA. "You learn about something, but you can't remember where you heard it. You can't remember who told you about it," Silva says. "These incidents happen more and more often as we go from middle age into older age." © 2022 npr

Related chapters from BN: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 28353 - Posted: 06.04.2022

By Laura Sanders Like all writers, I spend large chunks of my time looking for words. When it comes to the ultracomplicated and mysterious brain, I need words that capture nuance and uncertainties. The right words confront and address hard questions about exactly what new scientific findings mean, and just as importantly, why they matter. The search for the right words is on my mind because of recent research on COVID-19 and the brain. As part of a large brain-scanning study, researchers found that infections of SARS-CoV-2, the virus that causes COVID-19, were linked with less gray matter, tissue that’s packed with the bodies of brain cells. The results, published March 7 in Nature, prompted headlines about COVID-19 causing brain damage and shrinkage. That coverage, in turn, prompted alarmed posts on social media, including mentions of early-onset dementia and brain rotting. As someone who has reported on brain research for more than a decade, I can say those alarming words are not the ones that I would choose here. The study is one of the first to look at structural changes in the brain before and after a SARS-CoV-2 infection. And the study is meticulous. It was done by an expert group of brain imaging researchers who have been doing this sort of research for a very long time. As part of the UK Biobank project, 785 participants underwent two MRI scans. Between those scans, 401 people had COVID-19 and 384 people did not. By comparing the before and after scans, researchers could spot changes in the people who had COVID-19 and compare those changes with people who didn’t get the infection. © Society for Science & the Public 2000–2022.

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: 28246 - Posted: 03.19.2022

Yasemin Saplakoglu Imagine that while you are enjoying your morning bowl of Cheerios, a spider drops from the ceiling and plops into the milk. Years later, you still can’t get near a bowl of cereal without feeling overcome with disgust. Researchers have now directly observed what happens inside a brain learning that kind of emotionally charged response. In a new study published in January in the Proceedings of the National Academy of Sciences, a team at the University of Southern California was able to visualize memories forming in the brains of laboratory fish, imaging them under the microscope as they bloomed in beautiful fluorescent greens. From earlier work, they had expected the brain to encode the memory by slightly tweaking its neural architecture. Instead, the researchers were surprised to find a major overhaul in the connections. What they saw reinforces the view that memory is a complex phenomenon involving a hodgepodge of encoding pathways. But it further suggests that the type of memory may be critical to how the brain chooses to encode it — a conclusion that may hint at why some kinds of deeply conditioned traumatic responses are so persistent, and so hard to unlearn. “It may be that what we’re looking at is the equivalent of a solid-state drive” in the brain, said co-author Scott Fraser, a quantitative biologist at USC. While the brain records some types of memories in a volatile, easily erasable form, fear-ridden memories may be stored more robustly, which could help to explain why years later, some people can recall a memory as if reliving it, he said. Memory has frequently been studied in the cortex, which covers the top of the mammalian brain, and in the hippocampus at the base. But it’s been examined less often in deeper structures such as the amygdala, the brain’s fear regulation center. The amygdala is particularly responsible for associative memories, an important class of emotionally charged memories that link disparate things — like that spider in your cereal. While this type of memory is very common, how it forms is not well understood, partly because it occurs in a relatively inaccessible area of the brain. All Rights Reserved © 2022

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 3: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 28241 - Posted: 03.16.2022

By Linda Searing Health-care workers and others who are exposed on the job to formaldehyde, even in low amounts, face a 17 percent increased likelihood of developing memory and thinking problems later on, according to research published in the journal Neurology. The finding adds cognitive impairment to already established health risks associated with formaldehyde. As the level of exposure increases, those risks range from eye, nose and throat irritation to skin rashes and breathing problems. At high levels of exposure, the chemical is considered a carcinogen, linked to leukemia and some types of nose and throat cancer. A strong-smelling gas, formaldehyde is used in making building materials and plastics and often as a component of disinfectants and preservatives. Materials containing formaldehyde can release it into the air as a vapor that can be inhaled, which is the main way people are exposed to it. The study, which included data from more than 75,000 people, found that the majority of those exposed were workers in the health-care sector — nurses, caregivers, medical technicians and those working in labs and funeral homes. Other study participants who had been exposed to formaldehyde included workers in textile, chemistry and metal industries; carpenters; and cleaners. At highest risk were those whose work had exposed them to formaldehyde for 22 years or more, giving them a 21 percent higher risk for cognitive problems than those who had not been exposed. Using a battery of standardized tests, the researchers found that formaldehyde exposure created higher risk for every type of cognitive function that was tested, including memory, attention, reasoning, word recall and other thinking skills.

Related chapters from BN: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 28203 - Posted: 02.16.2022

Jordana Cepelewicz We often think of memory as a rerun of the past — a mental duplication of events and sensations that we’ve experienced. In the brain, that would be akin to the same patterns of neural activity getting expressed again: Remembering a person’s face, for instance, might activate the same neural patterns as the ones for seeing their face. And indeed, in some memory processes, something like this does occur. But in recent years, researchers have repeatedly found subtle yet significant differences between visual and memory representations, with the latter showing up consistently in slightly different locations in the brain. Scientists weren’t sure what to make of this transformation: What function did it serve, and what did it mean for the nature of memory itself? Now, they may have found an answer — in research focused on language rather than memory. A team of neuroscientists created a semantic map of the brain that showed in remarkable detail which areas of the cortex respond to linguistic information about a wide range of concepts, from faces and places to social relationships and weather phenomena. When they compared that map to one they made showing where the brain represents categories of visual information, they observed meaningful differences between the patterns. And those differences looked exactly like the ones reported in the studies on vision and memory. The finding, published last October in Nature Neuroscience, suggests that in many cases, a memory isn’t a facsimile of past perceptions that gets replayed. Instead, it is more like a reconstruction of the original experience, based on its semantic content. All Rights Reserved © 2022

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: 28202 - Posted: 02.12.2022

ByRodrigo Pérez Ortega A good workout doesn’t just boost your mood—it also boosts the brain’s ability to create new neurons. But exactly how this happens has puzzled researchers for years. “It’s been a bit of a black box,” says Tara Walker, a neuroscientist at the University of Queensland’s Brain Institute. Now, Walker and her colleagues think they have found a key: the chemical element selenium. During exercise, mice produce a protein containing selenium that helps their brains grow new neurons, the team reports today. Scientists may also be able to harness the element to help reverse cognitive decline due to old age and brain injury, the authors say. It’s a “fantastic” study, says Bárbara Cardoso, a nutritional biochemist at Monash University’s Victorian Heart Institute. Her own research has shown selenium—which is found in Brazil nuts, grains, and some legumes—improves verbal fluency and the ability to copy drawings correctly in older adults. “We could start thinking about selenium as a strategy” to treat or prevent cognitive decline in those who cannot exercise or are more vulnerable to selenium deficiency, she says, such as older adults, and stroke and Alzheimer’s disease patients. In 1999, researchers reported that running stimulates the brain to make new neurons in the hippocampus, a region involved in learning and memory. But which molecules were released into the bloodstream to spark this “neurogenesis” remained unclear. So 7 years ago, Walker and her colleagues screened the blood plasma of mice that had exercised on a running wheel in their cages for 4 days, versus mice that had no wheel. The team identified 38 proteins whose levels increased after the workout. © 2022 American Association for the Advancement of Science.

Related chapters from BN: Chapter 17: Learning and Memory; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 5: The Sensorimotor System
Link ID: 28185 - Posted: 02.05.2022

Dan Robitzski As the coronavirus pandemic continues, scientists are racing to understand the underlying causes and implications of long COVID, the umbrella term for symptoms that persist for at least 12 weeks but often last even longer and affect roughly 30 percent of individuals who contract COVID-19. Evidence for specific risk factors such as diabetes and the presence of autoantibodies is starting to emerge, but throughout the pandemic, one assumption has been that an important indicator of whether a COVID-19 survivor is likely to develop long COVID is the severity of their acute illness. However, a preprint shared online on January 10 suggests that even mild SARS-CoV-2 infections may lead to long-term neurological symptoms associated with long COVID such as cognitive impairment and difficulties with attention and memory, a suite of symptoms often lumped together as “brain fog.” In the study, which has not yet been peer-reviewed, scientists led by Stanford University neurologist Michelle Monje identified a pathway in COVID-19–infected mice and humans that almost perfectly matches the inflammation thought to cause chemotherapy-related cognitive impairment (CRCI), also known as “chemo fog,” following cancer treatments. On top of that, the preprint shows that the neuroinflammation pathway can be triggered even without the coronavirus infecting a single brain cell. As far back as March 2020, Monje feared that cytokine storms caused by the immune response to SARS-CoV-2 would cause the same neuroinflammation and symptoms associated with CRCI, she tells The Scientist. But because her lab doesn’t study viral infections, she had no way to test her hypothesis until other researchers created the appropriate models. In the study, Monje and her colleagues used a mouse model for mild SARS-CoV-2 infections developed at the lab of Yale School of Medicine biologist and study coauthor Akiko Iwasaki as well as brain tissue samples taken from people who had COVID-19 when they died to demonstrate that mild infections can trigger inflammation in the brain. © 1986–2022 The Scientist.

Related chapters from BN: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 28182 - Posted: 02.02.2022

Veronique Greenwood In the moment between reading a phone number and punching it into your phone, you may find that the digits have mysteriously gone astray — even if you’ve seared the first ones into your memory, the last ones may still blur unaccountably. Was the 6 before the 8 or after it? Are you sure? Maintaining such scraps of information long enough to act on them draws on an ability called visual working memory. For years, scientists have debated whether working memory has space for only a few items at a time, or if it just has limited room for detail: Perhaps our mind’s capacity is spread across either a few crystal-clear recollections or a multitude of more dubious fragments. The uncertainty in working memory may be linked to a surprising way that the brain monitors and uses ambiguity, according to a recent paper in Neuron from neuroscience researchers at New York University. Using machine learning to analyze brain scans of people engaged in a memory task, they found that signals encoded an estimate of what people thought they saw — and the statistical distribution of the noise in the signals encoded the uncertainty of the memory. The uncertainty of your perceptions may be part of what your brain is representing in its recollections. And this sense of the uncertainties may help the brain make better decisions about how to use its memories. The findings suggests that “the brain is using that noise,” said Clayton Curtis, a professor of psychology and neuroscience at NYU and an author of the new paper. All Rights Reserved © 2022

Related chapters from BN: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 28163 - Posted: 01.19.2022

Nicola Davis It’s a cold winter’s day, and I’m standing in a room watching my dog stare fixedly at two flower pots. I’m about to get an answer to a burning question: is my puppy a clever girl? Dogs have been our companions for millennia, domesticated sometime between 15,000 and 30,000 years ago. And the bond endures: according to the latest figures from the Pet Food Manufacturers Association 33% of households in the UK have a dog. But as well as fulfilling roles from Covid detection to lovable family rogue, scientists investigating how dogs think, express themselves and communicate with humans say dogs can also teach us about ourselves. And so I am here at the dog cognition centre at the University of Portsmouth with Calisto, the flat-coated retriever, and a pocket full of frankfurter sausage to find out how. We begin with a task superficially reminiscent of the cup and ballgame favoured by small-time conmen. Amy West, a PhD student at the centre, places two flower pots a few metres in front of Calisto, and appears to pop something under each. However, only one actually contains a tasty morsel. West points at the pot under which the sausage lurks, and I drop Calisto’s lead. The puppy makes a beeline for the correct pot. But according to Dr Juliane Kaminski, reader in comparative psychology at the University of Portsmouth, this was not unexpected. “A chimpanzee is our closest living relative – they ignore gestures like these coming from humans entirely,” she says. “But dogs don’t.” © 2022 Guardian News & Media Limited

Related chapters from BN: Chapter 6: Evolution of the Brain and Behavior; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 28162 - Posted: 01.19.2022

Sophie Fessl Mice raised in an enriched environment are better able to adapt and change than mice raised in standard cages, but why they show this higher brain plasticity has not been known. Now, a study published January 11 in Cell Reports finds that the environment could act indirectly: living in enriched environments changes the animals’ gut microbiota, which appears to modulate plasticity. The study “provides very interesting new insights into possible beneficial effects of environmental enrichment on the brain that might act via the gut,” writes Anthony Hannan, a neuroscientist at the Florey Institute of Neuroscience and Mental Health in Australia who was not involved in the study, in an email to The Scientist. “This new study has implications for how we might understand the beneficial effects of environmental enrichment, and its relevance to cognitive training and physical activity interventions in humans.” In previous studies, mice raised in what scientists call an enriched environment—one in which they have more opportunities to explore, interact with others, and receive sensory stimulation than they would in standard laboratory enclosures—have been better able to modify their neuronal circuits in response to external stimuli than mice raised in smaller, plainer cages. Paola Tognini, a neuroscientist at the University of Pisa and lead author of the new study, writes in an email to The Scientist that she “wondered if endogenous factors (signals coming from inside our body instead of the external world), such as the signals coming from the intestine, could also influence brain plasticity.” © 1986–2022 The Scientist.

Related chapters from BN: Chapter 13: Homeostasis: Active Regulation of the Internal Environment; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment; Chapter 13: Memory and Learning
Link ID: 28159 - Posted: 01.19.2022

Don Arnold All memory storage devices, from your brain to the RAM in your computer, store information by changing their physical qualities. Over 130 years ago, pioneering neuroscientist Santiago Ramón y Cajal first suggested that the brain stores information by rearranging the connections, or synapses, between neurons. Since then, neuroscientists have attempted to understand the physical changes associated with memory formation. But visualizing and mapping synapses is challenging to do. For one, synapses are very small and tightly packed together. They’re roughly 10 billion times smaller than the smallest object a standard clinical MRI can visualize. Furthermore, there are approximately 1 billion synapses in the mouse brains researchers often use to study brain function, and they’re all the same opaque to translucent color as the tissue surrounding them. A new imaging technique my colleagues and I developed, however, has allowed us to map synapses during memory formation. We found that the process of forming new memories changes how brain cells are connected to one another. While some areas of the brain create more connections, others lose them. Mapping new memories in fish Previously, researchers focused on recording the electrical signals produced by neurons. While these studies have confirmed that neurons change their response to particular stimuli after a memory is formed, they couldn’t pinpoint what drives those changes. © 2010–2022, The Conversation US, Inc.

Related chapters from BN: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 28149 - Posted: 01.12.2022

By Maria Temming It might seem like a fish needs a car like — well, like a fish needs a bicycle. But a new experiment suggests that fish actually make pretty good drivers. In the experiment, several goldfish learned to drive what is essentially the opposite of a submarine — a tank of water on wheels — to destinations in a room. That these fish could maneuver on land suggests that fishes’ understanding of space and navigation is not limited to their natural environment — and perhaps has something in common with landlubber animals’ internal sense of direction, researchers report in the Feb. 15 Behavioural Brain Research. Researchers at Ben-Gurion University of the Negev in Beer-Sheva, Israel taught six goldfish to steer a motorized water tank. The fishmobile was equipped with a camera that continually tracked a fish driver’s position and orientation inside the tank. Whenever the fish swam near one of the tank’s walls, facing outward, the vehicle trundled off in that direction. This goldfish knows how to use its wheels. Successfully navigating in a tank on land suggests that the animals understand space and direction in a way that lets them explore even in unfamiliar habitats. Fish were schooled on how to drive during about a dozen 30-minute sessions. The researchers trained each fish to drive from the center of a small room toward a pink board on one wall by giving the fish a treat whenever it reached the wall. During their first sessions, the fish averaged about 2.5 successful trips to the target. During their final sessions, fish averaged about 17.5 successful trips. By the end of driver’s ed, the animals also took faster, more direct routes to their goal. © Society for Science & the Public 2000–2022.

Related chapters from BN: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 28148 - Posted: 01.12.2022