By Yasemin Saplakoglu On warm summer nights, green lacewings flutter around bright lanterns in backyards and at campsites. The insects, with their veil-like wings, are easily distracted from their natural preoccupation with sipping on flower nectar, avoiding predatory bats and reproducing. Small clutches of the eggs they lay hang from long stalks on the underside of leaves and sway like fairy lights in the wind. The dangling ensembles of eggs are beautiful but also practical: They keep the hatching larvae from immediately eating their unhatched siblings. With sickle-like jaws that pierce their prey and suck them dry, lacewing larvae are “vicious,” said James Truman, a professor emeritus of development, cell and molecular biology at the University of Washington. “It’s like ‘Beauty and the Beast’ in one animal.” This Jekyll-and-Hyde dichotomy is made possible by metamorphosis, the phenomenon best known for transforming caterpillars into butterflies. In its most extreme version, complete metamorphosis, the juvenile and adult forms look and act like totally different species. Metamorphosis is not an exception in the animal kingdom; it’s almost a rule. More than 80% of the known animal species today, mainly insects, amphibians and marine invertebrates, undergo some form of metamorphosis or have complex, multistage life cycles. The process of metamorphosis presents many mysteries, but some of the most deeply puzzling ones center on the nervous system. At the center of this phenomenon is the brain, which must code for not one but multiple different identities. After all, the life of a flying, mate-seeking insect is very different from the life of a hungry caterpillar. For the past half-century, researchers have probed the question of how a network of neurons that encodes one identity — that of a hungry caterpillar or a murderous lacewing larva — shifts to encode an adult identity that encompasses a completely different set of behaviors and needs. Truman and his team have now learned how much metamorphosis reshuffles parts of the brain. In a recent study published in the journal eLife, they traced dozens of neurons in the brains of fruit flies going through metamorphosis. They found that, unlike the tormented protagonist of Franz Kafka’s short story “The Metamorphosis,” who awakes one day as a monstrous insect, adult insects likely can’t remember much of their larval life. Although many of the larval neurons in the study endured, the part of the insect brain that Truman’s group examined was dramatically rewired. That overhaul of neural connections mirrored a similarly dramatic shift in the behavior of the insects as they changed from crawling, hungry larvae to flying, mate-seeking adults. All Rights Reserved © 2023

Keyword: Learning & Memory
Link ID: 28860 - Posted: 07.27.2023

Geneva Abdul The so-called “brain fog” symptom associated with long Covid is comparable to ageing 10 years, researchers have suggested. In a study by King’s College London, researchers investigated the impact of Covid-19 on memory and found cognitive impairment highest in individuals who had tested positive and had more than three months of symptoms. The study, published on Friday in a clinical journal published by The Lancet, also found the symptoms in affected individuals stretched to almost two years since initial infection. “The fact remains that two years on from their first infection, some people don’t feel fully recovered and their lives continue to be impacted by the long-term effects of the coronavirus,” said Claire Steves, a professor of ageing and health at King’s College. “We need more work to understand why this is the case and what can be done to help.” An estimated two million people living in the UK were experiencing self-reported long Covid – symptoms continuing for more than four weeks since infection – as of January 2023, according to the 2023 government census. Commonly reported symptoms included fatigue, difficulty concentrating, shortness of breath and muscle aches. The study included more than 5,100 participants from the Covid Symptom Study Biobank, recruited through a smartphone app. Through 12 cognitive tests measuring speed and accuracy, researchers examined working memory, attention, reasoning and motor controls between two periods of 2021 and 2022. © 2023 Guardian News & Media Limited or

Keyword: Learning & Memory; Attention
Link ID: 28854 - Posted: 07.22.2023

Nicola Davis Science correspondent Taking part in activities such as chess, writing a journal, or educational classes in older age may help to reduce the risk of dementia, a study has suggested. According to the World Health Organization, more than 55 million people have the disease worldwide, most of them older people. However experts have long emphasised that dementia is not an inevitable part of ageing, with being active, eating well and avoiding smoking among the lifestyle choices that can reduce risk. Now researchers have revealed fresh evidence that challenging the brain could also be beneficial. Writing in the journal Jama Network Open, researchers in the US and Australia report how they used data from the Australian Aspree Longitudinal Study of Older Persons covering the period from 1 March 2010 to 30 November 2020. Participants in the study were over the age of 70, did not have a major cognitive impairment or cardiovascular disease when recruited between 2010 and 2014, and were assessed for dementia through regular study visits. In the first year, participants were asked about their social networks. They were also questioned on whether they undertook certain leisure activities or trips out to venues such as galleries or restaurants, and how frequently: never, rarely, sometimes, often or always. The team analysed data from 10,318 participants, taking into account factors such as age, sex, smoking status, education, socioeconomic status, and whether participants had other diseases such as diabetes. The results reveal that for activities such as writing letters or journals, taking educational classes or using a computer, increasing the frequency of participation by one category, for example from “sometimes” to “often”, was associated with an 11% drop in the risk of developing dementia over a 10-year period. Similarly, increased frequency of activities such as card games, chess or puzzle-solving was associated with a 9% reduction in dementia risk. © 2023 Guardian News & Media Limited

Keyword: Alzheimers; Learning & Memory
Link ID: 28851 - Posted: 07.19.2023

Lilly Tozer Injecting ageing monkeys with a ‘longevity factor’ protein can improve their cognitive function, a study reveals. The findings, published on 3 July in Nature Aging1, could lead to new treatments for neurodegenerative diseases. It is the first time that restoring levels of klotho — a naturally occurring protein that declines in our bodies with age — has been shown to improve cognition in a primate. Previous research on mice had shown that injections of klotho can extend the animals’ lives and increases synaptic plasticity2 — the capacity to control communication between neurons, at junctions called synapses. “Given the close genetic and physiological parallels between primates and humans, this could suggest potential applications for treating human cognitive disorders,” says Marc Busche, a neurologist at the UK Dementia Research Institute group at University College London. The protein is named after the Greek goddess Clotho, one of the Fates, who spins the thread of life. The study involved testing the cognitive abilities of old rhesus macaques (Macaca mulatta), aged around 22 years on average, before and after a single injection of klotho. To do this, researchers used a behavioural experiment to test for spatial memory: the monkeys had to remember the location of an edible treat, placed in one of several wells by the investigator, after it was hidden from them. Study co-author Dena Dubal, a physician-researcher at the University of California, San Francisco, compares the test to recalling where you left your car in a car park, or remembering a sequence of numbers a couple of minutes after hearing it. Such tasks become harder with age. The monkeys performed significantly better in these tests after receiving klotho — before the injections they identified the correct wells around 45% of the time, compared with around 60% of the time after injection. The improvement was sustained for at least two weeks. Unlike in previous studies involving mice, relatively low doses of klotho were effective. This adds an element of complexity to the findings, which suggests a more nuanced mode of actions than was previously thought, Busche says. © 2023 Springer Nature Limited

Keyword: Learning & Memory; Development of the Brain
Link ID: 28847 - Posted: 07.06.2023

Nicola Davis Taking a short nap during the day may help to protect the brain’s health as it ages, researchers have suggested after finding that the practice appears to be associated with larger brain volume. While previous research has suggested long naps could be an early symptom of Alzheimer’s disease, other work has revealed that a brief doze can improve people’s ability to learn. Now researchers say they have found evidence to suggest napping may help to protect against brain shrinkage. That is of interest, the team say, as brain shrinkage, a process that occurs with age, is accelerated in people with cognitive problems and neurodegenerative diseases, with some research suggesting this may be related to sleep problems. “In line with these studies, we found an association between habitual daytime napping and larger total brain volume, which could suggest that napping regularly provides some protection against neurodegeneration through compensating for poor sleep,” the researchers note. Writing in the journal Sleep Health, researchers at UCL and the University of the Republic in Uruguay report how they drew on data from the UK Biobank study that has collated genetic, lifestyle and health information from 500,000 people aged 40 to 69 at recruitment. The team used data from 35,080 Biobank participants to look at whether a combination of genetic variants that have previously been associated with self-reported habitual daytime napping are also linked to brain volume, cognition and other aspects of brain health. © 2023 Guardian News & Media Limited

Keyword: Sleep; Development of the Brain
Link ID: 28829 - Posted: 06.21.2023

Kerri Smith In a dimly lit laboratory in London, a brown mouse explores a circular tabletop, sniffing as it ambles about. Suddenly, silently, a shadow appears. In a split second, the mouse’s brain whirs with activity. Neurons in its midbrain start to fire, sensing the threat of a potential predator, and a cascade of activity in an adjacent region orders its body to choose a response — freeze to the spot in the hope of going undetected, or run for shelter, in this case a red acetate box stationed nearby. From the mouse’s perspective, this is life or death. But the shadow wasn’t cast by a predator. Instead, it is the work of neuroscientists in Tiago Branco’s lab, who have rigged up a plastic disc on a lever to provoke, and thereby study, the mouse’s escape behaviour. This is a rapid decision-making process that draws on sensory information, previous experience and instinct. Branco, a neuroscientist at the Sainsbury Wellcome Centre at University College London, has wondered about installing a taxidermied owl on a zip wire to create a more realistic experience. And his colleagues have more ideas — cutting the disc into a wingspan shape, for instance. “Having drones — that would also be very nice,” says Dario Campagner, a researcher in Branco’s lab. A mouse detects a looming threat and runs for cover. The shadow has been darkened. The set-up is part of a growing movement to step away from some of the lab experiments that neuroscientists have used for decades to understand the brain and behaviour. Such exercises — training an animal to use a lever or joystick to get a reward, for example, or watching it swim through a water maze — have established important principles of brain activity and organization. But they take days to months of training an animal to complete specific, idiosyncratic tasks. The end result, Branco says, is like studying a “professional athlete”; the brain might work differently in the messy, unpredictable real world. Mice didn’t evolve to operate a joystick. Meanwhile, many behaviours that come naturally — such as escaping a predator, or finding scarce food or a receptive mate — are extremely important for the animal, says Ann Kennedy, a theoretical neuroscientist at Northwestern University in Chicago, Illinois. They are “critical to survival, and under selective pressure”, she says. By studying these natural actions, scientists are hoping to glean lessons about the brain and behaviour that are more holistic and more relevant to everyday activity than ever before.

Keyword: Learning & Memory; Evolution
Link ID: 28822 - Posted: 06.14.2023

Kari Paul and Maanvi Singh Elon Musk’s brain-implant company Neuralink last week received regulatory approval to conduct the first clinical trial of its experimental device in humans. But the billionaire executive’s bombastic promotion of the technology, his leadership record at other companies and animal welfare concerns relating to Neuralink experiments have raised alarm. “I was surprised,” said Laura Cabrera, a neuroethicist at Penn State’s Rock Ethics Institute about the decision by the US Food and Drug Administration to let the company go ahead with clinical trials. Musk’s erratic leadership at Twitter and his “move fast” techie ethos raise questions about Neuralink’s ability to responsibly oversee the development of an invasive medical device capable of reading brain signals, Cabrera argued. “Is he going to see a brain implant device as something that requires not just extra regulation, but also ethical consideration?” she said. “Or will he just treat this like another gadget?” Neuralink is far from the first or only company working on brain interface devices. For decades, research teams around the world have been exploring the use of implants and devices to treat conditions such as paralysis and depression. Already, thousands use neuroprosthetics like cochlear implants for hearing. But the broad scope of capabilities Musk is promising from the Neuralink device have garnered skepticism from experts. Neuralink entered the industry in 2016 and has designed a brain-computer interface (BCI) called the Link – an electrode-laden computer chip that can be sewn into the surface of the brain and connects it to external electronics – as well as a robotic device that implants the chip. © 2023 Guardian News & Media Limited

Keyword: Robotics; Learning & Memory
Link ID: 28816 - Posted: 06.07.2023

by Adam Kirsch Giraffes will eat courgettes if they have to, but they really prefer carrots. A team of researchers from Spain and Germany recently took advantage of this preference to investigate whether the animals are capable of statistical reasoning. In the experiment, a giraffe was shown two transparent containers holding a mixture of carrot and courgette slices. One container held mostly carrots, the other mostly courgettes. A researcher then took one slice from each container and offered them to the giraffe with closed hands, so it couldn’t see which vegetable had been selected. In repeated trials, the four test giraffes reliably chose the hand that had reached into the container with more carrots, showing they understood that the more carrots were in the container, the more likely it was that a carrot had been picked. Monkeys have passed similar tests, and human babies can do it at 12 months old. But giraffes’ brains are much smaller than primates’ relative to body size, so it was notable to see how well they grasped the concept. Such discoveries are becoming less surprising every year, however, as a flood of new research overturns longstanding assumptions about what animal minds are and aren’t capable of. A recent wave of popular books on animal cognition argue that skills long assumed to be humanity’s prerogative, from planning for the future to a sense of fairness, actually exist throughout the animal kingdom – and not just in primates or other mammals, but in birds, octopuses and beyond. In 2018, for instance, a team at the University of Buenos Aires found evidence that zebra finches, whose brains weigh half a gram, have dreams. Monitors attached to the birds’ throats found that when they were asleep, their muscles sometimes moved in exactly the same pattern as when they were singing out loud; in other words, they seemed to be dreaming about singing. © 2023 Guardian News & Media Limited

Keyword: Evolution; Learning & Memory
Link ID: 28808 - Posted: 05.31.2023

Emily Waltz Researchers have been exploring whether zapping a person’s brain with electrical current through electrodes on their scalp can improve cognition.Credit: J.M. Eddin/Military Collection/Alamy After years of debate over whether non-invasively zapping the brain with electrical current can improve a person’s mental functioning, a massive analysis of past studies offers an answer: probably. But some question that conclusion, saying that the analysis spans experiments that are too disparate to offer a solid answer. In the past six years, the number of studies testing the therapeutic effects of a class of techniques called transcranial electrical stimulation has skyrocketed. These therapies deliver a painless, weak electrical current to the brain through electrodes placed externally on the scalp. The goal is to excite, disrupt or synchronize signals in the brain to improve function. Researchers have tested transcranial alternating current stimulation (tACS) and its sister technology, tDCS (transcranial direct current stimulation), on both healthy volunteers and those with neuropsychiatric conditions, such as depression, Parkinson’s disease or addiction. But study results have been conflicting or couldn’t be replicated, leading researchers to question the efficacy of the tools. The authors of the new analysis, led by Robert Reinhart, director of the cognitive and clinical neuroscience laboratory at Boston University in Massachusetts, say they compiled the report to quantify whether tACS shows promise, by comparing more than 100 studies of the technique, which applies an oscillating current to the brain. “We have to address whether or not this technique is actually working, because in the literature, you have a lot of conflicting findings,” says Shrey Grover, a cognitive neuroscientist at Boston University and an author on the paper. © 2023 Springer Nature Limited

Keyword: Learning & Memory
Link ID: 28807 - Posted: 05.31.2023

By Yasemin Saplakoglu Memories are shadows of the past but also flashlights for the future. Our recollections guide us through the world, tune our attention and shape what we learn later in life. Human and animal studies have shown that memories can alter our perceptions of future events and the attention we give them. “We know that past experience changes stuff,” said Loren Frank, a neuroscientist at the University of California, San Francisco. “How exactly that happens isn’t always clear.” A new study published in the journal Science Advances now offers part of the answer. Working with snails, researchers examined how established memories made the animals more likely to form new long-term memories of related future events that they might otherwise have ignored. The simple mechanism that they discovered did this by altering a snail’s perception of those events. The researchers took the phenomenon of how past learning influences future learning “down to a single cell,” said David Glanzman, a cell biologist at the University of California, Los Angeles who was not involved in the study. He called it an attractive example “of using a simple organism to try to get understanding of behavioral phenomena that are fairly complex.” Although snails are fairly simple creatures, the new insight brings scientists a step closer to understanding the neural basis of long-term memory in higher-order animals like humans. Though we often aren’t aware of the challenge, long-term memory formation is “an incredibly energetic process,” said Michael Crossley, a senior research fellow at the University of Sussex and the lead author of the new study. Such memories depend on our forging more durable synaptic connections between neurons, and brain cells need to recruit a lot of molecules to do that. To conserve resources, a brain must therefore be able to distinguish when it’s worth the cost to form a memory and when it’s not. That’s true whether it’s the brain of a human or the brain of a “little snail on a tight energetic budget,” he said. All Rights Reserved © 2023

Keyword: Learning & Memory; Attention
Link ID: 28787 - Posted: 05.18.2023

By Cordula Hölig, Brigitte Röder, Ramesh Kekunnaya Growing up in poverty or experiencing any adversity, such as abuse or neglect, during early childhood can put a person at risk for poor health, including mental disorders, later in life. Although the underlying mechanisms are poorly understood, some studies have shown that adverse early childhood experience leaves persisting (and possibly irreversible) traces in brain structure. As neuroscientists who are investigating sensitive periods of human brain development, we agree: safe and nurturing environments are a prerequisite for healthy brain development and lifelong well-being. Thus, preventing early childhood adversity undoubtedly leads to healthier lives. Poverty and adversity can cause changes in brain development. Harms can come from exposure to violence or toxins or a lack of nutrition, caregiving, perceptual and cognitive stimulation or language interaction. Neuroscientists have demonstrated that these factors crucially influence human brain development. Advertisement We don’t know whether these changes are reversed by more favorable circumstances later in life, however. Investigating this question in humans is extremely difficult. For one, multiple biological and psychological factors through which poverty and adversity affect brain development are hard to disentangle. That’s because they often occur together: a neglected child often experiences a lack of caregiving simultaneously with malnutrition and exposure to physical violence. Secondly, a clear beginning and end of an adverse experience is hard to define. Finally, it is almost impossible to fully reverse harsh environments in natural settings because most of the time it is impossible to move children out of their families or communities.. © 2023 Scientific American

Keyword: Development of the Brain; Learning & Memory
Link ID: 28783 - Posted: 05.13.2023

Heidi Ledford When Naomi Rance first started studying menopause and the brain, she pretty much had the field to herself. And what she was discovering surprised her. In studies of post-mortem brains, she had found neurons in a region called the hypothalamus that roughly doubled in size in women after menopause1. “This was changing so much in postmenopausal women,” says Rance, a neuropathologist at the University of Arizona in Tucson. “It had to be important.” This was the 1990s, and few other researchers were interested. Rance forged ahead on her own, painstakingly unravelling what the neurons were doing and finessing a way to study menopause symptoms in rats by tracking tiny temperature changes in their tails as a measure of hot flushes, a common symptom of menopause that is thought to be triggered in the hypothalamus. Thirty years later, a drug called fezolinetant, based on Rance’s discoveries, is being evaluated by the US Food and Drug Administration, with an approval decision expected in the first half of this year. If approved, fezolinetant could be a landmark: the first non-hormonal therapy to treat the source of hot flushes, a symptom that has become nearly synonymous with menopause and one that is experienced by about 80% of women going through the transition. (This article uses ‘women’ to describe people who experience menopause, while recognizing that not all people who identify as women go through menopause, and not all people who go through menopause identify as women.) Rance and others in the field, fezolinetant’s progress to this point is a sign that research into the causes and effects of menopausal symptoms is finally being taken seriously. In the next few years, the global number of postmenopausal women is expected to surpass one billion. But many women still struggle to access care related to menopause, and research into how best to manage such symptoms has lagged behind. That is slowly changing. Armed with improved animal models and a growing literature on the effects of existing treatments, more researchers are coming into the field to fill that gap. © 2023 Springer Nature Limited

Keyword: Hormones & Behavior; Learning & Memory
Link ID: 28778 - Posted: 05.10.2023

John Katsaras Charles Patrick Collier Dima Bolmatov Your brain is responsible for controlling most of your body’s activities. Its information processing capabilities are what allow you to learn, and it is the central repository of your memories. But how is memory formed, and where is it located in the brain? Although neuroscientists have identified different regions of the brain where memories are stored, such as the hippocampus in the middle of the brain, the neocortex in the top layer of the brain and the cerebellum at the base of the skull, they have yet to identify the specific molecular structures within those areas involved in memory and learning. Research from our team of biophysicists, physical chemists and materials scientists suggests that memory might be located in the membranes of neurons. Neurons are the fundamental working units of the brain. They are designed to transmit information to other cells, enabling the body to function. The junction between two neurons, called a synapse, and the chemistry that takes place between synapses, in the space called the synaptic cleft, are responsible for learning and memory. At a more fundamental level, the synapse is made of two membranes: one associated with the presynaptic neuron that transmits information, and one associated with the postsynaptic neuron that receives information. Each membrane is made up of a lipid bilayer containing proteins and other biomolecules. The changes taking place between these two membranes, commonly known as synaptic plasticity, are the primary mechanism for learning and memory. These include changes to the amounts of different proteins in the membranes, as well as the structure of the membranes themselves.

Keyword: Learning & Memory
Link ID: 28777 - Posted: 05.10.2023

By Kate Golembiewski On the one hand, this headgear looks like something a cyberfish would wear. On the other, it’s not far from a fashion statement someone at the Kentucky Derby might make. But scientists didn’t just affix this device for laughs: They are curious about the underlying brain mechanisms that allow fish to navigate their world, and how such mechanisms relate to the evolutionary roots of navigation for all creatures with brain circuitry. “Navigation is an extremely important aspect of behavior because we navigate to find food, to find shelter, to escape predators,” said Ronen Segev, a neuroscientist at Ben-Gurion University of the Negev in Israel who was part of a team that fitted 15 fish with cybernetic headgear for a study published on Tuesday in the journal PLOS Biology. Putting a computer on a goldfish to study how the neurons fire in its brain while navigating wasn’t easy. It takes a careful hand because a goldfish’s brain, which looks a bit like a small cluster of lentils, is only half an inch long. “Under a microscope, we exposed the brain and put the electrodes inside,” said Lear Cohen, a neuroscientist and doctoral candidate at Ben-Gurion who performed the surgeries to attach the devices. Each of those electrodes was the diameter of a strand of human hair. It was also tricky to find a way to perform the procedure on dry land without harming the test subject. “The fish needs water and you need him not to move,” he said. He and his colleagues solved both problems by pumping water and anesthetics into the fish’s mouth. Once the electrodes were in the brain, they were connected to a small recording device, which could monitor neuronal activity and which was sealed in a waterproof case, mounted on the fish’s forehead. To keep the computer from weighing the fish down and impeding its ability to swim, the researchers attached buoyant plastic foam to the device. © 2023 The New York Times Company

Keyword: Learning & Memory
Link ID: 28756 - Posted: 04.26.2023

By Oliver Whang What is the relationship between mind and body? Maybe the mind is like a video game controller, moving the body around the world, taking it on joy rides. Or maybe the body manipulates the mind with hunger, sleepiness and anxiety, something like a river steering a canoe. Is the mind like electromagnetic waves, flickering in and out of our light-bulb bodies? Or is the mind a car on the road? A ghost in the machine? Maybe no metaphor will ever quite fit because there is no distinction between mind and body: There is just experience, or some kind of physical process, a gestalt. These questions, agonized over by philosophers for centuries, are gaining new urgency as sophisticated machines with artificial intelligence begin to infiltrate society. Chatbots like OpenAI’s GPT-4 and Google’s Bard have minds, in some sense: Trained on vast troves of human language, they have learned how to generate novel combinations of text, images and even videos. When primed in the right way, they can express desires, beliefs, hopes, intentions, love. They can speak of introspection and doubt, self-confidence and regret. But some A.I. researchers say that the technology won’t reach true intelligence, or true understanding of the world, until it is paired with a body that can perceive, react to and feel around its environment. For them, talk of disembodied intelligent minds is misguided — even dangerous. A.I. that is unable to explore the world and learn its limits, in the ways that children figure out what they can and can’t do, could make life-threatening mistakes and pursue its goals at the risk of human welfare. “The body, in a very simple way, is the foundation for intelligent and cautious action,” said Joshua Bongard, a roboticist at the University of Vermont. “As far as I can see, this is the only path to safe A.I.” At a lab in Pasadena, Calif., a small team of engineers has spent the past few years developing one of the first pairings of a large language model with a body: a turquoise robot named Moxie. About the size of a toddler, Moxie has a teardrop-shaped head, soft hands and alacritous green eyes. Inside its hard plastic body is a computer processor that runs the same kind of software as ChatGPT and GPT-4. Moxie’s makers, part of a start-up called Embodied, describe the device as “the world’s first A.I. robot friend.” © 2023 The New York Times Company

Keyword: Intelligence; Robotics
Link ID: 28735 - Posted: 04.12.2023

Nicola Davis Science correspondent From squabbling over who booked a disaster holiday to differing recollections of a glorious wedding, events from deep in the past can end up being misremembered. But now researchers say even recent memories may contain errors. Scientists exploring our ability to recall shapes say people can make mistakes after just a few seconds – a phenomenon the team have called short-term memory illusions. “Even at the shortest term, our memory might not be fully reliable,” said Dr Marte Otten, the first author of the research from the University of Amsterdam. “Particularly when we have strong expectations about how the world should be, when our memory starts fading a little bit – even after one and a half seconds, two seconds, three seconds – then we start filling in based on our expectations.” Writing in the journal Plos One, Otten and colleagues note previous research has shown that when people are presented with a rotated or mirror-image letter, they often report seeing the letter in its correct orientation. While this had previously been put down to participants mis-seeing the shape, Otten and colleagues had doubts. “We thought that they are more likely to be a memory effect. So you saw it correctly, but as soon as you commit it to memory stuff starts going wrong,” said Otten. To investigate further, the researchers carried out four experiments. In the first, participants were screened to ensure they were able to complete basic visual memory tasks before being presented with a circle of six or eight letters, one or two of which were mirror-image forms. After a matter of seconds, participants were shown a second circle of letters which they were instructed to ignore – this acted as a distraction. They were then asked to select, from a series of options, a target shape that had been at particular location in the first circle, and rate their confidence in this choice. © 2023 Guardian News & Media Limited

Keyword: Learning & Memory
Link ID: 28730 - Posted: 04.09.2023

By Elizabeth Preston Several years ago, Christian Rutz started to wonder whether he was giving his crows enough credit. Rutz, a biologist at the University of St. Andrews in Scotland, and his team were capturing wild New Caledonian crows and challenging them with puzzles made from natural materials before releasing them again. In one test, birds faced a log drilled with holes that contained hidden food, and could get the food out by bending a plant stem into a hook. If a bird didn’t try within 90 minutes, the researchers removed it from the dataset. But, Rutz says, he soon began to realize he was not, in fact, studying the skills of New Caledonian crows. He was studying the skills of only a subset of New Caledonian crows that quickly approached a weird log they’d never seen before—maybe because they were especially brave, or reckless. The team changed their protocol. They began giving the more hesitant birds an extra day or two to get used to their surroundings, then trying the puzzle again. “It turns out that many of these retested birds suddenly start engaging,” Rutz says. “They just needed a little bit of extra time.” Scientists are increasingly realizing that animals, like people, are individuals. They have distinct tendencies, habits, and life experiences that may affect how they perform in an experiment. That means, some researchers argue, that much published research on animal behavior may be biased. Studies claiming to show something about a species as a whole—that green sea turtles migrate a certain distance, say, or how chaffinches respond to the song of a rival—may say more about individual animals that were captured or housed in a certain way, or that share certain genetic features. That’s a problem for researchers who seek to understand how animals sense their environments, gain new knowledge, and live their lives. © 2023 NautilusNext Inc.,

Keyword: Evolution; Intelligence
Link ID: 28724 - Posted: 04.01.2023

By Katherine Harmon Courage We all might wish for minds as retentive as a hard drive. Memory file created. Saved. Ready for access at any time. But don’t yet go wishing for the memory performance of AI. Artificial neural networks are prone to a troublesome glitch known, evocatively, as catastrophic forgetting. These seemingly tireless networks can keep learning tasks day and night. But sometimes, once a new task is learned, any recollection of an old task vanishes. It’s as if you learned to play tennis decently well, but after being taught to play water polo, you suddenly had no recollection of how to swing a racket. This apparent network overload put an idea in the head of Maxim Bazhenov, a professor who studies computational neuroscience and sleep at the University of California San Diego School of Medicine. Perhaps the spiking neural networks he was working with simply needed a rest. In natural sleep, he had seen that the same basic brain processes occur in humans and in honeybees, working over information accumulated during waking moments. “That machinery presumably was doing something useful” in order to be conserved across evolutionary paths, he says. So, he thought, why not try a similar state for the machines. The idea was to simply provide the artificial neural networks with a break from external stimuli, to instruct them to go into a sort of rest state. Like the dozing human brain, the networks were still active, but instead of taking in new information, they were mulling the old stuff, consolidating, surfacing patterns.

Keyword: Sleep; Learning & Memory
Link ID: 28709 - Posted: 03.18.2023

By Bruce Bower Monkeys in southern Thailand use rocks to pound open oil palm nuts, inadvertently shattering stone pieces off their makeshift nutcrackers. These flakes resemble some sharp-edged stone tools presumed to have been created on purpose by ancient hominids, researchers say. Thailand’s long-tailed macaques (Macaca fascicularis) produce shards that could easily be mistaken for stone flakes previously found at 17 East African hominid sites dating from about 3.3 million to 1.56 million years ago, say archaeologist Tomos Proffitt and colleagues. The finding suggests that ancient hominids may sometimes have created the stone flakes by accident while using rocks to smash nuts, bones or other objects, the scientists report March 10 in Science Advances. Previous research has already shown that rock-wielding capuchin monkeys in Brazil unwittingly produce hominid-like stone flakes (SN: 10/19/16). Observations of rock bashing by these two monkey species undermine a long-standing assumption that hominids must have intentionally made certain ancient stone flakes, including some of the earliest known examples of tools, Proffitt says (SN: 6/3/19). It’s time to reevaluate how such determinations are made, he contends. Proffitt’s group identified 219 complete and fragmented stone flakes at 40 macaque nut-cracking sites on the island where the monkeys live. The team also found rocks showing damage consistent with having been used either as pounding implements or pounding platforms. Some differences do exist between macaque and hominid stone flakes, says Proffitt, of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. For instance, many macaque flakes display battering damage on only one side, versus frequent two-sided damage on hominid artifacts. © Society for Science & the Public 2000–2023.

Keyword: Evolution; Intelligence
Link ID: 28699 - Posted: 03.11.2023

By Jacob Beck, Sam Clarke Imagine hosting a party. You arrange snacks, curate a playlist and place a variety of beers in the refrigerator. Your first guest shows up, adding a six-pack before taking one bottle for himself. You watch your next guest arrive and contribute a few more beers, minus one for herself. Ready for a drink, you open the fridge and are surprised to find only eight beers remaining. You haven't been consciously counting the beers, but you know there should be more, so you start poking around. Sure enough, in the crisper drawer, behind a rotting head of romaine, are several bottles. How did you know to look for the missing beer? It's not like you were standing guard at the refrigerator, tallying how many bottles went in and out. Rather you were using what cognitive scientists call your number sense, a part of the mind that unconsciously solves simple math problems. While you were immersed in conversation with guests, your number sense was keeping tabs on how many beers were in the fridge. For a long time scientists, mathematicians and philosophers have debated whether this number sense comes preinstalled or is learned over time. Plato was among the first in the Western tradition to propose that humans have innate mathematical abilities. In Plato's dialogue Meno, Socrates coaxes the Pythagorean theorem out of an uneducated boy by asking him a series of simple questions. Socrates's takeaway is that the boy had innate knowledge of the Pythagorean theorem all along; the questioning just helped him express it. In the 17th century John Locke rejected this idea, insisting that the human mind begins as a tabula rasa, or blank slate, with almost all knowledge acquired through experience. This view, known as empiricism, in contrast to Plato's nativism, was later further developed by John Stuart Mill, who argued that we learn two plus three is five by seeing many examples where it holds true: two apples and three apples make five apples, two beers and three beers make five beers, and so on.

Keyword: Development of the Brain; Learning & Memory
Link ID: 28693 - Posted: 03.08.2023