Chapter 17. Learning and Memory

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By Cade Metz REDWOOD CITY, Calif. — In the global race to build artificial intelligence, it was a missed opportunity. Jeff Hawkins, a Silicon Valley veteran who spent the last decade exploring the mysteries of the human brain, arranged a meeting with DeepMind, the world’s leading A.I. lab. Scientists at DeepMind, which is owned by Google’s parent company, Alphabet, want to build machines that can do anything the brain can do. Mr. Hawkins runs a little company with one goal: figure out how the brain works and then reverse engineer it. The meeting, set for April at DeepMind’s offices in London, never happened. DeepMind employs hundreds of A.I. researchers along with a team of seasoned neuroscientists. But when Mr. Hawkins chatted with Demis Hassabis, one of the founders of DeepMind, before his visit, they agreed that almost no one at the London lab would understand his work. Mr. Hawkins says that before the world can build artificial intelligence, it must explain human intelligence so it can create machines that genuinely work like the brain. “You do not have to emulate the entire brain,” he said. “But you do have to understand how the brain works and emulate the important parts.” At his company, called Numenta, that is what he hopes to do. Mr. Hawkins, 61, began his career as an engineer, created two classic mobile computer companies, Palm and Handspring, and taught himself neuroscience along the way. Now, after more than a decade of quiet work at Numenta, he thinks he and a handful of researchers working with him are well on their way to cracking the problem.On Monday, at a conference in the Netherlands, he is expected to unveil their latest research, which he says explains the inner workings of cortical columns, a basic building block of brain function. © 2018 The New York Times Company

Keyword: Learning & Memory; Robotics
Link ID: 25575 - Posted: 10.15.2018

Laura Sanders The brain’s hippocampi may be the film editors of our lives, slicing our continuous experiences into discrete cuts that can be stored away as memories. That’s the idea raised by a new study that analyzed brain scan data from people watching films such as “Forrest Gump.” “Research like this helps us identify ‘What is an event, from the point of view of the brain?’ ” says memory psychologist Gabriel Radvansky of the University of Notre Dame in Indiana. Many laboratory tests of memory involve taking in discrete, dull lists of information. “So much research is done with these little bits and pieces — words, pictures, things like that,” Radvansky says. But those dry tidbits aren’t what the human brain usually handles. “The mind is built to deal with complex events.” As a closer approximation to real life, researchers used brain imaging data collected earlier as part of a larger project: While undergoing a functional MRI, 15 people watched “Forrest Gump,” and 253 people watched Alfred Hitchcock’s television drama “Bang! You’re Dead.” A separate group of 16 observers watched each of the productions and pressed buttons to indicate when they thought one event ended and another began. With the data in hand, cognitive neuroscientists Aya Ben-Yakov and Rik Henson, both of the University of Cambridge, aligned participants’ brain activity with the transition points marked by the 16 observers. A brain structure called the hippocampus, known to be important for memory and navigation, seemed particularly active at these junctures, the team reports October 8 in the Journal of Neuroscience. When the researchers looked at hippocampus behavior over the entire shows, the brain structure was most active when the observers had indicated a shift from one event to another. |© Society for Science & the Public 2000 - 2018.

Keyword: Learning & Memory
Link ID: 25548 - Posted: 10.09.2018

By Daniel T. Willingham You must read this article to understand it, but many people feel reading is not how they learn best. They would rather listen to an explanation or view a diagram. Researchers have formalized those intuitions into theories of learning styles. These theories are influential enough that many states (including New York) require future teachers to know them and to know how they might be used in the classroom. But there’s no good scientific evidence that learning styles actually exist. Over the last several decades, researchers have proposed dozens of theories, each suggesting a scheme to categorize learners. The best known proposes that some of us like words and others like pictures, but other theories make different distinctions: whether you like to solve problems intuitively or by analyzing them, for example, or whether you prefer to tackle a complex idea with an overview or by diving into details. If one of these theories were right, it would bring important benefits. In the classroom, a brief test would categorize children as this type of learner or that, and then a teacher could include more of this or that in their schooling. In the workplace, a manager might send one employee a memo but communicate the same information to another in a conversation. Does such matching work? To find out, researchers must determine individuals’ supposed learning style and then ask them to learn something in a way that matches or conflicts with it. For example, in an experiment testing the visual-auditory theory, researchers determined subjects’ styles by asking about their usual mental strategies: Do you spell an unfamiliar word by sounding it out or visualizing the letters? Do you give directions in words or by drawing a map? Next, researchers read statements, and participants rated either how easily the statement prompted a mental image (a visual learning experience) or how easy it was to pronounce (an auditory learning experience). The auditory learners should have remembered statements better if they focused on the sound rather than if they created visual images, and visual learners should have shown the opposite pattern. But they didn’t. © 2018 The New York Times Company

Keyword: Learning & Memory
Link ID: 25547 - Posted: 10.08.2018

Jon Hamilton As a specialist in Alzheimer's prevention, Jessica Langbaum knows that exercising her mental muscles can help keep her brain sharp. But Langbaum, who holds a doctorate in psychiatric epidemiology, has no formal mental fitness program. She doesn't do crossword puzzles or play computer brain games. "Just sitting down and doing Sudoku isn't probably going to be the one key thing that's going to prevent you from developing Alzheimer's disease," she says. Instead of using a formal brain training program, she simply goes to work. "My job is my daily cognitive training," says Langbaum, the associate director of the Alzheimer's Prevention Initiative at the Banner Alzheimer's Institute in Phoenix. And that's true of most working people. "While you're still in the work force you are getting that daily challenge of multitasking, of remembering things, of processing information," she says. Langbaum offers that perspective as someone who has spent years studying the effects of brain training programs, and as someone who has seen Alzheimer's up close. "My grandfather was diagnosed with mild cognitive impairment when I was in graduate school getting my Ph.D.," she says. "That transitioned into full-blown Alzheimer's dementia." So Langbaum began to ask herself a question: "How can I in my career help ensure that we aren't suffering from the disease when we reach that age?" And she realized early on that puzzles and games weren't the answer because they tend to focus on one very narrow task. The result is like exercising just one muscle in your body, Langbaum says. That muscle will get stronger, but your overall fitness isn't going to change. © 2018 npr

Keyword: Learning & Memory; Alzheimers
Link ID: 25546 - Posted: 10.08.2018

By Rowan Hooper Let’s start with a number that many have come across in math class: pi, the ratio of a circle’s circumference to its diameter. It begins with 3.14159 . . . and carries on forever. It is infinite and irrational, never ending and never repeating, and people are drawn into its orbit. To some, the attraction is spiritual; to others, the pull may be explained by the “because it’s there” reasoning of mountaineers. Memory athletes — so called because of their intensive training in games of the mind — in particular are drawn to the endlessness of pi. Akira Haraguchi of Kisarazu, near Tokyo, recited pi to more than 100,000 digits in 2006, a feat that lasted more than 16 hours. To him, pi represents a religious quest for meaning. “Reciting pi’s digits has the same meaning as chanting the Buddhist mantra and meditating,” Haraguchi, who is 72, says. He is widely recognized as the champion of pi, although Guinness World Records has not validated his recitation. The official Guinness record holder is Rajveer Meena, 23, from Rajasthan, India. On March 21, 2015, Meena recited pi to 70,000 decimal places. (It took him 9 hours 7 minutes.) He said he wanted to show that despite a humble background, he could win the world’s toughest memory challenge. Memory wizards have varying motivations and use different techniques, but they all essentially convert the exercise into a story. When they recite the numbers, they are telling themselves a tale in their head and rendering it into digits. Haraguchi uses a system based on the Japanese kana alphabet. Translated roughly into English, the first 50 digits of his translation reads: “Well, I, that fragile being who left my hometown to find a peace of mind, is going to die in the dark corners; it’s easy to die, but I stay positive.” © 1996-2018 The Washington Post

Keyword: Learning & Memory
Link ID: 25545 - Posted: 10.08.2018

By Laura M. Holson Cat lovers of the world rejoice! In the long-simmering dispute over whether dogs are smarter than cats, a recent study published in the journal Learning & Behavior suggests that dogs are no more exceptional than other animals when it comes to canniness and intelligence. The news is sure to ignite debate (watch the fur fly!) among dog owners and scientists who study canine behavior. The authors reviewed existing studies and data on animal cognition and found that while dogs are smart and trainable, they are not “super smart,” despite what most dog owners will tell you. The idea for the study came about when Stephen Lea, an emeritus professor in the psychology department at the University of Exeter in Britain, was editor of Animal Cognition, a journal that seeks to explain cognition among humans and animals in the context of evolution. Dog research, he said in an interview last week, was quite popular in the 1990s and continues to be so. “I was getting a number of papers showing how remarkable the things were that dogs could do,” he said. When it came to other animals, though, scientific studies on intelligence barely trickled in, despite evidence to suggest that horses, chimpanzees and cats had tricks of their own. “Almost everything a dog claimed to do, other animals could do too,” Dr. Lea said. “It made me quite wary that dogs were special.” Sure, there is Chaser, a Border collie from Spartanburg, S.C., who was trained to understand 1,022 nouns. (His owner, John Pilley, a scientist who studied canine cognition, recently died.) Before that was a Border collie named Rico who learned to recognize the names of 200 items. But beyond those examples, Dr. Lea wondered: Had dog lovers (and scientists, for that matter) imbued their pets with extraordinary capabilities they did not possess? © 2018 The New York Times Company

Keyword: Learning & Memory; Evolution
Link ID: 25544 - Posted: 10.08.2018

By Jim Hopper On Monday October 1, Republican senators released “Analysis of Dr. Christine Blasey Ford’s Allegations,” a memo written by Rachel Mitchell, the prosecutor they hired to question Christine Blasey Ford and review other evidence. Ms. Mitchell’s “analysis” includes descriptions of Ford’s memories as not “consistent,” lacking “key details,” and uncorroborated by people she said were at the “party.” In the final two weeks of September, many Americans learned from the media (e.g., USA Today, Rolling Stone, Vox, NBC News, NPR) the distinction that memory researchers make between “central” and “peripheral” details, terms that reflect the commonsense understanding that we remember things that had significance to us and got our attention. Many people have also learned that stress and trauma greatly enhance the differential storage of central over peripheral details, and that the central details of traumatic experiences can get burned into our brains for the rest of our lives. But most people already knew that too, even if they hadn’t stopped to think about it. Advertisement These past few weeks, I’ve tried to help with that learning, by talking with reporters and sharing the expert testimony on trauma and memory that I could have provided to senators and the country, which was published by Scientific American and on my blog with Psychology Today, Sexual Assault and the Brain. There I explain central versus peripheral details, that stress amplifies their differential encoding and storage, and how sexual assault survivors—like traumatized soldiers and police—may protect themselves by clinging for years to superficial descriptions of events, which keep the most disturbing details out of their minds. © 2018 Scientific American

Keyword: Learning & Memory; Stress
Link ID: 25534 - Posted: 10.06.2018

Linda Holmes On Sunday's CBS Sunday Morning, Ted Koppel reminisced about the many profiles of media giant Ted Turner that have aired on the network, beginning all the way back in the 1970s, when he hadn't started CNN but had bought Atlanta's baseball and basketball teams. Now, about to turn 80, Turner told Koppel about his diagnosis of Lewy body dementia. He acknowledged that in addition to memory difficulties, it causes exhaustion. In fact, as he noted with a tinge of humor, he wasn't able to bring the name of the disease to mind even as he was talking about how it affected him. Turner is still active, however: He was seen not only practicing yoga but continuing to wander his immense Montana ranch on horseback. According to the National Institutes of Health, Lewy body dementia is caused by protein deposits in the brain — named "Lewy bodies" after the neurologist who discovered them. The deposits cause changes in brain chemistry that disrupt thinking and behavior as well as movement. The disease also reportedly affected actor Robin Williams prior to his death in 2014. © 2018 npr

Keyword: Alzheimers
Link ID: 25516 - Posted: 10.02.2018

By Sarah Hepola One of the trickiest things about blackouts is that you don’t necessarily know you’re having one. I wrote a memoir, so centered around the slips of memory caused by heavy drinking that it is actually called “Blackout,” and in the years since its 2015 release, I’ve heard from thousands of people who experienced them. No small number of those notes contain some version of this: “For years, I was having blackouts without knowing what they were.” Blackouts are like a philosophical riddle inside a legal conundrum: If you can’t remember a thing, how do you know it happened? In the days leading up to the Senate Judiciary Committee hearing on the Supreme Court nomination of Brett Kavanaugh, a theory arose that he might have drunk so much as a teenager that he did not remember his alleged misdeeds. The blackout theory was a way to reconcile two competing narratives. It meant that Christine Blasey Ford was telling the truth but so was Brett Kavanaugh. He simply did not remember what happened that night and therefore believed himself falsely accused. Several questions at the hearing were designed to get at this theory, but it gained little ground. I want to be clear, up front, that I cannot know whether Judge Kavanaugh experienced a blackout. But what I do know is that blackouts are both common and tragically misunderstood. Before the prosecutor Rachel Mitchell was mysteriously dispatched, she was aiming toward the above line of inquiry. “Have you ever passed out from drinking?” she asked. Kavanaugh’s answer was dismissive but slightly confusing: “I’ve gone to sleep, but I’ve never blacked out. That’s the allegation? That’s wrong.” A few clarifications. First, I dare you to find the heavy drinker who hasn’t passed out from too much booze. To say you were just sleeping is like my dad saying he’s resting his eyes when he’s napping. It’s a semantic dodge. © 2018 The New York Times Company

Keyword: Learning & Memory; Drug Abuse
Link ID: 25514 - Posted: 10.01.2018

By Jim Hopper Incomplete memories of sexual assault, including those with huge gaps, are understandable—if we learn the basics of how memory works and we genuinely listen to survivors. Such memories should be expected. They are similar to the memories of soldiers and police officers for things they’ve experienced in the line of fire. And a great deal of scientific research on memory explains why. Advertisement I’m an expert on psychological trauma, including sexual assault and traumatic memories. I’ve spent more than 25 years studying this. I’ve trained military and civilian police officers, prosecutors and other professionals, including commanders at Fort Leavenworth and the Pentagon. I teach this to psychiatrists in training at Harvard Medical School. As an expert witness, I review videos and transcripts of investigative interviews. It’s like using a microscope to examine how people recall—and don’t recall—parts of their assault experiences. I’ve seen poorly trained police officers not only fail to collect vital details, but actually worsen memory gaps and create inconsistences. Ignorance of how memory works is a major reason why sexual assault is the easiest violent crime to get away with, across our country and around the world. Yet when I teach military service members and police officers, it’s mostly about making light bulbs go on in their heads and helping them connect the dots from their own traumatic memories to those of sexual assault survivors. © 2018 Scientific American,

Keyword: Learning & Memory; Stress
Link ID: 25504 - Posted: 09.28.2018

By Carolyn Y. Johnson and Joel Achenbach The allegations of sexual assault against Judge Brett M. Kavanaugh have a common element of binge drinking, and highlight the powerful effects alcohol can have on adolescents and their still-developing brains. Alcohol not only changes behavior — sometimes with disastrous consequences — it can also interfere with memory formation, creating gaps that experts refer to as blackouts. “In the moment, the person can be functioning normally, with no sign there’s going to be memory impairment. But because those memories never get consolidated and stored, it’s like they never occurred, so you can’t recall them later on,” said Kate Carey, a clinical psychologist at Brown University School of Public Health. “Which doesn’t mean it didn’t happen.” Binge drinking and the imperfection of memory are likely to be discussed during Thursday’s hearing before the Senate Judiciary Committee. Christine Blasey Ford said the Supreme Court nominee became “stumbling drunk” and attacked her at a party in high school. Kavanaugh has denied the allegation. He also said in a television interview that he’d never had a blackout from alcohol. Binge drinking among U.S. high school students peaked in the early 1980s, when Kavanaugh was a student at Georgetown Prep. High school binge drinking has declined in recent decades in part because dozens of states, as well as the District of Columbia, raised the minimum legal drinking age to 21 in the 1980s, said Katherine Keyes, an epidemiologist at Columbia University and an expert on alcohol consumption.

Keyword: Drug Abuse; Learning & Memory
Link ID: 25499 - Posted: 09.27.2018

By Benedict Carey and Jan Hoffman When Judge Brett M. Kavanaugh and Christine Blasey Ford present their vastly different recollections to the Senate on Thursday, the quality and reliability of memory itself will be on trial. Judge Kavanaugh has emphatically denied allegations from Dr. Blasey that he tried to rape her when they were teenagers or ever committed sexual assault against anyone. Dr. Blasey and another accuser, Deborah Ramirez, have recounted their alleged incidents with both precise detail and gaping holes. Could Judge Kavanaugh’s accusers be mistaken about his identity? Could he somehow have erased the experiences they allege from his memory? Or, even, could all be telling what they genuinely believe is the truth? The biology of memory, while still far from worked out, helps to explain how vastly different accounts can emerge from a shared experience. Memory, by its nature and necessity, is selective, its details subject to revision and dissipation. From the dizzying stream of incoming perceptions, the brain stores, or “encodes,” the sights, sounds, sensations and emotions that it deems important or novel. The quality of preservation may depend not only on the intensity of emotion in the moment an event occurs but on the mechanics of how that event is recorded and retrieved — in some cases, decades later. “Recollection is always a reconstruction, to some extent — it’s not a videotape that preserves every detail,” said Richard J. McNally, a professor of psychology at Harvard University and the author of “Remembering Trauma.” “The details are often filled in later, or dismissed, and guessing may become part of the memory.” For a trauma victim, this encoding combines mortal fear and heart-racing panic with crystalline fragments of detail: the make of the gun, the color of the attacker’s eyes. The emotion is so strong that the fragments can become untethered from time and place. They may persist in memory even as other relevant details—the exact date, the conversation just before the attack, who else was in the room — fall out of reach. © 2018 The New York Times Company

Keyword: Learning & Memory
Link ID: 25495 - Posted: 09.26.2018

Nathaniel Comfort It’s never a good time for another bout of genetic determinism, but it’s hard to imagine a worse one than this. Social inequality gapes, exacerbated by climate change, driving hostility towards immigrants and flares of militant racism. At such a juncture, yet another expression of the discredited, simplistic idea that genes alone control human nature seems particularly insidious. And yet, here we are again with Blueprint, by educational psychologist Robert Plomin. Although Plomin frequently uses more civil, progressive language than did his predecessors, the book’s message is vintage genetic determinism: “DNA isn’t all that matters but it matters more than everything else put together”. “Nice parents have nice children because they are all nice genetically.” And it’s not just any nucleic acid that matters; it is human chromosomal DNA. Sorry, microbiologists, epigeneticists, RNA experts, developmental biologists: you’re not part of Plomin’s picture. Crude hereditarianism often re-emerges after major advances in biological knowledge: Darwinism begat eugenics; Mendelism begat worse eugenics. The flowering of medical genetics in the 1950s led to the notorious, now-debunked idea that men with an extra Y chromosome (XYY genotype) were prone to violence. Hereditarian books such as Charles Murray and Richard Herrnstein’s The Bell Curve (1994) and Nicholas Wade’s 2014 A Troublesome Inheritance (see N. Comfort Nature 513, 306–307; 2014) exploited their respective scientific and cultural moments, leveraging the cultural authority of science to advance a discredited, undemocratic agenda. Although Blueprint is cut from different ideological cloth, the consequences could be just as grave. © 2018 Springer Nature Limited.

Keyword: Genes & Behavior; Intelligence
Link ID: 25492 - Posted: 09.26.2018

Jacek Debiec Most of what you experience leaves no trace in your memory. Learning new information often requires a lot of effort and repetition – picture studying for a tough exam or mastering the tasks of a new job. It’s easy to forget what you’ve learned, and recalling details of the past can sometimes be challenging. But some past experiences can keep haunting you for years. Life-threatening events – things like getting mugged or escaping from a fire – can be impossible to forget, even if you make every possible effort. Recent developments in the Supreme Court nomination hearings and the associated #WhyIDidntReport action on social media have rattled the public and raised questions about the nature, role and impact of these kinds of traumatic memories. Leaving politics aside, what do psychiatrists and neuroscientists like me understand about how past traumas can remain present and persistent in our lives through memories? Imagine facing extreme danger, such as being held at gunpoint. Right away, your heart rate increases. Your arteries constrict, directing more blood to your muscles, which tense up in preparation for a possible life-or-death struggle. Perspiration increases, to cool you down and improve gripping capability on palms and feet for added traction for escape. In some situations, when the threat is overwhelming, you may freeze and be unable to move. Threat responses are often accompanied by a range of sensations and feelings. Senses may sharpen, contributing to amplified detection and response to threat. You may experience tingling or numbness in your limbs, as well as shortness of breath, chest pain, feelings of weakness, fainting or dizziness. Your thoughts may be racing or, conversely, you may experience a lack of thoughts and feel detached from reality. Terror, panic, helplessness, lack of control or chaos may take over. Copyright © 2010–2018

Keyword: Learning & Memory; Stress
Link ID: 25490 - Posted: 09.25.2018

Anthea Lacchia Just 10 minutes of light physical activity is enough to boost brain connectivity and help the brain to distinguish between similar memories, a new study suggests. Scientists at the University of California studying brain activity found connectivity between parts of the brain responsible for memory formation and storage increased after a brief interval of light exercise – such as 10 minutes of slow walking, yoga or tai chi. The findings could provide a simple and effective means of slowing down or staving off memory loss and cognitive decline in people who are elderly or have low levels of physical ability. The scientists asked 36 healthy volunteers in their early 20s to do 10 minutes of light exercise – at 30% of their peak oxygen intake – before assessing their memory ability. The memory test was then repeated on the same volunteers without exercising. The same experiment was repeated on 16 of the volunteers who had either undertaken the same kind of exercise or rested, with researchers scanning their brain to monitor activity. In the brains of those who had exercised they discovered enhanced communication between the hippocampus – a region important in memory storage – and the cortical brain regions, which are involved in vivid recollection of memories. “The memory task really was quite challenging,” said Michael Yassa, a neuroscientist at the University of California, Irvine, and project co-leader. The participants were first shown pictures of objects from everyday life – ranging from broccoli to picnic baskets – and later tested on how well they remembered the images. “We used very tricky similar items to to see if they would remember whether it was this exact picnic basket versus that picnic basket,” he said. © 2018 Guardian News and Media Limited

Keyword: Learning & Memory
Link ID: 25488 - Posted: 09.25.2018

Hannah Thomasy Transferring memories from one mind to another seems like something out of science fiction. But biologists from UCLA have recently found that memory transfer is in fact possible—at least in sea slugs. In the study, researchers in Professor David Glanzman’s lab examined memory in sea slugs using something called the siphon withdrawal reflex. The siphon is a sort of fleshy tube that sea slugs and other mollusks use to propel water in and out of their bodies. When the siphon is touched, the sea slug ordinarily withdraws it into its body as a protective reflex. The scientists “trained” the sea slugs, giving them a series of light shocks which caused them to become more sensitive to future stimuli. Then the researchers tested the slugs’ siphon withdrawal reflex 48 hours later. Sea slugs that had been shocked kept their siphons withdrawn for a significantly longer period of time than untrained sea slugs. This suggests that the conditioned sea slugs had formed a memory of their shocks. So far, nothing unusual. But then researchers removed RNA from the neurons of these trained sea slugs, and injected it into a new group—into sea slugs that hadn’t ever been shocked. Weirdly, even these otherwise naive sea slugs withdrew their siphons for much longer than normal when they were poked. In other words, they acted like they remembered being shocked, even though the shocks didn’t actually happen to them. These findings have been extremely controversial in the neuroscience community because they challenge the way that most researchers understand memory. For decades, scientists have believed that memories are stored in the brain’s synaptic connections. In other words, changing the connections between neurons (or groups of neurons) is what allows us to form and store memories. © 2017 Massive Science Inc.

Keyword: Learning & Memory
Link ID: 25451 - Posted: 09.15.2018

Diana Kwon Obesity is on the rise across the globe. The worldwide prevalence of the condition has nearly tripled over the last four decades, and approximately 13 percent of adults were obese in 2016. This staggering rise poses a public health concern: not only is obesity tied to bodily ailments such as cardiovascular disease and diabetes, epidemiological investigations have revealed that it is also linked to cognitive decline—and higher chances of developing dementia and other brain-related disorders later in life. Researchers have recently started to shed light on how weight gain affects the brain, and over the last few years, microglia, the brain’s resident immune cells, have emerged as the key culprit. Several rodent studies paint a picture of activated microglia gobbling up dendritic spines that form synapses in obese animals’ brains as the cause of cognitive decline. A study published today (September 10) in the Journal of Neuroscience provides strong new support for this theory. While prior studies have drawn robust associations between microglia and obesity-related cognitive decline, Elise Cope, a postdoc at Princeton University, says none had yet addressed whether those cells were actually causing the behavioral changes. “The novelty of our study was where we decided to see if blocking microglia using three different methods could actually prevent the dendritic spine loss and improve cognitive function,” Cope says. © 1986 - 2018 The Scientist.

Keyword: Obesity; Glia
Link ID: 25443 - Posted: 09.13.2018

By Elena Pasquinelli Ten years ago technology writer Nicholas Carr published an article in the Atlantic entitled “Is Google Making Us Stupid?” He strongly suspected the answer was “yes.” Himself less and less able to focus, remember things or absorb more than a few pages of text, he accused the Internet of radically changing people’s brains. And that is just one of the grievances leveled against the Internet and at the various devices we use to access it–including cell phones, tablets, game consoles and laptops. Often the complaints target video games that involve fighting or war, arguing that they cause players to become violent. But digital devices also have fervent defenders—in particular the promoters of brain-training games, who claim that their offerings can help improve attention, memory and reflexes. Who, if anyone, is right? The answer is less straightforward than you might think. Take Carr’s accusation. As evidence, he quoted findings of neuroscientists who showed that the brain is more plastic than previously understood. In other words, it has the ability to reprogram itself over time, which could account for the Internet’s effect on it. Yet in a 2010 opinion piece in the Los Angeles Times, psychologists Christopher Chabris, then at Union College, and Daniel J. Simons of the University of Illinois at Urbana-Champaign rebutted Carr’s view: “There is simply no experimental evidence to show that living with new technologies fundamentally changes brain organization in a way that affects one’s ability to focus,” they wrote. And the debate goes on. © 2018 Scientific American

Keyword: Learning & Memory; Attention
Link ID: 25440 - Posted: 09.12.2018

By James Gorman Chalk up another achievement for parrots, with an odd twist that raises questions about whether the experimenters or the birds know best. Anastasia Krasheninnikova and colleagues at the Max Planck Institute for Ornithology in Germany tested four species of parrots in an experiment that required trading tokens for food and recently reported their findings in the journal Scientific Reports. Would the birds resist an immediate reward to trade for something better? Many species have shown the ability to hold off on an immediate treat — like a dry corn kernel — for something tastier later on, like a bit of walnut. Chimpanzees, monkeys and cockatoos, among other species, can defer gratification. But using tokens for trading had not been tried before in birds, Dr. Krasheninnikova said. Here’s how it worked. First the birds, great green macaws, blue-throated macaws, blue-headed macaws and African grey parrots, learned that they could barter tokens for foods of different value — to the birds, that is. A metal hoop could be traded for a piece of dry corn, the lowest value food, a metal bracket for a medium value sunflower seed and a plastic ring for the highest value food, a piece of shelled walnut. The birds were then offered various choices, like a piece of corn or the ring. They all reliably chose to forego the corn and take the ring. Then they were able to trade the ring for a piece of walnut. © 2018 The New York Times Company

Keyword: Learning & Memory; Evolution
Link ID: 25437 - Posted: 09.11.2018

Laura Sanders Obesity can affect brainpower, and a study in mice may help explain how. In the brains of obese mice, rogue immune cells chomp nerve cell connections that are important for learning and memory, scientists report September 10 in the Journal of Neuroscience. Drugs that stop this synapse destruction may ultimately prove useful for protecting the brain against the immune cell assault. Like people, mice that eat lots of fat quickly pack on pounds. After 12 weeks of a high-fat diet, mice weighed almost 40 percent more than mice fed standard chow. These obese mice showed signs of diminished brainpower, neuroscientist Elizabeth Gould of Princeton University and colleagues found. Obese mice were worse at escaping mazes and remembering an object’s location than mice of a normal weight. On nerve cells, microscopic knobs called dendritic spines receive signals. Compared with normal-sized mice, obese mice had fewer dendritic spines in several parts of the mice’s hippocampi, brain structures important for learning and memory. The dendritic spine destruction comes from immune cells called microglia, the results suggest. In obese mice, higher numbers of active microglia lurked among these sparser nerve cell connections compared with mice of normal weights. When the researchers interfered with microglia in obese mice, dendritic spines were protected and the mice’s performance on thinking tests improved. |© Society for Science & the Public 2000 - 2018.

Keyword: Obesity; Learning & Memory
Link ID: 25431 - Posted: 09.11.2018