Chapter 17. Learning and Memory
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Dima Amso, The early years of parenthood involve so many rewarding firsts—when your infant cracks a toothless grin, when he crawls and later walks, and, of course, when he utters a real, nonbabble word. A mother once told me she found it sad that if she were to pass away suddenly, her toddler wouldn't remember her or these exciting years. It is true that most of us don't remember much, if anything, from our infancy. So at what point do children start making long-term memories? I must first explain the different types of memory we possess. As I type this, I am using procedural memory—a form of motor memory in which my fingers just know how to type. In contrast, declarative memories represent two types of long-term recall—semantic and episodic. Semantic memory allows us to remember general facts—for example, that Alfred Hitchcock directed the film Vertigo; episodic memory encompasses our ability to recall personal experiences or facts—that Vertigo is my favorite film. Episodic memories are most relevant for understanding our childhood recollections. Making an episodic memory requires binding together different details of an event—when it happened and where, how we felt and who was there—and retrieving that information later. The processes involve the medial temporal lobes, most notably the hippocampus, and portions of the parietal and prefrontal cortices, which are very important in memory retrieval. Imaging studies often show that the same regions that encode an episode—for example, the visual cortex for vivid visual experiences—are active when we recall that memory, allowing for a kind of “mental time travel” or replay of the event. © 2017 Scientific American
Riley Beggin Matt Herich uses a tDCS device that was made by another student he met on Reddit. Four 9-volt batteries and sticky self-adhesive electrodes are connected by a circuit board that sends a constant small current to the user's brain. Courtesy of Matt Herich Last October, Matt Herich was listening to the news while he drove door to door delivering pizzas. A story came on the radio about a technology that sends an electric current through your brain to possibly make you better at some things — moving, remembering, learning. He was fascinated. The neurotechnology is called transcranial direct current stimulation, or tDCS for short. At its simplest, the method involves a device that uses little more than a 9-volt battery and some electrodes to send a low-intensity electrical current to a targeted area of the brain, typically via a headset. More than a 1,000 studies have been published in peer-reviewed journals over the last decade suggesting benefits of the technique — maybe regulating mood, possibly improving language skills — but its effects, good or bad, are far from clear. Although researchers see possibilities for tDCS in treating diseases and boosting performance, it's still an exploratory technology, says Mark George, editor-in-chief of Brain Stimulation, a leading journal on neuromodulation. And leading experts have warned against at-home use of such devices. © 2017 npr
Keyword: Learning & Memory
Link ID: 23071 - Posted: 01.09.2017
By LISA FELDMAN BARRETT Think about the people in your life who are 65 or older. Some of them are experiencing the usual mental difficulties of old age, like forgetfulness or a dwindling attention span. Yet others somehow manage to remain mentally sharp. My father-in-law, a retired doctor, is 83 and he still edits books and runs several medical websites. Why do some older people remain mentally nimble while others decline? “Superagers” (a term coined by the neurologist Marsel Mesulam) are those whose memory and attention isn’t merely above average for their age, but is actually on par with healthy, active 25-year-olds. My colleagues and I at Massachusetts General Hospital recently studied superagers to understand what made them tick. Our lab used functional magnetic resonance imaging to scan and compare the brains of 17 superagers with those of other people of similar age. We succeeded in identifying a set of brain regions that distinguished the two groups. These regions were thinner for regular agers, a result of age-related atrophy, but in superagers they were indistinguishable from those of young adults, seemingly untouched by the ravages of time. What are these crucial brain regions? If you asked most scientists to guess, they might nominate regions that are thought of as “cognitive” or dedicated to thinking, such as the lateral prefrontal cortex. However, that’s not what we found. Nearly all the action was in “emotional” regions, such as the midcingulate cortex and the anterior insula. My lab was not surprised by this discovery, because we’ve seen modern neuroscience debunk the notion that there is a distinction between “cognitive” and “emotional” brain regions. © 2017 The New York Times Company
Alan Yu Being overweight can raise your blood pressure, cholesterol and risk for developing diabetes. It could be bad for your brain, too. A diet high in saturated fats and sugars, the so-called Western diet, actually affects the parts of the brain that are important to memory and make people more likely to crave the unhealthful food, says psychologist Terry Davidson, director of the Center for Behavioral Neuroscience at American University in Washington, D.C. He didn't start out studying what people ate. Instead, he was interested in learning more about the hippocampus, a part of the brain that's heavily involved in memory. He was trying to figure out which parts of the hippocampus do what. He did that by studying rats that had very specific types of hippocampal damage and seeing what happened to them. In the process, Davidson noticed something strange. The rats with the hippocampal damage would go to pick up food more often than the other rats, but they would eat a little bit, then drop it. Davidson realized these rats didn't know they were full. He says something similar may happen in human brains when people eat a diet high in fat and sugar. Davidson says there's a vicious cycle of bad diets and brain changes. He points to a 2015 study in the Journal of Pediatrics that found obese children performed more poorly on memory tasks that test the hippocampus compared with kids who weren't overweight. He says if our brain system is impaired by that kind of diet, "that makes it more difficult for us to stop eating that diet. ... I think the evidence is fairly substantial that you have an effect of these diets and obesity on brain function and cognitive function." © 2016 npr
By Drake Baer Convergent evolution is what happens when nature takes different courses from different starting points to arrive at similar results. Consider bats, birds, and butterflies developing wings; sharks and dolphins finding fins; and echidnas and porcupines sporting spines. Or, if you want to annoy a traditionalist scientist, talk about humans and octopuses — and how they may both have consciousness. This is the thrust of Other Minds: The Octopus, the Sea, and the Deep Origins of Consciousness, a new book by the scuba-diving, biology-specializing philosopher Peter Godfrey-Smith, originally of Australia and now a distinguished professor at the City University of New York’s graduate center. The book was written up by Olivia Judson in The Atlantic, and you should read the whole thing, but what I find mesmerizing is how categorically other the eight-tentacled ink-squirters are, and how their very nature challenges our conceptualizations of intelligence. “If we can make contact with cephalopods as sentient beings, it is not because of a shared history, not because of kinship, but because evolution built minds twice over,” Godfrey-Smith is quoted as saying. “This is probably the closest we will come to meeting an intelligent alien.” (He’s not the first to think so: The Hawaiian creation myth holds that octopuses are the only creatures left over from an earlier incarnation of the Earth, making them more proto-terrestrials than extraterrestrials.) © 2016, New York Media LLC.
By Laurence O’Dwyer Daniel Tammet correctly recited the first 22,514 digits of Pi over the course of five hours and nine minutes. Less well-known, but similarly impressive, is the ability of a Clark’s nutcracker (Nucifraga columbiana)—a bird commonly found along the western flanks of North America—to remember where it stores thousands of separate caches of food. Tammet, who has autism spectrum disorder, is a savant. Some researchers have proposed that Clark’s nutcrackers might also represent a type of autistic savant. However, the unique abilities of a person with an autism spectrum disorder and savant syndrome usually comes at the price of social deficits. Experts in animal cognition who have examined similar abilities in birds and other creatures maintain that nonhuman animals that exhibit savant-like behavior do not display any equivalent dysfunction. The prodigious memory of the Clark’s nutcracker seems to be accompanied by an enlarged hippocampus compared with related species of birds that have not developed caching abilities, but in all other respects the bird seems to function normally. The hippocampus is a brain structure that is crucial for memory formation. In other words, its hyper-performance in one domain does not appear to come at a cost in another. (Admittedly, it is difficult to determine whether Clark’s nutcrackers are socially competent birds.) The “gift at a price” idea stems in part from the left hemisphere dysfunction and right hemisphere compensation that is often associated with savant syndrome. © 1986-2016 The Scientist
By Veronique Greenwood Baffling grammar, strange vowels, quirky idioms and so many new words—all of this makes learning a new language hard work. Luckily, researchers have discovered a number of helpful tricks, ranging from exposing your ears to a variety of native speakers to going to sleep soon after a practice session. A pair of recent papers suggests that even when you are not actively studying, what you hear can affect your learning and that sometimes listening without speaking works best. In one study, published in 2015 in the Journal of the Acoustical Society of America, linguists found that people who took breaks from learning new sounds performed just as well as those who took no breaks, as long as the sounds continued to play in the background. The researchers trained two groups of people to distinguish among trios of similar sounds—for instance, Hindi has “p,” “b” and a third sound English speakers mistake for “b.” One group practiced telling these apart one hour a day for two days. Another group alternated between 10 minutes of the task and 10 minutes of a “distractor” task that involved matching symbols on a worksheet while the sounds continued to play in the background. Remarkably, the group that switched between tasks improved just as much as the one that focused on the distinguishing task the entire time. “There's something about our brains that makes it possible to take advantage of the things you've already paid attention to and to keep paying attention to them,” even when you are focused on something else, suggests Melissa Baese-Berk, a linguist at the University of Oregon and a co-author of the study. In a 2016 study published in the Journal of Memory and Language, Baese-Berk and another colleague found that it is better to listen to new sounds silently rather than practice saying them yourself at the same time. Spanish speakers learning to distinguish among sounds in the Basque language performed more poorly when they were asked to repeat one of the sounds during training. The findings square with what many teachers have intuited—that a combination of focused practice and passive exposure to a language is the best approach. “You need to come to class and pay attention,” Baese-Berk says, “but when you go home, turn on the TV or turn on the radio in that language while you're cooking dinner, and even if you're not paying total attention to it, it's going to help you.” © 2016 Scientific American
By Michael Price The titular detective of the BBC television series Sherlock possesses a “mind palace”—a highly organized mental catalog of nearly every memory he’s ever had. We mere mortals can’t match Holmes’s remarkable recollection, but when we store and recall memories, our brain activity probably looks a lot like his, according to a new study. The findings might help us find early warning signs of memory loss in diseases like Alzheimer’s. Previous research has found that when people perceive an event for the first time and when they are asked to remember it later, the same brain regions are activated. But whether different people encode the same memory in the same way has been a topic of debate. So scientists turned to Sherlock Holmes for answers. A group led by Janice Chen, a postdoc in the psychology department at Princeton University, and Yuan Chang Leong, a graduate student studying psychology at Stanford University in Palo Alto, California, strapped 22 study participants into a functional magnetic resonance imaging (fMRI) machine, which traces blood flow in the brain to measure brain activity. The scientists then showed them a 48-minute segment of BBC’s Sherlock. (Roughly the first half of the series’s first episode, “A Study in Pink,” for the curious superfans.) Immediately afterward, Chen asked the volunteers to tell her as much about the episode as they could. © 2016 American Association for the Advancement of Science.
Keyword: Learning & Memory
Link ID: 22956 - Posted: 12.06.2016
By CHRISTOPHER MELE Have you called your daughter by your wife’s name or your son by his brother’s name? Have you misplaced your car keys or forgotten where you parked at the mall? If you worry these might be signs of significant memory loss or the early stages of Alzheimer’s disease, which causes a slow deterioration in memory and reasoning skills, fear not, experts said. By the age of 45, the average person experiences a decline in memory, Dr. Gary W. Small, a professor of psychiatry and biobehavioral sciences at the David Geffen School of Medicine at the University of California, Los Angeles, said in an email. Forgetting facts or events over time, absent-mindedness and incorrectly recalling a detail are among six “normal” memory problems that should not cause concern, according to the Center for Brain-Mind Medicine at Brigham and Women’s Hospital in Boston. When people do experience normal memory decline related to aging, 85 percent of their complaints involve recalling people’s names, Dr. Small said. You can blame multitasking for overloading your mind. Think about the ways we are driven to distraction with smartphones and social media, for instance. “Whenever our brains are taxed by multiple demands, cognitive ‘slips’ or errors are more likely to occur due to a concept called memory ‘interference,’ ” Carrington Wendell, a neuropsychology specialist at the Anne Arundel Medical Group in Annapolis, Md., said in an email. Name mix-ups are also more likely to occur when the two names share the same beginning, middle or ending, such as Bob and Ben or Dave and Jake, and are the same sex and similar age, she added. © 2016 The New York Times Company
By PETER GODFREY-SMITH Around 2008, while snorkeling and scuba diving in my free time, I began watching the unusual group of animals known as cephalopods, the group that includes octopuses, cuttlefish and squid. The first ones I encountered were giant cuttlefish, large animals whose skin changes color so quickly and completely that swimming after them can be like following an aquatic, multi-armed television. Then I began watching octopuses. Despite being mollusks, like clams and oysters, these animals have very large brains and exhibit a curious, enigmatic intelligence. I followed them through the sea, and also began reading about them, and one of the first things I learned came as a shock: They have extremely short lives — just one or two years. I was already puzzled by the evolution of large brains in cephalopods, and this discovery made the questions more acute. What is the point of building a complex brain like that if your life is over in a year or two? Why invest in a process of learning about the world if there is no time to put that information to use? An octopus’s or cuttlefish’s life is rich in experience, but it is incredibly compressed. The particular puzzle of octopus life span opens up a more general one. Why do animals age? And why do they age so differently? A scruffy-looking fish that inhabits the same patch of sea as my cephalopods has relatives who live to 200 years of age. This seems extraordinarily unfair: A dull-looking fish lives for centuries while the cuttlefish, in their chromatic splendor, and the octopuses, in their inquisitive intelligence, are dead before they are 2? There are monkeys the size of a mouse that can live for 15 years, and hummingbirds that can live for over 10. Nautiluses (who are also cephalopods) can live for 20 years. A recent Nature paper reported that despite continuing medical advances, humans appear to have reached a rough plateau at around 115 years, though a few people will edge beyond it. The life spans of animals seem to lack all rhyme or reason. © 2016 The New York Times Company
By Jessica Boddy Memory researchers have shone light into a cognitive limbo. A new memory—the name of someone you've just met, for example—is held for seconds in so-called working memory, as your brain's neurons continue to fire. If the person is important to you, the name will over a few days enter your long-term memory, preserved by permanently altered neural connections. But where does it go during the in-between hours, when it has left your standard working memory and is not yet embedded in long-term memory? In Science, a research team shows that memories can be resurrected from this limbo. Their observations point to a new form of working memory, which they dub prioritized long-term memory, that exists without elevated neural activity. Consistent with other recent work, the study suggests that information can somehow be held among the synapses that connect neurons, even after conventional working memory has faded. "This is a really fundamental find—it's like the dark matter of memory," says Geoffrey Woodman, a cognitive neuroscientist at Vanderbilt University in Nashville who was not involved with the work. "It's hard to really see it or measure it in any clear way, but it has to be out there. Otherwise, things would fly apart." Cognitive neuroscientist Nathan Rose and colleagues at the University of Wisconsin (UW) in Madison initially had subjects watch a series of slides showing faces, words, or dots moving in one direction. They tracked the resulting neural activity using functional magnetic resonance imaging (fMRI) and, with the help of a machine learning algorithm, showed they could classify the brain activity associated with each item. Then the subjects viewed the items in combination—a word and face, for example—but were cued to focus on just one item. At first, the brain signatures of both items showed up, as measured in this round with electroencephalography (EEG). But neural activity for the uncued item quickly dropped to baseline, as if it had been forgotten, whereas the EEG signature of the cued item remained, a sign that it was still in working memory. Yet subjects could still quickly recall the uncued item when prompted to remember it a few seconds later. © 2016 American Association for the Advancement of Science.
Keyword: Learning & Memory
Link ID: 22947 - Posted: 12.03.2016
Rosie Mestel The 2016 US election was a powerful reminder that beliefs tend to come in packages: socialized medicine is bad, gun ownership is a fundamental right, and climate change is a myth — or the other way around. Stances that may seem unrelated can cluster because they have become powerful symbols of membership of a group, says Dan Kahan, who teaches law and psychology at Yale Law School in New Haven, Connecticut. And the need to keep believing can further distort people’s perceptions and their evaluation of evidence. Here, Kahan tells Nature about the real-world consequences of group affinity and cognitive bias, and about research that may point to remedies. This interview has been edited for length and clarity. One measure is how individualistic or communitarian people are, and how egalitarian or hierarchical. Hierarchical and individualistic people tend to have confidence in markets and industry: those represent human ingenuity and power. People who are egalitarian and communitarian are suspicious of markets and industry. They see them as responsible for social disparity. It’s natural to see things you consider honourable as good for society, and things that are base, as bad. Such associations will motivate people’s assessment of evidence. Can you give an example? In a study, we showed people data from gun-control experiments and varied the results1. People who were high in numeracy always saw when a study supported their view. If it didn’t support their view, they didn’t notice — or argued their way out of it. © 2016 Macmillan Publishers Limited
Anya Kamenetz Brains, brains, brains. One thing we've learned at NPR Ed is that people are fascinated by brain research. And yet it can be hard to point to places where our education system is really making use of the latest neuroscience findings. But there is one happy nexus where research is meeting practice: bilingual education. "In the last 20 years or so, there's been a virtual explosion of research on bilingualism," says Judith Kroll, a professor at the University of California, Riverside. Again and again, researchers have found, "bilingualism is an experience that shapes our brain for a lifetime," in the words of Gigi Luk, an associate professor at Harvard's Graduate School of Education. At the same time, one of the hottest trends in public schooling is what's often called dual-language or two-way immersion programs. Traditional programs for English-language learners, or ELLs, focus on assimilating students into English as quickly as possible. Dual-language classrooms, by contrast, provide instruction across subjects to both English natives and English learners, in both English and in a target language. The goal is functional bilingualism and biliteracy for all students by middle school. New York City, North Carolina, Delaware, Utah, Oregon and Washington state are among the places expanding dual-language classrooms. © 2016 npr
By Andy Coghlan Don’t go to bed angry. Now there’s evidence for this proverb: it’s harder to suppress bad memories if you sleep on them. The discovery could reveal new ways to treat people who suffer from conditions like post-traumatic stress disorder, and reinforces an earlier idea that it is possible to suppress bad memories through sleep deprivation. “The results are of major interest for treating the frequent clinical problem of unwanted memories, memories of traumatic events being the most prominent example,” says Christoph Nissen at the University of Freiburg Medical Center in Germany, who was not involved in the work. In the study, 73 male students memorised 26 mugshots, each paired with a disturbing image, such as a mutilated body, corpse or crying child. The next day they were asked to recall the images associated with half the mugshots and actively try to exclude memories of the rest of the associated images. The group were then directed to memorise another 26 pairs of mugshots and nasty images. Half an hour later they again thought about half the associated images and actively suppressed memories of the rest. Finally, they were asked to describe the image associated with each of the 52 mugshots. The idea was to see if trying to suppress a bad memory works better before or after sleep. © Copyright Reed Business Information Ltd.
By Virginia Morell At last, scientists may have an answer to a question every dog owner asks: Does your pet remember the things you do together? For people, at least, the ability to consciously recall personal experiences and events is thought to be linked to self-awareness. It shapes how we think about the past—and how we predict the future. Now, a new study suggests that dogs also have this type of memory, indicating that the talent may be more common in other animals than previously recognized. The study, “is a creative approach to trying to capture what’s on a dog’s mind,” says Alexandra Horowitz, a dog cognition scientist at Barnard College in New York City who was not involved in the research. The idea that nonhuman animals can consciously remember things they’ve done or witnessed in the past, called episodic memory, is controversial—largely because it’s thought that these animals aren’t self-aware. But scientists have shown that species like Western scrub jays, hummingbirds, rats, and the great apes—those that have to recall complex sequences of information in order to survive—have “episodiclike” memory. For instance, the jays remember what food they’ve hidden, where they stashed it, when they did so, and who was watching while they did it. But what about recalling things that aren’t strictly necessary for survival, or someone else’s actions? To find out whether dogs can remember such details, scientists asked 17 owners to teach their pets a trick called “do as I do.” The dogs learned, for instance, that after watching their owner jump in the air, they should do the same when commanded to “do it!” © 2016 American Association for the Advancement of Science.
Keyword: Learning & Memory
Link ID: 22906 - Posted: 11.25.2016
Ian Sample Science editor A leading psychologist whose research on human memory exposed her to death threats, lawsuits, personal abuse and a campaign to have her sacked has won a prestigious prize for her courage in standing up for science. Professor Elizabeth Loftus endured a torrent of abuse from critics who objected to her work on the unreliable nature of eyewitness testimonies, and her defining research on how people can develop rich memories for events that never happened. The work propelled Loftus into the heart of the 1990 “memory wars”, when scores of people who had gone into therapy with depression, eating disorders and other common psychological problems, came out believing they had recovered repressed memories for traumatic events, often involving childhood abuse. Loftus, now a professor of law and cognitive science at the University of California, Irvine, performed a series of experiments that showed how exposure to inaccurate information and leading questions could corrupt eyewitness testimonies. More controversially, she demonstrated how therapy and hypnosis could plant completely false childhood memories in patients. She went on to become an expert witness or consultant for hundreds of court cases. In the 1990s, thousands of repressed memory cases came to light, with affected patients taking legal action against family members, former neighbours, doctors, dentists and teachers. The accusations tore many families apart. As an expert witness in such cases, Loftus came under sustained attack from therapists and patients who were convinced the new-found memories were accurate. The abuse marked a distinct shift away from the good-natured debates she was used to having in academic journals. © 2016 Guardian News and Media Limited
Keyword: Learning & Memory
Link ID: 22890 - Posted: 11.19.2016
By Jessica Hamzelou You’ve got a spare hour before a big exam. How should you spend it? It seems napping is just as effective as revising, and could even have a longer-lasting impact. Repeatedly revising information to learn it makes sense. “Any kind of reactivation of a memory trace will lead to it being strengthened and reconsolidated,” says James Cousins at the Duke-NUS Medical School in Singapore. “With any memory, the more you recall it, the stronger the memory trace.” However, sleep is also thought to be vital for memory. A good night’s sleep seems to help our brains consolidate what we’ve learned in the day, and learning anything when you’re not well rested is tricky. Many people swear by a quick afternoon kip. So if you’ve got an hour free, is it better to nap or revise? Cousins, along with Michael Chee and their colleagues, also at Duke-NUS Medical School, set out to compare the two options. The team mocked-up a real student experience, and had 72 volunteers sit through presentations of about 12 different species of ants and crabs. The participants were asked to learn all about these animals, including their diets and habitats, for example. After 80 minutes of this, the students were given an hour to either watch a film, have a nap, or revise what they had just learned. After this hour, they had another 80 minutes of learning. Then they had to sit an exam in which they were asked 360 questions about the ants and the crabs. “The napping group got the best scores,” says Cousins, whose work was presented at the Society for Neuroscience annual meeting in San Diego, California on Tuesday. © Copyright Reed Business Information Ltd.
Kathleen Taylor The global rise in dementia should surprise no one. The figures — such as the 9.9 million new diagnoses each year — have been known for decades. As slow as we are to accept such vast changes on a personal, societal and political level, so research is slow to uncover why our brains become fragile with age. Neuroscientist and writer Kathleen Taylor's The Fragile Brain is about that research. But it is much more than a simple reflection on the best published hypotheses. Taylor has crafted a personal, astonishingly coherent review of our current state of knowledge about the causes of Alzheimer's disease and dementia, as well as possible solutions, from lifestyle adjustments to drug developments. Filled with elegant metaphors, her study covers the detail of molecular biology and larger-scale analysis, including epidemiological observations and clinical studies. It extends to dementia due to multiple sclerosis, stroke and encephalitis. For instance, some 5–30% of people who have a first stroke develop dementia. But the book's focus is Alzheimer's disease, and rightly so: it is what up to 80% of people with dementia are diagnosed with. Taylor begins with a shocking juxtaposition, setting the costs of age-related disorders and of dementia alongside the scarcity in funding. In Britain, Australia and the United States, for example, funding for dementia research is a fraction of that for cancer — in the United States, just 18%. She contextualizes with reflections on the history of dementia research, deftly unravelling the roles of pioneering scientists Alois Alzheimer, Franz Nissl and Emil Kraepelin in describing the condition. © 2016 Macmillan Publishers Limited,
By Marian Vidal-Fernandez, Ana Nuevo-Chiquero, The title of this article might trigger self-satisfied smiles among first-borns, and some concerns among the rest of us. Many studies show children born earlier in the family enjoy better wages and more education, but until now we didn’t really know why. Our recently published findings are the first to suggest advantages of first born siblings start very early in life—around zero to three years old! We observe parents changing their behaviour as new children are born, and offering less cognitive stimulation to children of higher birth order. It now seems clear that for those born and raised in high-income countries such as the United States, the UK and Norway, earlier-born children enjoy higher wages and education as adults—known as the “birth order effect”. Comparing two siblings, the greater the difference in their birth order, the greater the relative benefit to the older child. However, to date we’ve had no evidence that explains where such differences come from. We know it’s not an effect of family size, because the effect remains when comparing siblings within the same family and families with the same number of children. While it makes sense that parents earn more money and gain experience as they get older and have more children, they also need to divide their economic resources and attention among any children that arrive after the first born. We wondered where in childhood these differences began, and what the cause or causes might be. © 2016 Scientific American,
Laura Sanders A protein that can switch shapes and accumulate inside brain cells helps fruit flies form and retrieve memories, a new study finds. Such shape-shifting is the hallmark move of prions — proteins that can alternate between two forms and aggregate under certain conditions. In fruit flies’ brain cells, clumps of the prionlike protein called Orb2 stores long-lasting memories, report scientists from the Stowers Institute for Medical Research in Kansas City, Mo. Figuring out how the brain forms and calls up memories may ultimately help scientists devise ways to restore that process in people with diseases such as Alzheimer’s. The new finding, described online November 3 in Current Biology, is “absolutely superb,” says neuroscientist Eric Kandel of Columbia University. “It fills in a lot of missing pieces.” People possess a version of the Orb2 protein called CPEB, a commonality that suggests memory might work in a similar way in people, Kandel says. It’s not yet known whether people rely on the prion to store long-term memories. “We can’t be sure, but it’s very suggestive,” Kandel says. When neuroscientist Kausik Si and colleagues used a genetic trick to inactivate Orb2 protein, male flies were worse at remembering rejection. These lovesick males continued to woo a nonreceptive female long past when they should have learned that courtship was futile. In different tests, these flies also had trouble remembering that a certain odor was tied to food. |© Society for Science & the Public 2000 - 2016. All rights reserved.