Links for Keyword: Learning & Memory

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Arc protein 'could be key to memory loss', says study

Scientists have discovered more about the role of an important brain protein which is instrumental in translating learning into long-term memories. Writing in Nature Neuroscience, they said further research into the Arc protein's role could help in finding new ways to fight neurological diseases. The same protein may also be a factor in autism, the study said. Recent research found Arc lacking in the brains of Alzheimer's patients. Dr Steve Finkbeiner, professor of neurology and physiology at the University of California, who led the research at Gladstone Institutes, said lab work showed that the role of the Arc protein was crucial. "Scientists knew that Arc was involved in long-term memory, because mice lacking the Arc protein could learn new tasks, but failed to remember them the next day," he said. Further experiments revealed that Arc acted as a "master regulator" of the neurons during the process of long-term memory formation. The study explained that during memory formation, certain genes must be switched on and off at very specific times in order to generate proteins that help neurons lay down new memories. The authors found that it was Arc that directed this process, from inside the nucleus. Dr Finkbeiner said people who lack the protein could have memory problems. BBC © 2013

Related chapters from BP6e: Chapter 17: Learning and Memory; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 13: Memory, Learning, and Development
Link ID: 18253 - Posted: 06.10.2013

Decoding Space and Time in the Brain

By Aiden Arnold “…henceforth, space by itself, and time by itself, are doomed to fade away into mere shadows, and only a kind of union between the two will preserve an independent reality.” This now iconic quote spoken by Hermann Minkowski in 1906 captured the spirit of Albert Einstein’s recently published special theory of relativity. Einstein, in a stroke of mathematical genius, had shown that both space and time as independent mathematical constructs were mere illusions in the equations of relativity, conceding instead to a 4-dimensional construct which Minkowski adroitly termed space-time. While most people are familiar with the ensuing influence Einstein’s ideas had on both the academic and public conception of the physical universe, few people are aware a similar revolution against space and time is underway in the fields of experimental psychology and neuroscience. Spatial cognition is the study of how the mind’s cognitive architecture perceives, organizes and interacts with physical space. It has long been of interest to philosophers and scientists, with perhaps the biggest historical step towards our modern ideas occurring within Immanuel Kant’s Critique of Pure Reason (1781/1787). Kant argued that space as we know it is a preconscious organizing feature of the human mind, a scaffold upon which we’re able to understand the physical world of objects, extension and motion. In a sense, space to Kant was a window into the world, rather than a thing to be perceived in it. © 2013 Scientific American

Forgetting Is Harder for Older Brains

By Ian Chant Kids are wildly better than adults at most types of learning—most famously, new languages. One reason may be that adults' brains are “full,” in a way. Creating memories relies in part on the destruction of old memories, and recent research finds that adults have high levels of a protein that prevents such forgetting. Whenever we learn something, brain cells become wired together with new synapses, the connections between neurons that enable communication. When a memory fades, those synapses weaken. Researchers led by Joe Tsien, a neuroscientist at the Medical College of Georgia, genetically engineered mice to have high levels of NR2A, part of a receptor on the surface of some neurons that regulates the flow of chemicals such as magnesium and calcium in and out of a cell. NR2A is known to be more prevalent in the brains of mammals as they age. The engineered mice, though young, had adult levels of NR2A, and they showed some difficulty forming long-term memories. More dramatically, their brains could barely weaken their synapses, a process that allows the loss of useless information in favor of more recent data. A similar process may govern short-term memories as well. When you hear a friend ask for coffee, the details of her order don't just slip away in your mind—your brain must produce a protein that actively destroys the synapses encoding that short-term memory, according to a 2010 paper in Cell. Much psychological research supports the idea that forgetting is essential to memory and emotional health. Tsien's new work, published January 8 in Scientific Reports, suggests that older brains hold on to their connections more dearly—which helps to explain why learning is more laborious as we age and why memory trouble later in life so often involves the accidental recall of outdated information. © 2013 Scientific American

Who Was H.M.? Inside The Mind Of The Amnesiac Who Revolutionized Neuroscience

By Suzanne Corkin My friend’s father was a neurosurgeon. As a child, I had no idea what a neurosurgeon did. Years later, when I was a graduate student in the Department of Psychology at McGill University, this man reentered my life. While reading articles on memory in medical journals, I came across a report by a doctor who had performed a brain operation to cure a young man’s intractable epilepsy. The operation caused the patient to lose his capacity to establish new memories. The doctor who coauthored the article was my friend’s father, William Beecher Scoville. The patient was Henry. This childhood connection to Henry’s neurosurgeon made reading about the “amnesic patient, H.M.” more compelling. Later, when I joined Brenda Milner’s laboratory at the Montreal Neurological Institute, Henry’s case fell into my lap. For my PhD thesis, I was able to test him in 1962 when he came to Milner’s lab for scientific study. She had been the first psychologist to test Henry after his operation, and her 1957 paper with Scoville, describing Henry’s operation and its awful consequences, revolutionized the science of memory. I was trying to expand the scientific understanding of Henry’s amnesia by examining his memory through his sense of touch, his somatosensory system. My initial investigation with him was focused and brief, lasting one week. After I moved to MIT, however, Henry’s extraordinary value as a research participant became clear to me, and I went on to study him for the rest of his life, forty-six years. Since his death, I have dedicated my work to linking fifty-five years of rich behavioral data to what we will learn from his autopsied brain. © 2012 Popular Science

Related chapters from BP6e: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 18201 - Posted: 05.30.2013

Neuron growth in children 'leaves no room for memories'

The reason we struggle to recall memories from our early childhood is down to high levels of neuron production during the first years of life, say Canadian researchers. The formation of new brain cells increases the capacity for learning but also clears the mind of old memories. The findings were presented to the Canadian Association of Neuroscience. An expert at City University in London said the mouse study called into question some psychological theories. Neurogenesis, or the formation of new neurons in the hippocampus - a region of the brain known to be important for learning and remembering, reaches its peak before and after birth. It then declines steadily during childhood and adulthood. Dr Paul Frankland and Dr Sheena Josselyn, from the Hospital for Sick Children in Toronto and the University of Toronto, wanted to find out how the process of new neuron generation impacted on memory storage. They carried out their research on younger and older mice in the lab. Early amnesia In adult mice, they found that increasing neurogenesis after memory formation was enough to bring about forgetting. In infant mice, they discovered that decreasing neurogenesis after memory formation meant that the normal forgetting observed at this age did not occur. Their research suggests a direct link between a reduction in neuron growth and increased memory recall. They found the opposite to be true also - a decreased ability to remember when neurogenesis is increased (as happens during infancy). BBC © 2013

10,000 Hours May Not Make a Master After All

By Maia Szalavitz There are many roads to greatness, but logging 10,000 hours of practice to help you perfect a skill may not be sufficient. Based on research suggesting that practice is the essence of genius, best-selling author Malcolm Gladwell popularized the idea that 10,000 hours of appropriately guided practice was “the magic number of greatness,” regardless of a person’s natural aptitude. With enough practice, he claimed in his book Outliers, anyone could achieve a level of proficiency that would rival that of a professional. It was just a matter of putting in the time. But in the years since Gladwell first pushed the “10,000-hours rule,” researchers have engaged in a spirited debate over what that rule entails. It’s clear that not just any practice, but only dedicated and intensive honing of skills that counts. And is there magic in that 10,000th hour? In an attempt to answer some of these questions, and to delve further into how practice leads to mastery, Zach Hambrick, associate professor of psychology at Michigan State University, and his colleagues decided to study musicians and chess players. It helps that both skills are amenable to such analysis because players can be ranked almost objectively. So in their research, which was published in the journal Intelligence, they reanalyzed data from 14 studies of top chess players and musicians. They found that for musicians, only 30% of the variance in their rankings as performers could be accounted for by how much time they spent practicing. For chess players, practice only accounted for 34% of what determined the rank of a master player. © 2013 Time Inc. All rights reserved

Related chapters from BP6e: Chapter 17: Learning and Memory; Chapter 1: Biological Psychology: Scope and Outlook
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 1: An Introduction to Brain and Behavior
Link ID: 18182 - Posted: 05.22.2013

Still Charting Memory’s Depths

By CLAUDIA DREIFUS MONTREAL — In many ways, the Obama administration’s new plan to map the human brain has its origins in the work of Brenda Milner, the neuropsychologist whose detailed observations of an amnesia patient in the 1950s showed how memory is rooted in specific regions of the brain. “Prior to Brenda Milner’s discoveries, many behaviorists and some cognitive psychologists followed the lead of Freud and Skinner in abandoning biology as a useful guide to the study of memory,” the Nobel laureate Dr. Eric Kandel wrote in his memoir, “In Search of Memory.” “Milner’s work changed all that.” The amnesia patient, Henry Molaison (known during his lifetime only as H.M., to protect his privacy), died at 82 in 2008; his brain is now being dissected and digitally mapped in exquisite detail. But Dr. Milner is still very much alive. Two months short of her 95th birthday, she puts in full days at the Montreal Neurological Institute and Hospital, where she is studying left/right brain differences. We spoke in her offices here at “the Neuro” and at the annual meeting of the American Association for the Advancement of Science in Boston. Here is a condensed and edited version of the conversations. How did you come to work with H.M., perhaps the most famous patient in the history of neuroscience? In 1950, while working on a doctorate at McGill, I went to work here at the Montreal Neurological Institute to study the patients of Dr. Wilder Penfield. He’d created the Neuro as a place to pioneer the neurosurgical treatment of epilepsy. He’d developed a procedure for patients who were having epileptic seizures because of brain injuries where he’d excise the injured part of the brain. © 2013 The New York Times Company

Related chapters from BP6e: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 18181 - Posted: 05.21.2013

Trouble With Math? Maybe You Should Get Your Brain Zapped

by Emily Underwood If you are one of the 20% of healthy adults who struggle with basic arithmetic, simple tasks like splitting the dinner bill can be excruciating. Now, a new study suggests that a gentle, painless electrical current applied to the brain can boost math performance for up to 6 months. Researchers don't fully understand how it works, however, and there could be side effects. The idea of using electrical current to alter brain activity is nothing new—electroshock therapy, which induces seizures for therapeutic effect, is probably the best known and most dramatic example. In recent years, however, a slew of studies has shown that much milder electrical stimulation applied to targeted regions of the brain can dramatically accelerate learning in a wide range of tasks, from marksmanship to speech rehabilitation after stroke. In 2010, cognitive neuroscientist Roi Cohen Kadosh of the University of Oxford in the United Kingdom showed that, when combined with training, electrical brain stimulation can make people better at very basic numerical tasks, such as judging which of two quantities is larger. However, it wasn't clear how those basic numerical skills would translate to real-world math ability. © 2010 American Association for the Advancement of Science

Related chapters from BP6e: Chapter 17: Learning and Memory; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 14: Attention and Consciousness
Link ID: 18168 - Posted: 05.18.2013

New memories filmed in action for first tim

by Douglas Heaven Got a memory like a fish? The first study to visualise live memory retrieval in the whole brain has not only debunked the "three-second memory" myth, but also sheds light on the brain processes involved in forming long-term memories. Even the haziest recollections have a physical basis in the brain, but the mechanisms behind the formation and retrieval of memories are not well understood. By working with zebrafish, which are small and partially transparent, Hitoshi Okamoto at the RIKEN Brain Science Institute in Wako, Japan, and colleagues were able to study the whole brain at once. This allowed them to observe the roles played by different brain regions as a memory was retrieved. The team used fish with a genetically engineered fluorescent protein in the brain that glows less brightly when calcium levels increase – which occurs when neurons fire. They were able to study the activity of these proteins under a microscope. First, the team trained a group of fish to respond to a visual cue to avoid a small electric shock. Each fish was placed in a tank containing two compartments. When a red light shone in one compartment the fish had to swim to the other to avoid the shock. The researchers then selected the fish that had learned to perform the avoidance task successfully at least 80 per cent of the time and looked at the activity in their brains while a red light was switched on and off. © Copyright Reed Business Information Ltd.

Related chapters from BP6e: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 18167 - Posted: 05.18.2013

Cognitive Chickens and Memorable Sea Slugs

By Jason G. Goldman There is a rich tradition in psychology and neuroscience of using animals as models for understanding humans. Humans, after all, are enormously complicated creatures to begin even from a strictly biological perspective. Tacking on the messiness that comes with culture makes the study of the human mind tricky, at best. So, just as biomedical scientists have relied upon the humble mouse, psychological and cognitive scientists have too turned to our evolutionary cousins in the animal kingdom as a means of better understanding ourselves. In her new book Animal Wise, journalist Virginia Morrell recounts a conversation with one researcher who pointed out that decades of research were built upon “rats, pigeons, and college sophomores, preferably male.” The college undergrads stood in for all of humanity, the rats served as representatives of all other mammals, and pigeons served as a model for the rest of the animal kingdom. The silly part isn’t that non-human animals can be used effectively as a means of understanding more about our own species. The idea is simple: understand how a simple system works, and you can make careful inferences about the way that complex systems work. That is (or should be) obvious. In his interview with CNN today, memory research pioneer and Nobel Prize winner Eric Kandel said as much: “Rather than studying the most complex form of memory in a very complicated animal, we had to take the most simple form — an implicit form of memory — in a very simple animal.” © 2013 Scientific American

Related chapters from BP6e: Chapter 17: Learning and Memory; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 18161 - Posted: 05.16.2013

Brain training technique gets a critique

By Bruce Bower Provocative evidence that certain memory exercises make people smarter has sparked the rise of online brain-training programs such as Lumosity. But at least one type of brain training may not work as advertised, a new study finds. As expected, practicing improved volunteers’ performance on tests of memory and the ability to locate items quickly in busy scenes, say psychologist Thomas Redick of Indiana University Purdue University Columbus and his colleagues. That improvement did not, however, translate into higher scores on tests of intelligence and multitasking, the researchers report in the May Journal of Experimental Psychology: General. Redick’s investigation is part of a growing scientific debate about brain training, which is promoted by some companies as having a variety of mental benefits. Some researchers say that extensive instruction and training on memory tasks can indeed fortify reasoning and problem solving. Others are skeptical that vigorous memory sessions produce such wide-ranging effects. The dispute feeds into a longstanding scientific controversy about whether enriched environments can increase intelligence, as measured on IQ tests. What’s not up for debate is that many people feel smarter after brain training. In the new study, 10 of 23 individuals who completed memory sessions said that the program helped them to think, multitask and focus better in daily life. But the scientists say that even if some participants performed daily tasks better after memory training, they may simply have tried harder or felt better about their efforts due to a belief that training had strengthened their minds. © Society for Science & the Public 2000 - 2013

Related chapters from BP6e: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 18140 - Posted: 05.11.2013

A little brain training goes a long way

Alla Katsnelson People who use a ‘brain-workout’ program for just 10 hours have a mental edge over their peers even a year later, researchers report today in PLoS ONE1. The search for a regimen of mental callisthenics to stave off age-related cognitive decline is a booming area of research — and a multimillion-dollar business. But critics argue that even though such computer programs can improve performance on specific mental tasks, there is scant proof that they have broader cognitive benefits. For the study, adults aged 50 and older played a computer game designed to boost the speed at which players process visual stimuli. Processing speed is thought to be “the first domino that falls in cognitive decline”, says Fredric Wolinsky, a public-health researcher at the University of Iowa in Iowa City, who led the research. The game was developed by academic researchers but is now sold under the name Double Decision by Posit Science, based in San Francisco, California. (Posit did not fund the study.) Players are timed on how fast they click on an image in the centre of the screen and on others that appear around the periphery. The program ratchets up the difficulty as a player’s performance improves. Participants played the training game for 10 hours on site, some with an extra 4-hour ‘booster’ session later, or for 10 hours at home. A control group worked on computerized crossword puzzles for 10 hours on site. Researchers measured the mental agility of all 621 subjects before the brain training began, and again one year later, using eight well-established tests of cognitive performance. © 2013 Nature Publishing Group

Brain measurements predict math progress with tutoring

By Meghan Rosen A child who is good at learning math may literally have a head for numbers. Kids’ brain structures and wiring are associated with how much their math skills improve after tutoring, researchers report April 29 in the Proceedings of the National Academy of Sciences. Certain measures of brain anatomy were even better at judging learning potential than traditional measures of ability such as IQ and standardized test results, says study author Kaustubh Supekar of Stanford University. These signatures include the size of the hippocampus — a string bean–shaped structure involved in making memories — and how connected the area was with other parts of the brain. The findings suggest that kids struggling with their math homework aren’t necessarily slacking off, says cognitive scientist David Geary of the University of Missouri in Columbia. “They just may not have as much brain region devoted to memory formation as other kids.” The study could give scientists clues about where to look for sources of learning disabilities, he says. Scientists have spent years studying brain regions related to math performance in adults, but how kids learn is still “a huge question,” says Supekar. He and colleagues tested IQ and math and reading performance in 24 8- and 9-year-olds, then scanned their brains in an MRI machine. The scans measured the sizes of different brain structures and the connections among them. “It’s like creating a circuit diagram,” says study leader Vinod Menon, also of Stanford. © Society for Science & the Public 2000 - 2013

Humans are not the only copycats

Karen Ravn Birds of a feather may flock together, but do birds that flock together develop distinct cultures? Two studies published today in Science1, 2 find strong evidence that, at the very least, monkeys that troop together and whales that pod together do just that. And they manage it in the same way that humans do: by copying and learning from each other. A team led by Erica van de Waal, a primate psychologist at the University of St Andrews, UK, created two distinct cultures — 'blue' and 'pink' — among groups of wild vervet monkeys (Chlorocebus aethiops) in South Africa1. The researchers trained two sets of monkeys to eat maize (corn) dyed one of those two colours but eschew maize dyed the other colour. The scientists then waited to see how the groups behaved when newcomers — babies and migrating males — arrived. Both sets of newcomers seemed to follow social cues when selecting their snacks. Baby monkeys ate the same colour maize as their mothers. Seven of the ten males that migrated from one colour culture to another adopted the local colour preference the first time that they ate any maize. The trend was even stronger when they first fed with no higher-ranking monkey around, with nine of the ten males choosing the locally preferred variety. The only immigrant to buck this trend was a monkey who assumed the top rank in his new group as soon as he got there — and he may not have given a fig what anyone else ate. “The take-home message is that social learning — learning from others rather than through individual trial and error — is a more potent force in shaping wild animals’ behaviour than has been recognized so far,” says Andrew Whiten, an evolutionary and developmental psychologist at St Andrews and co-author of the paper. © 2013 Nature Publishing Group

Related chapters from BP6e: Chapter 6: Evolution of the Brain and Behavior; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 18079 - Posted: 04.27.2013

Clenching your fists creates a stronger memory

By Meghan Holohan Need to remember some important facts for that big presentation at work? Clench your right hand while preparing to remember. When giving that talk, ball up your left hand and you’ll call to mind those details, no problem. That’s the finding from a new study authored by Ruth Propper, an associate professor and director of the cerebral lateralization laboratory at Montclair State University. Propper has long been intrigued by how body movements impact how the brain works. While most people realize that the brain influences the body (the brain tells your arm there is an itch, and you feel it), less is understood about how the body sways the brain. Past research suggests that clenching our hands can evoke emotions. When people ball up their right hands, for example, the left sides of their brains become more active, causing what’s known as “approach emotions,” feelings such as happiness or excitement. By squeezing the left hand, people engage the right side of the brain, which controls “withdrawal emotions” such as introversion, fear, or anxiety. (It probably seems like these might be less useful, but they come in handy in dangerous situations.) Propper theorized that if clenching hands impacted feelings, these gestures might influence the brain in other ways. © 2013 NBCNews.com

Related chapters from BP6e: Chapter 17: Learning and Memory; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 15: Language and Our Divided Brain
Link ID: 18071 - Posted: 04.25.2013

Memory drug trialled in people with Down's syndrome

by Simon Makin The first drug specifically designed to improve cognitive impairment in Down's syndrome is being tested in humans. David Nutt, former drug policy adviser to the UK government, told delegates at the Festival of Neuroscience in London yesterday that he is collaborating with pharmaceutical company Roche in trials of a substance it developed, called RG1662. RG1662 reverses the effects of a chemical messenger in the brain called GABA – a neurotransmitter that inhibits brain activity. The drug acts on a specific type of brain receptor found mostly in the hippocampus, a part of the brain involved in memory. It is thought that it will reduce excessive inhibition in the hippocampus, thought to underlie memory and learning problems commonly seen in people with Down's. The study is currently assessing safety and tolerability of the drug in 33 adults with Down's, but researchers will also measure motor skills, reaction time and memory, and compare the results with those of people taking a placebo. The aim is to find appropriate doses to use in a full clinical trial, which Nutt says should happen this year. Roche said in a statement that RG1662 may help people with Down's as it has "a unique pharmacology that enables the targeting of GABA over-activity mainly in brain systems important for cognition, learning and memory". © Copyright Reed Business Information Ltd

Getting a Brain Boost Through Exercise

By GRETCHEN REYNOLDS Two new experiments, one involving people and the other animals, suggest that regular exercise can substantially improve memory, although different types of exercise seem to affect the brain quite differently. The news may offer consolation for the growing numbers of us who are entering age groups most at risk for cognitive decline. It was back in the 1990s that scientists at the Salk Institute for Biological Studies in La Jolla, Calif., first discovered that exercise bulks up the brain. In groundbreaking experiments, they showed that mice given access to running wheels produced far more cells in an area of the brain controlling memory creation than animals that didn’t run. The exercised animals then performed better on memory tests than their sedentary labmates. Since then, scientists have been working to understand precisely how, at a molecular level, exercise improves memory, as well as whether all types of exercise, including weight training, are beneficial. The new studies provide some additional and inspiring clarity on those issues, as well as, incidentally, on how you can get lab rats to weight train. For the human study, published in The Journal of Aging Research, scientists at the University of British Columbia recruited dozens of women ages 70 to 80 who had been found to have mild cognitive impairment, a condition that makes a person’s memory and thinking more muddled than would be expected at a given age. Mild cognitive impairment is also a recognized risk factor for increasing dementia. Seniors with the condition develop Alzheimer’s disease at much higher rates than those of the same age with sharper memories. Copyright 2013 The New York Times Company

Related chapters from BP6e: Chapter 17: Learning and Memory; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 5: The Sensorimotor System
Link ID: 18015 - Posted: 04.10.2013

Building on Experience

By Felicity Muth This move from my old site to the Scientific American network has also coincided with my own physical move from the UK to the USA to start some new research. Given this is the closing of a chapter of my life (or rather, my PhD thesis, which will now no doubt sit on a dusty shelf somewhere until a grad student picks it up in 10 years time to use as a door stop), I felt now might be an appropriate time to write a little bit about what I have been doing for the past three years. In the past I have only written about other people’s research, but given that I am now a few months beyond the shock (I will resist using the word ‘trauma’ here) of it ‘all being over’, I feel like it might be time now to share a bit of what I did over my PhD. In one of my first meetings with my PhD supervisor, she said to me, ‘The way that I see it, you can either spend three months reading the limited amount of literature in your subject area, or you can go to Africa and get some data for yourself.’ This may have been the point where I realised I had chosen a good topic to study. Not only did not having much ‘literature’ to read due to the dearth of previous work done on this topic mean that I could kid myself that I was an ‘expert’ in the field after a few weeks, it was also liberating to know that most experiments that I carried out would be finding out new things. So, even before moving my books into my new PhD office, I was on a plane to Botswana to collect data on the nest building behaviour of the Southern masked weaverbird. When I tell people that the aim of my research is to work out how birds learn how to build nests, I usually get one of two responses. The first is, ‘they don’t learn anything of course, nest building in birds is innate.’ The other response is ‘surely that’s been done already?’ But actually, both of these (perfectly reasonable) assumptions are incorrect. © 2013 Scientific American,

Related chapters from BP6e: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 17939 - Posted: 03.23.2013

Backwards signals appear to sensitize brain cells, rat study shows

When the mind is at rest, the electrical signals by which brain cells communicate appear to travel in reverse, wiping out unimportant information in the process, but sensitizing the cells for future sensory learning, according to a study of rats conducted by researchers at the National Institutes of Health. The finding has implications not only for studies seeking to help people learn more efficiently, but also for attempts to understand and treat post-traumatic stress disorder — in which the mind has difficulty moving beyond a disturbing experience. During waking hours, electrical signals travel from dendrites — antenna-like projections at one end of the cell — through the cell body. From the cell body, they then travel the length of the axon, a single long projection at the other end of the cell. This electrical signal stimulates the release of chemicals at the end of the axon, which bind to dendrites on adjacent cells, stimulating these recipient cells to fire electrical signals, and so on. When groups of cells repeatedly fire in this way, the electrical signals increase in intensity. Dr. Bukalo and her team examined electrical signals that traveled in reverse?from the cell’s axon, to the cell body, and out its many dendrites. The reverse firing, depicted in this diagram, happens during sleep and at rest, appearing to reset the cell and priming it to learn new information. It was previously known that, during sleep, these impulses were reversed, arising from waves of electrical activity originating deep within the brain. In the current study, the researchers found that these reverse signals weakened circuits formed during waking hours, apparently so that unimportant information could be erased from the brain. But the reverse signals also appeared to prime the brain to relearn at least some of the forgotten information. If the animals encountered the same information upon awakening, the circuits re-formed much more rapidly than when they originally encountered the information.

Related chapters from BP6e: Chapter 17: Learning and Memory; Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 10: Biological Rhythms and Sleep
Link ID: 17916 - Posted: 03.19.2013

Stanford scientists capture mouse memories

Peter Fimrite Scientists at Stanford University have tapped into the mind of the mouse and are now circulating information about how the pesky rodents think. A team of Stanford researchers planted tiny probes inside the brains of mice to detect what were essentially mouse memories, according to a study published last month in the online edition of Nature Neuroscience. The experiment involved the insertion of a needlelike microscope into the hippocampus - a part of the brain associated with spatial and episodic memory. The microscope detected cellular activity and broadcast digital images through a cell phone camera sensor that fit like a hat over the heads of the critters as they scampered around an enclosure. "We're not really reading their minds," said the lead researcher, Mark Schnitzer, who is an associate professor of biology and applied physics at Stanford. "What is the mind of a mouse, anyway? I don't know. What we're doing is reading a spatial map in the brain. It is one little component of many, many processes that are going on inside." Over the course of a month, the scientists were able to document patterns of activity in some 700 neurons and pinpoint areas of the brain where mice store long-term information. It is important, Schnitzer said, because long-term memory is an area of the brain that researchers are struggling to understand as they attempt to develop new therapies for neurodegenerative diseases, including Alzheimer's disease. "Those are clearly diseases in which information storage has been impaired," Schnitzer said. "Now that we can look at the neural code for how the spatial information is stored, it opens the door directly to subsequent experiments. That's the logical next step." © 2013 Hearst Communications Inc.

Related chapters from BP6e: Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 17908 - Posted: 03.18.2013

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Links for Keyword: Learning & Memory