Chapter 17. Learning and Memory

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By Ryan Dalton You might be forgiven for having never heard of the NotPetya cyberattack. It didn’t clear out your bank account, or share your social media passwords, or influence an election. But it was one of the most costly and damaging cyberattacks in history, for what it did target: shipping through ports. By the time the engineers at Maersk realized that their computers were infected with a virus, it was too late: worldwide shipping would grind to a halt for days. Imagine a similar situation, in which the target was another port: the synapse, the specialized port of communication between neurons. Much of our ability to learn and remember comes down to the behavior of synapses. What would happen then, if one neuron infected another with malware? Ports and synapses both run on rules, meant to ensure that their cargo can be exchanged not only quickly and reliably, but also adaptably, so that they can quickly adjust to current conditions and demands. This ‘synaptic plasticity’, is fundamental to the ability of animals to learn, and without it we would no more be able to tie our shoes than to remember our own names. Just as shipping rules are determined by treaties and laws, the rules of synaptic plasticity are written into a multitude of genes in our DNA. For example, one gene might be involved in turning up the volume on one side of the synapse, while another gene might ask the other side of the synapse to turn up the gain. Studying the function of these genes has been one of the core approaches to understanding what it is, at the microscopic level, to learn and to remember. © 2018 Scientific American

Keyword: Learning & Memory; Intelligence
Link ID: 25782 - Posted: 12.12.2018

In his enthralling 2009 collection of parables, Sum: Forty Tales from the Afterlives, the neuroscientist David Eagleman describes a world in which a person only truly dies when they are forgotten. After their bodies have crumbled and they leave Earth, all deceased must wait in a lobby and are allowed to pass on only after someone says their name for the last time. “The whole place looks like an infinite airport waiting area,” Eagleman writes. “But the company is terrific.” Most people leave just as their loved ones arrive — for it was only the loved ones who were still remembering. But the truly famous have to hang around for centuries; some, keen to be off, are with an “aching heart waiting for statues to fall”. Eagleman’s tale is an interpretation of what psychologists and social scientists call collective memory. Continued and shared attention to people and events is important because it can help to shape identity — how individuals see themselves as part of a group — and because the choice of what to commemorate, and so remember, influences the structures and priorities of society. This week in Nature Human Behaviour, researchers report a surprising discovery about collective memory: the pattern of its decay follows a mathematical law (C. Candia et al. Nature Hum. Behav. http://doi.org/cxq2; 2018). The attention we pay to academic papers, films, pop songs and tennis players decays in two distinct stages. In theory, the findings could help those who compete for society’s continued attention — from politicians and companies to environmental campaigners — to find ways to stay in the public eye, or at least in the public’s head. © 2018 Springer Nature Publishing AG

Keyword: Learning & Memory
Link ID: 25780 - Posted: 12.12.2018

By Benedict Carey A generation ago, parents worried about the effects of TV; before that, it was radio. Now, the concern is “screen time,” a catchall term for the amount of time that children, especially preteens and teenagers, spend interacting with TVs, computers, smartphones, digital pads, and video games. This age group draws particular attention because screen immersion rises sharply during adolescence, and because brain development accelerates then, too, as neural networks are pruned and consolidated in the transition to adulthood. On Sunday evening, CBS’s “60 Minutes” reported on early results from the A.B.C.D. Study (for Adolescent Brain Cognitive Development), a $300 million project financed by the National Institutes of Health. The study aims to reveal how brain development is affected by a range of experiences, including substance use, concussions, and screen time. As part of an exposé on screen time, “60 Minutes” reported that heavy screen use was associated with lower scores on some aptitude tests, and to accelerated “cortical thinning" — a natural process — in some children. But the data is preliminary, and it’s unclear whether the effects are lasting or even meaningful. Does screen addiction change the brain? Yes, but so does every other activity that children engage in: sleep, homework, playing soccer, arguing, growing up in poverty, reading, vaping behind the school. The adolescent brain continually changes, or “rewires” itself, in response to daily experience, and that adaptation continues into the early to mid 20s. What scientists want to learn is whether screen time, at some threshold, causes any measurable differences in adolescent brain structure or function, and whether those differences are meaningful. Do they cause attention deficits, mood problems, or delays in reading or problem-solving ability? © 2018 The New York Times Company

Keyword: Development of the Brain; Learning & Memory
Link ID: 25772 - Posted: 12.11.2018

Doing crossword puzzles and Sudoku does not appear to protect against mental decline, according to a new study. The idea of "use it or lose it" when it comes to our brains in later life has previously been widely accepted. The new Scottish study showed that people who regularly do intellectual activities throughout life have higher mental abilities. This provides a "higher cognitive point" from which to decline, say the researchers. But the study did not show that they decline any slower. The work, published in the BMJ, was undertaken by Dr Roger Staff at Aberdeen Royal Infirmary and the University of Aberdeen. It looked at 498 people born in 1936 who had taken part in a group intelligence test at the age of 11. This current study started when they were about 64 years old and they were recalled for memory and mental-processing-speed testing up to five times over a 15-year period. It found engagement in problem solving did not protect an individual from decline. However, engaging in intellectually stimulating activities on a regular basis was linked to level of mental ability in old age. The study uses modelling to look at associations and cannot prove any causal link. Also, many of the participants were unable to complete the whole study - some dropped out, others died. Image copyright Getty Images Previously, some studies have found that cognitive training can improve some aspects of memory and thinking, particularly for people who are middle-aged or older. They found so-called brain training may help older people to manage their daily tasks better. No studies have shown that brain training prevents dementia. And last year a report from the Global Council on Brain Health recommended that people should take part in stimulating activities such as learning a musical instrument, designing a quilt or gardening rather than brain training to help their brain function in later life. © 2018 BBC

Keyword: Alzheimers; Learning & Memory
Link ID: 25771 - Posted: 12.11.2018

By JoAnna Klein A macaw named Poncho starred in movies like “102 Dalmatians,” “Dr. Doolittle” and “Ace Ventura: Pet Detective” before retiring in England. She recently celebrated her 90th birthday. Alex, an African grey parrot who lived to 31, knew colors, shapes and numbers, and communicated using basic expressions. He could do what toddlers only do after a certain stage of development — know when something is hidden from view. And they’re just two of the many parrots in the world who have surprised us with their intelligence, skills and longevity. “Nature does these experiments for us, and then we have to go and ask, how did this happen?” said Dr. Claudio Mello, a neuroscientist at Oregon Health and Science University. So he and a team of nearly two dozen scientists looked for clues in the genome of the blue-fronted Amazon parrot in Brazil, his home country. After comparing its genome with those of dozens of other birds, the researchers’ findings suggest that evolution may have made parrots something like the humans of the avian world. In some ways, the long-lived feathered friends are as genetically different from other birds as humans are from other primates. Their analysis, published Thursday in Current Biology, also highlights how two very different animals — parrots and humans — can wind up finding similar solutions to problems through evolution. A general rule of life span in birds and other animals is the bigger or heavier you are, the longer you live. A small bird like a finch may live five to eight years, while bigger ones like eagles or cranes can live decades. The blue-fronted Amazon and some other parrots are even more exceptional, in that they can live up to 66 years — in some cases outliving their human companions. © 2018 The New York Times Company

Keyword: Intelligence; Evolution
Link ID: 25764 - Posted: 12.08.2018

One of the animals that's thought to give creatures like apes, dolphins and crows a run for their money when it comes to intelligence is the octopus. For those other animals, there's a pattern to how they evolved to be so smart — they live long, socially complex lives. But that's not the case for octopuses that live solitary lives for the year or two they usually survive. Now scientists think they've figured out how the octopus became so so smart, and it has to do with the loss of their shell through evolution. "Octopuses, unlike many other molluscs, they do not have a protective shell," said Piero Amodio, the lead author on the new study published in the journal Trends in Ecology & Evolution about how cephalopods (octopuses and their relatives) gained their intelligence. "So [octopuses] are very, very vulnerable to many kinds of predators — from fishes to marine mammals to birds — and the idea is that by becoming quite smart, this is a kind of weapon they can use to avoid being eaten." Amodio, a PhD student at the University of Cambridge, told Quirks & Quarks host Bob McDonald that this evolutionary process differs from those that led to intelligence in other groups of vertebrates. Intelligence in other vertebrates is thought to have arisen because they live long and socially complex lives. Building a brain is a metabolically labour intensive process, so it's a big investment for an animal to develop a big brain like in apes, dolphins, and crows — an investment they get a return on when they live a long time. ©2018 CBC/Radio-Canada.

Keyword: Evolution; Intelligence
Link ID: 25763 - Posted: 12.08.2018

By Dan Falk When the ghost of King Hamlet commands his son to “remember me,” the prince takes the message to heart, vowing to “wipe away” all that is trivial in his accumulated memory, so that “thy commandment alone shall live / Within the book and volume of my brain.” Of course, it’s not quite that simple, and we often find ourselves doing battle with our memories — struggling to recall something that we’ve forgotten, or wishing to forget something that nonetheless intrudes into consciousness. Humans are masters at leaping through time, vividly imagining the past while making richly detailed plans for the future. A long-forgotten memory can surface at any time. In Marcel Proust’s “In Search of Lost Time,” the narrator bites into a French pastry known as a madeleine and is instantly transported back in time. Suddenly a childhood memory “revealed itself” — it was the recollection of the snack his aunt used to share with him in her bedroom on Sunday mornings before mass. Poets and novelists got a head start, but for some 140 years now scientists, too, have been wrestling with memory. It’s this struggle that two Norwegian sisters, the novelist Hilde Østby and the neuropsychologist Ylva Østby, tackle in their engrossing book, “Adventures in Memory: The Science and Secrets of Remembering and Forgetting.” Copyright 2018 Undark

Keyword: Learning & Memory
Link ID: 25762 - Posted: 12.08.2018

By Jennifer Couzin-Frankel For the millions of people treated for cancer, “chemo brain” can be an unnerving and disabling side effect. It causes memory lapses, trouble concentrating, and an all-around mental fog, which appear linked to the treatment and not the disease. Although the cognitive effects often fade after chemotherapy ends, for some people the fog persists for years, even decades. And doctors and researchers have long wondered why. Now, a new study suggests an answer in the case of one chemotherapy drug: Brain cells called microglia may orchestrate chemo brain by disrupting other cells that help maintain the brain’s communication system. “I can’t tell you how many patients I see who look at me when I explain [chemo brain] and say, ‘I’ve been living with this for 10 years and thought I was crazy,’” says Michelle Monje, a pediatric neuro-oncologist and neuroscientist at Stanford University in Palo Alto, California. It’s still mostly a mystery how common long-term cognitive impairment is after chemo. In one recent study by clinical neuropsychologist Sanne Schagen at the Netherlands Cancer Institute in Amsterdam, it affected 16% of breast cancer survivors 6 months after treatment. Monje began to probe the cognitive effects of cancer treatment in the early 2000s, starting with radiation, a therapy that can be far more debilitating than chemotherapy. A Science paper she and her colleagues published in 2003 suggested radiation affected a type of brain cell called microglia, which protect the brain against inflammation. Just like immune cells in the blood, microglia—which make up at least 10% of all brain cells—become activated during injury or infection. © 2018 American Association for the Advancement of Science

Keyword: Neurotoxins; Glia
Link ID: 25759 - Posted: 12.07.2018

Laura Sanders The uterus is best known for its baby-growing job. But the female organ may also have an unexpected role in memory, a study in rats suggests. The results, published online December 6 in Endocrinology, counter the idea that the nonpregnant uterus is an extraneous organ. That may have implications for the estimated 20 million women in the United States who have had hysterectomies. In the study, female rats either underwent removal of the uterus, ovaries, both organs or neither. Six weeks after surgery, researchers led by behavioral neuroscientist Heather Bimonte-Nelson of Arizona State University in Tempe began testing the rats on water mazes with platforms that were hidden just below the surface. Compared with the other groups, rats that lacked only a uterus were worse at remembering where to find the platforms as the tests turned progressively harder. The results suggest that signals that go from the uterus to the brain are somehow involved in remembering multiple bits of information at the same time. Rats lacking just a uterus had differences in their hormone levels, too, even though these rats kept their hormone-producing ovaries. Researchers have known for decades that hormones released by the ovaries can influence the brain. But finding that the uterus on its own can influence memory is a surprise, says neuroendocrinologist Victoria Luine of Hunter College of the City University of New York. Because many women have their uteruses removed but keep their ovaries, “this revelation brings up some interesting questions to explore.” |© Society for Science & the Public 2000 - 2018

Keyword: Learning & Memory; Hormones & Behavior
Link ID: 25757 - Posted: 12.07.2018

By Carl Zimmer To demonstrate how smart an octopus can be, Piero Amodio points to a YouTube video. It shows an octopus pulling two halves of a coconut shell together to hide inside. Later the animal stacks the shells together like nesting bowls — and carts them away. “It suggests the octopus is carrying these tools around because it has some understanding they may be useful in the future,” said Mr. Amodio, a graduate student studying animal intelligence at the University of Cambridge in Britain. But his amazement is mixed with puzzlement. For decades, researchers have studied how certain animals evolved to be intelligent, among them apes, elephants, dolphins and even some birds, such as crows and parrots. But all the scientific theories fail when it comes to cephalopods, a group that includes octopuses, squid and cuttlefish. Despite feats of creativity, they lack some hallmarks of intelligence seen in other species. “It’s an apparent paradox that’s been largely overlooked in the past,” said Mr. Amodio. He and five other experts on animal intelligence explore this paradox in a paper published this month in the journal Trends in Ecology and Evolution. For scientists who study animal behavior, intelligence is not about acing a calculus test or taking a car apart and putting it back together. Intelligence comprises sophisticated cognitive skills that help an animal thrive. That may include the ability to come up with solutions to the problem of finding food, for example, or a knack for planning for some challenge in the future. Intelligent animals don’t rely on fixed responses to survive — they can invent new behaviors on the fly. © 2018 The New York Times Company

Keyword: Intelligence; Evolution
Link ID: 25741 - Posted: 12.01.2018

By Neuroskeptic The science story of the past week was the claim from Chinese scientist He Jiankui that he has created gene-edited human babies. Prof. He reports that two twin girls have been born carrying modifications of the gene CCR5, which is intended to protect them against future HIV risk. It’s far from clear yet whether the gene-editing that He described has actually taken place – no data has yet been presented. The very prospect of genetically-modifying human beings has, however, led to widespread concern, with He’s claims being described as “monstrous“, “crazy” and “unethical”. All of which got me wondering: could there ever be a neuroscience experiment which attracted the same level of condemnation? What I’m asking here is whether there are neuroscience advances that would be considered inherently unethical. It would, of course, be possible to carry out any neuroscience experiment in an unethical way, by forcing or tricking people into participation. But are there experiments which would be unethical even if all the participants gave full, informed consent at every stage? Here are a couple of possibilities: Intelligence enhancement: Suppose it were possible to substantially boost human intelligence through some kind of technological means, perhaps a drug, or through brain stimulation. I suspect that many people would see this prospect as an ethical problem, because it would give users a definite advantage over non-users and thus, in effect, force people to use the technology in order to keep up. It would be a similar situation to the problem of doping in sports: if doping were widespread, it would be very difficult for non-dopers to compete.

Keyword: Learning & Memory; Intelligence
Link ID: 25738 - Posted: 12.01.2018

By Diana Kwon For almost a decade, cleaning rituals ruled Kathrine’s life. The middle-aged resident of Bergen, a coastal town in the southern tip of Norway, was consumed by a fear of germs and contamination that led to endless cycles of tidying, vacuuming and washing. “I realized that I was facing a catastrophe,” Kathrine Mydland-aas, now 41, recalls. “I couldn’t help the kids with homework, couldn’t make dinner for them, couldn’t give them hugs. I didn’t do anything but cleaning. I tried to quit, but the rituals always won.” Last year, around nine years after Mydland-aas’s cleaning rituals began, a psychologist diagnosed her with obsessive-compulsive disorder (OCD) and referred her to a clinic at the Haukeland University Hospital in Bergen. There, a team was administering a behavioral therapy for the condition that, to Mydland-aas’s surprise, was only four days long. “I thought, what can they do in four days?” she says. “[But] it changed my life.” Mydland-aas is one of more than 1,200 people who have received the Bergen four-day treatment for OCD, a concentrated form of exposure therapy designed by two Norwegian psychologists, Gerd Kvale and Bjarne Hansen. The four-day protocol has recently gained international attention for its effectiveness and efficiency—last month Time magazine named the pair, who are both currently affiliated with the Haukeland University Hospital and the University of Bergen, as two of this year’s 50 most influential people in healthcare. © 2018 Scientific American

Keyword: OCD - Obsessive Compulsive Disorder; Learning & Memory
Link ID: 25736 - Posted: 11.30.2018

Jef Akst After publishing a 2014 study showing that noninvasive magnetic stimulation of the brain boosted people’s ability to remember an association between two items, Northwestern University neuroscientist Joel Voss began fielding a lot of questions from patients and their families. “We’re of course guarded in the publication talking about what we found—small but reliable increases in memory ability,” he says (Science, 345:1054–57). But some of the news coverage of that paper alluded to the procedure’s potential to treat Alzheimer’s disease and other memory-related disorders. “I got calls—at least two a day for quite a long period of time—and emails: ‘My loved one is suffering from X, Y, or Z; thank God now you can cure it. How do we get to your lab?’” Voss says. He would have to explain to them that this was a scientific study, not an approved treatment. “There are a million steps between here and there, and maybe it would never work—we don’t really know.” But Voss’s team continues to connect those dots, in hopes that one day the technique—the use of magnetic fields to influence activity in neurons close to the brain’s surface—could help patients with any number of brain disorders, and perhaps cognitively healthy people as well. In August, the researchers reported that transcranial magnetic stimulation (TMS) could moderately improve episodic memory—the ability to remember people, events, and other things you’ve encountered in your life (as opposed to, say, how to do something)—when targeted at the correct part of the brain. Voss and his colleagues were interested in activating the hippocampus, a structure near the brain’s center that serves as a hub of memory production and storage. Because the hippocampus itself is inaccessible by TMS—the magnetic field falls off precipitously with depth, explains Voss—the researchers instead targeted areas of the brain where activity correlated with activity in the hippocampus, to try to activate the networks that link more-superficial regions with the deep-brain structure. © 1986 - 2018 The Scientist

Keyword: Learning & Memory
Link ID: 25722 - Posted: 11.27.2018

Shawna Williams In 1987, political scientist James Flynn of the University of Otago in New Zealand documented a curious phenomenon: broad intelligence gains in multiple human populations over time. Across 14 countries where decades’ worth of average IQ scores of large swaths of the population were available, all had upward swings—some of them dramatic. Children in Japan, for example, gained an average of 20 points on a test known as the Wechsler Intelligence Scale for Children between 1951 and 1975. In France, the average 18-year-old man performed 25 points better on a reasoning test in 1974 than did his 1949 counterpart.1 Flynn initially suspected the trend reflected faulty tests. Yet in the ensuing years, more data and analyses supported the idea that human intelligence was increasing over time. Proposed explanations for the phenomenon, now known as the Flynn effect, include increasing education, better nutrition, greater use of technology, and reduced lead exposure, to name but four. Beginning with people born in the 1970s, the trend has reversed in some Western European countries, deepening the mystery of what’s behind the generational fluctuations. But no consensus has emerged on the underlying cause of these trends. A fundamental challenge in understanding the Flynn effect is defining intelligence. At the dawn of the 20th century, English psychologist Charles Spearman first observed that people’s average performance on a variety of seemingly unrelated mental tasks—judging whether one weight is heavier than another, for example, or pushing a button quickly after a light comes on—predicts our average performance on a completely different set of tasks. Spearman proposed that a single measure of general intelligence, g, was responsible for that commonality. © 1986 - 2018 The Scientist

Keyword: Intelligence; Learning & Memory
Link ID: 25714 - Posted: 11.24.2018

Ashley Yeager For an hour a day, five days a week, mice in Hiroshi Maejima’s physiology lab at Hokkaido University in Sapporo, Japan, hit the treadmill. The researcher’s goal in having the animals follow the exercise routine isn’t to measure their muscle mass or endurance. He wants to know how exercise affects their brains. Researchers have long recognized that exercise sharpens certain cognitive skills. Indeed, Maejima and his colleagues have found that regular physical activity improves mice’s ability to distinguish new objects from ones they’ve seen before. Over the past 20 years, researchers have begun to get at the root of these benefits, with studies pointing to increases in the volume of the hippocampus, development of new neurons, and infiltration of blood vessels into the brain. Now, Maejima and others are starting to home in on the epigenetic mechanisms that drive the neurological changes brought on by physical activity. In October, Maejima’s team reported that the brains of rodents that ran had greater than normal histone acetylation in the hippocampus, the brain region considered the seat of learning and memory.1 The epigenetic marks resulted in higher expression of Bdnf, the gene for brain-derived neurotrophic factor (BDNF). By supporting the growth and maturation of new nerve cells, BDNF is thought to promote brain health, and higher levels of it correlate with improved cognitive performance in mice and humans. With a wealth of data on the benefits of working out emerging from animal and human studies, clinicians have begun prescribing exercise to patients with neurodegenerative diseases such as Parkinson’s and Alzheimer’s, as well as to people with other brain disorders, from epilepsy to anxiety. Many clinical trials of exercise interventions for neurodegenerative diseases, depression, and even aging are underway. Promising results could bolster the use of exercise as a neurotherapy. © 1986 - 2018 The Scientist

Keyword: Learning & Memory; Muscles
Link ID: 25713 - Posted: 11.24.2018

Andrew Anthony Of all the mysteries of the mind, perhaps none is greater than memory. Why do we remember some things and forget others? What is memory’s relationship to consciousness and our identities? Where and how is memory stored? How reliable are our memories? And why did our memory evolve to be so rich and detailed? In a sense there are two ways of looking at memory: the literary and the scientific. There is the Proustian model in which memory is about meaning, an exploration of the self, a subjective journey into the past. And then there is the analytical model, where memory is subjected to neurological study, psychological experiments and magnetic resonance imaging. A new book – or rather a recent translation of a two-year-old book – by a pair of Norwegian sisters seeks to marry the two approaches. The co-authors of Adventures in Memory: The Science and Secrets of Remembering and Forgetting are Ylva Østby, a clinical neuropsychologist, and Hilda Østby, an editor and novelist. Their book begins in 1564, with Julius Caesar Arantius performing a dissection of a human brain. Cutting deep into the temporal lobe, where it meets the brain stem, he encounters a small, wormlike ridge of tissue that resembles a sea horse. He calls it hippocampus – or “horse sea monster” in Latin. The significance of this discovery would take almost 400 years to come to light. As with so much to do with our understanding of the brain, the breakthrough came through a malfunction. An American named Henry Molaison suffered from acute epilepsy, and in 1953 he underwent an operation in which the hippocampi from both sides of his brain were removed. The surgery succeeded in controlling his epilepsy but at the cost of putting an end to his memory. © 2018 Guardian News and Media Limited

Keyword: Learning & Memory
Link ID: 25699 - Posted: 11.19.2018

Ned Rozell Alaska chickadees have proven themselves brainier than Colorado chickadees. A researcher at the University of California Davis once compared black-capped chickadees from Anchorage to chickadees from Windsor, Colorado, and found that the Alaska birds cached more sunflower seeds and found the seeds quicker when they later searched for them. The Alaska chickadees also had brains that contained more neurons than those of Colorado chickadees. Vladimir Pravosudov of the UC Davis psychology department performed the study to test the notion that northern birds would be better at hiding and finding seeds than birds in a more moderate climate. He chose to capture birds in Anchorage, which has a day length of about 5 hours, 30 minutes on Dec. 22, and compare them to birds he captured near Windsor, about 50 miles north of Denver, where the Dec. 22 day length is about 9 hours, 15 minutes. With the help of biologist Colleen Handel of the U.S. Geological Survey in Anchorage, Pravosudov captured 15 black-capped chickadees using a mist net at bird feeders around Anchorage in fall 2000. He later captured 12 black-capped chickadees near Windsor. All the birds went to his lab in Davis, where he gave them the same food and amount of daylight for 45 days. After 45 days he tested eight birds from Alaska and eight from Colorado in a room with 70 caching holes drilled in wooden blocks and trees. In late summer through fall, black-capped chickadees gather and hide seeds, insects and other foods to retrieve later, when they have fewer hours of daylight to feed and less food is available. Though black-capped chickadees live their entire lives within a few square acres, the species ranges from as far north as Anaktuvuk Pass in Alaska to as far south as New Mexico. © 2018 Anchorage Daily News

Keyword: Learning & Memory; Evolution
Link ID: 25689 - Posted: 11.16.2018

Laura Sanders SAN DIEGO — Mice yanked out of their community and held in solitary isolation show signs of brain damage. After a month of being alone, the mice had smaller nerve cells in certain parts of the brain. Other brain changes followed, scientists reported at a news briefing November 4 at the annual meeting of the Society for Neuroscience. It’s not known whether similar damage happens in the brains of isolated humans. If so, the result have implications for the health of people who spend much of their time alone, including the estimated tens of thousands of inmates in solitary confinement in the United States and elderly people in institutionalized care facilities. The new results, along with other recent brain studies, clearly show that for social species, isolation is damaging, says neurobiologist Huda Akil of the University of Michigan in Ann Arbor. “There is no question that this is changing the basic architecture of the brain,” Akil says. Neurobiologist Richard Smeyne of Thomas Jefferson University in Philadelphia and his colleagues raised communities of multiple generations of mice in large enclosures packed with toys, mazes and things to climb. When some of the animals reached adulthood, they were taken out and put individually into “a typical shoebox cage,” Smeyne said. This abrupt switch from a complex society to isolation induced changes in the brain, Smeyne and his colleagues later found. The overall size of nerve cells, or neurons, shrunk by about 20 percent after a month of isolation. That shrinkage held roughly steady over three months as mice remained in isolation. |© Society for Science & the Public 2000 - 2018

Keyword: Stress; Learning & Memory
Link ID: 25649 - Posted: 11.06.2018

Jon Hamilton You hear a new colleague's name. You get directions to the airport. You glance at a phone number you're about to call. These are the times you need working memory, the brain's system for temporarily holding important information. "Working memory is the sketchpad of your mind; it's the contents of your conscious thoughts," says Earl Miller, a professor of neuroscience at MIT's Picower Institute for Learning and Memory. It's also "a core component of higher cognitive functions like planning or language or intelligence," says Christos Constantinidis, a professor of neurobiology and anatomy at Wake Forest University. Miller and Constantinidis agree that working memory is critical to just about everything the brain does. They also agree that problems with working memory are a common symptom of brain disorders such as autism and schizophrenia. But they are on opposite sides of a lively debate about how working memory works. Both scientists are presenting evidence to support their position at the Society for Neuroscience meeting in San Diego this week. They also faced off with dual perspectives in the Journal of Neuroscience in August. Constantinidis backs what he calls the standard model of working memory, which has been around for decades. It says that when we want to keep new information like a phone number, neurons in the front of the brain start firing — and keep firing. © 2018 npr

Keyword: Learning & Memory
Link ID: 25647 - Posted: 11.05.2018

Laura Sanders Taking a monthlong break from pot helps clear away young people’s memory fog, a small study suggests. The results show that not only does marijuana impair teenagers’ and young adults’ abilities to take in information, but that this memory muddling may be reversible. Scientists have struggled to find clear answers about how marijuana affects the developing brain, in part because it’s unethical to ask children to begin using a drug for a study. But “you can do the opposite,” says neuropsychologist Randi Schuster. “You can get kids who are currently using, and pay them to stop.” For a study published October 30 in the Journal of Clinical Psychiatry, Schuster and her colleagues did just that. The team recruited 88 Boston-area youngsters ages 16 to 25 years old who reported using marijuana at least once a week, and offered 62 of them money to quit for a month. Participants were paid more money as the experiment went along, with top earners banking $535 for their month without pot. The money “worked exceptionally well,” says Schuster, of Massachusetts General Hospital in Boston and Harvard Medical School. Urine tests showed that 55 of the 62 participants stopped using marijuana for the 30 days of the experiment. Along with regular drug tests, participants underwent attention and memory tests. Tricky tasks that required close monitoring of number sequences and the directions and locations of arrows revealed that, over the month, young people’s ability to pay attention didn’t seem to be affected by their newfound abstinence. |© Society for Science & the Public 2000 - 2018

Keyword: Drug Abuse; Learning & Memory
Link ID: 25628 - Posted: 10.31.2018