Chapter 17. Learning and Memory
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By Dan Hurley, New studies are raising the hope of finding a pill to improve the intellectual abilities of people with Down syndrome. One study, published online by the journal Translational Psychiatry, is the first ever to show that a drug might improve the verbal memory of people with the disorder. Although the benefits appeared modest and the study was small, Down syndrome experts meeting last week in Washington called it a major development after more than a decade of research in mice and test tubes. “A lot of us are well aware of progress we’ve seen . . . in the past five to 10 years,” said Jamie Edgin, a developmental psychologist at the University of Arizona in Tucson. Among those advances, she said, are tests designed to measure the cognitive abilities of people with Down syndrome. The development of mice with the genetic equivalent of Down syndrome, essential for studies of possible drug treatments, has been another milestone. “There’s a lot of excitement,” Edgin said. The drug used in the recent study, Namenda, is approved for treating Alzheimer’s disease. Although it has shown only a slim and temporary benefit for that condition, a 2007 study of mice with the genetic equivalent of Down syndrome showed that it almost entirely normalized their ability to learn and remember. The effects in humans appeared far less striking. Alberto Costa, a physician and neuroscientist at the University of Colorado in Denver, ran a test involving 42 young adults with Down syndrome, half of whom received a placebo. After 16 weeks, most of the people who received Namenda performed better on tests of memory than they had at the beginning of the study. But the effect was statistically significant on only one of the 14 tests, which some researchers at last week’s meeting said they considered disappointing. © 1996-2012 The Washington Post
By Laura Sanders Light use of the club drug Ecstasy may cause subtle memory deficits. People who popped just three Ecstasy tablets a month over the course of a year saw their memory slip on a laboratory test, scientists report online July 25 in Addiction. The new results offer some of the best evidence yet that the drug can change the brain, says psychiatric neuroscientist Ronald Cowan of Vanderbilt University Medical Center in Nashville. “It’s been very, very difficult to convince people that there’s a causative effect of the drug,” he says. “This adds strong evidence to that.” Scientists debate whether Ecstasy, a drug that brings euphoria, boundless energy and heightened sensory experiences, can actually harm the brain in part by screwing with cells that produce the chemical messenger serotonin. Past studies have been notoriously hard to interpret because brain differences seen between Ecstasy users and nonusers could have existed long before the drug use began. And people who use Ecstasy frequently tend to use other drugs too, making it hard to tease out Ecstasy’s effect. For the study, Daniel Wagner of the University of Cologne in Germany and his colleagues wanted to catch people as they started using Ecstasy. The team recruited 149 people who had used Ecstasy five or fewer times and ran the subjects through a battery of brain tests looking for signs of mental deficits. One year later, the team retested 43 people who had not used Ecstasy since being recruited, and 23 who had used 10 or more Ecstasy pills in that time. These people reported using an average of 33.6 tablets. © Society for Science & the Public 2000 - 2012
By Dwayne Godwin and Jorge Cham In 1953, Henry Molaison underwent radical surgery in an attempt to stop his epileptic seizures... © 2012 Scientific American,
By Ruth Williams Until recently, most scientists believed that neurons were the all-important brain cells controlling mental functions and that the surrounding glial cells were little more than neuron supporters and “glue.” Now research published in March in Cell reveals that astrocytes, a type of glia, have a principal role in working memory. And the scientists made the discovery by getting mice stoned. Marijuana impairs working memory—the short-term memory we use to hold on to and process thoughts. Think of the classic stoner who, midsentence, forgets the point he was making. Although such stupor might give recreational users the giggles, people using the drug for medical reasons might prefer to maintain their cognitive capacity. To study how marijuana impairs working memory, Giovanni Marsicano of the University of Bordeaux in France and his colleagues removed cannabinoid receptors—proteins that respond to marijuana's psychoactive ingredient THC—from neurons in mice. These mice, it turned out, were just as forgetful as regular mice when given THC: they were equally poor at memorizing the position of a hidden platform in a water pool. When the receptors were removed from astrocytes, however, the mice could find the platform just fine while on THC. The results suggest that the role of glia in mental activity has been overlooked. Although research in recent years has revealed that glia are implicated in many unconscious processes and diseases, this is one of the first studies to suggest that glia play a key role in conscious thought. “It's very likely that astrocytes have many more functions than we thought,” Marsicano says. “Certainly their role in cognition is now being revealed.” © 2012 Scientific American,
By Laura Sanders In a paradoxical twist, people with amnesia can get bogged down by too many memories. Unwanted, irrelevant information crowds in and prevent amnesiac patients from recognizing objects, scientists report in the July 12 Neuron. The finding suggests that amnesia isn’t strictly a memory problem, and it may even point out ways to help people with the disorder live more normally. Most people consider amnesia a breakdown of memory that leaves people unable to recall a conversation they had minutes earlier, says study coauthor Morgan Barense of the University of Toronto. While it’s true that people with amnesia have striking memory deficits, “the real picture is more complicated,” she says. People with amnesia caused by damage to a brain region near the ears called the perirhinal cortex also have problems recognizing objects, Barense and colleagues found. In the study, two people with this form of amnesia assessed a series of pictures of two objects — squiggly blobs with distinctive patterns of lines. The objects, shown at different rotations, were either identical or slightly different. At first, people with amnesia were just as good as people with functioning recall at deciding whether the two objects were the same. But as the experiment wore on, participants’ performance started to crash. “They’re doing fine, they’re doing fine — and then all of a sudden, it was like a switch flipped,” says Barense. After ruling out other possibilities, the researchers landed on what Barense calls a “wildly paradoxical conclusion” to explain the crash: too many memories. © Society for Science & the Public 2000 - 2012
Keyword: Learning & Memory
Link ID: 17030 - Posted: 07.12.2012
By Kara Rogers The honeybee brain is dynamic and full of surprises. For instance, much like the human brain, its neurons not only modulate their activity in response to sensory stimuli but also alter their gene and protein expression patterns—changes that in bees are so dramatic as to essentially rewire the brain. And even more remarkable is that this plasticity is strongly influenced by social environment, a feature that was underscored recently by the discovery that bees who changed social roles effectively reversed the aging of their brains. The reversal, described in terms of recovery of learning ability, occurred when older honeybees reverted from foraging tasks to caring for newborn bees and was linked to increased brain levels of stress response and antioxidant proteins, which serve important cellular maintenance and repair functions. One of the proteins was similar to the mammalian enzyme peroxiredoxin-6 (Prx6). In humans, Prx6 defends against oxidative stress and inflammation associated with Alzheimer disease and Huntington disease, indicating that a better understanding of the molecules involved in brain plasticity and cognitive recovery in honeybees could inform research on dementia and related conditions. The new findings are especially intriguing for what they suggest about the influence of social environment on cognitive function. Studies in humans have linked strong social relationships with increased likelihood for survival and declining social engagement in mid- to late-life with increasing risk of dementia. However, relatively little is known about the significance of social environment in the context of human cognitive function and aging. © 2012 Scientific American,
by Krystnell A. Storr For California ground squirrels, survival against rattlesnakes often comes down to one basic question: Are you willing to "shake it?" By holding their tails upright and thrashing them from side to side, the animals notify predators that any attempt to turn them into a meal is likely to end in failure. Now researchers have discovered that this tail-waving behavior has a dual purpose. Not only does it ward off predators, but it also warns other squirrels of potential danger, forcing rattlesnakes to find new hunting grounds. Pacific rattlesnakes (Crotalus oreganus oreganus) are patient hunters. They wait for hours in or around the burrows of California ground squirrels (Otospermophilus beecheyi). When an unsuspecting squirrel gets close enough, the snake delivers a venomous bite, releases the animal, and hunts for the dead body later. Scientists knew that some squirrels avoid attack by shaking their tails after seeing a snake, but sometimes squirrels did this even when they didn't detect a predator. Were they clued into some sort of alarm call or just waving at random? Matthew Barbour and Rulon Clark decided to investigate things from a snake's perspective. Armed with snake tongs and bags, the San Diego State University ecologists trekked into the California wilderness and captured and anesthetized 22 rattlesnakes, surgically implanting them with small tracking devices. As soon as the snakes recovered, the duo released them back into the wild, keeping tabs on them with the tracking devices and security cameras set up around several squirrel burrows. © 2010 American Association for the Advancement of Science.
Jon Bardin Growing up in the suburbs of New York City, Takao Hensch learned German from his father, Japanese from his mother and English from the community around him. “I was always wondering,” he says, “what is it that makes it so easy to learn languages when you're young, and so hard once you begin to get older?” Today, as a neuroscientist at Boston Children's Hospital in Massachusetts, Hensch is at the forefront of efforts to answer that question in full molecular detail. Language acquisition is just one of many processes that go through a 'sensitive' or 'critical' period — an interval during development when the neural circuits responsible for that process can be sculpted, and radically changed, by experience (see 'Open and shut'). During critical periods, children can make rapid progress at discerning facial features that look like their own, recognizing spoken language and locating objects in space. But within a few months or years, each window of opportunity slams shut, and learning anything new in that realm becomes difficult, if not impossible. Or maybe not. What Hensch and others in the small, but rapidly advancing, field of critical-period research are finding is that those windows can be prised back open. “For the first time, we are beginning to understand the biology that underlies critical periods,” says Hensch. And that understanding is suggesting ways to intervene in various neural disorders, including intractable conditions such as adult amblyopia, in which information from one eye is not correctly processed by the brain, and possibly even autism. The work could even lead to 'plasticity pills' that enhance learning or help to wipe out traumatic memories. © 2012 Nature Publishing Group,
by Andy Coghlan One of the key elements of memory – how we store and retrieve words according to what they mean – has been unravelled by analysing electrical signals from people's brains while they recalled lists of words. Although the discovery cannot identify the individual words being filed, which could effectively make a very basic form of mind-reading possible, it does for the first time reveal the electrical circuitry vital for storing words according to what they mean, rather than where they came in a sequence, for example. "Our main focus is on how people organise their memories," says Jeremy Manning, currently at Princeton University. "So we looked at the degree to which people organised their memories according to the meanings of words." Calling Roget The researchers recruited 46 patients with epilepsy who had already had electrodes implanted in their brains for treatment purposes. The electrodes allowed the researchers to measure electrical activity in the brain as the participants viewed lists of 15 to 20 words. A minute later, the patients were asked to recall aloud as many as possible, in any order. Collectively, the participants viewed 1550 lists, including a total of 24,760 words. The researchers included within each list words with similar meanings or associations, such as "goose" and "duck", to see if recall of one prompted recollection of the other. © Copyright Reed Business Information Ltd.
By Laura Sanders A dreamland ditty played softly during a nap helps people hit the right notes while awake. Soft tones during sleep creep into the napping brain and strengthen playing skills, researchers report online June 24 in Nature Neuroscience. The results don’t mean that after a nighttime Beethoven sonata, a piano novice will wake up with the ability to play it. But the results do suggest that an existing skill can be sharpened during a nap, says study coauthor Ken Paller of Northwestern University in Evanston, Ill. Earlier work by Paller and others has found that sound and odor cues during sleep can improve a person’s memory for the locations of objects. The new study extends those results by showing that a learned skill — in this instance, playing music — can also be influenced during sleep. Although these sorts of experiments are just getting started, “the door is wide open,” Paller says. Musical ability, athletic prowess and other talents that normally require a lot of practice may be amenable to boosts during sleep. Before the easy job of having a nap, 16 right-handed participants in the study had to do some actual work. Volunteers learned two different not-very-catchy tunes, played with their left hands on the a, s, d and f keys of a computer. In an arrangement similar to that of Guitar Hero, circles that floated up the screen told participants which key to hit and when. © Society for Science & the Public 2000 - 2012
SETH BORENSTEIN, AP Science Writer WASHINGTON (AP) — The more we study animals, the less special we seem. Baboons can distinguish between written words and gibberish. Monkeys seem to be able to do multiplication. Apes can delay instant gratification longer than a human child can. They plan ahead. They make war and peace. They show empathy. They share. "It's not a question of whether they think — it's how they think," says Duke University scientist Brian Hare. Now scientists wonder if apes are capable of thinking about what other apes are thinking. The evidence that animals are more intelligent and more social than we thought seems to grow each year, especially when it comes to primates. It's an increasingly hot scientific field with the number of ape and monkey cognition studies doubling in recent years, often with better technology and neuroscience paving the way to unusual discoveries. This month scientists mapping the DNA of the bonobo ape found that, like the chimp, bonobos are only 1.3 percent different from humans. Says Josep Call, director of the primate research center at the Max Planck Institute in Germany: "Every year we discover things that we thought they could not do." Call says one of his recent more surprising studies showed that apes can set goals and follow through with them. © 2012 Hearst Communications Inc.
By Madeline Haller Prepping for a big presentation but can't seem to remember any of the content? Blame your sweet tooth. A diet high in sugar may hamper your memory and ability to learn, says a study published in the Journal of Physiology. Researchers had two groups of rats drink water mixed with fructose, a type of sugar. One of the groups also received omega-3 fatty acids as a part of their diet. After 6 weeks, the rats who drank only sugar water completed a maze slower than the omega-3-fed mice. (We know you're not a mouse -- but you can still take steps to navigate the maze of life. Check out these 27 Ways to Power Up Your Brain.) Not only were they slower in the maze, the rats who drank only sugar water had higher triglyceride, glucose, and insulin levels. It appears that they entered a state of insulin resistance, which is where the hormone insulin becomes less effective at lowering your blood sugar, says Fernando Gomez-Pinilla, Ph.D., lead study author and a professor of neurosurgery at the David Geffen School of Medicine at UCLA. Here's how it works: Insulin, in addition to controlling blood sugar, also influences the ways in which your brain cells operate. And within the hippocampus -- the part of the brain responsible for short-term and long-term memory -- insulin signaling actually facilitates memory. Therefore, an insulin resistance may be what's causing a disruption in the rats' ability to recall the route they'd learned 6 weeks ago, the researchers hypothesize. © 2012 msnbc.com
By ANAHAD O'CONNOR A new study adds to growing evidence that the complications of diabetes may extend to the brain, causing declines in memory, attention and other cognitive skills. The new research showed that over the course of about a decade, elderly men and women with diabetes — primarily Type 2, the form of the disease related to obesity and inactivity — had greater drops in cognitive test scores than other people of a similar age. The more poorly managed their disease, the greater the deterioration in mental function. And the declines were seen not just in those with advanced diabetes. The researchers found that people who did not have diabetes at the start of the study but developed it later on also deteriorated to a greater extent than those without the disease. “What we’ve shown is a clear association with diabetes and cognitive aging in terms of the slope and the rate of decline on these cognitive tests,” said Dr. Kristine Yaffe, a professor of psychiatry and neurology at the University of California, San Francisco. “That’s very powerful.” While correlation does not equal causation and the relationship between diabetes and brain health needs further study, the findings, if confirmed, could have significant implications for a large segment of the population. Nationwide, nearly a third of Americans over the age of 65, or roughly 11 million people, have diabetes. By 2034, about 15 million Medicare-eligible Americans are expected to have the disease. Previous studies have shown that Type 2 diabetes correlates with a higher risk of Alzheimer’s disease and dementia later in life. But how one leads to the other has not been well understood. Copyright 2012 The New York Times Company
By Laura Sanders In what seems like a blow for humanity, a very smart chimpanzee in Japan crushes any human challenger at a number memory game. After the numbers 1 through 9 make a split-second appearance on a computer screen, the chimp, Ayumu, gets to work. His bulky index finger flies gracefully across the screen, tapping white squares where the numbers had appeared, in order. So far, no human has topped him. Ayumu’s talent caused a stir when researchers first reported it in 2007 (SN: 12/8/2007, p. 355). Since then, the chimp’s feat has grown legendary, even earning him a starring role in a recent BBC documentary. But psychologist Nicholas Humphrey says the hype may be overblown. In an upcoming Trends in Cognitive Sciences essay, Humphrey floats a different explanation for Ayumu’s superlative performance, one that leaves humans’ memory skills unimpugned: Ayumu might have a curious brain condition that allows him to see numbers in colors. If Humphrey’s wild idea is right, the chimpanzee’s feat has nothing to do with memory. “When you get extraordinary results, you need to look for extraordinary ideas to explain them,” says Humphrey, of Darwin College at Cambridge University in England. The idea came to him after listening to two presentations at a consciousness conference in 2011. Tetsuro Matsuzawa of the Primate Research Institute at Kyoto University in Japan described his research on the memory skills of Ayumu, his mother Ai, and two other mom-offspring pairs. And neuroscientist David Eagleman of Baylor College of Medicine in Houston talked about the brain condition known as synesthesia, which causes people to attach sensory experiences to letters or numbers. A synesthete might always see the number four as blue, for instance. © Society for Science & the Public 2000 - 2012
By PERRI KLASS, M.D. Like many other pediatricians, I do not wear a white coat. Many of us believe that babies and small children suffer from a special form of “white coat syndrome,” that mix of trepidation and anxiety that some adults experience — to the point of high blood pressure — in a medical setting. The pediatric version is easy to diagnose: Doctor in white coat walks into room, kid starts to cry. I worry that a child like this has recalled shots or an unpleasant ear check and has connected that memory to a particular garment, rather than to my face, or my exam room, or my stethoscope. But how realistic is that? Do babies remember past events? Starting when? Recent investigations of memory formation raise fascinating questions about how young children store and retrieve experiences and information. In some ways, I believe we tend to exalt the memory-related feats of the infant and the toddler. True, they can learn language, even more than one; sorting out words and syntax from the surrounding noise is in many ways a defining human use of memory. Nora Newcombe, a professor of psychology at Temple University, points out that there may be evolutionary reasons that this kind of memory — semantic memory — is so strong in the early years of life, when babies are faced with learning so many facts about the world. And yet, every adult lacks memories from the very early years. Freud called it “infantile amnesia,” describing “the peculiar amnesia which veils from most people (not from all!) the first years of their childhood.” Not surprisingly, he felt we repress those early childhood memories because they contain the beginnings of sexual feeling. Copyright 2012 The New York Times Company
by Dan Hurley Marilyn Monroe and Jane Russell appeared outside Grauman’s Chinese Theatre to write their names and leave imprints of their hands and high heels in the wet concrete. Down on their knees, supported by a velvet-covered pillow for their elbows, they wrote “Gentlemen Prefer Blondes” in looping script, followed by their signatures and the date, 6-26-53. But how did those watching the events of that day manage to imprint a memory trace of it, etching the details with neurons and synapses in the soft cement of the brain? Where and how are those memories written, and what is the molecular alphabet that spells out the rich recollections of color, smell, and sound? After more than a century of searching, an answer was recently found, strangely enough, just eight miles from Grauman’s. Although not located on any tourist map, the scene of the discovery can be reached easily from Hollywood Boulevard by heading west on Sunset to the campus of UCLA. There, amid one of the densest clusters of neuroscience research facilities in the world, stands the Gonda (Goldschmied) Neuroscience and Genetics Research Center. And sitting at a table in the building’s first-floor restaurant, the Café Synapse, is the neuroscientist who has come closer than anyone ever thought possible to finding the place where memories are written in the brain. That spot, the physical substrate of a particular memory, has long been known in brain research as an engram. Decades of scientific dogma asserted that engrams exist only in vast webs of connections, not in a particular place but in distributed neural networks running widely through the brain. Yet a series of pioneering studies have demonstrated that it is possible to lure specific memories into particular neurons, at least in mice. If those neurons are killed or temporarily inactivated, the memories vanish. If the neurons are reactivated, the memories return. These same studies have also begun to explain how and why the brain allocates each memory to a particular group of cells and how it links them together and organizes them—the physical means by which the scent of a madeleine, the legendary confection that sparked Marcel Proust’s memory stream, leads to remembrance of things past. © 2012, Kalmbach Publishing Co.
Keyword: Learning & Memory
Link ID: 16895 - Posted: 06.11.2012
by Zoë Corbyn If you want to enhance your memory, consider moving up a mountain. The spatial recall of mountain chickadees – tiny songbirds that inhabit high regions of the western US – is better the higher up they live. Vladimir Pravosudov of the University of Nevada, in Reno, and his colleagues collected 48 juvenile birds (Poecile gambeli) from three different elevations in the Sierra Nevada mountains. Chickadees that lived just 600 metres higher than others had larger hippocampi – a part of the brain strongly linked to memory. Not only that, they were also better at remembering where food was hidden in lab tests. It makes sense that birds living higher up would have a better memory, says Pravosudov. Mountain chickadees are "scatter hoarders", storing their favourite winter food of pine seeds in thousands of different spots among the trees. At higher altitudes, where it stays cold for longer, birds must store more seeds, and remember where they cached them. The effect could apply to other scatter-hoarding species, says Pravosudov, though he rules out most squirrels and rodents, which are either not active during the winter or put everything in one place and so do not need a better memory. Could global warming change things? Very possibly. "The selection pressure that the winter provides will be less, so the birds are going to get dumber," says Pravosudov. Time to consider a simpler pantry? Journal reference: Animal Behaviour, DOI: 10.1016/j.anbehav.2012.04.018 © Copyright Reed Business Information Ltd.
By Julian De Freitas What did you eat for dinner one week ago today? Chances are, you can’t quite recall. But for at least a short while after your meal, you knew exactly what you ate, and could easily remember what was on your plate in great detail. What happened to your memory between then and now? Did it slowly fade away? Or did it vanish, all at once? Memories of visual images (e.g., dinner plates) are stored in what is called visual memory. Our minds use visual memory to perform even the simplest of computations; from remembering the face of someone we’ve just met, to remembering what time it was last we checked. Without visual memory, we wouldn’t be able to store—and later retrieve—anything we see. Just as a computer’s memory capacity constrains its abilities, visual memory capacity has been correlated with a number of higher cognitive abilities, including academic success, fluid intelligence (the ability to solve novel problems), and general comprehension. For many reasons, then, it would be very useful to understand how visual memory facilitates these mental operations, as well as constrains our ability to perform them. Yet although these big questions have long been debated, we are only now beginning to answer them. Memories like what you had for dinner are stored in visual short-term memory—particularly, in a kind of short-term memory often called “visual working memory.” Visual working memory is where visual images are temporarily stored while your mind works away at other tasks—like a whiteboard on which things are briefly written and then wiped away. We rely on visual working memory when remembering things over brief intervals, such as when copying lecture notes to a notebook. © 2012 Scientific American
Keyword: Learning & Memory
Link ID: 16853 - Posted: 05.31.2012
By Meehan Crist For decades researchers have known that our ability to remember everyday experiences depends on a slender belt of brain tissue called the hippocampus. Basic memory functions, such as forming new memories and recalling old ones, were thought to be performed along this belt by different sets of neurons. Now findings suggest that the same neurons in fact perform both these very different functions, changing from one role to another as they age. The vast majority of these hippocampal neurons, called granule cells, develop when we are very young and remain in place throughout our lives. But about 5 percent develop in adulthood through the birth of new neurons, a process known as neurogenesis. Young granule cells help form new memories, but as they get older they switch roles to helping recall the past. Newer granule cells pick up the slack, taking on the role of helping to form new memories. Susumu Tonegawa of the Massachusetts Institute of Technology and his colleagues published the findings on March 30 in the journal Cell. Tonegawa’s team tested the role of these adult-born cells by genetically engineering mice in which the old cells could be selectively turned off. They then put the mice through a series of mazes and fear-conditioning tests, which demonstrated that young granule cells are essential to forming separate memories of similar events, whereas old granule cells are essential to recalling past events based on small cues. This discovery suggests that memory impairments common in aging and in post-traumatic stress disorder may be connected to an imbalance of old and new cells. “If you don’t have a normal amount of young cells, you may have a problem distinguishing between two events that would be seen as different by healthy people,” Tonegawa says. At the same time, the presence of too many old cells would make it easier to recall traumatic past experiences based on current cues. © 2012 Scientific American,
By Ferris Jabr Lia Kvavilashvili sat in her office at the University of Hertfordshire, mentally reviewing a study she had recently published. She knew that there was a particular statistical measure that might have been useful in the study, but she could not remember its name. Frustrated, she got up to make a cup of tea. Suddenly the word "hurdle" popped into her mind, unannounced, uninvited. Kvavilashvili—who grew up in Georgia speaking Georgian, Russian and Estonian, and only started to learn English at age 13—had no idea what "hurdle" meant. She looked it up in her dictionary. The second definition was underlined. Although she had no conscious recollection of it, Kvavilashvili had evidently looked up the meaning of "hurdle" before. Somehow, she concluded, her subconscious knew that the word was relevant to her difficulty remembering the name of the useful statistical measure. She had just experienced what she and a few other psychologists call "mind-pops"—fragments of knowledge, such as words, images or melodies that drop suddenly and unexpectedly into consciousness. In most cases, mind-pops seem completely irrelevant to the moments in time and thought into which they intrude. But Kvavilashvili is discovering that mind-pops are not truly random—they are linked to our experiences and knowledge of the world, albeit with hidden threads. Research on mind-pops is preliminary, but so far studies suggest that the phenomenon is genuine and common. Some people notice their mind-pops far more often than others and frequent mind-popping could quicken problem solving and boost creativity. However, in some people's minds—such as those with schizophrenia—mind-pops might evolve from benign phenomena into unsettling hallucinations. © 2012 Scientific American