By Laura Sanders An element of surprise may be the key to whitewashing a painful memory. People who encountered something unexpected were better able to shake a troubling association, a new laboratory study finds. The results, published in the Feb. 15 Science, bring scientists closer to being able to weaken traumatic memories with help from a drug. Understanding how the brain forms and reforms traumatic memories might lead to treatments that would help people who suffer from post-traumatic stress disorder and other anxiety disorders. “The idea that an original memory could have the sting taken out of it — that’s been very appealing,” says psychiatrist Roger Pitman of Harvard Medical School and Massachusetts General Hospital, who was not involved in the research. Memories are not written in neural stone. Recent results in animals and humans have shown that once called to mind, painful memories’ emotional edges can be blunted. Experiments have used certain drugs to weaken associations between a memory and a negative response. But the details of how and why those drugs work haven’t been clear. The new result may have uncovered a previously underappreciated step in that weakening process: In order for the emotional response tied to a memory to wither, something unexpected must happen while the person is recalling the memory. This mismatch between what a person expects and what actually happens — called a prediction error — puts a memory into a wobbly, vulnerable form that can be washed out, says study coauthor Merel Kindt of the University of Amsterdam. © Society for Science & the Public 2000 - 2013

Keyword: Learning & Memory; Aggression
Link ID: 17810 - Posted: 02.16.2013

By Samuel McNerney How much does environment influence intelligence? Several years ago University of Virginia Professor Eric Turkheimer demonstrated that growing up in an impoverished and chaotic household suppresses I.Q. – without nurture, innate advantages vanish. What about genes? They matter too. After decades of research most psychologists agree that somewhere between 50% and 80% of intelligence is genetic. After all, numerous studies demonstrate that identical twins raised apart have remarkably similar I.Q.’s. A 2008 paper out of the University of Michigan turned all of this on its head. The researchers led by Susanne M. Jaeggi and Martin Buschkuehl, now at the University of Maryland, found that participants who engaged in short sessions of “cognitive training” that targeted working memory with a simple but difficult game known as the n-back task boosted a core feature of general intelligence called fluid intelligence. Crystalized intelligence improves with age and experience. Fluid intelligence, in contrast, is the capacity to make insights, solve new problems and perceive new patterns to new situations independent of previous knowledge. For decades researchers believed that fluid intelligence was immutable during adulthood because it was largely determined by genetics. The implication of the 2008 study suggested otherwise: with some cognitive training people could improve fluid intelligence and, therefore, become smarter. This brings me to a brand new paper recently published in the journal Neuroscience by DRDC Toronto researcher and Adjunct Assistant Professor of Psychology at the University of Toronto-Scarborough, Oshin Vartanian. In the study, Vartanian and his team asked if working memory training improved performance on a test of divergent thinking known as the Alternate Uses Task. Psychological research demonstrates that divergent thinking “loads” on working memory, meaning that when people engage a divergent thinking task their working memory capacity is accessed accordingly. © 2013 Scientific American,

Keyword: Intelligence; Aggression
Link ID: 17771 - Posted: 02.06.2013

Mo Costandi Deterioration of a specific brain region impairs sleep quality as people age, leading to poorer memory retention, according to research published today in Nature Neuroscience1. Ageing is associated with the gradual loss of brain cells, sleep disturbances and declining memory function, but how these factors are related to each other has been unclear. Neuroscientist Bryce Mander at the University of California, Berkeley, and his colleagues recruited 33 healthy adults — 18 around the age of 20, and 15 ranging from late sixties to late seventies — all with normal mental function, and asked them to memorize a list of word pairs. The participants were asked to recall some of the word pairs ten minutes later, then left to sleep overnight while the researchers recorded the electrical activity of their brains. The next morning, volunteers were asked to recall selected words from the list again while having their brains scanned. In keeping with earlier studies, the older adults performed less well than the younger ones on the memory test, and showed significant reductions in the slow brain waves associated with deep sleep. The extent of deep-sleep disruption was related to the degree of memory impairment, with those exhibiting the least slow-wave activity performing the worst. These differences were also associated with a reduction of grey matter in a part of the brain called the medial prefrontal cortex. © 2013 Nature Publishing Group,

Keyword: Sleep; Aggression
Link ID: 17723 - Posted: 01.28.2013

By Erin Wayman Photographer Bill Wallauer was following a group of chimpanzees in Tanzania’s Gombe Stream National Park one March day when a young female caught his eye. She had climbed a tree, inserted a thin, peeled branch into a hole and was fishing out carpenter ants. Wallauer, of the Jane Goodall Institute, took out his video camera and filmed the chimp as she slurped up insects for several minutes. What Wallauer witnessed wasn’t supposed to happen. Though chimps in other areas use tools to collect carpenter ants, scientists studying the Kasekela chimp community at Gombe had rarely seen the behavior since Jane Goodall began her fieldwork there in 1960. Before Wallauer’s 1994 observation, researchers had seen only one other instance of the behavior, in 1978. This type of tool use was considered a fluke. But when Robert O’Malley, a primatologist now at Kenyon College in Gambier, Ohio, went to Gombe in the late 2000s, he noticed many of the Kasekela chimps regularly fishing for ants. He wondered why, after decades with only a couple of sporadic sightings, ant probing had become a widespread habit. Because of meticulous record keeping at Gombe, O’Malley and his colleagues had a rare opportunity to reconstruct the origin of this behavior. An adult female immigrant who joined the Kasekela group in the early 1990s, the team concluded, introduced ant fishing, a common practice in her previous community. The finding, reported late last year in Current Anthropology, marks the first time in the more than 50-year history of chimp field studies that anyone has documented the transfer of a cultural tradition from one wild chimp group to another. © Society for Science & the Public 2000 - 2013

Keyword: Learning & Memory; Aggression
Link ID: 17720 - Posted: 01.28.2013

By DOUGLAS QUENQUA Learning becomes more difficult as we age not because we have trouble absorbing new information, but because we fail to forget the old stuff, researchers say. Mice whose brains were genetically modified to resemble those of adult humans showed no decrease in the ability to make the strong synaptic connections that enable learning — a surprise to neuroscientists at the Medical College of Georgia at Georgia Regents University, whose findings appear in the journal Scientific Reports. Yet as the modified mice entered adulthood, they were less capable of weakening connections that already existed, and that made it hard for them to form robust new long-term memories. Think of it as writing on a blank piece of white paper versus a newspaper page, said the lead author, Joe Z. Tsien. “The difference is not how dark the pen is,” he said, “but that the newspaper already has writing on it.” The researchers focused on two proteins — NR2A and NR2B — long known to play a role in the forging of new connections in the brain. Before puberty, the brain produces more NR2B than NR2A; in adulthood, the ratio reverses. By prodding mice to produce more NR2A than NR2B, effectively mimicking the postpubescent brain, scientists expected the subjects to have trouble forming strong connections. Instead, the mice showed no trouble creating new short-term memories, but brain scans showed that they struggled to weaken the connections that had formed older long-term memories. © 2013 The New York Times Company

Keyword: Learning & Memory; Aggression
Link ID: 17701 - Posted: 01.22.2013

By Cheryl Murphy Enhancing your level of vision on demand sounds like something out of a comic book. Superman, if you recall, had the power to turn his x-ray vision on and off like a light switch. So is x-ray vision possible? I’m sorry to say: no. The ability of our naked eyes to see through layers of objects remains an idea conjured up in the minds of science fiction writers. However, the possibility of training your brain to flip to a heightened level of visual discrimination and detection whenever you want may in fact be a reality. Last month, researchers in Switzerland found that participants who were successfully trained to consciously up-regulate the level of activity in their early visual cortex as seen by neurofeedback on fMRI in real time were also able to voluntarily give their level of visual discrimination and detection a boost. This study may sound like science fiction but it is not. Here is how it was done. Sixteen, young healthy participants with normal or corrected-to-normal vision were told to focus on a central fixation light while they imagined high resolution pictures of changing color, shape and intensity in a particular part of their visual field which the researchers called the target region of interest. They visualized such things as writing their name in the air, a boat sailing on the ocean, patterns of spinning wheels and spirals, a model walking down the runway or their pet. They received on-the-spot visual feedback indicating how well their visualizations were boosting their brain activity to aid in their brain training. By imagining these detailed objects, seven out of the sixteen participants were able to train themselves to consciously up-regulate activity in areas of their early visual cortex over the course of a series of separate training sessions. In essence what the participants did was learn how to jump-start their visual cortex. Once their visual cortex was held at a higher state of activity, it was more sensitive and could better detect other stimuli in the target region of interest where they projected their visualizations. © 2013 Scientific American

Keyword: Vision; Aggression
Link ID: 17659 - Posted: 01.08.2013

Ed Yong For years, a particular protein has been cast as a lynchpin of long-term memory. Inhibiting this enzyme could erase old memories, whereas adding it could strengthen faded ones1–3. But two independent groups of US scientists have now seriously challenged the role of this 'memory molecule' by developing mice that completely lack it — and showing that these mice have no detectable memory problems. Their results are published today in Nature4, 5. The excitement around the enzyme, called protein kinase M-ζ (PKM-ζ), started building in 2006, when Todd Sacktor at the SUNY Downstate Medical Center in New York City wiped out established spatial memories in rats. He did so by injecting their brains with ZIP, a small peptide that is meant to block the enzyme1. Other teams obtained similar results, erasing different types of memory by injecting ZIP into various brain regions in rodents, flies and sea slugs. And in 2011, Sacktor did the opposite: he strengthened rats' memory of unpleasant tastes by injecting their brains with viruses carrying extra copies of PKM-ζ3. These fascinating studies suggested that long-term memory, rather than being static and stable, is surprisingly fragile, and depends on the continuous activity of a single enzyme. Richard Huganir of Johns Hopkins University in Baltimore, Maryland, was intrigued by these results, but was concerned that much of the data depended on the actions of ZIP. He and his collaborators took a different route, by deleting two genes — one for PKM-ζ and one for a related protein called PKC-ζ — in embryonic mice4. Working independently, Robert Messing and colleagues at the University of California, San Francisco, created similar mice5. © 2013 Nature Publishing Group

Keyword: Learning & Memory
Link ID: 17653 - Posted: 01.05.2013

Barry Gordon The intuitive notion of a “photographic” memory is that it is just like a photograph: you can retrieve it from your memory at will and examine it in detail, zooming in on different parts. But a true photographic memory in this sense has never been proved to exist. Most of us do have a kind of photographic memory, in that most people's memory for visual material is much better and more detailed than our recall of most other kinds of material. For instance, most of us remember a face much more easily than the name associated with that face. But this isn't really a photographic memory; it just shows us the normal difference between types of memory. Even visual memories that seem to approach the photographic ideal are far from truly photographic. These memories seem to result from a combination of innate abilities, combined with zealous study and familiarity with the material, such as the Bible or fine art. Sorry to disappoint further, but even an amazing memory in one domain, such as vision, is not a guarantee of great memory across the board. That must be rare, if it occurs at all. A winner of the memory Olympics, for instance, still had to keep sticky notes on the refrigerator to remember what she had to do during the day. So how does an exceptional, perhaps photographic, memory come to be? It depends on a slew of factors, including our genetics, brain development and experiences. It is difficult to disentangle memory abilities that appear early from those cultivated through interest and training. Most people who have exhibited truly extraordinary memories in some domain have seemed to possess them all their lives and honed them further through practice. © 2012 Scientific American

Keyword: Learning & Memory
Link ID: 17645 - Posted: 01.01.2013

By DAVID DOBBS Psychological trauma dims tens of millions of lives around the world and helps create costs of at least $42 billion a year in the United States alone. But what is trauma, exactly? Both culturally and medically, we have long seen it as arising from a single, identifiable disruption. You witness a shattering event, or fall victim to it — and as the poet Walter de la Mare put it, “the human brain works slowly: first the blow, hours afterward the bruise.” The world returns more or less to normal, but you do not. In 1980, the Diagnostic and Statistical Manual of Mental Disorders defined trauma as “a recognizable stressor that would evoke significant symptoms of distress in almost everyone” — universally toxic, like a poison. But it turns out that most trauma victims — even survivors of combat, torture or concentration camps — rebound to live full, normal lives. That has given rise to a more nuanced view of trauma — less a poison than an infectious agent, a challenge that most people overcome but that may defeat those weakened by past traumas, genetics or other factors. Now, a significant body of work suggests that even this view is too narrow — that the environment just after the event, particularly other people’s responses, may be just as crucial as the event itself. The idea was demonstrated vividly in two presentations this fall at the Interdisciplinary Conference on Culture, Mind and Brain at the University of California, Los Angeles. Each described reframing a classic model of traumatic experience — one in lab rats, the other in child soldiers. © 2012 The New York Times Company

Keyword: Stress; Aggression
Link ID: 17637 - Posted: 12.27.2012

By GRETCHEN REYNOLDS Anyone whose resolve to exercise in 2013 is a bit shaky might want to consider an emerging scientific view of human evolution. It suggests that we are clever today in part because a million years ago, we could outrun and outwalk most other mammals over long distances. Our brains were shaped and sharpened by movement, the idea goes, and we continue to require regular physical activity in order for our brains to function optimally. The role of physical endurance in shaping humankind has intrigued anthropologists and gripped the popular imagination for some time. In 2004, the evolutionary biologists Daniel E. Lieberman of Harvard and Dennis M. Bramble of the University of Utah published a seminal article in the journal Nature titled “Endurance Running and the Evolution of Homo,” in which they posited that our bipedal ancestors survived by becoming endurance athletes, able to bring down swifter prey through sheer doggedness, jogging and plodding along behind them until the animals dropped. Endurance produced meals, which provided energy for mating, which meant that adept early joggers passed along their genes. In this way, natural selection drove early humans to become even more athletic, Dr. Lieberman and other scientists have written, their bodies developing longer legs, shorter toes, less hair and complicated inner-ear mechanisms to maintain balance and stability during upright ambulation. Movement shaped the human body. But simultaneously, in a development that until recently many scientists viewed as unrelated, humans were becoming smarter. Their brains were increasing rapidly in size. Copyright 2012 The New York Times Company

Keyword: Evolution; Aggression
Link ID: 17635 - Posted: 12.27.2012

Julian Richards, deputy editor, newscientist.com Let's take it from the top again... Human singing stars these days rely on Auto-Tune technology to produce the right pitch, but this songbird does it the old way - by listening out for its own mistakes. And it's also smart enough to ignore notes that are too far off to be true. Brains monitor their owners' physical actions via the senses, and use this feedback to correct mistakes in those actions. Many models of learning assume that the bigger the perceived mistake, the bigger the correction will be. Samuel Sober at Emory University in Atlanta, Georgia, and Michael Brainard of the University of California, San Francisco, suspected that the system is a bit cleverer than that - otherwise, for instance, a bird might over-correct its singing if it confused external sounds with its own voice, or if its brain made a mistake in processing sounds. They decided to fool Bengalese finches into thinking that they were singing out of tune, and measured what happened at different levels of this apparent tone-deafness. To do this, they fitted the birds with the stylish headphones shown in the photo above and fed them back the sound of their own singing, processed to sound sharper than it really was. The researchers sharpened the birdsong by degrees ranging from a quarter-tone to one-and-a-half tones. They found that the birds learned to "correct" their pitch more accurately and more quickly when they heard a smaller mistake than when they heard a large one. It was also clear that the bird brains took "errors" seriously when they fell within the normal range of pitches in the bird's song: the birds seemed to ignore errors outside this range. © Copyright Reed Business Information Ltd

Keyword: Hearing; Aggression
Link ID: 17627 - Posted: 12.22.2012

By Jason G. Goldman While second nature to many of us, driving a car is actually a fairly complex process. At its most stripped down version, first you sit in the driver’s seat, then you start the engine, then you shift into gear, and then you must simultaneously steer while keeping your foot on the gas pedal. That doesn’t include things like adjusting your mirrors, verifying that you won’t drive into another person or car, and so on. In one sense, it is incredibly impressive that three dogs in New Zealand have learned – in a fairly rudimentary way – to drive a car. They sit in the driver’s seat, shift into gear, operate the steering wheel, and step on the accelerator. Those deserving the true accolades however are not the dogs, but the human trainers for their impressive patience and determination. The training that led man’s best friend to operate a car is no different from the kind of training behind the bird shows found at zoos all over the world, or the dolphin, killer whale, seal, or sea lion displays you might see at Sea World. It’s the same kind of training that scientists use to probe the emotional and cognitive lives of rats, mice, and the other critters that populate their laboratories. At the end of the day, it all comes down to a form of learning first described by Edward L. Thorndike at the beginning of the 1900s, which was later expanded and popularized by B.F. Skinner and taught to every student of Introductory Psychology: operant conditioning. While classical conditioning is a form of learning that binds external stimuli to reflexive, involuntary responses, operant conditioning involves voluntary behaviors, and is maintained over time by the consequences that follow those behaviors. In one experiment, Skinner placed pigeons individually into experimental chambers (sometimes referred to as “Skinner boxes”) that were designed to deliver food rewards at systematic intervals. He found that by rewarding a bird after it displayed a desired behavior, he could motivate the bird to increase the frequency of that particular behavior. © 2012 Scientific American

Keyword: Learning & Memory
Link ID: 17607 - Posted: 12.14.2012

By Brian Mossop Ten years into serving a life sentence for the rape of Jennifer Thompson, Ronald Cotton stepped out of prison a free man. It took that long for DNA evidence to exonerate Cotton, refuting a weak case built mostly on eyewitness accounts. According to Simon's new book In Doubt, despite advances in DNA forensic technologies, eyewitness testimony remains the most common way to nab criminals in the Anglo-American justice system. The problem, however, is that our mind often subconsciously twists the evidence to coincide with our biases, and we end up incarcerating innocent people. Simon, a professor of law and psychology at the University of Southern California, says that the false conviction rate, based on exoneration data from capital murder cases, is estimated to be near 5 percent, although that figure represents only a fraction of those wrongly imprisoned. Eyewitness testimony boils down to how well the witness remembers the event. Studies have shown that a victim of a crime may remember a specific piece of information from the horrid event, such as the attacker's jacket or a strange smell, but fail to recall other details. Investigators are left with a weak profile of the perpetrator. In Cotton's case, the victim initially chose two men from the lineup, and only after repeated questioning from investigators could Thompson say Cotton was her assailant. © 2012 Scientific American

Keyword: Learning & Memory
Link ID: 17564 - Posted: 12.03.2012

Smoking "rots" the brain by damaging memory, learning and reasoning, according to researchers at King's College London. A study of 8,800 people over 50 showed high blood pressure and being overweight also seemed to affect the brain, but to a lesser extent. Scientists involved said people needed to be aware that lifestyles could damage the mind as well as the body. Their study was published in the journal Age and Ageing. Researchers at King's were investigating links between the likelihood of a heart attack or stroke and the state of the brain. Data about the health and lifestyle of a group of over-50s was collected and brain tests, such as making participants learn new words or name as many animals as they could in a minute, were also performed. They were all tested again after four and then eight years. Decline The results showed that the overall risk of a heart attack or stroke was "significantly associated with cognitive decline" with those at the highest risk showing the greatest decline. It also said there was a "consistent association" between smoking and lower scores in the tests. BBC © 2012

Keyword: Drug Abuse; Aggression
Link ID: 17534 - Posted: 11.26.2012

By Simon J Makin “One hundred repetitions three nights a week for four years – sixty-two thousand four hundred repetitions make one truth.” These are the thoughts of Bernard Maxwell as he reflects on The World State’s sleep-teaching technique, hypnopaedia, in Aldous Huxley’s Brave New World, before concluding: “Idiots!” Huxley was using the idea to explore social conditioning and control in a dystopian future, rather than what we might call “useful” learning, but the promise of effortless learning while we sleep is an idea that refuses to go away, as evidenced by the continued existence of dubious sleep learning “courses”. The possibility was dismissed scientifically in the 1950s after an experiment showing that people who were played the answers to a list of questions while they slept could not recall any of them the next day, unless they had also shown electrical brain activity indicating they were waking up. But evidence is now growing that the sleeping brain can, in fact, be taught in certain, limited ways. The most striking demonstration of this comes from a recent study published in Nature Neuroscience, in which people learned to associate sounds with smells while they were asleep. Pleasant and unpleasant odours were paired with different sounds played to sleeping participants and their “sniff responses” were measured. Pleasant smells provoked stronger sniffs and when the sounds paired with these smells were later played alone they still provoked stronger sniffs than those that had been paired with unpleasant odours. This was true both while the participants were still asleep and after they awoke and, unsurprisingly, they had no awareness of having learned anything. This is a limited form of learning known as conditioning, famous since Pavlov and his dog, and it can’t be used for learning anything as complex as, say, language vocab. © 2012 Scientific American

Keyword: Sleep; Aggression
Link ID: 17522 - Posted: 11.21.2012

Sandrine Ceurstemont, editor, New Scientist TV Improving your mathematical skills could now be as easy as playing a Kinect video game in a hat. In preliminary tests of the system, developed by Roi Cohen Kadosh and colleagues from the University of Oxford, participants were better with numbers after just two days of training. In this video, our technology features editor Sally Adee gives the game a go while testing a new cap that wirelessly delivers electrical brain stimulation. The device is controlled by a computer, which controls things like the duration of the zapping. Although it can stimulate various brain regions, in this case it sends current to the right parietal cortex. "The parietal region is involved in numerical understanding," says Cohen Kadosh. "So amplifying the function of this region should lead to a better performance." So far, the team has shown that brain stimulation while doing computer-based mathematics exercises helped maintain better mathematical skills in adults even six months later. But Cohen Kadosh thinks that the Kinect game is much more promising as a training tool because it's fun and engaging. By requiring a player to represent a fraction by moving their body to position it on a line, the gameplay also integrates three key components linked to mathematical ability: numerical understanding, the ability to perceive the spatial relationship of visual representations and embodiment. Cohen Kadosh believes this enhances the training. © Copyright Reed Business Information Ltd

Keyword: Intelligence; Aggression
Link ID: 17500 - Posted: 11.17.2012

By Hal Arkowitz and Scott O. Lilienfeld When Mick Jagger first sang “What a drag it is getting old,” he was 23 years old. Now at 69, he is still a veritable Jumpin' Jack Flash on stage. Jagger seems to have found the secret to staying physically fit in his advancing years, but getting old can be a drag on the psyche. Many older adults fear memory loss and worry they are headed down the road to dementia, such as Alzheimer's disease. Every time they forget their keys, leave a door unlocked or fail to remember a name, they are reminded of this nagging concern. In most cases, however, such annoying incidents are part of normal age-related memory loss, not a sign of impending dementia. Although lots of older adults think such a decline is inevitable, there is good news for many of them. Researchers have developed an array of helpful methods and activities that exercise our minds and bodies that can help keep the older mind in relatively good condition. In this column, we examine the most promising ways to shore up memory in the normal aging brain. Memory is not a single entity. The term encompasses several types of remembering, not all of which decline with age. For instance, older people still retain their vocabulary, along with general knowledge about the world (semantic memory). They can also perform certain routine tasks, such as making an omelet or typing on a computer (procedural memory), about as well as they could when they were younger. People do become worse, however, at recalling recent events in their lives (episodic memory) or where they first learned a piece of information (source memory), managing the temporary storage of short-term information (working memory), and remembering to do things in the future (prospective memory). © 2012 Scientific American

Keyword: Learning & Memory; Aggression
Link ID: 17491 - Posted: 11.14.2012

By SINDYA N. BHANOO Fairywrens teach their chicks a password, a unique note, to differentiate them from imposters. “We call this an incubation call,” said Mark Hauber, an animal behaviorist at Hunter College at the City University of New York and an author of the study, which appears in the journal Current Biology. “The more times the mother calls, the better the mimicry of the chicks.” The teaching begins a few days before the birds hatch. And while “the cuckoo chick is very adaptable and tries out many begging calls until it sounds similar to the fairywren,” Dr. Hauber said, it also has a shorter incubation period. So it hatches several days before fairywren chicks, leaving it little time to practice and perfect the passwordlike call of the fairywren mother. Generally, when a cuckoo hatches it throws out the other eggs in the nest. When a mother does not hear her unique call from her babies, she abandons the nest. Male fairywrens help their mates care for their young, so the mother teaches her mate and any other helpers the password through the performance of a special song. “In the future we’d like to do some brain imaging on the embryos using noninvasive functional M.R.I.’s,” Dr. Hauber said. “We want to see how these embryos are listening, practicing and learning these relevant vocalizations.” © 2012 The New York Times Company

Keyword: Sexual Behavior; Aggression
Link ID: 17485 - Posted: 11.13.2012

By GRETCHEN REYNOLDS In recent years, some research has suggested that a high-fat diet may be bad for the brain, at least in lab animals. Can exercise protect against such damage? That question may have particular relevance now, with the butter-and cream-laden holidays fast approaching. And it has prompted several new and important studies. The most captivating of these, presented last month at the annual meeting of the Society for Neuroscience in New Orleans, began with scientists at the University of Minnesota teaching a group of rats to scamper from one chamber to another when they heard a musical tone, an accepted measure of the animals’ ability to learn and remember. For the next four months, half of the rats ate normal chow. The others happily consumed a much greasier diet, consisting of at least 40 percent fat. Total calories were the same in both diets. After four months, the animals repeated the memory test. Those on a normal diet performed about the same as they had before; their cognitive ability was the same. The high-fat eaters, though, did much worse. Then, half of the animals in each group were given access to running wheels. Their diets didn’t change. So, some of the rats on the high-fat diet were now exercising. Some were not. Ditto for the animals eating the normal diet. For the next seven weeks, the memory test was repeated weekly in all of the groups. During that time, the performance of the rats eating a high-fat diet continued to decline so long as they didn’t exercise. Copyright 2012 The New York Times Company

Keyword: Obesity; Aggression
Link ID: 17468 - Posted: 11.08.2012

Seniors who take common medications to treat insomnia, anxiety, itching or allergies may have symptoms of forgetfulness or trouble concentrating, a new review concludes. About 90 per cent of people aged 65 and older take at least one prescription medication and almost half take five or more, studies suggest. About 90 per cent of people aged 65 and older take at least one prescription medication, U.S. research suggests.About 90 per cent of people aged 65 and older take at least one prescription medication, U.S. research suggests. (iStock) As people increasingly report memory and attention problems and seek testing for early dementia, researchers in Montreal wanted to see how medications can induce such symptoms. Dr. Cara Tannenbaum, research chair at the Montreal Geriatric University Institute and her co-authors in Montreal, Calgary, Australia and the U.S. reviewed 162 studies on medications most likely to affect memory, creating what's called an amnesia effect, or affect brain functions like attention and concentration that are called non-amnestic. "There is a consistent body of evidence suggesting that drug-induced mild cognitive impairment can occur with episodic use of medications for insomnia, anxiety, [itching] or allergy symptoms," the study's authors concluded in the journal Drugs & Aging. "Combined amnestic and non-amnestic deficits occur with the use of benzodiazepine agents and may partially underlie older adults' frequent complaints of forgetfulness or difficulty concentrating." © CBC 2012

Keyword: Learning & Memory; Aggression
Link ID: 17465 - Posted: 11.07.2012