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By Neuroskeptic Claims that children with autism have abnormal brain white matter connections may just reflect the fact that they move about more during their MRI scans. So say a team of Harvard and MIT neuroscientists, including Nancy “Voodoo Correlations” Kanwisher, in a new paper: Spurious group differences due to head motion in a diffusion MRI study. Essentially, the authors show how head movement during a diffusion tensor imaging (DTI) scan causes apparant differences in the integrity of white matter tracts, like these ones: In comparisons of two randomized groups of healthy children – in whom no white matter differences ought to appear – spurious effects were seen whenever one group moved more than the other: As for autism, the authors found that kids with autism moved more, on average, than controls, and that matching the two groups by motion reduced the magnitude of the group differences in white matter (though many remained significant). Technically, the motion-related differences manifested as increases in RD and reductions in FA; these were localized: The pathways that exhibited the most substantial motion-induced group differences in our data were the corpus callosum and the cingulum bundle. Perhaps this is related to their proximity to non-brain voxels (such as the ventricles) … deeper brain areas appear to be more affected than more superﬁcial ones, thus distance from the head coils may also be a factor. The good news is that there’s a simple fix: entering the motion parameters, extracted from the DTI data itself, as a covariate in the analysis. The authors show that this is extremely effective. The bad news is that most researchers don’t do this.
Peter Hildebrand Neuroscience is a rapidly growing field, but one that is usually thought to be too complex and expensive for average Americans to participate in directly. Now, an explosion of cheap scientific devices and online tutorials are on the verge of changing that. This change could have exciting implications for our future understanding of the brain. From 1995 to 2005, the amount of money spent on neuroscience research doubled. A lot of that research used medical devices, like MRI and CT Scan machines, and drugs that everyday citizens don’t have access to. Even in colleges, experience with powerful research equipment is reserved for upperclassmen and graduate students. The lowlier castes can work with models or dissect animal brains, but as scientist and engineer Greg Gage points out in this TED video, the brain isn’t like the heart or the lungs. You can’t tell how it works just by looking at it. Gage is calling for “neuro-revolution,” in which scientists and inventors come together to put the tools for learning neuroscience into the hands of the public. He may be onto something too, because those tools are looking more accessible than ever before. One of the most well publicized examples of this punk rock revolution has been Gage’s own “SpikerBox,” which he co-developed with Tim Marzullo. Roughly the size of your fist, the SpikerBox is a small collection of electronic components bolted between two squares of orange plastic. Coming out of one end are two pins that you can use to record the electrical activity of nerve cells in, say, a recently severed cockroach leg. There’s also a port that allows you to attach the box to a smartphone or tablet, and watch the spikes of activity as the neurons are stimulated. © 2013 Salon Media Group, Inc.
Keyword: Brain imaging
Link ID: 18976 - Posted: 11.26.2013
Scientists at the National Institutes of Health have used RNA interference (RNAi) technology to reveal dozens of genes which may represent new therapeutic targets for treating Parkinson’s disease. The findings also may be relevant to several diseases caused by damage to mitochondria, the biological power plants found in cells throughout the body. “We discovered a network of genes that may regulate the disposal of dysfunctional mitochondria, opening the door to new drug targets for Parkinson’s disease and other disorders,” said Richard Youle, Ph.D., an investigator at the National Institute of Neurological Disorders and Stroke (NINDS) and a leader of the study. The findings were published online in Nature. Dr. Youle collaborated with researchers from the National Center for Advancing Translational Sciences (NCATS). Mitochondria are tubular structures with rounded ends that use oxygen to convert many chemical fuels into adenosine triphosphate, the main energy source that powers cells. Multiple neurological disorders are linked to genes that help regulate the health of mitochondria, including Parkinson’s, and movement diseases such as Charcot-Marie Tooth Syndrome and the ataxias. Some cases of Parkinson’s disease have been linked to mutations in the gene that codes for parkin, a protein that normally roams inside cells, and tags damaged mitochondria as waste. The damaged mitochondria are then degraded by cells’ lysosomes, which serve as a biological trash disposal system. Known mutations in parkin prevent tagging, resulting in accumulation of unhealthy mitochondria in the body.
Ed Yong A large international group set up to test the reliability of psychology experiments has successfully reproduced the results of 10 out of 13 past experiments. The consortium also found that two effects could not be reproduced. Psychology has been buffeted in recent years by mounting concern over the reliability of its results, after repeated failures to replicate classic studies. A failure to replicate could mean that the original study was flawed, the new experiment was poorly done or the effect under scrutiny varies between settings or groups of people. To tackle this 'replicability crisis', 36 research groups formed the Many Labs Replication Project to repeat 13 psychological studies. The consortium combined tests from earlier experiments into a single questionnaire — meant to take 15 minutes to complete — and delivered it to 6,344 volunteers from 12 countries. The team chose a mix of effects that represent the diversity of psychological science, from classic experiments that have been repeatedly replicated to contemporary ones that have not. Ten of the effects were consistently replicated across different samples. These included classic results from economics Nobel laureate and psychologist Daniel Kahneman at Princeton University in New Jersey, such as gain-versus-loss framing, in which people are more prepared to take risks to avoid losses, rather than make gains1; and anchoring, an effect in which the first piece of information a person receives can introduce bias to later decisions2. The team even showed that anchoring is substantially more powerful than Kahneman’s original study suggested. © 2013 Nature Publishing Group
Link ID: 18974 - Posted: 11.26.2013
By Jill U. Adams, Every morning I am greeted by Facebook friends complaining of sleepless nights or awakenings. I know the feeling — as do many other Americans. In a 2005 survey of 1,506 Americans by the National Sleep Foundation, 54 percent reported at least one symptom of insomnia — difficulty falling asleep, waking a lot during the night, waking up too early or waking up feeling unrefreshed — at least a few nights a week over the previous year. Thirty-three percent said they had experienced symptoms almost every night. If insomnia visited me that often, I’d be tempted to pick up something at the pharmacy — something easy, something safe, something that didn’t involve making a doctor’s appointment. Indeed, 10 to 20 percent of Americans take over-the-counter sleep aids each year, according to the American Academy of Sleep Medicine. The way they’re marketed, over-the-counter sleep aids sound very appealing: The new product ZzzQuil (yes, from the maker of NyQuil) promises “a beautiful night’s sleep;” an ad says you’ll “fall asleep faster and stay asleep longer” after using Unisom. Companies marketing the herb valerian root and the hormone melatonin as over-the-counter sleep aids make similar claims. But what’s the evidence that supports these claims? “It’s quite lean,” says Andrew Krystal, who directs the sleep research program at Duke University. Over-the-counter sleep aids work differently from prescription drugs for insomnia. Most are simply antihistamines in sheep’s clothing. (Yes, that’s a joke.) The majority of them — ZzzQuil, TylenolPM and Unisom SleepGels — contain diphenhydramine as the active ingredient, the same compound in Benadryl. (Unisom SleepTabs use doxylamine, another antihistamine.) © 1996-2013 The Washington Post
Link ID: 18973 - Posted: 11.26.2013
By RONI CARYN RABIN Women are more likely than men to die after a heart attack, and some researchers have suggested a reason: Doctors may be misdiagnosing women more often because their symptoms differ from those experienced by men. But a study published Monday indicates that too much has been made of gender differences in chest pain, the hallmark symptom of heart disease. Although the researchers found some distinctions, no pattern was clearly more characteristic of women or could be used to improve heart attack diagnosis in women, the authors concluded. “We should stop treating women differently at the emergency room when they present with chest pain and discomfort,” said Dr. Maria Rubini Gimenez, a cardiologist at University Hospital Basel and lead author of the new study, published in JAMA Internal Medicine. Instead, she said, all patients with acute chest pain must be evaluated for heart attack with appropriate diagnostics, including an electrocardiogram and blood tests. Roughly 80 percent of people who have chest pain and discomfort are suffering from indigestion, acid reflux or another relatively benign condition, said Dr. John G. Canto, director of the chest pain center at Lakeland Regional Medical Center in Lakeland, Fla., who has researched heart attack diagnosis. “The trick is, how do you figure out the 15 to 20 percent actually having a heart attack?” he said. The new research confirms “that there is a lot of overlap in symptoms between patients who are having a heart attack and those who aren’t, and there is a lot of overlap in symptoms between men and women.” The new study examined 2,475 patients, including 796 women, who reported to emergency rooms at nine hospitals in Switzerland, Spain and Italy complaining of acute chest pain between April 21, 2006, and Aug. 12, 2012. Copyright 2013 The New York Times Company
A whiff of oxytocin may help love not fade away. Researchers asked 20 unmarried men in multiyear relationships to rank the attractiveness of pictures of their partner, acquaintances, and strangers. When the men received a nasal spray of oxytocin—which is released by the body during sexual arousal—they rated their partners more highly but not the other women. MRI scans show that after an oxytocin dose, areas of the brain associated with rewards, which also drive drug addiction, were more active when the men saw pictures of their partner, the researchers report online today in the Proceedings of the National Academy of Sciences. The finding could help explain the biological roots of monogamy in humans: Being in a long-term relationship raises a person's oxytocin levels, which in turn increase the psychological reward of spending more time with that person. The cycle, the team concluded, could literally lead to an addiction to one’s lover. © 2013 American Association for the Advancement of Science
By James Gallagher Health and science reporter, BBC News Steroids given to help premature babies develop may also be slightly increasing the risk of mental health disorders, say researchers. The drugs are often given to pregnant mothers at risk of a premature birth to help the baby's lungs prepare for life outside the womb. The study, in the journal PLoS One, showed there was a higher risk of attention disorders at age eight. The charity Bliss said it reinforced the need for regular health checks. Being born too soon can lead to long-term health problems and the earlier the birth the greater the problems. One immediate issue is the baby's lungs being unprepared to breathe air. Steroids can help accelerate lung development. However, the study by researchers at Imperial College London and the University of Oulu in Finland showed the drugs may also be affecting the developing brain. They compared what happened to 37 premature children whose mother was injected with steroids with 185 premature children, of the same weight and gestational age, who were not exposed to the extra dose of steroid. When the children were followed to the age of eight, there was a higher incidence of attention deficit hyperactivity disorder. No difference could be detected at age 16, but this may have been due to the small size of the study. BBC © 2013
By MARY LOU JEPSEN IN my early 30s, for a few months, I altered my body chemistry and hormones so that I was closer to a man in his early 20s. I was blown away by how dramatically my thoughts changed. I was angry almost all the time, thought about sex constantly, and assumed I was the smartest person in the entire world. Over the years I had met guys rather like this. I was not experimenting with hormone levels out of idle curiosity or in some kind of quirky science experiment. I was on hormone treatments because I’d had a tumor removed along with part of my pituitary gland, which makes key hormones the body needs to function. This long journey may have started as early as 1978, when I was 13. I spent a summer in intensive care with an unknown disease. After that summer, I never thought I would live a long life. So I wanted to live, to do interesting, fascinating work in the limited time I thought I had left. I took on the math-intensive art form of holography, and in my early 20s traveled the world, living on university fellowships to pursue this esoteric craft. I didn’t date much, really — perhaps because I didn’t have many hormones, though I didn’t know that at the time. I worked as an artist, played in a band, met Andy Warhol, Christo, Lou Reed and David Byrne. I had fun. But the gravity of my illness grew in the 1990s. The growth that shut down my pituitary gland’s ability to produce hormones did so insidiously over many years. By my early 20s it was, I suspect in retrospect, causing misdiagnosis of symptoms that were most likely caused by lack of hormones like cortisol. No diagnosis was found, despite the efforts of many doctors. I was a doctoral student in electrical engineering at an Ivy League school, but was growing progressively worse. I routinely slept about 20 hours a day, lived with a constant blistering headache and frequent vomiting, and was periodically wheelchair-bound. Large sections of my skin cycled through a rainbow of colors and sores, half of my face wouldn’t move as if Novocain had been applied. I drooled. Worse: I felt stupid. I couldn’t subtract anymore. I couldn’t make a to-do list, let alone accomplish items on one. I recognized that I wasn’t capable of continuing in graduate school. Utterly defeated, I filled out the paperwork to drop out. © 2013 The New York Times Company
By NATASHA SINGER One afternoon a few months ago, a 45-year-old sales representative named Mike called “The Dr. Harry Fisch Show,” a weekly men’s health program on the Howard Stern channel on Sirius XM Radio, where no male medical or sexual issue goes unexplored. “I feel like a 70-year-old man in a 45-year-old body,” Mike, from Vancouver, British Columbia, told Dr. Fisch on the live broadcast. “I want to feel good. I don’t want to feel tired all day.” A regular listener, Mike had heard Dr. Fisch, a Park Avenue urologist and fertility specialist, talk about a phenomenon called “low testosterone” or “low T.” Dr. Fisch likes to say that a man’s testosterone level is “the dipstick” of his health; he regularly appears on programs like “CBS This Morning” to talk about the malaise that may coincide with low testosterone. He is also the medical expert featured on IsItLowT.com, an informational website sponsored by AbbVie, the drug maker behind AndroGel, the best-selling prescription testosterone gel. Like many men who have seen that site or commercials or online quizzes about “low T,” Mike suspected that diminished testosterone was the cause of his lethargy. And he hoped, as the marketing campaigns seem to suggest, that taking a prescription testosterone drug would make him feel more energetic. “I took your advice and I went and got my testosterone checked,” Mike told Dr. Fisch. Mike’s own physician, he related, told him that his testosterone “was a little low” and prescribed a testosterone medication. Mike also said he had diabetes and high blood pressure and was 40 pounds overweight. Dr. Fisch explained that conditions like obesity might be accompanied by decreased testosterone and energy, and he urged Mike to exercise more and to lose weight. But if Mike had trouble overhauling his diet and exercise habits, Dr. Fisch said, taking testosterone might give him the boost he needed to do so. “If it gives you more energy to exercise,” Dr. Fisch said of the testosterone drug, “I’m all for it.” © 2013 The New York Times Company
By Janet Davison, CBC News If headlines in the past few weeks are to be believed, a "Flesh-eating 'zombie' drug" that could devour users "from the inside out" is finding its way onto American streets. Then came reports suggesting that "krokodil," a cheap and highly addictive homemade substitute for heroin that surfaced first in Russia about 10 years ago, had appeared in Ontario's Niagara region. But so far, neither the U.S. Drug Enforcement Agency nor Health Canada has identified krokodil, also known as desomorphine, in any samples they've analyzed since the DEA found two instances of it in 2004. And police in Niagara are now saying the reported cases of the drug — an ugly concoction of codeine mixed with common products such as gasoline, lighter fluid, paint thinner or industrial cleaning oil — haven't been medically confirmed. Krokodil is named for the Russian word for crocodile and its tendency to turn users' skin rough and scaly. The injectable opioid can cause brain damage and severe tissue damage, sometimes leading to gangrene, amputations and even death. It has also been linked to pneumonia, blood poisoning, meningitis, liver and kidney problems, rotting gums and bone infections. The horrific health problems the drug has caused among the well over 100,000 users in Russia and Ukraine have been well documented by researchers in publications such as the International Journal of Drug Policy. But so far there is no solid, official proof that krokodil has reached Canada. The recent news reports about the drug coupled with the lack of hard evidence to back them up underline how difficult it is for health and law enforcement officials to keep up with the evolving mix of street drugs. © CBC 2013
Keyword: Drug Abuse
Link ID: 18967 - Posted: 11.25.2013
by Erika Engelhaupt If you had to have a prosthetic hand, would you want it to look like a real hand? Or would you prefer a gleaming metallic number, something that doesn’t even try to look human? A new study looks at one of the issues that prosthetic designers and wearers face in making this decision: the creepy factor. People tend to get creeped out by robots or prosthetic devices that look almost, but not quite, human. So Ellen Poliakoff and colleagues at the University of Manchester in England had people rate the eeriness of various prosthetic hands. Forty-three volunteers looked at photographs of prosthetic and real hands. They rated both how humanlike (realistic) the hands were and how eerie they were, defined as “mysterious, strange, or unexpected as to send a chill up the spine.” Real human hands were rated both the most humanlike and the least eerie (a good thing for humans). Metal hands that were clearly mechanical were rated the least humanlike, but less eerie overall than prosthetic hands made to look like real hands, the team reports in the latest issue of Perception. The realistic prosthetics, like the rubber hand shown above, fell into what's known as the uncanny valley. That term, invented by roboticist Matsuhiro Mori in 1970, describes how robots become unnerving as they come to look more humanlike. The superrealistic Geminoid DK robot and the animated characters in the movie The Polar Express suffer from this problem. They look almost human, but not quite, and this mismatch between expectation and reality is one of the proposed explanations for the uncanny valley. In particular, if something looks like a human but doesn’t quite move like one, it’s often considered eerie. © Society for Science & the Public 2000 - 2013
Barn owl nestlings recognise their siblings' calls, according to researchers. Instead of competing aggressively for food, young barn owls are known to negotiate by calling out. A team of scientists in Switzerland discovered that the owlets have remarkably individual calls. They suggest this is to communicate each birds' needs and identity in the nest. The findings were announced in the Journal of Evolutionary Biology by Dr Amelie Dreiss and colleagues at the University of Lausanne, Switzerland. Barn owls (Tyto alba) are considered one of the most widespread species of bird and are found on every continent except Antarctica. An average clutch size ranges between four and six eggs but some have been known to contain up to 12. Previous studies have highlighted how barn owl nestlings, known as owlets, negotiate with their siblings for food instead of fighting. While their parents search for food the owlets advertise their hunger to their brothers and sisters by calling out. "These vocal signals deter siblings from vocalizing and from competing for the prey at parental return," explained Dr Dreiss. "If there is a disagreement, they can escalate signal intensity little by little, always without physical aggression, until less hungry siblings finally withdraw from the contest." BBC © 2013
One afternoon in October 2005, neuroscientist James Fallon was looking at brain scans of serial killers. As part of a research project at UC Irvine, he was sifting through thousands of PET scans to find anatomical patterns in the brain that correlated with psychopathic tendencies in the real world. “I was looking at many scans, scans of murderers mixed in with schizophrenics, depressives and other, normal brains,” he says. “Out of serendipity, I was also doing a study on Alzheimer’s and as part of that, had brain scans from me and everyone in my family right on my desk.” “I got to the bottom of the stack, and saw this scan that was obviously pathological,” he says, noting that it showed low activity in certain areas of the frontal and temporal lobes linked to empathy, morality and self-control. Knowing that it belonged to a member of his family, Fallon checked his lab’s PET machine for an error (it was working perfectly fine) and then decided he simply had to break the blinding that prevented him from knowing whose brain was pictured. When he looked up the code, he was greeted by an unsettling revelation: the psychopathic brain pictured in the scan was his own. Many of us would hide this discovery and never tell a soul, out of fear or embarrassment of being labeled a psychopath. Perhaps because boldness and disinhibition are noted psychopathic tendencies, Fallon has gone all in towards the opposite direction, telling the world about his finding in a TED Talk, an NPR interview and now a new book published last month, The Psychopath Inside. In it, Fallon seeks to reconcile how he—a happily married family man—could demonstrate the same anatomical patterns that marked the minds of serial killers. “I’ve never killed anybody, or raped anyone,” he says. “So the first thing I thought was that maybe my hypothesis was wrong, and that these brain areas are not reflective of psychopathy or murderous behavior.”
Robert N. McLay, author of At War with PTSD: Battling Post Traumatic Stress Disorder with Virtual Reality, responds: post-traumatic stress disorder (PTSD) can appear after someone has survived a horrific experience, such as war or sexual assault. A person with PTSD often experiences ongoing nightmares, edginess and extreme emotional changes and may view anything that evokes the traumatic situation as a threat. Although medications and talk therapy can help calm the symptoms of PTSD, the most effective therapies often require confronting the trauma, as with virtual-reality-based treatments. These computer programs, similar to a video game, allow people to feel as if they are in the traumatic scenario. Just as a pilot in a flight simulator might use virtual reality to learn how to safely land a plane without the risk of crashing, a patient with PTSD can learn how to confront painful reminders of trauma without facing any real danger. Virtual-reality programs have been built to simulate driving, the World Trade Center attacks, and combat scenarios in Vietnam and Iraq. The level of the technology varies considerably, from a simple headset that displays rather cartoonish images to Hollywood-quality special effects. A therapist typically observes what patients are seeing while they navigate the virtual experience. They can coach a patient to take on increasingly difficult challenges while making sure that the person does not become overwhelmed. To do so, some therapists may connect the subject to physiological monitoring devices; others may use virtual reality along with talk therapy. In the latter scenario, the patient recites the story of the trauma and reflects on it while passing through the simulation. The idea is to desensitize patients to their trauma and train them not to panic, all in a controlled environment. © 2013 Scientific American
Medical marijuana can alleviate pain and nausea, but it can also cause decreased attention span and memory loss. A new study in mice finds that taking an over-the-counter pain medication like ibuprofen may help curb these side effects. "This is what we call a seminal paper," says Giovanni Marsicano, a neuroscientist at the University of Bordeaux in France who was not involved in the work. If the results hold true in humans, they "could broaden the medical use of marijuana," he says. "Many people in clinical trials are dropping out from treatments, because they say, ‘I cannot work anymore. I am stoned all the time.’ ” People have used marijuana for hundreds of years to treat conditions such as chronic pain, multiple sclerosis, and epilepsy. Studies in mice have shown that it can reduce some of the neural damage seen in Alzheimer's disease. The main psychoactive ingredient, tetrahydrocannabinol (THC), is approved by the Food and Drug Administration to treat anorexia in AIDS patients and the nausea triggered by chemotherapy. Although recreational drug users usually smoke marijuana, patients prescribed THC take it as capsules. Many people find the side effects hard to bear, however. The exact cause of these side effects is unclear. In the brain, THC binds to receptors called CB1 and CB2, which are involved in neural development as well as pain perception and appetite. The receptors are normally activated by similar compounds, called endocannabinoids, that are produced by the human body. When one of these compounds binds to CB1, it suppresses the activity of an enzyme called cyclooxygenase-2 (COX-2). The enzyme has many functions. For instance, painkillers such as ibuprofen and aspirin work by blocking COX-2. Researchers have hypothesized that the suppression of COX-2 could be the cause of THC's side effects, such as memory problems. © 2013 American Association for the Advancement of Science
By R. Douglas Fields San Diego—Would we have Poe’s Raven today if the tormented author had taken lithium to suppress his bipolar illness? Not likely, considering the high frequency of psychiatric illnesses among writers and artists, concluded psychiatrist Kay Jamison of Johns Hopkins Medical School speaking last week at the Society for Neuroscience annual meeting in San Diego. Madness electrifies the creative process, Jamison concluded, but this difficult drug-use dilemma raises an even more provocative question: Would we have Lucy in the Sky with Diamonds had the Beatles not taken LSD? Lord Tennyson, Virginia Woolf and Vincent Van Gogh are familiar examples of artists and writers who suffered serious mental illnesses, but Jamison explained that psychiatric illness was the cruel engine of their creativity. Tracing their family pedigrees, she showed that many of these artists’ siblings, parents and descendants were institutionalized in mental hospitals, committed suicide, or endured life-long struggles with mania, despair, schizophrenia or other mental disorders. The genetic backbone to mental illness is strong. Ernest Hemingway and his supermodel granddaughter Margaux Hemingway both killed themselves. Separated from one another in environment and experience by a generation, their fates were inevitably tethered by their DNA. In all, seven members of the Hemingway family died at their own hand. This raises the question of why the genes of such devastating brain dysfunctions should persist in the human gene pool. Statistics show that among all categories of creative artists, writers suffer by far the highest incidence of bipolar disorder, outstripping all other artistic professions. Why? Jamison concludes that the manic phase of bipolar disorder infuses the writer with furious energy and limitless stamina. The author foregoes sleep, is driven to take daring risks, expands their imagination and embraces grandiose thinking. © 2013 Scientific American
By BENEDICT CAREY Grading college students on quizzes given at the beginning of every class, rather than on midterms or a final exam, increases both attendance and overall performance, scientists reported Wednesday. The findings — from an experiment in which 901 students in a popular introduction to psychology course at the University of Texas took their laptops to class and were quizzed online — demonstrate that the computers can act as an aid to teaching, not just a distraction. Moreover, the study is the latest to show how tests can be used to enhance learning as well as measure it. The report, appearing in the journal PLoS One, found that this “testing effect” was particularly strong in students from lower-income households. Psychologists have known for almost a century that altering the timing of tests can affect performance. In the past decade, they have shown that taking a test — say, writing down all you can remember from a studied prose passage — can deepen the memory of that passage better than further study. The new findings stand as a large-scale prototype for how such testing effects can be exploited in the digital era, experts said, though they cautioned that it was not yet clear how widely they could be applied. “This study is important because it introduces a new method to implement frequent quizzing with feedback in large classrooms, which can be difficult to do,” said Jeffrey D. Karpicke, a professor of psychology at Purdue, who was not involved in the study. He added, “This is the first large study to show that classroom quizzing can help reduce achievement gaps” due to socioeconomic background. © 2013 The New York Times Company
Keyword: Learning & Memory
Link ID: 18960 - Posted: 11.23.2013
by Simon Makin "The only thing we have to fear is fear itself," said Franklin D. Roosevelt. He might have been onto something: research suggests that the anticipation of pain is actually worse than the pain itself. In other words, people are happy to endure a bit more pain, if it means they spend less time waiting for it. Classical theories of decision-making suppose that people bring rewards forward and postpone punishments, because we give far-off events less weight. This is called "temporal discounting". But this theory seems to go out the window when it comes to pain. One explanation for this is that the anticipation of pain is itself unpleasant, a phenomenon that researchers have appropriately termed "dread". To investigate how dread varies with time, Giles Story at University College London, and his colleagues, hooked up 33 volunteers to a device that gave them mild electric shocks. The researchers also presented people with a series of choices between more or less mildly painful shocks, sooner or later. During every "episode" there was a minimum of two shocks, which could rise to a maximum of 14, but before they were given them, people had to make a choice such as nine extra shocks now or six extra shocks five episodes from now. The number of shocks they received each time was determined by these past choices. Although a few people always chose to experience the minimum pain, 70 per cent of the time, on average, participants chose to receive the extra shocks sooner rather than a smaller number later. By varying the number of shocks and when they occurred, the team was able to figure out that the dread of pain increased exponentially as pain approached in time. Similar results occurred in a test using hypothetical dental appointments. © Copyright Reed Business Information Ltd.
By Victoria Gill Science reporter, BBC News Great tits use different alarm calls for different predators, according to a scientist in Japan. The researcher analysed the birds' calls and found they made "jar" sounds for snakes and "chicka" sounds for crows and martens. This, he says, is the first demonstration birds can communicate vocally about the type of predator threatening them. The findings are published in the journal Animal Behaviour. From his previous observations, the researcher, Dr Toshitaka Suzuki, from the Graduate University for Advanced Studies in Kanagawa, found great tits appeared to be able to discriminate between different predators. To test whether they could also communicate this information, he placed models of three different animals that prey on nestlings - snakes, crows and martens - close to the birds' nest boxes. He then recorded and analysed the birds' responses. "Parents usually make alarm calls when they approach and mob the nest predators," said Dr Suzuki. "They produced specific 'jar' alarm calls for the snakes and the same 'chicka' alarm call in response to both the crows and martens," he said. But a closers analysis of the sounds showed the birds had used different "note combinations" in their crow alarm calls from those they had used for the martens. Dr Suzuki thinks the birds might have evolved what he called a "combinatorial communication system" - combining different notes to produce calls with different meanings. Since snakes are able to slither into nest boxes, they pose a much greater threat to great tit nestlings than other birds or mammals, so Dr Suzuki says it makes sense that the birds would have a specific snake alarm call. BBC © 2013