By Jason G. Goldman In 1976, psychologists John and Sandra Condry of Cornell University had 204 human adults view videotaped footage of an infant boy named David and infant girl named Dana, and asked them to describe the infants’ facial expressions and dispositions. They described their findings in an article in the journal Child Development. In the video, infants were shown responding to various stimuli, which were not visible to the viewer. For example, they’d be shown a teddy bear, so that their reaction could be recorded. They were also videotaped responding to a loud buzzer and to a jack-in-the-box. Participants described David’s response to the jack-in-the-box, for example, as “anger,” while they described Dana’s response to the same toy as “fear.” Participants rated David’s emotional responses to all three stimuli as more “intense” than Dana’s. Here’s the catch: David and Dana were the same infant. Each of the experiment participants were shown the same video of the same infant. Half of them were told the infant was a nine-month-old boy named David, and half were told the infant was a nine-month-old girl named Dana. That they described the “two” infants in such different ways was evidence that the participants’ perceptions were at least based in part upon pre-existing biases and preconceptions about the different ways in which boys and girls experience the world. Now, a group of researchers from Tokyo and Berlin have published a new finding about the relationship between personality and genetics in captive elephants. They collected genetic information from the blood, feces, tissues, cheek swabs, or hair of 196 Asian (Elephas maximus) and African elephants (Loxodonta africana) in Japanese, American, and Canadian zoos, and sanctuaries in Thailand. Personality information was collected for a seventy-five of those elephants by distributing to questionnaires to their keepers. Each elephant was assessed by more than one keeper. An improved understanding of elephant personality would be not only extremely interesting from a basic science perspective, but also extremely useful for more effectively maintaining captive elephant populations in zoos and sanctuaries. The better that zookeepers and curators understand the psychology of the animals in their collections, the better the quality of care can be, which directly impacts animal welfare. © 2012 Scientific American  

Keyword: Genes & Behavior
Link ID: 17313 - Posted: 09.29.2012

  Sandrine Ceurstemont, editor, New Scientist TV Think an object can't be in two places at once? This animation shows how the perceived location of a dot is influenced by what's happening around it. In this video, a flashing dot is surrounded by two diamonds that shift across the screen. When they move horizontally, the dot seems to shift sideways and slightly upwards. In a second version, in which the corners of the diamonds are obscured, the dot appears to move diagonally. In fact, the dot never changes place. The illusion is the work of Peter Kohler from Dartmouth College in Hanover, New Hampshire, and his team. Kohler has been trying to determine if the dot's perceived shift in position is caused by the overall motion of the diamonds or that of its components. For example, although the shapes as a whole are moving sideways, viewing the edges in isolation shows that segments of the diamonds are moving upwards. "Our results show that global motion does influence the shift," he says. "But the fact that even the unoccluded diamond does not yield a purely horizontal shift indicates that local signals are also very important." The team now plans to investigate how quickly our brain perceives the shift. "Integration of local and global motion is known to take about 150 milliseconds," says Kohler. "It would be interesting to see if the effect takes a similar amount of time to kick in." By presenting the illusion for very short amounts of time, the researchers will be able to determine if different versions are initially perceived in the same way. "We also have fMRI work under way to identify brain areas that represent the perceived shifted location rather than the actual location," says Kohler. The illusion was recently presented at the European Conference on Visual Perception in Alghero, Italy. © Copyright Reed Business Information Ltd.  

Keyword: Vision
Link ID: 17312 - Posted: 09.29.2012

By Gary Stix 14 inSharHuntington’ disease, which killed folk singer Woody Guthrie, seems to put into overdrive the main chemical that turns on brain cells, ultimately leading to their death. The normal function of the neurotransmitter glutamate, the chemical overproduced in Huntington’s, is also intimately involved with learning. Researchers from Ruhr University and the University of Dortmund in Germany have been intrigued by the question of whether the neurodegeneration initiated by glutamate in this genetic disorder is all bad. Is it simply  burning out brain circuits? Or might an excess of the chemical also help presymptomatic carriers of the Huntington’s gene or even patients with the disease itself,  learn some things faster or better? “Neurotransmission causes cell death but we know from the vast amount of literature that learning processes very much depend on glutamate neurotransmission; so there may be two effects of one and the same process,” says Christian Beste of Ruhr University. “On the one hand this process may lead to neurodegeneration. But on the other hand, it may augment a cognitive process that depends on glutamate transmission.” Beste is the lead author on a paper published this month in Current Biology that found that those who have the genetic mutation for Huntington’s but who have yet to develop inevitable symptoms of the disease perform better on a learning task than a control group that lacks the mutation. The 29 Huntington’s gene carriers learned to detect twice as fast as the 45 controls a change in brightness of a small bar as its orientation on a computer screen altered. In fact, the Huntington’s carriers with the most pronounced mutations—the number of repetitions of a short DNA segment determines how early disease onset occurs—logged the best performance. © 2012 Scientific American,  

Keyword: Huntingtons
Link ID: 17311 - Posted: 09.29.2012

by Melissa Lee Phillips Giving a whole new meaning to "pregnancy brain," a new study shows that male DNA—likely left over from pregnancy with a male fetus—can persist in a woman's brain throughout her life. Although the biological impact of this foreign DNA is unclear, the study also found that women with more male DNA in their brains were less likely to have suffered from Alzheimer's disease—hinting that the male DNA could help protect the mothers from the disease, the researchers say. During mammalian pregnancy, the mother and fetus exchange DNA and cells. Previous work has shown that fetal cells can linger in the mother's blood and bone for decades, a condition researchers call fetal microchimerism. The lingering of the fetal DNA, research suggests, may be a mixed blessing for a mom: The cells may benefit the mother's health—by promoting tissue repair and improving the immune system—but may also cause adverse effects, such as autoimmune reactions. One question is how leftover fetal cells affect the brain. Researchers have shown that fetal microchimerism occurs in mouse brains, but they had not shown this in humans. So a team led by autoimmunity researcher and rheumatologist J. Lee Nelson of the Fred Hutchinson Cancer Research Center in Seattle, Washington, took samples from autopsied brains of 59 women who died between the ages of 32 and 101. By testing for a gene specific to the Y chromosome, they found evidence of male DNA in the brains of 63% of the women. (The researchers did not have the history of the women's pregnancies.) The male DNA was scattered across multiple brain regions, the team reports online today in PLoS ONE. © 2010 American Association for the Advancement of Science

Keyword: Development of the Brain; Sexual Behavior
Link ID: 17310 - Posted: 09.27.2012

By James Gallagher Health and science reporter, BBC News Too many people may be damaging their health by self-medicating with sleeping pills, according to the Royal Pharmaceutical Society. It said half of people with insomnia diagnosed themselves and took medication without seeking medical advice. However, the society said insomnia was often part of other physical or mental health problems which needed treating. The warning was based on the findings of a survey of 2,077 people. Insomnia is difficulty in getting to sleep, staying asleep or getting enough good quality sleep night after night. One in three people in the UK are thought to have bouts of insomnia. It can be caused by psychiatric problems such as depression, anxiety disorders and schizophrenia. Other illnesses including heart disease, Alzheimer's disease and hormonal problems can also disturb the normal pattern of sleep. In the survey, 30% of people said they had taken sleeping pills for more than a month without getting advice while 14% had gone six months. One pharmacist, Paul Johnson, said: "It's worrying that so many people are overusing sleeping remedies. "They can be effective for short-term treatment of mild insomnia but should not be taken for long periods without advice because they can hide a serious health problem which could get worse if it remains untreated. BBC © 2012

Keyword: Sleep
Link ID: 17309 - Posted: 09.27.2012

FRANK JORDANS, Associated Press BERLIN (AP) — More than half the cases of severe intellectual disability caused by genetic defects are the result of random mutations, not inherited, a European study published Thursday suggests. The findings of the small-scale study give hope to parents of children born with a severe intellectual disabilities who are worried about having another baby with the same condition, said Anita Rauch, a researcher at the Institute of Medical Genetics in Zurich who was one of the study's lead authors. It examined the genetic makeup of 51 children, both of their parents and a control group. The study concluded that in at least 55 percent of cases there was no evidence that parents carried faulty genes responsible for the disability. "The average chances of having another child with the same disability are usually estimated at eight percent, but if we know that it was caused by a random mutation the chances of recurrence drop dramatically," Rauch said. Hans-Hilger Ropers, the director of Berlin's Max Planck Institute for Molecular Genetics, who was not involved in the study, said the basic science appeared sound but noted that it excluded children whose parents were blood relatives and so the results could be biased toward random mutations. Ropers said a larger study that included subjects from parts of the world where marriage between blood relatives is more common could produce different results. © 2012 Hearst Communications Inc.

Keyword: Development of the Brain; Genes & Behavior
Link ID: 17308 - Posted: 09.27.2012

Clint Witchalls James R. Flynn is Professor Emeritus at the University of Otago, New Zealand. Flynn researches intelligence and is best known for the discovery that, over the past century, IQs have been rising at a rate of about 3 points per decade (the Flynn-effect). In advance of his new book on the subject, Clint Witchalls asked him about this and some of Professor Flynn's more recent research findings: Clint Witchalls: How has our way of thinking and of solving problems changed over the past century? James R. Flynn: Today we take it for granted that using logic on the abstract is an ability we want to cultivate and we are interested in the hypothetical. People from 1900 were not scientifically oriented but utilitarian and they used logic, but to use it on the hypothetical or on abstractions was foreign to them. Alexander Luria [a Soviet psychologist] went to talk to headmen in villages in rural Russia and he said to them: "Where there is always snow, bears are white. At the North Pole there is always snow, what colour are the bears there?" And they said: "I've only seen brown bears." And he said: "What do my words convey?" And they said: "Such a thing as not to be settled by words but by testimony." They didn't settle questions of fact by logic, they settled them by experience. Your research found that we have gained 30 points on IQ tests in a century. What is the reason? The ultimate cause of why IQs are rising is the industrial revolution. The proximate cause is how our minds differ from people in 1900 when in the test room. And the intermediate causes, of course, are more cognitively demanding work roles, more cognitively demanding leisure, more formal schooling, and smaller families. © independent.co.uk

Keyword: Intelligence; Learning & Memory
Link ID: 17307 - Posted: 09.27.2012

by Jessica Hamzelou ALZHEIMER'S disease is more prevalent in older people, but we have never known why. Now it seems that about 80 per cent of our brain cells are vulnerable to a process that can turn them toxic. For the first time, cells in the brains of people with Alzheimer's have been shown to "senesce" - a mechanism that stops them dividing and starts them on a path of destruction. With hundreds of experimental treatments for the disease falling by the wayside, we need a new target and it seems as if we have now found one. The discovery of huge numbers of senescent cells in people with Alzheimer's suggests that they play a key role in the condition. Cells that continually replicate in the body, such as those in the skin, lung and kidney, eventually accumulate DNA damage - typically with age. Not all of these damaged cells die though, instead some senesce. When this happens, biological changes within the cell prevent it from dividing or carrying out its normal functions. Research suggests that senescing cells also start producing proteins that trigger inflammation. "It's pretty clear that cell senescence evolved to protect us against cancer," says Judith Campisi of the Buck Institute for Research on Aging in Novato, California. The idea is that once cells accumulate DNA damage, they senesce to avoid incorrect division that can lead to cancer. The benefit of this mechanism over self-destruction is that it sends out a call to the immune system to destroy nearby cells that might also be affected. © Copyright Reed Business Information Ltd.

Keyword: Alzheimers
Link ID: 17306 - Posted: 09.27.2012

By Sandra G. Boodman, The 80th birthday party for Josephine van Es marked two milestones, only one of which was apparent at the time. Held in November 2004 at her daughter’s house in Rehoboth Beach, Del., the event was a celebration of her longevity, good health and loving family. It also marked one of the last times van Es can remember feeling well and not beset by the pain that developed soon afterward and has left the inside of her mouth feeling perpetually scalded and with a constant metallic taste. “It’s awful,” said van Es, 87, who says the burning is worse than the taste, which she likens to “sucking on a penny.” Her daughter Karen van Es says that her mother’s problem has taken a toll on both their lives. For nearly eight years, she has taken time from her job at a Northern Virginia veterinary clinic to ferry her mother, who lives independently in a condominium in Lewes, Del., to doctors in Delaware, Philadelphia and Washington. She also has contacted specialists in Florida and Canada hoping one would propose an effective remedy for an ailment that took more than a year to diagnose and has so far eluded treatment. “She tells me, ‘I just feel rotten all the time,’ ” said Karen van Es, 63, an only child who speaks to her mother every day and sees her often. “My mother has lost confidence as a result of this,” Karen van Es said, adding that she often feels helpless and frustrated about not being able to do more. © 1996-2012 The Washington Post

Keyword: Chemical Senses (Smell & Taste); Pain & Touch
Link ID: 17305 - Posted: 09.26.2012

By GRETCHEN REYNOLDS Can you improve your body’s ability to remember by making it move? That rather odd-seeming question stimulated researchers at the University of Copenhagen to undertake a reverberant new examination of just how the body creates specific muscle memories and what role, if any, exercise plays in the process. To do so, they first asked a group of young, healthy right-handed men to master a complicated tracking skill on a computer. Sitting before the screen with their right arm on an armrest and a controller similar to a joystick in their right hand, the men watched a red line squiggle across the screen and had to use the controller to trace the same line with a white cursor. Their aim was to remain as close to the red squiggle as possible, a task that required input from both the muscles and the mind. The men repeated the task multiple times, until the motion necessary to track the red line became ingrained, almost automatic. They were creating a short-term muscle memory. The term “muscle memory” is, of course, something of a misnomer. Muscles don’t make or store memories. They respond to signals from the brain, where the actual memories of any particular movement are formed and filed away. But muscle memory — or “motor memory,” as it is more correctly referred to among scientists — exists and can be quite potent. Learn to ride a bicycle as a youngster, abandon the pastime and, 20 years later, you’ll be able to hop on a bicycle and pedal off. Copyright 2012 The New York Times Company

Keyword: Learning & Memory
Link ID: 17304 - Posted: 09.26.2012

By Gary Stix Market researcher SharpBrains has predicted that the brain fitness industry will range anywhere from $2 billion to $8 billion in revenues by 2015. That’s a wide swath, but the companies that sell brain-tuning software could conceivably hit at least the low end of their sales target by then. The question that persists is whether any of these games and exercises actually enhance the way your brain works, whether it be memory, problem solving or the speed with which you execute a mental task. True, study participants often get better at doing an exercise that is supposedly related to a given facet of cognition. But the ability to master a game or ace a psych test often doesn’t translate into better cognition when specific measures of intelligence are assayed later. One area of research that has shown some promise relates to a method of boosting the mental scratchpad of working memory— keeping in your head a telephone number long enough to dial, for instance. Some studies have demonstrated that a particular technique to energize working memory betters the reasoning and problem-solving abilities known as fluid intelligence. Yet two new studies have now called into question the earlier research on working memory. A recent online publication in the Journal of Experimental Psychology led by a group at the Georgia Institute of Technology showed that 20 sessions on a working memory task did not did not result in a later acing of tests of cognitive ability. Similarly, a group at Case Western Reserve University tried the same “dual n-back test” and published a report in the journal Intellgence that found that better scores did not produce higher tallies for working memory and fluid intelligence. An n-back test requires keeping track of a number, letter or image “n” places back. A dual n-back demands the simultaneous remembering of both a visual and auditory cue perceived a certain number of places back. © 2012 Scientific American

Keyword: Learning & Memory
Link ID: 17303 - Posted: 09.26.2012

The brain that revolutionized physics now can be downloaded as an app for $9.99. But it won't help you win at Angry Birds. While Albert Einstein's genius isn't included, an exclusive iPad application launched Tuesday promises to make detailed images of his brain more accessible to scientists than ever before. Teachers, students and anyone who's curious also can get a look. A medical museum under development in Chicago obtained funding to scan and digitize nearly 350 fragile and priceless slides made from slices of Einstein's brain after his death in 1955. The application will allow researchers and novices to peer into the eccentric Nobel winner's brain as if they were looking through a microscope. "I can't wait to find out what they'll discover," said Steve Landers, a consultant for the National Museum of Health and Medicine Chicago who designed the app. "I'd like to think Einstein would have been excited." After Einstein died, a pathologist named Thomas Harvey performed an autopsy, removing the great man's brain in hopes that future researchers could discover the secrets behind his genius. Harvey gave samples to researchers and collaborated on a 1999 study published in the Lancet. That study showed a region of Einstein's brain - the parietal lobe - was 15 percent wider than normal. The parietal lobe is important to the understanding of math, language and spatial relationships. © 2012 Hearst Communications Inc

Keyword: Miscellaneous
Link ID: 17302 - Posted: 09.26.2012

By Sarah Estes and Jesse Graham It might be time to pencil in "awe cultivation" on your to-do list. Although religious thinkers like Søren Kierkegaard cast awe as a state of existential fear and trembling, new research by psychologists at Stanford and the University of Minnesota shows that experiencing awe can actually increase well-being, by giving people the sense that they have more time available. That sounds much more enjoyable than trying to power through one more hour on Redbull and fumes. Just what is this elusive emotion, and how can one nurture it in our time-pressed world? Although awe has played a significant role in the histories of religion, art, and other transcendental pursuits, it has received scant attention from emotion researchers. Noting the paucity of data, social psychologists Dacher Keltner and Jonathan Haidt developed a working prototype in a 2003 paper, delineating awe's standing in the research taxonomy. After reviewing accounts of psychological, sociological, religious, artistic, and even primordial awe (awe toward power), the researchers surmised that awe universally involved the perception of vastness and the need to accommodate the experience into one's present worldview. That is, awe is triggered by some experience so expansive (in either a positive or negative way) that one’s mental schemas have to be adjusted in order to process it. Nearly ten years later, awe research is beginning to come into its own. The self-help market has continued to grow quickly, and research on positive emotions has kept apace. Even corporations and politicians have taken note of some of the ways that emotion research links into everything from productivity to voting and buying behavior. So it should come as no surprise that psychologists are now experimenting in domains formerly left to clergy, clinicians, and artists. © 2012 Scientific American,

Keyword: Attention
Link ID: 17301 - Posted: 09.26.2012

By PAULINE W. CHEN, M.D. Recounting her father’s struggle with cancer was difficult for the young woman, even several years after his death. He’d endured first surgery and then chemotherapy and radiation, she told me, and the cancer had gone into remission. He was thrilled, but the aggressive treatment left him with chronic, debilitating pain. Once active, he struggled to get around in his own home. “It wasn’t the cancer that got him,” the daughter said. “It was the pain.” Her father had turned to all of his doctors, with little relief. His surgeon had looked at his operative wounds, pronounced them well healed, then stated that they were in no way responsible for his disability. Both his cancer doctor and his radiation doctor congratulated him on being in remission but then declined to prescribe pain medications since they were no longer treating him and couldn’t provide ongoing follow-up and dosing guidance. His primary care doctor listened intently to his descriptions of his limitations, but then prescribed only small amounts of pain meds that offered fleeting relief at best. “I’ll never forget what my father had to go through,” she said, weeping. “I wouldn’t wish this on anyone.” I wish I could have reassured her that her father’s case was unusual. Sadly, according to a new study in The Journal of Clinical Oncology, a significant percentage of cancer patients continue to suffer from pain as her father did. Copyright 2012 The New York Times Company

Keyword: Pain & Touch; Drug Abuse
Link ID: 17300 - Posted: 09.26.2012

Analysis by Tracy Staedter From the department of "I hope this never happens to me," scientists have used a laser to manipulate the behavior of a worm. First, a research team from the Howard Hughes Medical Institute genetically engineered a tiny, transparent worm called Caenorhabditis elegans to have neurons that give off fluorescent light. This allowed the neurons to be tracked during experiments. The scientists also engineered the neurons to be sensitive to light, which made it possible to activate them with pulses of laser light. Next, they built a movable table for the worm to crawl on, keeping it aligned beneath a camera and laser. They used the laser to activate a single neuron at a time. By doing so, they were able to control a worm's behavior and its senses. In tests, which the researchers published in the journal Nature, the laser made the worm turn left or right and move through a loop. The laser also tricked the worm brain into thinking food was nearby. The worm, in turn, wiggled toward what it thought was a meal. The research, which on the surface seems like a bit of a circus, actually is important because it shows scientists which neurons are responsible for what. "If we can understand simple nervous systems to the point of completely controlling them, then it may be a possibility that we can gain a comprehensive understanding of more complex systems," said Sharad Ramanathan, an Assistant Professor of Molecular and Cellular Biology, and of Applied Physics. "This gives us a framework to think about neural circuits, how to manipulate them, which circuit to manipulate and what activity patterns to produce in them." © 2012 Discovery Communications, LLC

Keyword: Development of the Brain
Link ID: 17299 - Posted: 09.26.2012

by Gisela Telis In the industrialized world, women live at least 5 years longer, on average, than men. Scientists have attributed that difference to everything from healthier habits to hardier cells. Now, a new study that analyzes the longevity of eunuchs, or castrated men, suggests that testosterone may play a part in shortening men's lives. The idea that testosterone, the male sex hormone, affects lifespan isn't new. Neutered dogs and other animals that have had their sources of testosterone removed often live longer than their intact counterparts. But studies on the connection between castration and longevity in humans are harder to come by, and the results have been inconclusive. A 1969 study of institutionalized patients in Kansas found that castrated men lived an average of 14 years longer than other men in the same facility, but a 1993 study of Italian castrati (singers castrated as boys to preserve their high voices) found nothing unusual about their longevity. Almost 5 years ago, biologist Kyung-Jin Min of Inha University in Incheon, Korea, found himself considering this lack of data while watching a Korean TV drama about eunuchs. Min began to wonder if Korea's rich historical records could shed light on the link between castration and longevity in humans. Until the late 19th century, Korean rulers employed eunuchs to serve the royal court. These eunuchs were allowed to marry and adopt castrated boys as their sons. The Yang-Se-Gye-Bo, a genealogical record of the eunuch families, has survived, and it documents the birth and death dates and other personal details of 385 eunuchs who lived between the mid-16th century and the mid-19th century. © 2010 American Association for the Advancement of Science.

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 17298 - Posted: 09.25.2012

By RICHARD A. FRIEDMAN, M.D. You will never guess what the fifth and sixth best-selling prescription drugs are in the United States, so I’ll just tell you: Abilify and Seroquel, two powerful antipsychotics. In 2011 alone, they and other antipsychotic drugs were prescribed to 3.1 million Americans at a cost of $18.2 billion, a 13 percent increase over the previous year, according to the market research firm IMS Health. Those drugs are used to treat such serious psychiatric disorders as schizophrenia, bipolar disorder and severe major depression. But the rates of these disorders have been stable in the adult population for years. So how did these and other antipsychotics get to be so popular? Antipsychotic drugs have been around for a long time, but until recently they were not widely used. Thorazine, the first real antipsychotic, was synthesized in the 1950s; not just sedating, it also targeted the core symptoms of schizophrenia, like hallucinations and delusions. Later, it was discovered that antipsychotic drugs also had powerful mood-stabilizing effects, so they were used to treat bipolar disorder, too. Then, starting in 1993, came the so-called atypical antipsychotic drugs like Risperdal, Zyprexa, Seroquel, Geodon and Abilify. Today there are 10 of these drugs on the market, and they have generally fewer neurological side effects than the first-generation drugs. Originally experts believed the new drugs were more effective than the older antipsychotics against such symptoms of schizophrenia as apathy, social withdrawal and cognitive deficits. But several recent large randomized studies, like the landmark Catie trial, failed to show that the new antipsychotics were any more effective or better tolerated than the older drugs. © 2012 The New York Times Company

Keyword: Schizophrenia
Link ID: 17297 - Posted: 09.25.2012

By Tori Rodriguez Feeling sociable or reckless? You might have toxoplasmosis, an infection caused by the microscopic parasite Toxoplasma gondii, which the CDC estimates has infected about 22.5 percent of Americans older than 12 years old. Researchers tested participants for T. gondii infection and had them complete a personality questionnaire. They found that both men and women infected with T. gondii were more extroverted and less conscientious than the infection-free participants. These changes are thought to result from the parasite's influence on brain chemicals, the scientists write in the May/June issue of the European Journal of Personality. “Toxoplasma manipulates the behavior of its animal host by increasing the concentration of dopamine and by changing levels of certain hormones,” says study author Jaroslav Flegr of Charles University in Prague, Czech Republic. Although humans can carry the parasite, its life cycle must play out in cats and rodents. Infected mice and rats lose their fear of cats, increasing the chance they will be eaten, so that the parasite can then reproduce in a cat's body and spread through its feces. In humans, T. gondii's effects are more subtle; the infected population has a slightly higher rate of traffic accidents, studies have shown, and people with schizophrenia have higher rates of infection—but until recent years, the parasite was not thought to affect most people's daily lives. In the new study, a pattern appeared in infected men: the longer they had been infected, the less conscientious they were. © 2012 Scientific American,

Keyword: Emotions
Link ID: 17296 - Posted: 09.25.2012

by Emily Underwood A human newborn's brain is uniquely impressionable, allowing social interactions and the environment to shape its development. But this malleability may come with a price, a new study finds. A comparison of juvenile chimpanzee and human brains suggests that differences in the development of myelin—the fatty sheath that surrounds nerve fibers—may contribute not only to our unusual adaptability, but also to our vulnerability to psychiatric diseases that start in early adulthood. Research increasingly suggests that psychiatric illnesses like depression and schizophrenia may involve problems with the timing of neural signals, says Douglas Fields, a neuroscientist at the National Institutes of Health in Bethesda, Maryland, who was not involved in the study. The nerve fibers, or axons, that connect neurons are usually protected by myelin, which enhances the neural relay of information throughout the brain. "Myelin speeds transmission of information [by] at least 50 times," Fields says, "so it matters a great deal whether or not an axon becomes myelinated." Humans start out with comparatively few myelinated axons as newborns. We experience a burst of myelin development during infancy that is followed by a long, slow growth of myelin that can last into our thirties, says Chet Sherwood, a neuroscientist at George Washington University in Washington, D.C., and a co-author of the new study. In contrast, other primates, such as macaques, start out with significantly more myelin at birth, but stop producing it by the time they reach sexual maturity. However, Sherwood says, "extraordinarily little data exists" on brain growth and the development of myelin in our closest genetic relatives, chimpanzees. © 2010 American Association for the Advancement of Science.

Keyword: Development of the Brain; Evolution
Link ID: 17295 - Posted: 09.25.2012

By Ilana Yurkiewicz It’s tough to prove gender bias. In a real-world setting, typically the most we can do is identify differences in outcome. A man is selected for hire over a woman; fewer women reach tenure track positions; there’s a gender gap in publications. Bias may be suspected in some cases, but the difficulty in using outcomes to prove it is that the differences could be due to many potential factors. We can speculate: perhaps women are less interested in the field. Perhaps women make lifestyle choices that lead them away from leadership positions. In a real-world setting, when any number of variables can contribute to an outcome, it’s essentially impossible to tease them apart and pinpoint what is causative. The only way to do that would be by a randomized controlled experiment. This means creating a situation where all variables other than the one of interest are held equal, so that differences in outcome can indeed be attributed to the one factor that differs. If it’s gender bias we are interested in, that would mean comparing reactions toward two identical human beings – identical in intelligence, competence, lifestyle, goals, etc. – with the one difference between them that one is a man and one is a woman. Not exactly a situation that exists in the real world. But in a groundbreaking study published in PNAS last week by Corinne Moss-Racusin and colleagues, that is exactly what was done. On Wednesday, Sean Carroll blogged about and brought to light the research from Yale that had scientists presented with application materials from a student applying for a lab manager position and who intended to go on to graduate school. Half the scientists were given the application with a male name attached, and half were given the exact same application with a female name attached. Results found that the “female” applicants were rated significantly lower than the “males” in competence, hireability, and whether the scientist would be willing to mentor the student. © 2012 Scientific American,

Keyword: Sexual Behavior
Link ID: 17294 - Posted: 09.25.2012