By Gregory Park , David Lubinski and Camilla P. Benbow Ninety years ago, Stanford psychologist Lewis Terman began an ambitious search for the brightest kids in California, administering IQ tests to several thousand of children across the state. Those scoring above an IQ of 135 (approximately the top 1 percent of scores) were tracked for further study. There were two young boys, Luis Alvarez and William Shockley, who were among the many who took Terman’s tests but missed the cutoff score. Despite their exclusion from a study of young “geniuses,” both went on to study physics, earn PhDs, and win the Nobel prize. How could these two minds, both with great potential for scientific innovation, slip under the radar of IQ tests? One explanation is that many items on Terman’s Stanford-Binet IQ test, as with many modern assessments, fail to tap into a cognitive ability known as spatial ability. Recent research on cognitive abilities is reinforcing what some psychologists suggested decades ago: spatial ability, also known as spatial visualization, plays a critical role in engineering and scientific disciplines. Yet more verbally-loaded IQ tests, as well as many popular standardized tests used today, do not adequately measure this trait, especially in those who are most gifted with it. Spatial ability, defined by a capacity for mentally generating, rotating, and transforming visual images, is one of the three specific cognitive abilities most important for developing expertise in learning and work settings. Two of these, quantitative and verbal ability, are quite familiar due to their high visibility in standardized tests like the Scholastic Aptitude Test (SAT). A spatial ability assessment may include items involving mentally rotating an abstract image or reasoning about an illustrated mechanical device functions. All three abilities are positively correlated, such that someone with above average quantitative ability also tends to have above average verbal and spatial ability. © 2010 Scientific American

Keyword: Intelligence; Attention
Link ID: 14629 - Posted: 11.04.2010

Deborah Blum, IN THE summer of 1991, neuroscientist Simon LeVay published a paper that would make him famous. It reported a study that clearly demonstrated a structural difference between the brains of gay and straight men. For nearly two decades since, LeVay has been in pursuit of more evidence to support the study's core implication: that sexual orientation derives from biology, not from personal choice. Gay, Straight, and the Reason Why is the third popular book that he has published on the topic, and its publication raises two different but equally important questions. First, how far has the science of sexual orientation advanced since LeVay's seminal paper? Second, how far has the research - and effort by advocates like LeVay to spread its message - increased acceptance of gay people by the straight majority? The answer to the first is: not as much as we could hope. I was dismayed to discover that many of the most influential studies cited here spring from previous decades. I'm all for historical context, but when a chapter on the importance of biology in sexuality contains 32 citations and 23 of them date to the year 2000 or earlier, a book can feel a bit dated. I would venture to guess that the dearth of notable recent findings is due in part to the political climate of the last decade, which has not been particularly eager to fund sex research. Thankfully, though, there are some very good recent studies in human development, gender and, more sparsely, sexual orientation. LeVay does a deft job of pulling these varying threads together into his own theory of homosexuality, which nicely balances solid science and common sense. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior
Link ID: 14628 - Posted: 11.04.2010

by Debora MacKenzie Groups in Germany and the US have been testing electronic implants aimed at restoring vision to people with retinal dystrophy. The condition is hereditary or age-related, and causes degeneration of the photoreceptors – light-sensitive cells in the retina – leading to blindness. It affects 15 million people worldwide. Eberthart Zrenner and colleagues at the University of Tübingen in Germany have developed a microchip carrying 1500 photosensitive diodes that slides into the retina where the photoreceptors would normally be. The diodes respond to light, and when connected to an outside power source through a wire into the eye, can stimulate the nearby nerves that normally pass signals to the brain, mimicking healthy photoreceptors. The team reports that their first three volunteers could all locate bright objects. One could recognise normal objects and read large words. Nerves in the eye normally adapt to visual input and stop transmitting signals after a short time. Tiny movements of the eye overcome this by constantly projecting the image back and forth between neighbouring nerve cells so that each has time to recover and resume transmitting signals. Because the implant is inside the eye, this mechanism worked normally in the trials. Another device being tested sends images from a head-mounted camera to ocular nerves, but as the image forms outside the eye the tiny movements cannot maintain it and patients must rapidly shake their head instead. © Copyright Reed Business Information Ltd.

Keyword: Robotics; Vision
Link ID: 14627 - Posted: 11.04.2010

by Karen Heyman One-third of stroke survivors never recover enough brain function to live on their own. Now scientists think they know why. Once a stroke kills a swath of brain cells, a neurotransmitter known as GABA impairs the surviving, apparently healthy, brain tissue. Targeting GABA could help a stroke-afflicted brain better overcome its damage, the researchers suggest. When a stroke hits, physicians have few options. If they catch it early enough, they can administer the clot-busting drug tPA to keep even more brain cells from dying—but tPA is not appropriate for all types of stroke. Physicians can also prescribe physical therapy, which can occasionally help recover impaired motor function. Yet there are no approved drugs that help the brain heal. For its part, the brain appears to try a sort of natural drug therapy to limit the spread of damage. It releases extra amounts of GABA, which reduces the firing of neurons. GABA initially prevents stroke-damaged brain tissue from becoming overexcited and dying. But University of California, Los Angeles (UCLA), investigators led by Thomas Carmichael, a specialist in stroke, and Istvan Mody, an expert in inhibition, wondered whether GABA might also interfere with the brain's plasticity, the ability of healthy regions to take over for injured ones. Previous studies had tried to address this question, but they produced confusing results. The UCLA team hypothesized that others had failed to distinguish between two types of inhibition—phasic, in which GABA acts upon specific receptors at nerve cell sites called synapses, and tonic, in which the neurotransmitter acts on other receptors elsewhere on the nerve cell. © 2010 American Association for the Advancement of Science.

Keyword: Stroke; Brain imaging
Link ID: 14626 - Posted: 11.04.2010

By Nathan Seppa MRI scans of stroke patients can indicate when the stroke occurred, a revelation that could allow more aggressive treatment to limit brain damage, French researchers report online November 2 in Radiology. For a person arriving at a hospital with a stroke, the clock is ticking. When a clot obstructs an artery in the brain, millions of neurons are lost with each passing minute as tissue is starved of blood and oxygen. A clot-busting drug called tPA, or tissue plasminogen activator, can often dissolve the clot and free up the vessel. But the drug is generally considered safe to administer only in the first three to 4½ hours after a stroke begins (SN: 10/25/08, p. 16). Stoke patients typically get a CT scan, which enables doctors to discern whether the stroke results from a blood clot or, less commonly, from a hemorrhage, which shows up as a dark mass on the CT, says neurologist Andrew Barreto of the University of Texas Medical School at Houston. MRI, or magnetic resonance imaging, is used much less often and usually only at large medical centers. Unfortunately, a CT scan cannot pinpoint when a stroke began. Neither can many patients, either because they can’t recall exactly when their symptoms first appeared or because they woke up already in the throes of a stroke. In such cases, doctors “guesstimate” the stroke’s onset, Barreto says, but hesitate to give tPA if too many hours might have passed. Giving tPA too late won’t help tissue that’s already dead and risks causing a brain bleed. After the tPA window closes there is little doctors can do but monitor the patient. © Society for Science & the Public 2000 - 2010

Keyword: Stroke; Brain imaging
Link ID: 14625 - Posted: 11.04.2010

Michael Marshall, environment reporter This boa constrictor has no father. She was born in 2009 by parthenogenesis, otherwise known as "virgin birth". This makes her one of the first parthenogenetic vertebrate animals who have made it to adulthood. The mother snake responsible had two litters, one in 2009 and another in 2010, producing a total of 22 offspring. All were female, and all had the same rare "caramel" body colour. Genetic analysis has confirmed that they are not related to any of the males the female had mated with (Biology Letters, DOI: 10.1098/rsbl.2010.0793). In another first, the young snakes have two W chromosomes. Snakes determine their sex differently to humans: males have two Z chromosomes and females have a Z and a W. So in theory, the mother snake's parthenogenetic offspring should have been either ZZ or WW. But WW animals have never been found, and have only been produced in the lab with great difficulty. It's not clear how these WW snakes are able to survive, or indeed why the mother would have produced so many of them. Parthenogenesis is often used as a last-resort technique so that females can reproduce when there are no males around. So you would expect that the mother would produce some male offspring as well as females. Long thought to be vanishingly rare, parthenogenesis is becoming more common the more scientists look for it. For instance, in 2003 a Burmese python in an Amsterdam zoo produced embryos parthenogenetically, but they were not allowed to develop so we do not know if they were truly viable. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior
Link ID: 14624 - Posted: 11.04.2010

by Michael Marshall Picture the frustration. You spend weeks assembling the perfect home for your mate, dragging heavy objects around until they are just so. You see off any other males who take an interest in her by showing off your impressive size and musculature. You are king of your domain. Then, just as your girl is laying her eggs in the snug little nursery you've prepared, some weedy little cheat slips in ahead of you and fertilises the lot. This is the infuriating fate that befalls many male Lamprologus callipterus, which are regularly cuckolded by so-called dwarf males. Despite their occasional success, however, dwarf males struggle to father many children. Lamprologus is a cichlid, one of the most diverse animal groups in existence, despite being mostly confined to three large lakes in Africa. The Lake Victoria cichlids are particularly diverse, with over 300 species sharing the water. Male Lamprologus weigh 12 times as much as the females. This is the largest male-female size difference among species where the males are larger, far exceeding the factor-of-three difference in great bustards, which show the greatest difference among birds. The male fish have no grounds for smugness, though: in other species giant females take things much further, with female blanket octopuses reaching almost 200 times the length of the male. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Evolution
Link ID: 14623 - Posted: 11.04.2010

by Andy Coghlan A little thing called methylation means that parental neglect, or eating a poor diet, could lead to depression or schizophrenia two generations later WHAT if your bad habits mean that your children and even their children end up with a psychiatric disorder? That is one of the implications of a study in rodents that suggests poor diet and parental neglect can leave their mark on the genes of your children and your children's children. A cryptic epigenetic code added to the DNA of mice shows for the first time that changes in gene activity can pass down three generations. It is likely that the same mechanisms are at work in humans. Epigenetics deals with the regulation of gene activity within a cell - which genes are switched on or off, and when it happens (see diagram). Every cell in the body contains the same DNA but epigenetic settings on cells in the bone and blood, for example, mean the tissues do very different jobs. The epigenetic consequences of a huge range of environmental factors are under investigation, from exposure to drugs, chemicals and hormones, to the impact of poor maternal care in infancy, and the likelihood that they are as heritable as DNA. So far, most epigenetic research has focused on cancer because epigenetic marks unique to cancer cells may set them apart from healthy tissue. Now it's the turn of psychiatric illness. The latest results will be presented this week in Washington DC at the annual meeting of the American Society for Human Genetics (ASHG). © Copyright Reed Business Information Ltd.

Keyword: Stress; Genes & Behavior
Link ID: 14622 - Posted: 11.04.2010

David Perlman, Chronicle Science Editor The tiny zebrafish is fascinating to scientists who study them for insights into genetics and evolution, and as models of human behavior. And they're equally charming for hobbyists who appreciate their ability as swift swimmers in their aquariums. Now two UC researchers in San Francisco and Berkeley have discovered how the nerves and brains of the boldly striped, inch-long fish can distinguish between the sight of small, quick-moving prey and larger objects looming before their eyes that might be hungry predators. And one nerve scientist leading the group likened the fish's ability to make that distinction in its nervous system to a baseball batter's instant ability to grab a hit at a pitcher's oncoming fastball. Filippo Del Bene at UCSF and Claire Wyart of UC Berkeley, both post-doctoral fellows, experimented with nerve cells in the brains of zebrafish larvae and found how the larvae's specialized cells are structured to receive different kinds of signals from the optic nerves in the retinas of their eyes. The larval brains of these fish are transparent. So when the two researchers labeled specific neurons with a newly developed fluorescent protein, they could watch as those nerve cells flashed brightly when they were activated by small and fast-moving objects seen by their eyes while electrical signals were transmitted by their optic nerves to their brains. © 2010 Hearst Communications Inc.

Keyword: Vision; Development of the Brain
Link ID: 14621 - Posted: 11.04.2010

Nicole Baute Living Reporter Stroke victims are 12 per cent more likely to die within seven days if they arrive at the hospital on the weekend, according to a study of more than 20,000 Ontario patients. The study, published today in Neurology, found that patients received the same major interventions — brain scans, clot-busting medications and admission to stroke units — regardless of when they were admitted. Dr. Moira Kapral, a researcher at the Institute for Clinical Evaluative Sciences and one of the study’s authors, says it is possible that the weekend effect is caused by “an accumulation of small deficiencies in care” — including secondary treatment that is nonetheless crucial for recovery. For example, she says, there might be fewer or less-experienced staff working on the weekends. Or patients might experience delays in access to rehabilitation experts, such as physiotherapists who help stroke patients regain mobility or speech pathologists who do swallowing assessments to determine whether or not it’s safe to eat. Further research is necessary to examine these possibilities. In the meantime, says Kapral, health-care administrators should try to determine what is causing the increased mortality gap. “I think hospitals should really look at their weekend practices in terms of staffing and resources to see if there are things that can be done to improve care on weekends.” © Copyright Toronto Star 1996-2010

Keyword: Stroke
Link ID: 14620 - Posted: 11.04.2010

By Steve Connor Can science shed some light on Stephen Fry's comments about female sexuality? Do women really find sex disgusting and only partake of the gruesome act in order to get their man to "commit", as he suggested in an interview with Attitude magazine? The deep frying of Fry for his ill-chosen words, which he insists were made in jest and taken out of context, is perhaps unjustified. The science suggests that he may have a point, but only if the long view of human sexuality is taken into account – in other words, the reason why sex has evolved in the first place. Biologically, sex is a way of mixing the genes between two individuals in order to produce a genetic variety in the offspring that would not exist with asexual reproduction, such as cloning. Many animals and plants engage in sexual reproduction because it confers an advantage, and the fact that sex has been practised for many hundreds of millions of years by a vast plethora of lifeforms attests to its biological importance. But explaining the reasons for sexual reproduction does not explain why we have just two sexes, and why males and females are so different to one another. To understand that we need to understand the two competing and mutually exclusive "strategies" employed by each sex in order to reproduce. Females produce egg cells, which are relatively large structures representing a sizeable investment in the future compared to sperm cells. This investment gets magnified substantially in female mammals, including humans, who get pregnant, lactate and are involved in years of strenuous childcare. ©independent.co.uk

Keyword: Sexual Behavior; Evolution
Link ID: 14619 - Posted: 11.02.2010

A molecular pathway within the brain’s reward circuitry appears to contribute to alcohol abuse, according to laboratory mouse research supported by the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the National Institutes of Health (NIH). The findings, published online today in Proceedings of the National Academy of Sciences, also provide evidence that the pathway may be a promising new target for the treatment of alcohol problems. The mammalian target of rapamycin complex 1, or mTORC1, is a group of proteins found in cells throughout the body. An important part of the cellular machinery, mTORC1 sends signals that help regulate the size and number of cells. Scientists have also found that it is involved in other cellular processes. For example, in the central nervous system, mTORC1 has been linked to processes related to learning and memory. Because problems in the cellular mechanisms that underlie learning and memory can contribute to alcohol abuse disorders, NIAAA-supported researchers at the Ernest Gallo Clinic and Research Center of the University of California, San Francisco (UCSF) hypothesized that mTORC1 might be involved in alcohol problems. In laboratory studies conducted with mice, researchers led by Dorit Ron, Ph.D., a Gallo Center principal investigator and a professor of neurology at UCSF, measured an increase in mTORC1 cellular products in the nucleus accumbens of mice that had consumed alcohol — an indication that alcohol activates the mTORC1 pathway. The nucleus accumbens is a brain region that in rodents and humans is part of the reward system that affects craving for alcohol and other addictive substances. They then showed that rapamycin, an immunosuppressant drug that blocks the mTORC1 pathway, decreased excessive alcohol consumption, binge drinking, and alcohol-seeking behavior in the rodents. Rapamycin is currently used to prevent the rejection of transplanted organs.

Keyword: Drug Abuse
Link ID: 14618 - Posted: 11.02.2010

Ben Goldacre When the BBC tells you, in a headline, that libido problems are in the brain and not in the mind, you might find yourself wondering what the difference between the two is supposed to be, and whether a science article can really be assuming – in 2010 – that its readers buy into a strange Cartesian dualism in which the self is contained by a funny little spirit entity in constant and elaborate pneumatic connection with the corporeal realm. But first let's consider the experiment they're reporting on. As far as we know (because this experiment has not yet been published, only presented at a conference), some researchers took seven women with a "normal" sex drive, and 19 women diagnosed with "hypoactive sexual desire disorder". Participants watched a series of erotic films in a scanner while an MRI machine took images of blood flow in their brains: the women with a normal sex drive had an increased flow of blood to some parts of their brain associated with emotion, while those with low libido did not. Dr Michael Diamond, one of the researchers, tells the Mail: "Being able to identify physiological changes, to me provides significant evidence that it's a true disorder as opposed to a societal construct". In the Metro, he goes further: "Researcher Dr Michael Diamond said the findings offer 'significant evidence' that persistent low sex drive – known as hypoactive sexual desire disorder (HSDD) – is a genuine physiological disorder and not made up." © Guardian News and Media Limited 2010

Keyword: Brain imaging; Sexual Behavior
Link ID: 14617 - Posted: 11.02.2010

by Nathan Collins Could a fetus lying in the womb be planning its future? The question comes from the discovery that brain areas thought to be involved in introspection and other aspects of consciousness are fully formed in newborn babies. Resting state networks (RSNs), sometimes called the "dark energy of the brain", are patterns of low-frequency brain activity that are constantly active, even when a person is asleep. Activity in one RSN, the default mode network, drops when someone is engaged in a task, and it may be involved in introspective activities like envisioning the future – what some would call a facet of consciousness. Previous studies suggest that this network only fully develops during childhood, but David Edwards and colleagues at Imperial College London have now shown it is fully formed at birth. The finding came as the team investigated the relationship between RSNs and cognitive functions. They scanned the brains of 70 babies born up to three months early, whose development served as a proxy for fetal development. While rates of progression varied, RSNs for vision, touch, movement and decision-making were largely complete by 40 weeks, as was the default mode network. © Copyright Reed Business Information Ltd.

Keyword: Development of the Brain; Attention
Link ID: 14616 - Posted: 11.02.2010

By APRIL DEMBOSKY SACRAMENTO — In the three years since her son Diego was given a diagnosis of autism at age 2, Carmen Aguilar has made countless contributions to research on this perplexing disorder. She has donated all manner of biological samples and agreed to keep journals of everything she’s eaten, inhaled or rubbed on her skin. Researchers attended the birth of her second son, Emilio, looking on as she pushed, leaving with Tupperware containers full of tissue samples, the placenta and the baby’s first stool. Now the family is in yet another study, part of an effort by a network of scientists across North America to look for signs of autism as early as 6 months. (Now, the condition cannot be diagnosed reliably before age 2.) And here at the MIND Institute at the University of California Davis Medical Center, researchers are watching babies like Emilio in a pioneering effort to determine whether they can benefit from specific treatments. So when Emilio did show signs of autism risk at his 6-month evaluation — not making eye contact, not smiling at people, not babbling, showing unusual interest in objects — his parents eagerly accepted an offer to enroll him in a treatment program called Infant Start. The treatment is based on a daily therapy, the Early Start Denver Model, that is based on games and pretend play. It has been shown in randomized trials to significantly improve I.Q., language and social skills in toddlers with autism, and researchers say it has even greater potential if it can be started earlier. Copyright 2010 The New York Times Company

Keyword: Autism
Link ID: 14615 - Posted: 11.02.2010

By PAM BELLUCK About half of adolescents who recovered from major depression became depressed again within five years, regardless of what treatment or therapy they received to get over their initial depression, a new study shows. The study, published Monday in Archives of General Psychiatry, also found that girls were more likely to have another major depression, which surprised researchers because, as adults, women have not been considered more likely to have a recurrence than men. In the study, nearly 200 adolescents, 12 to 17, received 12 weeks of fluoxetine (Prozac), cognitive behavioral therapy, both, or a placebo pill. (Those not receiving cognitive therapy met with a psychiatrist for basic support.) Placebo-takers who did not improve after 12 weeks could choose any of the other treatments. Researchers had previously found that those receiving the Prozac-and-cognitive-therapy combination recovered faster from the first depression. So they expected those youths to be less prone to another depression. But that did not happen. After 36 weeks, improvement for everyone was similar, researchers said, and by two years most completely recovered. But by five years, 47 percent suffered another major depression, no matter what treatment had helped them recover. Copyright 2010 The New York Times Company

Keyword: Depression; Development of the Brain
Link ID: 14614 - Posted: 11.02.2010

People who take regular exercise during their free time are less likely to have symptoms of depression and anxiety, a study of 40,000 Norwegians has found. But physical activity which is part and parcel of the working day does not have the same effect, it suggests. Writing in the British Journal of Psychiatry, the researchers said it was probably because there was not the same level of social interaction. The charity Mind said that exercise and interaction aids our mental health. Higher levels of social interaction during leisure time were found to be part of the reason for the link. Researchers from the Institute of Psychiatry at King's College London teamed up with academics from the Norwegian Institute of Public Health and the University of Bergen in Norway to conduct the study. Participants were asked how often, and to what degree, they undertook physical activity in their leisure time and during the course of their work. Researchers also measured participants' depression and anxiety using the Hospital Anxiety and Depression Scale. BBC © MMX

Keyword: Depression
Link ID: 14613 - Posted: 11.01.2010

Alcohol is more harmful than heroin or crack, according to a study published in medical journal the Lancet. The report is co-authored by Professor David Nutt, the former UK chief drugs adviser who was sacked by the government in October 2009. It ranks 20 drugs on 16 measures of harm to users and to wider society. Tobacco and cocaine are judged to be equally harmful, while ecstasy and LSD are among the least damaging. Prof Nutt refused to leave the drugs debate when he was sacked from his official post by the former Labour Home Secretary, Alan Johnson. He went on to form the Independent Scientific Committee on Drugs, a body which aims to investigate the drug issue without any political interference. One of its other members is Dr Les King, another former government adviser who quit over Prof Nutt's treatment. Members of the group, joined by two other experts, scored each drug for harms including mental and physical damage, addiction, crime and costs to the economy and communities. BBC © MMX

Keyword: Drug Abuse
Link ID: 14612 - Posted: 11.01.2010

By SINDYA N. BHANOO The ancestors of humans and other primates like apes and monkeys may have originated in Asia, not Africa, a new study in the journal Nature reports. There has long been debate about the matter, but a recent discovery of anthropoid fossils including two previously unidentified species and one known species provides new clues. The fossils are about 38 million years old and were uncovered in a rock formation in southern Libya. The anthropoids were small, rodent-size creatures that looked similar to larger, modern-day primates, but weighed just 4 to 17 ounces. “At least one of these anthropoids appears to be clearly related to the older Asian form described in Myanmar,” said Jean-Jacques Jaeger, a paleontologist at the University of Poitiers in France and the study’s lead author. “This indicates that there was migration from Asia.” But there is another possibility: that the anthropoids originated in Africa and migrated to Asia, and that they have even older ancestors in Africa that have not yet been discovered. Copyright 2010 The New York Times Company

Keyword: Evolution
Link ID: 14611 - Posted: 11.01.2010

by Liz Day Dating advice, guys: Looking "masculine" may not get you anywhere with the ladies. Skin tone is what really makes a difference. Or so say researchers from University of Bristol and Brunel University, who published in a recent issue of online science journal PLoS ONE. They found that color information is more influential than shape information, upending prior thought on masculinity's link to attractiveness. Previous research studies had suggested that female animals prefer males with exaggerated male traits, such as large antlers and eye-catching peacock tails. Souped-up levels of testosterone are thought to contribute to the very masculine features, while also stressing the immune system. Thus, only high quality males can "afford" exposure to immune stress. Succinctly put, males with masculine shaped faces would appear to be more attractive, healthier partners for mating. Instead, this study found that skin color trumped masculine facial features. To clarify, skin color was measured in tones of lightness, redness and yellowness, and did not involve race or ethnicity. The authors believe that color matters because it fluctuates and is condition-dependent. Thus, skin color could better signal the health of a male partner at that moment, instead of an evolutionary facial structure that has been inherited over generations. © 2010 Discovery Communications, LLC

Keyword: Sexual Behavior; Evolution
Link ID: 14610 - Posted: 11.01.2010