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Alison Abbott If you have to make a complex decision, will you do a better job if you absorb yourself in, say, a crossword puzzle instead of ruminating about your options? The idea that unconscious thought is sometimes more powerful than conscious thought is attractive, and echoes ideas popularized by books such as writer Malcolm Gladwell’s best-selling Blink. But within the scientific community, ‘unconscious-thought advantage’ (UTA) has been controversial. Now Dutch psychologists have carried out the most rigorous study yet of UTA — and find no evidence for it. Their conclusion, published this week in Judgement and Decision Making, is based on a large experiment that they designed to provide the best chance of capturing the effect should it exist, along with a sophisticated statistical analysis of previously published data1. The report adds to broader concerns about the quality of psychology studies and to an ongoing controversy about the extent to which unconscious thought in general can influence behaviour. “The bigger debate is about how clever our unconscious is,” says cognitive psychologist David Shanks of University College London. “This carefully constructed paper makes a great contribution.” Shanks published a review last year that questioned research claiming that various unconscious influences, including UTA, affect decision making2. © 2015 Nature Publishing Group
|By Daniel Yudkin Imagine you are with some friends at a concert, and the bouncer approaches the group and says that, because you are all looking so ravishing tonight, he’s been instructed to offer one of you—just one!—a backstage pass to meet the artist. Do you raise your hand? For most people, this would be a no-brainer: who wouldn’t leap at the chance to meet a famous singer or secure a long-sought autograph? The results of a recent study, published in Psychological Science by Gus Cooney, Daniel Gilbert, and Timothy Wilson, however, suggest taking a second’s pause before snapping up that backstage pass. Cooney, Gilbert, and Wilson suspected that extraordinary experiences—like meeting a musical idol—carry hidden costs. They hypothesized that, while such occurrences undoubtedly make us happier in the moment, they also risk separating us from our peers, leading to a sense of isolation so unpleasant as to outweigh whatever enjoyment they initially confer. To test this idea, the researchers recruited subjects in groups of four and had them watch a video clip. Of the group, three were told that they would watch a clip that previous viewers had given a 2-star rating; the remaining subject, by contrast, was granted the opportunity to view a special 4-star clip. After watching the videos, all four subjects were given some time to talk amongst themselves, and then each reported on their general happiness. © 2015 Scientific American
Link ID: 20527 - Posted: 01.28.2015
Ian Sample, science editor People who carry a mutated gene linked to longer lifespan have extra tissue in part of the brain that seems to protect them against mental decline in old age. The finding has shed light on a biological pathway that researchers now hope to turn into a therapy that slows the progression of Alzheimer’s disease and other forms of dementia. Brain scans of more than 400 healthy men and women aged 53 and over found that those who carried a single copy of a particular gene variant had a larger brain region that deals with planning and decision making. Further tests on the group found that those with an enlarged right dorsolateral prefrontal cortex (rDLPFC), as the brain region is known, fared better on a series of mental tasks. About one in five people inherits a single copy of the gene variant, or allele, known as KL-VS, which improves heart and kidney function, and on average adds about three years to human lifespan, according to Dena Dubal, a neurologist at University of California, San Francisco. Her latest work suggests that the same genetic mutation has broader effects on the brain. While having a larger rDLPFC accounted for only 12% of the improvement in people’s mental test scores, Dubal suspects the gene alters the brain in other ways, perhaps by improving the connections that form between neurons.
/ by Tanya Lewis, LiveScience You know the feeling: the dryness in the mouth, the stickiness in the throat and the creeping salivation — thirst. But what causes feelings of thirst in the brain? In a new study, scientists used laser light to activate groups of neurons in the brains of mice. By targeting specific neuron groups, the scientists could make the animals drink even if they weren't thirsty, and stop drinking even if they were thirsty. Understanding how the brain causes feelings of thirst could help scientists learn what goes awry in disorders that make people drink too much or too little fluid, researchers say. "Thirst has attracted a lot of interest because it is such a basic function for all organisms," said Yuki Oka, a neuroscientist currently at the California Institute of Technology and co-author of the study published today (Jan. 26) in the journal Nature. Before this study, scientists knew which brain regions were activated by dehydration and hydration. "But key information was missing as to which were controlling thirst," Oka told Live Science. In the new study, Oka and a team of colleagues at Columbia University used a technique called optogenetics to pinpoint the origin of thirst impulses in the brains of mice. The researchers injected the mouse brains with a virus that made certain cells sensitive to laser light, and when scientists shone the laser on those cells, it caused them to turn nerve impulses "on" or "off." © 2015 Discovery Communications, LLC.
Link ID: 20525 - Posted: 01.28.2015
By Eliot Marshall In perhaps the most famous study of childhood neglect, researchers have closely tracked the progress, or lack of it, in children who lived as infants in Romania’s bleak orphanages and are now teenagers. A new analysis now shows that these children, who display a variety of behavioral and cognitive problems, have less white matter in their brains than do a group of comparable children in local families. The affected brain regions include nerve bundles that support attention, general cognition, and emotion processing. The work suggests that sensory deprivation early in life can have dramatic anatomical impacts on the brain and may help explain the previously documented long-term negative affects on behavior. But there’s some potential good news: A small group of children who were taken out of orphanages and moved into foster homes at age 2 appeared to bounce back, at least in brain structure. “This is an exciting and important study,” says Harvard Medical School psychiatric researcher Martin Teicher, who directs the developmental biopsychiatry research program at McLean Hospital in Belmont, Massachusetts. The “crucial question” of whether children can recover from the setbacks of early adversity had not been answered before, he adds. The work is based on MRI scans and other measures taken in Romania by researchers at the Bucharest Early Intervention Project (BEIP). The group, headed by neurologist Charles Nelson of Harvard Medical School, was spurred to action by the collapse of Romania’s Nicolae Ceauceșcu regime in 1989, which had shunted tens of thousands of unwanted children into state-run orphanages. Nelson says that caretakers in the orphanages worked in factorylike shifts; children might see as many as 17 different caretakers in a week. Infants rarely enjoyed the one-on-one interactions that are considered essential to normal development. © 2015 American Association for the Advancement of Science
|By Christof Koch Faces are the glue that holds us together and that gives us our identity. All of us but the visually impaired and blind are experts at recognizing people's identity, gender, age and ethnicity from looking at their faces. First impressions of attractiveness or competence take but a brief glimpse of somebody's face. Newly born infants already tend to fixate on faces. This bias also turns up in art. Paintings and movies are filled with faces staring at the viewer. Who can forget the endless close-ups of the feuding husband and wife in Ingmar Bergman's Cimmerian masterpiece Scenes from a Marriage? Because recognizing a face is so vital to our social lives, it comes as no surprise that a lot of real estate in the cerebral cortex—the highly convoluted region that makes up the bulk of our brain—is devoted to a task crucial to processing faces and their identity. We note whether someone looks our way or not. We discern emotional expressions, whether they register joy, fear or anger. Indeed, functional brain imaging has identified a set of adjacent regions, referred to as the fusiform face area (FFA), that are situated on the left and the right sides of the brain, at the bottom of the temporal lobe of the cerebral cortex. The FFA turns up its activity when subjects look at portraits or close-ups of faces or even when they just think about these images. Two just published studies of the brain's visual networks, including the FFA, enlarge what we know about the physical basis of face perception. Both explore the unique access to the brain afforded by patients whose epileptic seizures have proved resistant to drugs. A surgical treatment finds the locations in the brain where the hypersynchronized activity that characterizes a seizure begins before spreading from its point of origin to engulf one or sometimes both hemispheres. If a single point—a focus where the seizure begins—can be found, it can be removed. After this procedure, a patient usually has significantly fewer seizures—and some remain seizure-free. To triangulate the location of the focus, neurosurgeons insert electrodes into the brain to monitor electrical activity that occurs during a seizure. © 2015 Scientific American
Link ID: 20523 - Posted: 01.27.2015
David Cox Bernd Heinrich was on a hike through the woods of New England when he observed something which would go on to change our perception of animal psychology. A group of ravens had gathered to feed on a dead moose. But rather than choosing to keep the bounty for themselves, they were making a strange call, one which seemed to be deliberately attracting more ravens to the feast. A biologist at the University of Vermont, Heinrich was initially confused. By helping their competitors, the ravens appeared to be defying all natural biological instinct. But as it transpired, their motivation was actually deeply selfish. The birds were juveniles who had discovered the moose in an adult raven’s territory. By inviting other ravens to join them, their intrusion was more likely to go unchallenged. Last month, an astonishing video emerged of a rhesus macaque successfully resuscitating another of its species which had been electrocuted at a train station in India. It is tempting to describe the sustained display of persistence and apparent concern as almost human. But there is a danger in viewing animal behaviour through the misty lens of human emotion. What both Heinrich’s “sharing ravens’ and the macaques of Kampur do provide is a window into the gradual evolution of one of the most human of traits – altruism. Altruism in its purest form should be an entirely selfless action. “If there’s any kind of selfish interest at stake, like secretly hoping for a return favour or even doing it deliberately because you know it will make you feel good, then that doesn’t really count at all,” says psychologist Michael Platt of the Center for Cognitive Neuroscience at Duke University, North Carolina.
By ERICA GOODE A goat frolics with a baby rhinoceros. A pig nestles up to a house cat. A rat snake makes nice with the dwarf hamster originally intended as its lunch. Few things seem to capture the public imagination more reliably than friendly interactions between different species — a fact not lost on Anheuser-Busch, which during Sunday’s Super Bowl will offer a sequel to “Puppy Love,” its wildly popular 2014 Budweiser commercial about friendship between a Clydesdale and a yellow Labrador puppy. The earlier Super Bowl spot has drawn more than 55 million views on YouTube. Videos of unlikely animal pairs romping or snuggling have become so common that they are piquing the interest of some scientists, who say they invite more systematic study. Among other things, researchers say, the alliances could add to an understanding of how species communicate, what propels certain animals to connect across species lines and the degree to which some animals can adopt the behaviors of other species. “There’s no question that studying these relationships can give you some insight into the factors that go into normal relationships,” said Gordon Burghardt, a professor in the departments of psychology and ecology and evolutionary biology at the University of Tennessee, who added that one video he liked to show students was of a small and persistent tortoise tussling over a ball with a Jack Russell terrier. “Even one example raises the possibility that there’s something interesting going on here,” Dr. Burghardt said. Science has not entirely ignored unusual interactions between species. Biologists have described relationships formed to achieve a specific goal, like the cooperative hunting between groupers and moray eels. And in the mid-1900s, Konrad Lorenz and other ethologists demonstrated that during critical periods after birth, certain birds and other animals would follow the first moving object they saw, whether animal, human or machine, a phenomenon known as imprinting. Dr. Lorenz was famously photographed with a gaggle of “imprinted” geese trailing behind him. © 2015 The New York Times Company
By Will Boggs MD (Reuters Health) – There are so many different genetic forms of autism that using the singular term, autism, is misleading, researchers say. “We believe a better term to use is ‘the autisms,’ or ‘the autism spectrum disorders’ (that is, plural),” Dr. Stephen W. Scherer told Reuters Health by email. “There are many different forms of autism. In other words, autism is more of a collection of different disorders that have a common clinical manifestation.” The DNA of affected individuals varies remarkably, his team found. Two-thirds of brothers and sisters with what’s still called autism spectrum disorder, or ASD, showed different genetic changes. Scherer, from The Hospital for Sick Children in Toronto, Ontario, Canada, is part of a team that aims to identify all the genetic changes in individuals with ASD. In the U.S., the Centers for Disease Control and Prevention (CDC) estimates that 1 in 68 children (1 in 42 boys and 1 in 189 girls) have an autism spectrum disorder. Recent estimates in Europe, the CDC says, are that one to two percent of children there are affected. When Scherer's team looked for genetic changes in the entire DNA from 85 pairs of brothers and sisters with ASD and their parents, they found an average of roughly 73 genetic changes per set of DNA -- but only 36 of the 85 families (42.4 percent) had mutations that researchers could relate to genes already linked in some way to ASD. © 2015 Scientific American
Link ID: 20520 - Posted: 01.27.2015
Over-the-counter sleeping aids and hayfever treatments can increase the risk of Alzheimer’s disease, a study has found. The sleeping medication Nytol and anti-allergy pills Benadryl and Piriton all belong to a class of drug highlighted in a warning from researchers. Each of these drugs has “anticholinergic” blocking effects on the nervous system that are said – at higher doses – to raise the likelihood of developing Alzheimer’s and other forms of dementia significantly over several years. Other drugs on the risk list include older “tricyclic” antidepressants such as doxepin, and the bladder control treatment Ditropan (oxybutynin). Many of these medicines are taken by vulnerable older people, according to the scientists, who say their findings have public health implications. Anticholinergic drugs block a nervous system chemical transmitter called acetylcholine, which can lead to side-effects including drowsiness, blurred vision and poor memory. People with Alzheimer’s disease are known to lack acetylcholine. The leader of the US study, Professor Shelly Gray, director of the geriatric pharmacy programme at the University of Washington School of Pharmacy, said: “Older adults should be aware that many medications – including some available without a prescription, such as over-the-counter sleep aids – have strong anticholinergic effects. And they should tell their healthcare providers. “Of course, no one should stop taking any therapy without consulting their healthcare provider. Healthcare providers should regularly review their older patients’ drug regimens – including over-the-counter medications – to look for chances to use fewer anticholinergic medications at lower doses.”
|By Tori Rodriguez Scientists have studied brain structure for decades, so most disease-related structural anomalies have been long known. New findings of this nature are rare—yet last summer one neuroscientist studying depression published just that. Over nine years of sorting through countless brain images, Jerome J. Maller of Monash University and Alfred Hospital in Melbourne noticed a particular type of brain abnormality that seemed to show up more often in depressed patients. Their occipital lobes were often wrapped around each other. Maller and his colleagues investigated further and found that depressed patients are indeed three times as likely to have wraparound lobes. Occipital bending occurred in 35.3 percent of the depressed patients and 12.5 percent of the control subjects, according to their paper, published in Brain. The effect was even more pronounced in women: 45.8 percent of female patients with major depressive disorder exhibited occipital bending versus only 5.9 percent of women without depression, possibly because women's brains fit more snugly in their skulls than men's do. Previous studies have also found that occipital bending is more common in patients with schizophrenia. Maller suggests the lobes may wrap around each other when space for brain growth becomes constricted, perhaps because the brain is not doing enough neural pruning—the process by which the brain gets rid of neurons that are no longer needed. Indeed, many other studies have found that depressed brains are hyperconnected. Maller does not know if the finding will have clinical implications beyond helping to diagnose depression, but experts hope that this avenue of research will eventually lead to a deeper understanding of the disorder. “It really suggests some significant biological basis for at least some forms of depression,” says William Hopkins, a professor of neuroscience at Georgia State University, who was not involved in the study. © 2015 Scientific American
By Ling Xin For many, the hardest part of learning to speak Chinese is mastering its complex tonal variations. Now, new research suggests a surprising explanation for how those tones arose: a humid climate. By examining the correlation between humidity and the role of tone in more than 3700 languages, scientists found that tonal languages are remarkably rare in arid regions like Central Europe, whereas languages with complex tone pitches are prevalent in relatively humid regions such as the tropics, subtropical Asia, and Central Africa. Humidity keeps the voice box moist and elastic, allowing it to produce correct and complex tones, the scientists explain online this month in the Proceedings of the National Academy of Sciences. “If the United Kingdom had been a humid jungle, English may also have developed into a tonal language,” they claim. So, next time you go to your Chinese class, don’t forget to wet your whistle! © 2015 American Association for the Advancement of Science.
Link ID: 20517 - Posted: 01.26.2015
By Tina Hesman Saey Gustometer guhs-TOH-meh-ter n. A device used to squirt measured amounts of liquids into the mouth of a person in a taste study. Researchers often pair the instrument with brain scanning technology. Recently, a study of wine tasting pitted 10 of the top sommeliers from France and Switzerland against 10 novices. Researchers led by Lionel Pazart of Besançon University Hospital in France custom-built a gustometer to conduct the blind taste test. The scientists compared how brain activity changed when people tasted chardonnay, pinot noir or water. When sipping wine, the experts had greater activity in several parts of their brains, including regions involved in memory, than novices did, the researchers report in October in Frontiers in Behavioral Neuroscience. Sommeliers’ expertise may allow them to process sensory input about a wine — its taste and bouquet — while simultaneously recalling other information, such as the reputation of the winery that produced the beverage. Citations L. Pazart et al. An fMRI study on the influence of sommeliers’ expertise on the integration of flavor. Frontiers in Behavioral Neuroscience Vol. 8, October 16, 2014. doi: 10.3389/fnbeh.2014.00358. © Society for Science & the Public 2000 - 2015.
Keyword: Chemical Senses (Smell & Taste)
Link ID: 20516 - Posted: 01.26.2015
Simon Parkin A few months before she died, my grandmother made a decision. Bobby, as her friends called her (theirs is a generation of nicknames), was a farmer’s wife who not only survived World War II but also found in it justification for her natural hoarding talent. ‘Waste not, want not’ was a principle she lived by long after England recovered from a war that left it buckled and wasted. So she kept old envelopes and bits of cardboard cereal boxes for note taking and lists. She kept frayed blankets and musty blouses from the 1950s in case she needed material to mend. By extension, she was also a meticulous chronicler. She kept albums of photographs of her family members. She kept the airmail love letters my late grandfather sent her while he travelled the world with the merchant navy in a box. Her home was filled with the debris of her memories. Yet in the months leading up to her death, the emphasis shifted from hoarding to sharing. Every time I visited my car would fill with stuff: unopened cartons of orange juice, balls of fraying wool, damp, antique books, empty glass jars. All things she needed to rehome now she faced her mortality. The memories too began to move out. She sent faded photographs to her children, grandchildren and friends, as well as letters containing vivid paragraphs detailing some experience or other. On 9 April, the afternoon before the night she died, she posted a letter to one of her late husband’s old childhood friends. In the envelope she enclosed some photographs of my grandfather and his friend playing as young children. “You must have them,” she wrote to him. It was a demand but also a plea, perhaps, that these things not be lost or forgotten when, a few hours later, she slipped away in her favourite armchair. © 2015 BBC
By Ben Thomas The past several years have brought two parallel revolutions in neuroscience. Researchers have begun using genetically encoded sensors to monitor the behavior of individual neurons, and they’ve been using brief pulses of light to trigger certain types of neurons to activate. These two techniques are known collectively as optogenetics—the science of using light to read and activate genetically specified neurons—but until recently, most researchers have used them separately. Though many had tried, no one had succeeded in combining optogenetic readout and stimulation into one unified system that worked in the brains of living animals. But now, a team led by Michael Hausser, a neuroscientist at University College London’s Wolfson Institute for Biomedical Research, has succeeded in creating just such a unified optogenetic input/output system. In a paper published this January in the journal Nature Methods [Scientific American is part of the Nature Publishing Group], the team explain how they’ve used the system to record complex signaling codes used by specific sets of neurons and to “play” those codes back by reactivating the same neural firing patterns they recorded, paving the way to get neural networks in the brains of living animals to recognize and respond to the codes they send. “This is going to be a game-changer,” Hausser says. Conventional optogenetics starts with genes. Certain genes encode instructions for producing light-sensitive proteins. By introducing these genes into brain cells, researchers are able to trick specific populations of those cells—all the neurons in a given brain region that respond to dopamine, for example—to fire their signals in response to tiny pulses of light. © 2015 Scientific American
Keyword: Brain imaging
Link ID: 20514 - Posted: 01.23.2015
By Bruce Bower Alexithymia: An inability to find words to describe one’s own feelings Mental health workers regard alexithymia as more akin to a personality trait than to a mental disorder. Many people with psychiatric conditions such as autism spectrum disorder and panic disorder — characterized by physical symptoms with emotional causes — also display alexithymia. Researchers are finding that alexithymia has the same effect on people with and without mental disorders and that it undermines the ability to describe others’ feelings as well as one’s own. A study appearing online January 21 in Royal Society Open Science found that nine of 21 young women with eating disorders had difficulty recognizing others’ facial emotions and that this characteristic was probably related to alexithymia, not some inherent feature of anorexia or bulimia. The researchers also looked at 21 women who had alexithymia but no psychiatric disorders and found that seven had comparable problems identifying others’ expressions of happiness, fear and other emotions. Citations R. Brewer et al. Emotion recognition deficits in eating disorders are explained by co-occurring alexithymia. Royal Society Open Science. Published online January 21, 2015. doi: 10.1098/rsos.140382. © Society for Science & the Public 2000 - 2015.
by Catherine Brahic Move over Homo habilis, you're being dethroned. A growing body of evidence – the latest published this week – suggests that our "handy" ancestor was not the first to use stone tools. In fact, the ape-like Australopithecus may have figured out how to be clever with stones before modern humans even evolved. Humans have a way with flint. Sure, other animals use tools. Chimps smash nuts and dip sticks into ant nests to pull out prey. But humans are unique in their ability to apply both precision and strength to their tools. It all began hundreds of thousands of years ago when a distant ancestor began using sharp stone flakes to scrape meat off skin and bones. So who were those first toolmakers? In 2010, German researchers working in Ethiopia discovered markings on two animal bones that were about 3.4 million years old. The cut marks had clearly been made using a sharp stone, and they were at a site that was used by Lucy's species, Australopithecus afarensis. The study, led by Shannon McPherron of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, was controversial. The bones were 800,000 years older than the oldest uncontested stone tools, and at the time few seriously thought that australopithecines had been tool users. Plus, McPherron hadn't found the tool itself. The problem, says McPherron, is that if we just go on tools that have been found, we must conclude that one day somebody made a beautifully flaked Oldowan hand axe, completely out of the blue. That seems unlikely. © Copyright Reed Business Information Ltd.
Link ID: 20512 - Posted: 01.23.2015
By Susan Chenelle and Audrey Fisch “Lord of the Flies” has been a classroom staple for decades, perhaps because the issues of bullying and male aggression remain central concerns in the lives of adolescents, even if they aren’t stranded on a desert island. “To Study Aggression, a Fight Club for Flies” zeros in on the issue of male aggression, but in fruit flies, rather than humans. The connections, beyond the titular, are tantalizing. James Gorman, the science reporter, is focused on research about the neuropeptide tachykinin, produced in the brains of male fruit flies only. When researchers manipulated the neurons, they could decrease aggression in the flies. What does this suggest about the neuroscience of aggression? And what is the relationship between aggression and gender? Below, we match Mr. Gorman’s article with a passage from Chapter 8 of “Lord of the Flies” in which Jack leads his peers in the hunt of a sow. At this point in the novel, Jack has overthrown Ralph and Piggy’s attempts to establish order and civility among the boys. Jack has won over a majority of the boys, and in this scene the group engages in a collective hunt for food that transforms itself into a kind of orgy of male violence. The gender politics of the scene are striking: The attack on the mother pig calls out for careful analysis. The boys are, for example, “wedded to her in lust” and climactically “heavy and fulfilled upon her” at the moment of her killing. What point is William Golding trying to make, here and elsewhere in the novel, about the nature of these young men and the ways in which they turn to and relish in aggression and violence? Key Question: What is the relationship between aggression and gender? © 2015 The New York Times Company
by Linda Geddes OUR personality literally shapes our world. It helps determine how many friends we have, which jobs we excel in and how we cope with adversity. Now it seems it may even play a role in our health – and not just in terms of any hypochondriac tendencies we harbour, but also how prone our bodies are to getting sick in the first place. It is a provocative idea but one that has been steadily gaining traction. We think of conscientiousness, for example, as a positive trait because it suggests caution, careful planning and an aversion to potential danger. But could it also be a symptom of underlying weakness in the immune system? That's one interpretation of a study published last month that sought to pick apart the links between personality traits and the immune system. It found that highly conscientious people had lower levels of inflammation; an immune response that helps the body fight infection and recover from injury. Highly extrovert people had higher levels. This may mean that extroverts are more physically robust – at least while they're young. While this sounds like good news, there's also a downside since sustained inflammation over a lifetime may leave you vulnerable to diabetes, atherosclerosis and cancer. "The biggest take-home message is that what happens in our health is connected to what happens in our heads and what happens in our lives," says Steven Cole at the University of California in Los Angeles (UCLA), who supervised the research. © Copyright Reed Business Information Ltd.
Link ID: 20510 - Posted: 01.22.2015
By Elizabeth Pennisi In the animal kingdom, humans are known for our big brains. But not all brains are created equal, and now we have new clues as to why that is. Researchers have uncovered eight genetic variations that help determine the size of key brain regions. These variants may represent “the genetic essence of humanity,” says Stephan Sanders, a geneticist and pediatrician at the University of California, San Francisco, who was not involved in the study. These results are among the first to come out of the ENIGMA (Enhancing Neuro Imaging Genetics through Meta-Analysis) collaboration, involving some 300 scientists from 33 countries. They contributed MRI scans of more than 30,000 people, along with genetic and other information, most of which had been collected for other reasons. “This paper represents a herculean effort,” Sanders says. Only by pooling their efforts could the researchers track down subtle genetic influences on brain size that would have eluded discovery in smaller studies. “We were surprised we found anything at all,” says Paul Thompson, a neuroscientist at the University of Southern California in Los Angeles. But in the end, “we were able to identify hot points in the genome that help build the brain.” For the analyses, Thompson and his colleagues looked for single-letter (nucleotide base) changes in DNA that correspond to the sizes of key brain regions. One region, the hippocampus, stores memories and helps one learn. Another, called the caudate nucleus, makes it possible to ride a bike, play an instrument, or drive a car without really thinking about it. A third is the putamen, which is involved in running, walking, and moving the body as well as in motivation. The researchers did not try to examine the neocortex, the part of the brain that helps us think and is proportionally much bigger in humans than in other animals. The neocortex has crevices on its surface that look so different from one individual to the next that it’s really hard to measure consistently across labs. © 2015 American Association for the Advancement of Science