by Rachel Nowak, Melbourne POSTURES adopted by young babies who were born prematurely are a powerful indicator of their intelligence later in life. Observing these postures could identify individuals who should be monitored for signs of learning difficulties. The early movements of babies are already used to predict which ones may go on to develop cerebral palsy, a physical disability caused by disruption of the nervous system. Phillipa Butcher of the Australian National University in Canberra and colleagues wondered if they could also predict intellectual impairments early on. "If you can identify those at risk of a lower intelligence you can intervene earlier by providing a richer learning environment," says Butcher. They turned to babies born very preterm - at less than 33 weeks - as these children are more likely to have low IQs than typically developing children. The team filmed 65 such babies 11 to 16 weeks after they were born, and counted how many normal postures they held in the space of 5 minutes. Such postures included the fingers of one hand being made to point in different directions at once, a sign that they can move their fingers independently, or lying on their back with their head held straight rather than lolling to one side, which is difficult for babies due to their relatively heavy heads. Years later, they tested the intelligence of the children, at ages 7 to 11, and found that all 16 of those babies who adopted just one or zero normal postures had IQs below the average of 100, while 60 per cent of those who held two or more normal postures had IQs above 100 (The Journal of Child Psychology and Psychiatry, DOI: 10.1111/j.1469-7610.2009.02066.x). © Copyright Reed Business Information Ltd

Keyword: Development of the Brain; Intelligence
Link ID: 12948 - Posted: 06.24.2010

by Nick Lane Forget the sweat and contorted posturing, just think about the biology. Sex is nuts. Cloning makes much more sense A clone, after all, just quietly gets on with copying itself. And since every clone can produce more clones, cloning produces far more offspring. There is no need for males - a waste of space, as hard-line feminists and evolutionists agree. What's more, each clone has a combination of genes that has already been found fit for purpose. Sex, by contrast, randomly mixes genes into new and untested amalgams. And the horrors of sex don't end there. There is the problem of finding a mate, and fighting off rivals. Not to mention the risk of picking up horrible diseases like AIDS and all sorts of selfish replicators that exploit sex to spread themselves through the genome. Queen of problems All this made sex the "queen of evolutionary problems" in the 20th century, taxing some of the finest minds in biology. The issue isn't just explaining why almost all plants and animals engage in sex. It is also explaining why the life forms that ruled the planet for billions of years and remain by far the most abundant - the bacteria - manage fine without it. That suggests that the ubiquity of sex among complex organisms has something to do with their ancient evolutionary history, not just the more recent past. Could there be some deep connection between the evolution of sex and the evolution of complex cells more than a billion years ago? © Copyright Reed Business Information Ltd

Keyword: Sexual Behavior; Evolution
Link ID: 12947 - Posted: 06.24.2010

By CARA BUCKLEY and JAMES ESTRIN It was after midnight. Nearly everyone inside the Hebrew Home at Riverdale, which hugs the banks of the Hudson River in the northern Bronx, was fast asleep. The group crept past a large fish tank and rounded a corner, startling a security guard who jumped at the sight of them: seven tiny women with lights glinting off their silvery hair. Then the guard noticed a young employee pushing one of the women in a wheelchair, and relaxed. It was just the night-care group, out for a supervised stroll. One of the ladies began singing a salsa song, creakily sashaying her hips. Another took note and grinned. “Shake it, don’t break it,” she called out. The seven women all have Alzheimer’s disease or dementia, and are part of the Hebrew Home’s ElderServe at Night, a dusk-to-dawn drop-off program intended to strengthen their decaying minds while sating their thirst to be active after dark. Alzheimer’s is an irreversible brain disease that destroys memory, and it is one form of dementia, a disorder marked by the loss of mental functions. Nighttime can be treacherous for people with dementia, who are often struck by sleeplessness or night terrors and prone to wandering about. This agitation and disorientation, called “sundowning,” is especially vexing for relatives trying to care for them at home, and often hastens their placement in nursing homes. Copyright 2009 The New York Times Company

Keyword: Alzheimers
Link ID: 12946 - Posted: 06.24.2010

By Larry Greenemeier Having proved in 2004 that plugging a sensor into the human brain's motor cortex could turn the thoughts of paralysis victims into action, a team of Brown University scientists now has the green light from the U.S. Food and Drug Administration (FDA) and the Massachusetts General Hospital (MGH) institutional review board to expand its efforts developing technology that reconnects the brain to lifeless limbs. Brown's BrainGate Neural Interface System—conceived in 2000 with the help of a $4.25-million U.S. Defense Department grant—includes a baby aspirin–size brain sensor containing 100 electrodes, each thinner than a human hair, that connects to the surface of the motor cortex (the part of the brain that enables voluntary movement), registers electrical signals from nearby neurons, and transmits them through gold wires to a set of computers, processors and monitors. (ScientificAmerican.com in 2006 wrote about one patient's experience using BrainGate during its first phase of trials.) The researchers designed BrainGate to assist those suffering from spinal cord injuries, muscular dystrophy, brain stem stroke, amyotrophic lateral sclerosis (ALS, or Lou Gehrig's Disease), and other motor neuron diseases. During the initial testing five years ago, patients suffering from paralysis demonstrated their ability to use brain signals sent from their motor cortex to control external devices such as computer screen cursors and robotic arms just by thinking about them. "The signals may have been disconnected from the (participant's) limb, but they were still there," says Leigh Hochberg, a Brown associate professor of engineering and a vascular and critical care neurologist at MGH who is helping lead the research. © 1996-2009 Scientific American Inc

Keyword: Robotics; Regeneration
Link ID: 12945 - Posted: 06.24.2010

By Laura Sanders Gray hair may be a mark of distinction in some circles, but it’s also a sign of a depleted stem cell population. DNA damage causes stem cells that produce hair-color cells in mice to lose their “stemness,” leaving brown hair gray, a report in the June 12 Cell shows. The results suggest a new way stem cell populations can be depleted as cells accumulate DNA damage over time. The new study “opens up a new paradigm for how we’re going to study stem cell aging in many systems,” comments Kevin Mills of the Jackson Laboratory in Bar Harbor, Maine. The report “fills in what’s been a hole in our understanding of stem cell biology.” Colorful locks depend on a group of special cells in hair follicles called melanocyte stem cells. Each of these cells divides into two cells: One that replaces itself and another that differentiates into a pigment-producing daughter cell called a melanocyte, which imbues hair with its browns, reds and blacks. Earlier research has suggested that the depletion of these stem cells was to blame for grayness. But how exactly these stem cells disappeared was mysterious. With no more stem cells around to produce melanocytes, hair turns gray. Emi Nishimura at Tokyo Medical and Dental University in Japan and her colleagues tracked the fate of these stem cells and grayness in mice exposed to DNA-damaging radiation. The exposure level was fairly high, intended to magnify the effects of DNA damage that cells gradually accumulate with age. © Society for Science & the Public 2000 - 2009

Keyword: Stress
Link ID: 12944 - Posted: 06.24.2010

By Jennifer Couzin-Frankel In mad cow disease, misfolded proteins called prions punch holes in the brain, eventually destroying it. Inherited prion diseases, which are rare and passed through families, do the same thing. But it's long been a puzzle why prions attack neurons more than other types of cells, and how they do their damage. In a new study, researchers propose that prions deplete a poorly understood protein that normally keeps nerve cells healthy. The theory still has a ways to go before it's proven, but researchers are intrigued by this potential new twist on a mysterious disease. Prions are a faulty version of a healthy protein called PrP; when it misfolds, the results are disastrous. Yet researchers don't know exactly why. One argument suggests that whereas healthy PrP is normally located on the cell's surface, prions go astray and end up in the cytosol, the liquid found inside cells, somehow destroying them. The new study bolsters this theory. The first clues came in a paper published in 2003. In that work, researchers reported that mice lacking an obscure protein, Mahogunin, suffered a form of neurodegeneration much like prion disease. Cell biologists Ramanujan Hegde and Oishee Chakrabarti of the National Institute of Child Health and Human Development in Bethesda, Maryland, decided to probe deeper into the Mahogunin connection. © 2009 American Association for the Advancement of Science

Keyword: Prions
Link ID: 12943 - Posted: 06.24.2010

by Ewen Callaway For decades scientists have tried, mostly in vain, to explain where intelligence resides in our brains. The answer, a new study suggests, is everywhere. After analysing the brain as an incredibly dense network of interconnected points, a team of Dutch scientists has found that the most efficiently wired brains tend to belong to the most intelligent people. And improving this efficiency with drugs offers a tantalising – though still unproven – means of boosting intelligence, say researchers. The concept of a networked brain isn't so different from the transportation grids used by cars and planes, says Martijn van den Heuvel, a neuroscientist at Utrecht University Medical Center who led the new study. "If you're flying from New York to Amsterdam, you can do it in a direct flight. It's much more effective than going from New York, then to Washington, and then to Amsterdam. It's exactly the same idea in the brain," he says. Instead of airports, van den Heuvel's team mapped the communications between tiny slivers of brain measured by a functional magnetic resonance imaging (fMRI) machine. Rather than scan the brains of subjects performing mental tasks, as most fMRI studies do, researchers took 8-minute-long snapshots of the brains of 19 volunteers, as they did nothing in particular. © Copyright Reed Business Information Ltd.

Keyword: Intelligence; Learning & Memory
Link ID: 12942 - Posted: 06.24.2010

By Rachael Rettner Our large brains may make us cognitively superior to chimps, but, according to a new hypothesis, we could be paying a price for our sizable cerebrum: a higher rate of cancer. Chimpanzees are thought to be the closest evolutionary relative to humans, and we share around 98 percent of our genes with these primates. But for years, scientists have observed that chimps have a surprisingly low cancer rate compared to humans. To find out why this might be, John McDonald, a researcher at Georgia Tech, turned to the human and chimp genome. Many past studies have looked at differences in how genes are expressed among humans and chimps. McDonald and his colleagues re-examined the data of a previous gene expression study and added some previously excluded information. They looked for differences in gene expression in several tissues, including the brain, liver, testes and kidneys. McDonald wanted to test a hypothesis that the difference in cancer rates between the species could be due to differences in the way their cells self-destroy themselves — an important biological process known as programmed cell death or apoptosis. The researchers saw that some of the genes for apoptosis were expressed differently in humans than in chimps, and their data suggests that human cells are not as efficient at carrying out programmed cell death as chimp cells, at least in the brain and other studied tissues. © 2009 LiveScience.com.

Keyword: Evolution
Link ID: 12941 - Posted: 06.24.2010

By Jesse Bering It is a little-known fact that a life lived without enemies would be an extraordinarily dull affair. One person who understood this very clearly was the nineteenth century British essayist William Hazlitt, whose misanthropic-sounding On the Pleasure of Hating was in fact a gracefully written ode to this much maligned social emotion: “Without something to hate,” wrote Hazlitt, “we should lose the very spring of thought and action. Life would turn to a stagnant pool, were it not ruffled by the jarring interests, the unruly passions of men.” Suddenly the idea of a utopian society, where everyone is satisfied, equal and good, sounds like a rather drab and stultifying place. Heaven, according to this view, would be a special kind of Hell, a land filled with the souls of smiling, slumbering idiots intoxicated by unending love, understanding and pleasant company. (And an especially interminable ocean of boredom, since one couldn’t even escape through death.) Or consider, where would Bill O’Reilly be without the “Liberal Left” that so angers him, Richard Dawkins without the “dyed-in-the-wool” believers who’ve become the bane of his existence, or prosecutorial talk show host Nancy Grace without the “scum” she abhors so passionately? (Writer Jean Genet, who spent the first half of his life as a cog in the French penal system, pointed out that criminals were just as important to society as were those who despised them. After all, said Genet, an entire industry of people—lawyers, judges, jailers, clerks, guards, legislators, psychiatrists, counselors and so on—were only able to pay their taxes, feed their children and furnish their homes through the tireless labors of criminals.) Without someone to hate, these pundits would be considerably poorer, no doubt, without a soapbox to stand on and void of any unique social function. With all this in mind, I suppose it was a very wise PR person who once told me that if ever I found myself universally liked, this would be a sign that I was doing something very wrong. © 1996-2009 Scientific American Inc.

Keyword: Emotions
Link ID: 12940 - Posted: 06.24.2010

By Susan Milius They may wear too much pink to fit in among macho fliers. But when male Anna’s hummingbirds swoop out of the sky, they pull more g’s than any known vertebrate stunt flier outside a cockpit, says Chris Clark of the University of California, Berkeley. During breeding season, the male hummingbirds soar some 30 meters and then dive, whizzing by a female so fast that their tail feathers chirp in the wind (SN: 8/25/07, p. 125). As the birds pull out of their plunge to avoid crashing, they experience forces more than nine times the force of gravity, Clark reports online June 9 in a biomechanical analysis in Proceedings of the Royal Society B. Anna’s (Calypte anna) have become one of the most common hummingbirds in backyards and parks along the West Coast. The males of the species are marked by dramatic pink plumage on their heads. The stunt flier’s great swoop forms one of the centerpieces of his courtship display to win female attention. The bird orients his display dive in relation to the sun so that his female audience will get the brightest view. “They look like a little magenta fireball dropping out of the sky,” Clark says. Clark “has found amazing things about this display,” says Doug Altshuler of University of California, Riverside, who also studies hummingbirds. The new paper shows “to what extraordinary lengths these birds are willing to go to impress potential mates” and could open new opportunities for studying sexual selection. © Society for Science & the Public 2000 - 2009

Keyword: Sexual Behavior
Link ID: 12939 - Posted: 06.24.2010

by Ewen Callaway Children who look and smell like their father receive more of their support, compared to kids who resemble dad less. The study of 30 Senegalese families has provided the first direct link between a father's investment in his children and his physical resemblance to them, though other work has hinted at this connection. For instance, a study conducted at London's Heathrow Airport found that fathers invested extra time and money in children who looked and behaved like them, compared with dads who said their kid's looks and personalities differed from their own. Such uncharitable behaviour may seem shocking, but evolutionary theory predicts it. Without a DNA test and an appearance on the Jerry Springer Show, a father can never be absolutely certain that a child is his own. Therefore, it makes evolutionary sense to divvy out limited resources – be they time, food or money – to children more likely to be legitimate. The behaviour has an evolutionary advantage because there are always going to be illegitimate children, says Alexandra Alvergne, a biological anthropologist at the Institute of Evolutionary Sciences in Montpellier, France, who led the new study. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Evolution
Link ID: 12938 - Posted: 06.24.2010

by Andy Coghlan CHILDREN with attention-deficit hyperactivity disorder might appear rowdy and indisciplined, but they are actually trying to cope with a faulty perception of time. What to most of us seems like a short stretch of time would drag unbearably for someone with ADHD, says Katya Rubia of the Institute of Psychiatry at King's College London. Her team's research, reported this week, adds to a growing body of evidence for the importance of time perception in a wide range of psychological disorders. ADHD affects around 5 per cent of children globally, most of them boys. Studies relating to the disorder have focused on patients' short attention spans and impulsive behaviour. But ADHD is characterised by a shortage of dopamine, which is known to affect time perception, so Rubia and her colleagues wanted to know if this was the source of the kids' problems. The researchers used MRI scans to show that 12 boys with ADHD had less activity than usual in the frontal lobe, the basal ganglia and the cerebellum, all areas of the brain known to be crucial for time perception. These boys were also worse than 12 other boys at estimating how long circles appeared on a screen before vanishing. When they were given the drug methylphenidate, aka Ritalin, which boosts dopamine levels and is used to treat ADHD, brain activity in the ADHD group became indistinguishable from that of the healthy boys. "Ritalin enhances brain regions that are important for time perception in ADHD children," concludes Rubia. The results are published in a special issue of Philosophical Transactions of the Royal Society B, which is devoted to time perception (DOI: 10.1098/rstb.2009.0014). © Copyright Reed Business Information Ltd.

Keyword: ADHD; Attention
Link ID: 12937 - Posted: 06.24.2010

By Mike Jay The date of the first operation under anesthetic, Oct. 16, 1846, ranks among the most iconic in the history of medicine. It was the moment when Boston, and indeed the United States, first emerged as a world-class center of medical innovation. The room at the heart of Massachusetts General Hospital where the operation took place has been known ever since as the Ether Dome, and the word "anesthesia" itself was coined by the Boston physician and poet Oliver Wendell Holmes to denote the strange new state of suspended consciousness that the city's physicians had witnessed. The news from Boston swept around the world, and it was recognized within weeks as a moment that had changed medicine forever. But what precisely was invented that day? Not a chemical - the mysterious substance used by William Morton, the local dentist who performed the procedure, turned out to be simply ether, a volatile solvent that had been in common use for decades. And not the idea of anesthesia - ether, and the anesthetic gas nitrous oxide, had both been thoroughly inhaled and explored. As far back as 1525, the Renaissance physician Paracelsus had recorded that it made chickens "fall asleep, but wake up again after some time without any bad effect," and that it "extinguishes pain" for the duration. What the great moment in the Ether Dome really marked was something less tangible but far more significant: a huge cultural shift in the idea of pain. Operating under anesthetic would transform medicine, dramatically expanding the scope of what doctors were able to accomplish. What needed to change first wasn't the technology - that was long since established - but medicine's readiness to use it. © 2009 NY Times Co.

Keyword: Pain & Touch
Link ID: 12936 - Posted: 06.24.2010

Matt Walker Chimpanzees remember the exact location of all their favourite fruit trees. Their spatial memory is so precise that they can find a single tree among more than 12,000 others within a patch of forest, primatologists have found. More than that, the chimps also recall how productive each tree is, and decide to travel further to eat from those they know will yield the most fruit. Acquiring such an ability may have helped drive the evolution of sophisticated primate brains. Emmanuelle Normand and Christophe Boesch of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany teamed up with Simone Ban of the University of Cocody in Abidjan, Cote d'Ivoire to investigate the spatial memory of chimpanzees in the wild. "We were amazed by the apparent easiness by which chimpanzees discover highly productive fruit trees. Or how after being separated from other group members for hours or days, they could join each other silently at a large fruit tree, like if they would have had an appointment at this place," says Normand. To find out how they do it, Normand's team first mapped the location of 12,499 individual trees growing within the home range of a group of chimpanzees living in the Tai National Park in the Cote d'Ivoire. They identified each tree and used GPS to map its precise position. (C)BBC

Keyword: Learning & Memory; Evolution
Link ID: 12935 - Posted: 06.09.2009

By Carolyn Y. Johnson Scientists are trying a new approach to unravel the workings of the autistic brain: the neurological equivalent of banging a patient's knee with a hammer to test reflexes. Instead of a hammer, though, researchers are pressing a flat paddle against patients' heads and creating a magnetic field that triggers brain cell activity. As the quest to understand autism has grown more urgent, researchers have used brain scanners to peer into autistic minds, searched for faulty genes, and scrutinized the play of 1-year-olds. The work has provided theories - but few concrete answers - about what goes awry to cause social isolation, repetitive behaviors, and communication problems that afflict an estimated one in 150 children with autism spectrum disorders. The hunt has focused on everything from "mirror neurons," brain cells some re searchers think enable people to understand other's actions and intentions, to an overgrowth of local connections in the brain. Now a small but growing number of researchers see hope in a tool called transcranial magnetic stimulation, which lets scientists spark activity in specific areas of the brain and watch what happens to patients' behavior. The technology may illuminate some of the biology behind the disease, and some specialists speculate it may one day offer a treatment. © 2009 NY Times Co.

Keyword: Autism
Link ID: 12934 - Posted: 06.24.2010

By Carolyn Y. Johnson Little Joe clutched the mesh fence that separated him from the outside world. But the 16-year-old western lowland gorilla, famed for his 2003 escape from the Franklin Park Zoo, wasn't contemplating another jailbreak. He was doing business. Senior zookeeper Brandi Baitchman had presented him with two colored dowels - gorilla cash in an experiment to see whether Joe could grasp the concept of money. The blue dowel could be traded for monkey chow, a favorite delicacy. The white one was worth nothing. Without a hint of hesitation, and quicker than a stock floor trader, Joe picked blue. Baitchman slipped a chow pellet into his mouth. For nearly a year, Joe and other gorillas at the Boston zoo's tropical forest exhibit have been guinea pigs in experiments exploring the reasoning of gorillas - and the origins of human economic behavior. For years, scientists have examined when and why people take risks, delay gratification, or work for a reward. Harvard University scientists have been visiting the zoo three days a week to learn whether there are roots of such human traits even in a species that never developed its own stock exchange or global monetary system. "Right now, we're focusing on what we're calling gorilla economics," said Katherine McAuliffe, a Harvard graduate student in the Cognitive Evolution Laboratory who began working with Joe last summer. "What sort of ecological context might select for certain kinds of decision-making?" © 2009 NY Times Co

Keyword: Learning & Memory; Evolution
Link ID: 12933 - Posted: 06.24.2010

By NATALIE ANGIER If you wanted to push yourself to the outermost chalk line of human endurance, you might consider an ultramarathon, or a solo row across the Atlantic Ocean, or being nominated to the United States Supreme Court. Muse Opiang was working as a field research officer when he became seized by a passion for the long-beaked echidna. Or you could try studying the long-beaked echidna, one of the oldest, rarest, shyest, silliest-looking yet potentially most illuminating mammals on earth. Muse Opiang was working as a field research officer when he became seized by a passion for the long-beaked echidna, or Zaglossus bartoni, which are found only in the tropical rain forests of New Guinea and a scattering of adjacent islands. He had seen them once or twice in captivity and in photographs — plump, terrier-size creatures abristle with so many competing notes of crane, mole, pig, turtle, tribble, Babar and boot scrubber that if they didn’t exist, nobody would think to Photoshop them. He knew that the mosaic effect was no mere sight gag: as one of just three surviving types of the group of primitive egg-laying mammals called monotremes, the long-beaked echidna is a genuine living link between reptiles and birds on one branch, and more familiar placental mammals like ourselves on the next. Mr. Opiang also knew that, whereas members of the two other monotreme genuses, the duck-billed platypus and short-beaked echidna, had been studied for years — last May, the entire genetic code of the platypus was published to great fanfare — the life of the long-beaked echidna remained obscure and unsung. Copyright 2009 The New York Times Company

Keyword: Evolution
Link ID: 12932 - Posted: 06.24.2010

By Michael Shermer FULLERTON, CALIF.—If you want to wait by the phone for your next college-aged daughter's call home, you should mark the days of her menstrual cycle on your calendar. Well, not exactly. But that was one reasonable conclusion of research presented here last week at the 21st annual conference of the Human Behavior and Evolution Society (HBES) at California State University, Fullerton, by Elizabeth Pillsworth, a graduate student in Martie Haselton's lab at the University of California, Los Angeles. Haselton studies sexual attraction, relationships, and how fertility cycles influence mate preferences and choices (for instance, women dress in a more sexually provocative manner during the high fertility phase of the month). In an interesting twist on this body of research, Pillsworth studied the effects of the fertility phase in women on the incest taboo—specifically, how often college-aged women phoned their dads (versus their moms) during the month. Wow. It never ceases to amaze me how clever scientists can be in thinking up new research paradigms: Who would have ever thought of correlating cell phone calls with estrus cycles? Pillsworth and Haselton (and their colleague Debra Lieberman) did! And the results were most revealing. But first, some background. On the 200th anniversary of Darwin's birth and the 150th anniversary of the publication of The Origin of Species, Darwinian principles have finally come online in mainstream psychology. HBES is the official organization of evolutionary psychologists and a champion of applying Darwinian thinking to human psychology, and its conferences seem to be gaining steam. © 1996-2009 Scientific American Inc.

Keyword: Evolution; Hormones & Behavior
Link ID: 12931 - Posted: 06.24.2010

Sleep deprivation is known to impair memory and may cause other health problems. On the other hand, dreaming has long been credited for creative thinking, from Kekule’s famed discovery of the ring structure of the chemical benzene to Paul McCartney’s song "Yesterday." Now new research is illuminating the role of REM sleep — the sleep stage in which dreams occur– in creative problem solving. In their study of 77 healthy volunteers, University of California, San Diego sleep researchers researchers Sara Mednick, Denise Cai, and their colleagues found that a daytime nap boosts performance on a standard test of creative problem solving, but only if the nap includes REM, or rapid-eye-movement sleep. "This is the first time that REM sleep has ever been shown to be directly connected to a boost in creativity, and also that this is done in a daytime nap," says Mednick. She hopes the study adds some insight into insight for scientists and the public. "If REM sleep is helping solve creative problems, then there’s something specific about the associative networks that occurs during REM sleep that allows these unconnected bits of information to finally connect and associate," she says. "That’s interesting from its own basic science perspective." ©2009 ScienCentral

Keyword: Sleep; Learning & Memory
Link ID: 12930 - Posted: 06.24.2010

by Ewen Callaway Most of the time the brain works as it ought to: limbs move, memories are retrieved and experiences processed. But occasionally things go awry. In tip-of-the-tongue experiences, for instance, words suddenly and perplexingly go missing only to reappear seconds or minutes later. Another brain quirk – déjà vu – confirms the fallibility of memory. Now two new studies have shed light on both phenomena. Nearly everyone has tip-of-the-tongue moments, but bilinguals seem especially prone to these momentary lapses in vocabulary, says Jennie Pyers, a psychologist at Wellesley College in Massachusetts. One possible explanation is that similar-sounding words compete for our brain's attention. Since bilinguals know twice as many words as monolinguals, there's more chance for tip-of-the-tongue experiences. "Often when we're having tip-of-the-tongue experiences, words that sound the same come to mind," Pyers says. "There's a sense that you do know the first letter; there's a sense that you might know how many syllables it is." Alternatively, they could occur when our brains recall rarely used words, Pyers says. "It's much easier to retrieve a word like 'knife' than 'guillotine'." It's a…, it's a… Since bilinguals, by definition, speak two languages, they are bound to use many individual words less frequently than monolinguals. © Copyright Reed Business Information Ltd

Keyword: Language; Attention
Link ID: 12929 - Posted: 06.24.2010