By BENEDICT CAREY The passionate, sometimes rhythmic, language-like patter that pours forth from religious people who “speak in tongues” reflects a state of mental possession, many of them say. Now they have some neuroscience to back them up. Researchers at the University of Pennsylvania took brain images of five women while they spoke in tongues and found that their frontal lobes — the thinking, willful part of the brain through which people control what they do — were relatively quiet, as were the language centers. The regions involved in maintaining self-consciousness were active. The women were not in blind trances, and it was unclear which region was driving the behavior. The images, appearing in the current issue of the journal Psychiatry Research: Neuroimaging, pinpoint the most active areas of the brain. The images are the first of their kind taken during this spoken religious practice, which has roots in the Old and New Testaments and in charismatic churches established in the United States around the turn of the 19th century. The women in the study were healthy, active churchgoers. “The amazing thing was how the images supported people’s interpretation of what was happening,” said Dr. Andrew B. Newberg, leader of the study team, which included Donna Morgan, Nancy Wintering and Mark Waldman. “The way they describe it, and what they believe, is that God is talking through them,” he said. Dr. Newberg is also a co-author of “Why We Believe What We Believe.” Copyright 2006 The New York Times Company

Keyword: Language; Brain imaging
Link ID: 9591 - Posted: 06.24.2010

By ERIC NAGOURNEY Emergency room doctors trying to figure out the best way to treat someone who has just had a stroke would be able to follow a more informed course of action if they had an M.R.I. scan of the patient’s brain, a new study finds. For about a decade, doctors have been able to turn to drugs known as clot busters, which can significantly improve the outcome for people whose strokes are caused by a blockage in a blood vessel. The problem is that many strokes involve bleeding in the brain, not clotting, and the clot busters can be fatal in those cases. Although the two types of strokes are different, their symptoms can be the same, and the CT scans commonly given to patients at the hospital can shed only a little light. In the new study, however, researchers led by Dr. Gregory W. Albers of Stanford found that M.R.I. scans could provide information that makes it clearer which patients will benefit from clot busters. The scans may also increase the window of time doctors have to administer them. Under current guidelines, the drugs should not be given more than three hours after a stroke — a problem because many patients do not come in for treatment until after that time has passed. But armed with the M.R.I. results, which show which parts of the brain are damaged beyond repair and which can still be saved, doctors may be able to give the drug later, the study said. Copyright 2006 The New York Times Company

Keyword: Stroke; Brain imaging
Link ID: 9590 - Posted: 06.24.2010

By AMANDA SCHAFFER In ancient Rome, patients with unbearable head pain were sometimes treated with jolts from the electricity-producing black torpedo fish, or electric ray. A.D. 41 In ancient Rome doctors treated the throbbing pain of migraine headaches by applying an electric fish like the black torpedo, top, directly to the head. 2006 It doesn't smell and its shocks are more predictable, but the occipital nerve stimulator, implanted in the head and buttocks, operates on the same principle, bottom. Scribonius Largus, physician to Emperor Claudius, was a staunch advocate of the remedy. “To immediately remove and permanently cure a headache, however long-lasting and intolerable, a live black torpedo is put on the place which is in pain, until the pain ceases and the part grows numb,” he wrote in the first century. Electric fish have long disappeared from the medical armamentarium. And patients with headaches are most frequently treated with pharmaceuticals. But recently, electrical or electromagnetic devices that hark back to the head-zapping torpedo fish have come into vogue among the country’s most prominent migraine researchers. Two different kinds of stimulatory devices are now in large-scale clinical trials for possible use in patients with the most severe migraine cases. Many researchers believe that such devices are likely to play a greater role in migraine treatment in the future. Copyright 2006 The New York Times Company

Keyword: Pain & Touch
Link ID: 9589 - Posted: 06.24.2010

Costa Rican teens who were iron-deficient as infants continue to lag behind their peers in cognitive test scores, with a wider gap for children at lower socioeconomic levels, according to study results published in the November issue of Archives of Pediatrics & Adolescent Medicine, one of the JAMA/Archives journals. Several previous studies have shown that children with low levels of iron in their blood do worse than those without an iron deficiency on tests that measure cognitive skills, such as thinking, learning and memory, according to background information in the article. About one-fifth to one-fourth of children around the world have iron deficiency anemia, in which a lack of iron causes problems with hemoglobin--the compound that red blood cells use to transport oxygen through the bloodstream. Many more have low iron without anemia. Children from poor, minority or immigrant backgrounds are more likely to be iron-deficient. Betsy Lozoff, M.D., University of Michigan, Ann Arbor, and colleagues studied the long-term effects of iron deficiency and socioeconomic status in a group of 185 children from an urban area in Costa Rica. The children, who were an average of 17 months old when the study began in 1983 to 1985, were screened for iron deficiency at their first visit. They were given cognitive tests (on which the index, or overall average score, is 100) then and again at ages 5, 11 to 14, 15 to 18 and 19 years. Those who had low iron levels in infancy even after three months of iron therapy were compared with those who had normal iron levels either without or after treatment.

Keyword: Development of the Brain; Intelligence
Link ID: 9588 - Posted: 11.07.2006

By Paul Raffaele Led by five trackers from the Mongandu tribe, I tread through a remote rain forest in the Democratic Republic of the Congo, on the trail of the bonobo, one of the world's most astonishing creatures. Along with the chimpanzee, it's our closest relative, with whom we share almost 99 percent of our genes. The last of the great apes to be discovered, it could be the first to become extinct in the wild: in the past few decades, bonobo habitat has been overrun by soldiers, and the apes have been slaughtered for food. Most estimates put the number of bonobos left in the wild at less than 20,000. As the narrow trail plunges into a gloomy, rain-soaked tunnel through tall trees, Leonard, the head tracker, picks up a fallen leaf and brings it to his nose. "Bonobo urine," he murmurs. High above I see a large, dark, hairy creature propped between the trunk and bough of a sturdy hardwood. "The alpha male," Leonard whispers. "He's sleeping. Keep quiet, because it means there are bonobos all around us." We creep toward the tree and sit beneath it. I try to ignore the fiery bites of ants crawling over my arms and legs as we wait for the bonobos to awaken. They are known to be gregarious, exceptionally intelligent primates, and the only apes whose society is said to be matriarchal...and orgiastic: they have sexual interactions several times a day and with a variety of partners. While chimpanzees and gorillas often settle disputes by fierce, sometimes deadly fighting, bonobos commonly make peace by engaging in feverish orgies in which males have intercourse with females and other males, and females with other females. No other great apes—a group that includes eastern gorillas, western gorillas, Bornean orangutans, Sumatran orangutans, chimps and, according to modern taxonomists, human beings—indulge themselves with such abandon. Copyright Smithsonian Institute

Keyword: Aggression; Sexual Behavior
Link ID: 9587 - Posted: 06.24.2010

ANN ARBOR, Mich. -- A new brain study finds major differences between women with serious depression and healthy women in a brain-chemical system that's crucial to stress and emotions. The study adds further evidence that depression has its roots in specific alterations within the brain -- specifically in the endogenous opioid system that is a central part of the brain's natural pain and stress-reduction system. The findings also show significant variation between individuals with depression – variation that seems to be linked to whether or not the patients respond to an antidepressant medication. The study, performed by researchers at the University of Michigan Medical School affiliated with the U-M Depression Center, is published in the November issue of the Archives of General Psychiatry. It's based on brain imaging, blood chemistry and other data from 14 women with major depression, and 14 healthy women of about the same age and background. The women with depression were not taking antidepressants when the study began. "This work gives further evidence of individual differences in brain mechanisms that are altered in major depression," says senior author Jon-Kar Zubieta, M.D., Ph.D., the Jenkins Research Professor of Depression and associate professor of psychiatry and radiology. "We found these differences in the response of the endogenous opioid system. Some women, but not others, with major depression, showed exaggerated responses in this system when undergoing an emotional challenge."

Keyword: Depression; Sexual Behavior
Link ID: 9586 - Posted: 06.24.2010

By Michael Balter For decades, human evolution researchers have debated whether Neandertals and modern humans interbred. Most scientists have come down on the side that any romances between these hominid cousins must have been fleeting at best. But a new study suggests that a few of these passing dalliances might have had a major impact on the evolution of the Homo sapiens brain. If so, Neandertals, although long extinct, may have left humanity a lasting genetic gift. Some anthropologists have argued that a handful of hominid skeletons show features of both Neandertals and modern humans (Science, 11 February 2005, p. 841). But so far sequencing of Neandertal ancient DNA has turned up no signs of such interbreeding (Science, 11 July 1997, p. 176). As a result, most researchers have considered the two species genetically separate. Now, University of Chicago geneticist Bruce Lahn and his colleagues report evidence that at least one gene might have bridged the evolutionary divide. Lahn's team analyzed the origins of the gene microcephalin, thought to be involved in regulating brain growth. Last year, the team reported in Science that a particular variant of the gene, now present in 70% of the world's population, arose about 37,000 years ago and quickly spread around the globe. Apparently the variant, known as haplogroup D, was favored by natural selection, although no one is sure of its function (Science, 9 September 2005, p. 1662). © 2006 American Association for the Advancement of Science

Keyword: Evolution
Link ID: 9585 - Posted: 06.24.2010

New research suggests that offering methamphetamine abusers an incentive-based behavioral therapy program called contingency management (CM — also known as Motivational Incentives), along with psychosocial therapy is more effective than psychosocial therapy alone. The study was supported by the National Institute on Drug Abuse (NIDA), National Institutes of Health, and is published in the November 2006 issue of the American Journal of Psychiatry. A CM program applies rules and consequences to help people change their behavior. In other words, participants are in treatment with contingencies, or rewards. In this case, the rules required production of drug-free urine samples. The rewards were plastic chips that could be exchanged for prizes. Other examples of CM awards might be raffle tickets, or small prizes that could be exchanged for a larger prize. The more the patient follows the rules, the more chips they earn. If the rules are not followed, they can lose chips. Previous studies have shown the effectiveness of CM as a treatment for stimulant abuse (primarily cocaine). This most recent study suggests that CM can help methamphetamine abusers to stop or reduce their abuse of the drug for a longer time than individuals who receive the standard treatment as usual but do not receive such incentives, or rewards. “Methamphetamine abuse is associated with numerous medical consequences, such as rapid, irregular heartbeat, stroke, severe dental problems, psychosis, and addiction, and constitutes one of the nation’s most serious public health problems,” says Dr. Elias A. Zerhouni, director of the National Institutes of Health.

Keyword: Drug Abuse
Link ID: 9584 - Posted: 06.24.2010

Michael Hill, Associated Press — Think much about that popcorn while you're eating it? Or that plate of pasta? That bowl of soup? Probably not. But Cornell University marketing professor Brian Wansink does. A lot. Wansink isn't concerned about the food, exactly, but why you eat it. His goal is to uncover hidden cues that influence how much we eat. He wants to know if people grab more M&M's from a bowl if there are more colors (yes), if people tend to eat less popcorn at comic films like "My Big Fat Greek Wedding" than during gloomy films (yes) and whether people are tuned into the subtle prompts like mood and setting that affect their eating (generally, no). After years of sometimes unorthodox research, Wansink argues that a good way to lose weight is not by obsessing over carbs or banning trans fats, but by addressing dietary "hidden persuaders." He lays out the case in his new book, "Mindless Eating, Why We Eat More than We Think We Eat." "So much of the answer lies not in counting calories, not in legislating, but in the middle range of what we can do by changing some of our own habits," Wansink said during an interview in his Food and Brand Lab on Cornell's upstate New York campus. © 2006 Discovery Communications Inc.

Keyword: Obesity
Link ID: 9583 - Posted: 06.24.2010

Roxanne Khamsi Chronic fatigue syndrome may be linked to childhood trauma, according to two new studies. It suggests there is a strong psychological component to the mysterious disorder, which is characterised by unexplained fatigue, the researchers say. Christine Heim at Emory University in Atlanta, Georgia, US, and colleagues carried out a survey of 100 adults aged about 50-years-old, 43 of whom had CFS. Participants were asked whether they had experienced neglect or emotional, physical or sexual abuse during their childhood. Those diagnosed with CFS were significantly more likely to have experienced childhood abuse, the team found. CFS patients were also more likely than the control subjects to have psychiatric disorders, such as depression and anxiety. Heim believes that mental illness is a contributing factor but not a cause of CFS – not all of the CFS patients had a psychiatric disorder, she notes. Nevertheless, CFS might have a larger psychological component than some experts believe, Heim says. Some researchers currently promote the idea that CFS is a purely biological illness. But Heim says that biology and experience probably both contribute to the disorder. It is unclear why trauma and stress may predispose a person to CFS, but such experiences early in life might influence brain development, she speculates. © Copyright Reed Business Information Ltd.

Keyword: Stress
Link ID: 9582 - Posted: 06.24.2010

Kerri Smith Zapping people's brains with an electric current while they sleep might not sound such a good idea. But by boosting natural brain waves it can improve memory, as new work shows. This approach might one day help us learn better or provide new treatments for sleep disorders. One of the functions of sleep is generally agreed to be the consolidation of memories: certain tasks learned before a snooze are remembered better than if no nap follows. Now Jan Born and his colleagues at the University of Lübeck in Germany think they know why. One theory holds that levels of brain chemicals, or neuromodulators, are what affects memory during sleep. But Born wanted to test a competing idea — that waves, or oscillations, of electrical activity are responsible. To pinpoint which part of sleep contributes to strengthening memory, the team used a weak electrical current to boost brain activity during deep sleep. Oscillations in electrical activity occur naturally, at different frequencies, during different sleep phases throughout the night. Oscillations are fastest during rapid eye movement (REM) sleep, and slowest in phases of deep sleep. Boosting the slow waves seems to be the key to boosting memory, says Born. ©2006 Nature Publishing Group

Keyword: Sleep; Learning & Memory
Link ID: 9581 - Posted: 06.24.2010

TALLAHASSEE, Fla. -- People who get scared when they experience a pounding heart, sweaty palms or dizziness -- even if the cause is something as mundane as stress, exercise or caffeine -- are more likely to develop a clinical case of anxiety or panic disorder, according to a Florida State University researcher in Tallahassee, Fla. While other researchers have proposed a connection between this so-called "anxiety sensitivity" and a range of anxiety problems, the study by FSU psychology professors N. Brad Schmidt and Jon Maner and University of Vermont Professor Michael Zvolensky provides the first evidence that anxiety sensitivity is a risk factor in the development of anxiety disorders. The study will be published in the December issue of the Journal of Psychiatric Research. "The findings offer an exciting possibility for prevention of anxiety and panic reactions among high-risk individuals," Schmidt said, explaining that the key is to teach people cognitive and behavioral skills to reduce their anxiety sensitivity so that it does not lead to a serious problem. People with anxiety sensitivity perceive their physical responses to certain triggers as a sign of imminent personal harm. They not only fear their reactions, they also fear that other people will detect their anxiety, which only serves to increase their anxiety and puts them at risk for a panic attack, according to Schmidt.

Keyword: Emotions
Link ID: 9580 - Posted: 11.07.2006

By Tom Jackman Severely mentally ill people in Fairfax County whose families are trying to get them emergency help are being released without receiving treatment -- or even a hearing -- because there are not enough independent psychologists to examine them. Nineteen people held involuntarily on temporary orders have been released from hospitals since mid-October, authorities said. Fairfax mental health experts and police are trying to keep track of those let back out on the street. But with each release, lawyers and police officers are becoming increasingly concerned about the danger to the public. Mentally ill people in Fairfax have become violent in the past. In May, a mentally ill teenager, whose family had repeatedly tried to get him help, drove into the Sully police station parking lot and fatally shot two officers before being killed himself. "There is a very serious public safety issue here," said Kaye Fair, director of emergency services for the Fairfax-Falls Church Community Services Board, which provides mental health services. "People that, by definition, are dangerous to themselves or others are being released without a hearing." Faced with the shortage, the Community Services Board began using its own psychologists and social workers for the examinations. That prompted a new interpretation of Virginia law by three special justices in Fairfax that the board's employees were not independent, and they began dismissing cases. © 2006 The Washington Post Company

Keyword: Schizophrenia
Link ID: 9579 - Posted: 06.24.2010

By Paul Raffaele To better understand bonobo intelligence, I traveled to Des Moines, Iowa, to meet Kanzi, a 26-year-old male bonobo reputedly able to converse with humans. When Kanzi was an infant, American psychologist Sue Savage-Rumbaugh tried to teach his mother, Matata, to communicate using a keyboard labeled with geometric symbols. Matata never really got the hang of it, but Kanzi—who usually played in the background, seemingly oblivious, during his mother’s teaching sessions—picked up the language. Savage-Rumbaugh and her colleagues kept adding symbols to Kanzi’s keyboard and laminated sheets of paper. First Kanzi used 6 symbols, then 18, finally 348. The symbols refer to familiar objects (yogurt, key, tummy, bowl), favored activities (chase, tickle), and even some concepts considered fairly abstract (now, bad). Kanzi learned to combine these symbols in regular ways, or in what linguists call"proto-grammar."Once, Savage-Rumbaugh says, on an outing in a forest by the Georgia State University laboratory where he was raised, Kanzi touched the symbols for"marshmallow"and"fire."Given matches and marshmallows, Kanzi snapped twigs for a fire, lit them with the matches and toasted the marshmallows on a stick. Savage-Rumbaugh claims that in addition to the symbols Kanzi uses, he knows the meaning of up to 3,000 spoken English words. She tests his comprehension in part by having someone in another room pronounce words that Kanzi hears through a set of headphones. Kanzi then points to the appropriate symbol on his keyboard. But Savage-Rumbaugh says Kanzi also understands words that aren’t a part of his keyboard vocabulary; she says he can respond appropriately to commands such as"put the soap in the water"or"carry the TV outdoors." Copyright Smithsonian Institute

Keyword: Language; Intelligence
Link ID: 9578 - Posted: 06.24.2010

Anxiety and depression can make a person feel as if he’s battling his own brain, complete with wounds and scars. Traumatic events — war, divorce, the death of a loved one — can trigger these disorders, and scientists are just beginning to clarify the biological connection. Now, working neuron by neuron, researchers have found that life experiences actually appear to change the length and complexity of individual brain cells. In a recent study published in The Journal of Neuroscience, Rockefeller University scientists show that chronic daily stress affected neurons in two different areas of the rat brain, showing for the first time a link between anxiety symptoms and the dynamic anatomy of the brain. One of the characteristic manifestations of prolonged stress is decreased performance in tasks that require attention, including the ability to shift focus as well as to learn and unlearn information. Bruce McEwen, Rockefeller’s Alfred E. Mirsky Professor and head of the Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology, was interested in finding out how this translates to changes in the brain itself. So he and Conor Liston, a graduate student in McEwen’s lab, compared neuronal change in stressed and unstressed rats. The researchers stressed out a dozen rats by keeping them in painless restraints for six hours a day. Then, after 21 days, they used a complex progression of trials to test how quickly the rats learned to make associations between different cues and the location of hidden food. First, Liston provided two different materials for the rats to dig in, such as sand and sawdust, and buried food consistently under only one. Next, he left the food in the same material but scented it with strong spices (like cumin or nutmeg) that were unrelated to the food’s location. © 2004-2005 The Rockefeller University.

Keyword: Stress; Attention
Link ID: 9577 - Posted: 06.24.2010

By Michael Balter When it comes to separating humans from other animals, researchers agree that it's what's between the ears that counts most. Indeed, changes in brain-related genes appear to explain the often vast differences between human and chimp cognition. Now scientists have discovered that the spaces between these genes can be just as important. Once thought of as junk, noncoding sequences of DNA fill in the gaps between genes and make up more than 90 percent of our genome. Recently, scientists have discovered that these stretches of DNA contain regulatory elements that control how and when nearby genes are turned on and off (ScienceNOW, 16 August). An international team led by genome researcher Edward Rubin of the Lawrence Berkeley National Laboratory in California wondered how many of these noncoding regions might play a role in human evolution. The team looked at 110,549 human noncoding DNA sequences that seem to have been conserved during mammalian evolution. Using statistical tests, Rubin and his colleagues found 992 sequences that appeared to have undergone changes during human evolution that were not due to simple chance, suggesting that the genetic alterations were due to natural selection. The team then used two existing gene databases, called Gene Ontology and Entrez Gene, to match the noncoding sequences with the functions of the coding genes closest to them. © 2006 American Association for the Advancement of Science.

Keyword: Evolution; Genes & Behavior
Link ID: 9576 - Posted: 06.24.2010

Roxanne Khamsi Applying a gentle electric current to the brain during sleep can significantly boost memory, researchers report. A small new study showed that half an hour of this brain stimulation improved students’ performance at a verbal memory task by about 8%. The approach enhances memory by creating a form of electrical current in the brain seen in deep sleep, the researchers suggest. Jan Born at the University of Luebeck in Germany, and colleagues, recruited 13 healthy medical students for the study and gave them a list of word associations, such as “bird” and “air”, to learn late in the evening. Afterwards, researchers placed two electrodes on the forehead and one behind each ear of the volunteers and let them sleep. The students’ various sleep stages were monitored using an electroencephalogram (EEG) machine. When the students entered a period of light sleep, Born’s team started to apply a gentle current in one-second-long pulses, every second, for about 30 minutes. The EEG readings revealed that this current had put students into a deeper state of sleep. The next morning, the students performed about 8% better on the word memory test than when they underwent the same type of memory experiment without brain stimulation. Born believes this memory boost was due to the pattern of the applied current mimicking that seen in naturally occurring deep sleep, where memory consolidation is thought to take place. © Copyright Reed Business Information Ltd.

Keyword: Sleep; Learning & Memory
Link ID: 9575 - Posted: 06.24.2010

Sportswomen are more prone to injuries at certain times during their menstrual cycle, a study paper suggests. The Swedish research, by a PHD student at Luleċ University, included 30 of the nation's top women's soccer teams. Of the 319 female players studied, half received injuries, most commonly to the ankle, knee and thigh. Compared with team mates on the oral contraceptive pill, women were more injury-prone when they had their period than when they were not menstruating. It is not clear exactly why this is, but researcher Inger Jacobson believes it might be related to hormonal fluctuations during the menstrual cycle. For example, the level of a hormone called relaxin, which relaxes or slackens the ligaments, goes up around menstruation. Other studies have drawn similar conclusions. Published work has shown women perform worse on a skill called joint position sense - judging the position of a limb joint, such as the extent to which the knee is bent (flexed) or straight (extended) - around the time of their period. Coordination, postural control, reaction time and judgement may also be affected, experts believe. Oestrogen is known to affect pain perception, thus a sportswoman might be more likely to report injuries during low-oestrogen states, such as around the time of her period, suggests Ms Jacobson. (C)BBC

Keyword: Hormones & Behavior
Link ID: 9574 - Posted: 11.04.2006

In the 2000 presidential campaign, many observers labeled Al Gore as stiff. Lauren Solomon, an image consultant, has worked with politicians and executives for 13 years on how to handle themselves in public speaking situations. She thinks the problem wasn't just his language, it was his body language. "If you don't believe that there is a link between your words and your gestures, then you're only going to get half of the languaged message across to your audience," she says. Colgate University neuroscientist Spencer Kelly found that hand gestures actually influence how our brain processes speech. "Some people think that gestures are actually separate from language," he says. "I believe they are part of language and that means if you're going to understand language, you can't just focus on speech, you have to focus on speech and gesture." Kelly used an electroencephalograph (EEG) machine to measure the electrical brain activity of volunteers while they were shown gestures that contradict what's spoken. "I present gestures that convey one piece of information like gesturing to the shortness of an object and then I present a word like 'tall,'" Kelly says. He found that while witnessing contradictory gestures, volunteers produced the same brain wave pattern as people listening to confusing language -- called the N400 effect. © ScienCentral, 2000-2006.

Keyword: Language
Link ID: 9573 - Posted: 06.24.2010

By Gretchen Vogel Humans excel at following conventions. In France, acquaintances greet one another with a kiss on the cheek. In Japan, they bow. The different greetings have no inherent use on their own--and they would each lose their meaning when performed in the wrong context. But are humans the only animals to use such social conventions? A new study in chimps suggests not; the primates can learn an arbitrary behavior and pass it along to their groupmates. The behaviour in question involved objects that chimps would normally deem useless. Graduate student Kristin Bonnie of the Yerkes National Primate Research Center in Atlanta, Georgia, and her colleagues provided two groups of chimpanzees with either a bucket with a hole cut in the side or a container with a large tube sticking out of the top. Out of sight of the other group members, the researchers trained one high-ranking female from each group to deposit tokens into either the bucket or the tube. The team then sat back and watched to see if that trained behavior would spread. Indeed, the other animals quickly realized that the trained group member was receiving treats--apple or banana slices--for picking up the tokens and placing them in a container. Although treats were available for chimps that used either receptacle, each group followed their leader and used just one of the two options. There was only one exception: A low-ranking female in one group figured out she could get rewards for using the second container, but none of her group members followed her lead. © 2006 American Association for the Advancement of Science.

Keyword: Evolution
Link ID: 9572 - Posted: 06.24.2010