By Patricia Reaney LONDON (Reuters) - Exposure to industrial chemicals in the womb or early in life can impair brain development but only a handful are controlled to protect children, researchers said on Wednesday. There is also a lack of research and testing to identify which chemicals cause the most harm or how they should be regulated, they added. "Only a few substances, such as lead and mercury, are controlled with the purpose of protecting children," said Philippe Grandjean of Harvard School of Public Health in Boston, Massachusetts and the University of Southern Denmark. "The 200 other chemicals that are known to be toxic to the human brain are not regulated to prevent adverse effects on the fetus or a small child," he added. In a review published online by The Lancet medical journal, Grandjean and Philip Landrigan of the Mount Sinai School of Medicine in New York identified 202 industrial chemicals known to be toxic to the human brain. They suggested millions of children worldwide may have been harmed by toxic chemicals and may suffer learning disabilities and developmental disorders. But only substances such as lead, methylmercury and polychlorinated byphenyls (PCBs) have been sufficiently studied and regulated. © 1996-2006 Scientific American, Inc.

Keyword: Development of the Brain; Neurotoxins
Link ID: 9596 - Posted: 06.24.2010

Stanford University neuroscientists have designed a gene that enhances memory and learning ability in animals under stress. Writing in the Nov. 8 issue of the Journal of Neuroscience, the Stanford team says that the experimental technique might one day lead to new forms of gene therapy that can reduce the severe neurological side effects of steroids, which are prescribed to millions of patients with arthritis, asthma and other illnesses. "Steroids can mess up the part of the brain involved in judgment and cognition," said neuroendocrinologist Robert Sapolsky, co-author of the study. "In extreme cases it's called steroid dementia. Ideally, if you could deliver this gene safely, it would protect the person from some of these cognitive side effects, while allowing the steroid to do whatever helpful thing it should be doing elsewhere in the body." Sapolsky, the John A. and Cynthia Fry Gunn Professor of Biological Sciences and a professor of neurology and neurological sciences at Stanford, has conducted numerous experiments on the damaging physiological effects of stress and has written extensively on the subject, including a 1995 book, "Why Zebras Don't Get Ulcers." In the Journal of Neuroscience study, Sapolsky and his colleagues focused on the effect of stress on the hippocampus, a part of the brain that's important for learning and memory.

Keyword: Stress; Learning & Memory
Link ID: 9595 - Posted: 11.08.2006

By Jocelyn Kaiser Nobody likes coming down with a fever, but feeling hot may do a body good. Researchers report online 5 November in Nature Immunology that a fever in mice revs up the immune response by helping white blood cells enter lymph nodes, where they join the battle against microbial invaders. All mammals can develop fever when they're sick enough, and even cold-blooded animals with infections, such as fish and lizards, will seek warmth to raise their body temperatures. This suggests that fever somehow helps the body conquer the bugs. Immunologist Sharon Evans of Roswell Park Cancer Institute in Buffalo, New York, and coworkers are studying how fever affects the movement of white blood cells, or lymphocytes, from the blood into lymphoid tissue, where they learn to recognize and fight pathogens. Lymphocytes constantly circulate through blood vessels within lymph nodes and other lymphoid organs, but only some actually enter lymphoid tissue by crossing the walls of the vessels, known as high endothelial venules (HEVs). Fever increases blood flow, which means more lymphocytes flow through lymphoid tissues. Evans' team had previously shown that fever also assists the passage of lymphocytes into lymphoid tissue, but they hadn't figured out what was happening on a molecular level. © 2006 American Association for the Advancement of Science.

Keyword: Neuroimmunology
Link ID: 9594 - Posted: 06.24.2010

For the first time, scientists at the Max Planck Institute for Neurobiology in Martinsried near Munich have been able to show how two nerve cells communicate with each other from different hemispheres in the visual centre. This astoundingly simple circuit diagram could at a later date provide a model for algorithms to be deployed in technical systems (Nature Neuroscience, October 10, 2006) Movements in space create in humans and animals so-called optical flow fields which are characteristic for the movement in question. In a forward movement, the objects flow by laterally, objects at the front increase in size and objects further away hardly change at all. At a higher level in the visual centre in the brain, there must be a computation of the visual information, so that animals can differentiate between their own movement and movement of their environment and are able to correct their course if necessary. It is important for the analysis of flow fields that the movement information from both eyes is merged so that the whole flow field can be assessed. In their current study, Karl Farrow, Jürgen Haag and Alexander Borst have for the first time proved the direct link between two nerve cells, one in each half of the brain, combining the movement signals from both the facetted eyes of a fly. In the blow fly, the nerve cells that analyse optical flow fields, called tangential cells, are located in the lobula plate. There are only 60 of these tangential cells for each half of the brain and each of these 60 cells can be identified individually. The scientists in Martinsried have looked closely at one cell, the H2 cell.

Keyword: Development of the Brain
Link ID: 9593 - Posted: 11.08.2006

PITTSBURGH—Happiness and other positive emotions play an even more important role in health than previously thought, according to a study published in the journal Psychosomatic Medicine by Carnegie Mellon University Psychology Professor Sheldon Cohen. The paper will be available online at www.psychosomaticmedicine.org/. This recent study confirms the results of a landmark 2004 paper in which Cohen and his colleagues found that people who are happy, lively, calm or exhibit other positive emotions are less likely to become ill when they are exposed to a cold virus than those who report few of these emotions. In that study, Cohen found that when they do come down with a cold, happy people report fewer symptoms than would be expected from objective measures of their illness. In contrast, reporting more negative emotions such as depression, anxiety and anger was not associated with catching colds. That study, however, left open the possibility that the greater resistance to infectious illness among happier people may not have been due to happiness, but rather to other characteristics that are often associated with reporting positive emotions such as optimism, extraversion, feelings of purpose in life and self-esteem. Cohen's recent study controls for those variables, with the same result: The people who report positive emotions are less likely to catch colds and also less likely to report symptoms when they do get sick. This held true regardless of their levels of optimism, extraversion, purpose and self-esteem, and of their age, race, gender, education, body mass or prestudy immunity to the virus.

Keyword: Neuroimmunology; Emotions
Link ID: 9592 - Posted: 06.24.2010

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