Researchers have discovered that Broca's area in the brain--best known as the region that evolved to manage speech production--is a major "executive" center in the brain for organizing hierarchies of behaviors. Such planning ability, from cooking a meal to organizing a space mission, is considered one of the hallmarks of human intelligence. The researchers found that Broca's area--which lies on the left side of the brain about in the temple region--and its counterpart on the right side activate when people are asked to organize plans of action. They said their finding of the general executive function of Broca's area could explain its key role in language production. Importantly, the researchers found that this executive function of these cortical regions was distinct from the organization of temporal sequences of actions. The researchers, Etienne Koechlin and Thomas Jubault of Université Pierre et Marie Curie and Ecole Normale Supérieure, described their experiments in the June 15, 2006, issue of Neuron. In their experiments, the researchers asked volunteers to execute a sequence of button presses when they saw colored squares or letters on a screen. Koechlin and Jubault designed their experiment so that they could precisely distinguish hierarchical planning of tasks from the temporal organization of tasks. The subjects were asked to perform both simple sequences of button presses in response to a stimulus, "simple action chunks," and "superordinate action chunks." Simple action chucks were single motor acts that required sequential action. Superordinate action chunks included "a sequence of categorization tasks, like sorting a deck of playing cards first by color, then by suit, then by rank."

Keyword: Language
Link ID: 9034 - Posted: 06.15.2006

As any gambler knows, the most important decision is where to play. Some flit from table to table, machine to machine and game to game. Others prefer to settle in for the long haul. Now researchers have used those tendencies to probe the function of the human brain as it chooses between the familiar and the unknown. Nathaniel Daw and John O'Doherty of University College London and their colleagues employed slot machines and functional magnetic resonance imaging (fMRI) to investigate how 14 healthy subjects decided between reaping steady profits at a given slot machine or testing the profit potential of a new one. Scientists call the behavior of utilizing a known resource exploitation; the term they give to the behavior of seeking an even better resource is exploration. Although exploitation seems the safe bet, survival can depend on judicious use of exploration. "The desire to select what seems the richest option is always balanced against the desire to choose a less familiar option that might turn out to serve better," Daw explains. "Most people switch between exploring and exploiting seamlessly and this has always made it hard to distinguish between someone who is doing something they know will offer the highest payout and a person who is testing out new options." To so distinguish, the neuroscientists set up four slot machines to pay off at four different average rates. After each trial, these payoffs changed randomly from machine to machine. In order to discover which slot machine paid the most, a given subject would have to try it at the risk of abandoning a higher paying machine. After the tests, the subjects reported occasionally trying different machines to find the highest reward and sometimes sticking with a slot that they thought offered the most. © 1996-2006 Scientific American, Inc. All

Keyword: Attention
Link ID: 9033 - Posted: 06.24.2010

Ronald Kahn, president of Boston's Joslin Diabetes Center, and his team have identified genes that correlate to where our bodies store fat. He said that, "They're fundamental genes" that are among those that map out how we should grow. He explained that these developmental genes, "tell us that our head should be at one end and that our feet should be at the other ... and these genes also determine both potentially how much fat we have and where that fat is deposited." Kahn says fat location is important in diabetes research because, "Fat that is located in our belly, what we call central obesity, makes us more prone to diabetes than fat located elsewhere in our body, like our hips or thighs." Kahn says it's because, "This fat creates more insulin resistance…[and]…that insulin is the major hormone that controls our blood sugar." Writing in Proceedings of the National Academy of Sciences, Kahn says he and his team found this connection by studying fat in both mice and in people. Kahn says, "We're very excited about this insight into obesity and body fat distribution because this is the first time we've ever had a clue as to how these aspects of our body are so fundamentally determined with these early developmental genes." © ScienCentral, 2000-2006.

Keyword: Obesity; Genes & Behavior
Link ID: 9032 - Posted: 06.24.2010

UPTON, NY -- Ask anyone who has been addicted to drugs and they'll tell you that the mere sight of someone using their drug of choice -- or even people, places, or objects associated with drug use -- can trigger an intense desire for the drug. Using sophisticated brain-imaging techniques at the U.S. Department of Energy's Brookhaven National Laboratory, scientists from the National Institute on Drug Abuse (NIDA), Brookhaven Lab, and the University of Pennsylvania have uncovered the brain chemistry that underlies such "cue-induced" craving in cocaine addicts. The work, which appears in the June 14, 2006 issue of the Journal of Neuroscience, suggests new targets for medications aimed at treating addiction. "Drug craving triggered by cues, such as the sight, smell, and other sensory stimuli associated with a particular drug like cocaine, is central to addiction and poses an obstacle to successful therapy for many individuals," says NIDA Director Nora D. Volkow, lead author on the study and former Associate Laboratory Director for life sciences research at Brookhaven Lab. "Today we can actually see increases in specific brain activities that are linked to this experience. If we can understand the mechanisms related to cue-induced craving, we can develop more effective treatment strategies to counteract it." Previous research conducted at Brookhaven and elsewhere has shown that all addictive drugs increase the level of dopamine -- a neurotransmitter, or chemical messenger, associated with feelings of reward and pleasure -- in a part of the brain known as the nucleus accumbens.

Keyword: Drug Abuse
Link ID: 9031 - Posted: 06.15.2006

By Michael Hochman Shy people may be quiet, but there's a lot going on in their heads. When they encounter a frightening or unfamiliar situation--meeting someone new, for example--a brain region responsible for negative emotions goes into overdrive. But new research indicates that shy people may be more sensitive to all sorts of stimuli, not just frightening ones. The findings come courtesy of brain scans of 13 extremely shy adolescents and 19 outgoing ones. Researchers, led by Amanda Guyer, a development psychologist at the National Institutes of Health in Bethesda, Maryland, placed each child in a functional magnetic resonance imaging machine and had them play games in which they could win or lose money. The study subjects--who were classified as either shy or outgoing based on psychological testing--were instructed to press a button as quickly as possible after being shown a signal. If they pressed the button in time, they won money, or at least prevented themselves from losing it. Both groups performed similarly, and there was no difference in the activity of their amygdalas--the brain region that governs fear. Shy children, however, showed two to three times more activity in their striatum, which is associated with reward, than outgoing children, the team reports in the 14 June issue of the Journal of Neuroscience. "Up until now, people thought that [shyness] was mostly related to avoidance of social situations," says co-author and child psychiatrist Monique Ernst. "Here we showed that shy children have increased activity in the reward system of the brain as well." © 2006 American Association for the Advancement of Science.

Keyword: Brain imaging; Stress
Link ID: 9030 - Posted: 06.24.2010

By Tracy Staedter, Discovery News — A new study could take the mystery out of a horse whisperer’s job. The Equine Vocalization Project is compiling a database of horse talk and behavior in an attempt to correlate nuances in their whinnies with differences in their stress levels. The information could help shed light on the communication styles of other equines, such as donkeys and zebras, and even improve how veterinarians, behaviorists, breeders or other animal handlers relate to horses. "You would like to find that you get a particular whinny for a particular situation," said physicist David Browning, an adjunct professor at the University of Rhode Island, who along with Peter Scheifele, a research associate at the University of Connecticut, announced their project last week at the Acoustical Society of America in Providence, RI. Unlike the monotonal vocalizations of cows, goats, and sheep, horses emit a range of sounds from snorts, blows and sighs to whinnies, which also come in the form of nickers and squeals. Browning’s initial acoustical studies have shown that whinnies have the greatest changes in frequency and could contain information about specific situations. © 2006 Discovery Communications Inc.

Keyword: Language; Stress
Link ID: 9029 - Posted: 06.24.2010

By NICHOLAS BAKALAR Trying to get someone's attention? Looking angry may be the key. The face most likely to stand out in a crowd is an irate one, according to a new study, and men are better than women at picking up the anger that a face conveys. On the other hand, women are more adept at detecting more socially relevant expressions that communicate happiness, sadness, surprise and disgust. "The really interesting effect," said Mark A. Williams, the study's lead author, "is the difference between males and females." Dr. Williams, a postdoctoral fellow at the Massachusetts Institute of Technology, and his co-author, Jason B. Mattingley, a psychology professor at the University of Melbourne in Australia, set out to measure how efficiently the emotions conveyed by facial expressions are identified in a large group by others. The results appear in the June issue of Current Biology. In the experiment, they showed arrays of human faces to 78 men and 78 women, using photographs displaying angry, fearful, happy, sad, surprised, disgusted or neutral expressions. First, participants were shown a group of four photographs depicting three neutral expressions and one expression that was clearly angry — brow compressed, eyes narrowed, teeth flashing in a menacing grimace. The subjects were asked to pick out, as quickly as they could, the angry face from all the others. Copyright 2006 The New York Times Company

Keyword: Emotions; Sexual Behavior
Link ID: 9028 - Posted: 06.24.2010

Researchers at Rush University Medical Center, Chicago, and Ceregene Inc., San Diego, have successfully used gene therapy to preserve motor function and stop the anatomic, cellular changes that occur in the brains of mice with Huntington’s disease (HD). This is the first study to demonstrate that, using this delivery method, symptom onset might be prevented in HD mice with this treatment. Results of the study were published in the Proceedings of the National Academy of Sciencesof the United States, June 13, 2006. “This could be an important step toward a disease modifying therapy,” says co-author Jeffrey H. Kordower, Ph.D., director of the Research Center for Brain Repair at Rush. “We could potentially be stopping the disease process in its tracks, delaying symptoms from ever showing up.” Huntington's disease is an inherited degenerative disease that progressively robs patients of the ability to think, judge appropriately, control their emotions and perform coordinated tasks. HD typically begins in mid-life, between the ages of 40 and 50. There is no effective treatment or cure for this fatal illness that affects 30,000 Americans and places another 75,000 at risk. Kordower says this research, if eventually applied to humans, could help those who have HD or, due to the presence of a genetic test, are known to be destined to get HD. © Rush University Medical Center,

Keyword: Huntingtons
Link ID: 9027 - Posted: 06.24.2010

By Jennifer Viegas, Discovery News — Seasonal changes cause fat to shift locations in our body, thus altering the shape of our figures at certain times of the year, according to a new study. Varying testosterone levels drive the shape changes, the study suggests. The hormone, often associated with brawn and aggressiveness, fluctuates over the seasons in both men and women. The most evident changes occur within the waist and hip region, the study determined. When testosterone levels rose, women became less curvy as fat shifted toward the waist. Other research has determined that the opposite happens in men, who retain more fat in the abdominal region when testosterone levels fall. The scientists examined seasonal testosterone fluctuations in the saliva of 220 women and 127 men. They also measured the waists and hips of the female study participants over the seasons. "We found that women’s and men’s testosterone is highest in the fall," said Sari van Anders, who led the research. "As well, women’s waist-to-hip ratio (how big the waist is relative to the hips) is highest during the fall, and central measures of fat deposition, like abdominal fat, were also somewhat higher in the fall (for women)." © 2006 Discovery Communications Inc.

Keyword: Biological Rhythms; Hormones & Behavior
Link ID: 9026 - Posted: 06.24.2010

Rowan Hooper A DNA vaccine has successfully reduced the symptoms of Alzheimer's disease in mice. The result could signal the first preventative and restorative treatment vaccine for Alzheimer’s without serious side effects. Alzheimer’s disease progresses as small proteins called amyloid beta (Ab) peptides are overproduced, forming plaques in the brain that interfere with its function. Memory loss and mental deterioration follow. A vaccination approach – getting the immune system to clean up the plaques – has been considered the most promising way to tackle the disease, but its success has been limited, until now. In 2002, for example, the US pharmaceutical company Elan halted trials of a vaccine that raised antibodies against Ab peptides, after some patients suffered brain inflammation (see Key Alzheimer's vaccine trial abandoned). The new vaccine is different because instead of using the Ab peptide itself to stimulate antibody production, it uses a stretch of DNA that codes for the Ab peptide, says Yoh Matsumoto, at the Tokyo Metropolitan Institute for Neuroscience, Japan, who led the research. Since DNA vaccination stimulates the immune system more gently than peptide vaccination, it should also avoid the brain swelling seen in the Elan trial. © Copyright Reed Business Information Ltd

Keyword: Alzheimers
Link ID: 9025 - Posted: 06.24.2010

Certain variants of a simple sugar ameliorate Alzheimer's-like disease in mice, according to a new study by Canadian researchers. Although the new studies are still in the early stages, the findings could lead to new therapies that prevent or delay the onset of Alzheimer's disease. The new studies show that some types of a sugar called cyclohexanehexol—also known as inositol—prevented the accumulation of amyloid â deposits, a hallmark of Alzheimer's disease. Scyllo-inositol treatment also improved cognitive abilities in the mice and allowed them to live a normal lifetime. The study appeared in advance online publication of the journal Nature Medicine on June 11, 2006. HHMI international research scholar and senior author Peter St George-Hyslop cautioned that the chemicals tested in these studies are not the type of inositol sold commercially as a nutritional supplement. That type—myo-inositol—has been shown previously to be ineffective at breaking up amyloid aggregates, he said. In the brain of a person with Alzheimer's disease, small proteins called amyloid â aggregate into plaques, and a protein called tau clumps into neurofibrillary tangles. The brain becomes inflamed and neurons atrophy and die. It's not completely clear what kind of amyloid â peptide (monomers, oligomeric aggregates, or fibrillar aggregates) is responsible for the onset of disease, said St George-Hyslop of the University of Toronto. "Because we were able to show that scyllo-inositol specifically dispersed the high-molecular-weight oligomeric aggregates, this study confirms that the initiating event is the accumulation of oligomeric aggregates of amyloid â peptide,” he said. © 2006 Howard Hughes Medical Institute.

Keyword: Alzheimers
Link ID: 9024 - Posted: 06.24.2010

By Joel Garreau Studying with diligent friends is fine, says Heidi Lessing, a University of Delaware sophomore. But after a couple of hours, it's time for a break, a little gossip: "I want to talk about somebody walking by in the library." One of those friends, however, is working too hard for dish -- way too hard. Instead of joining in the gossip, "She says, 'Be quiet,' " Lessing says, astonishment still registering in her voice. Her friend's attention is laserlike, totally focused on her texts, even after an evening of study. "We were so bored," Lessing says. But the friend was still "really into it. It's annoying." The reason for the difference: Her pal is fueled with "smart pills" that increase her concentration, focus, wakefulness and short-term memory. As university students all over the country emerge from final exam hell this month, the number of healthy people using bootleg pharmaceuticals of this sort seems to be soaring. Such brand-name prescription drugs "were around in high school, but they really exploded in my third and fourth years" of college, says Katie Garrett, a 2005 University of Virginia graduate. © 2006 The Washington Post Company

Keyword: Drug Abuse; Learning & Memory
Link ID: 9023 - Posted: 06.24.2010

By N. R. KLEINFIELD Dr. John Newcomer is a psychiatrist who generally treats people with severe ailments of the mind and spirit. But before his patients sit down, before he hears about their clammy paranoia or renegade voices, Dr. Newcomer wants to know about their waist size. He steers them to a scale to learn their weight. He orders a blood sugar test. If big numbers come up, he begins a conversation about Type 2 diabetes, a disease associated with obesity that is appearing with alarming frequency among the mentally ill. "Uncontrolled diabetes can ruin a person's life as much as uncontrolled schizophrenia," said Dr. Newcomer, a professor of psychiatry at Washington University School of Medicine in St. Louis. In fact, among the mentally ill, roughly one in every five appear to develop diabetes — about double the rate of the general population. This is a little-recognized surge, but one that is jolting mental health professionals into rethinking how they care for an often neglected population. For decades, psychiatrists have worried primarily about patients' mental states, making sure they did no harm to themselves or others because of unrelenting voices or a smothering depression. Copyright 2006 The New York Times Company

Keyword: Schizophrenia; Obesity
Link ID: 9022 - Posted: 06.24.2010

By Virginia Hughes A few years ago, scientists found that the common fruit fly, Drosophila melanogaster, sleeps in a remarkably human-like way. Now a new study on fruit fly brains shows that a specific brain region—previously linked to the fly's memories of smell—is also vital to sleep. These results support the idea that memory consolidation may play a big part in fly sleep, and, likely, human sleep. "The link between sleep and learning a lot of people can identify with – particularly college students who pull all-nighters," says lead researcher Jena Pitman of Northwestern University, "But that link is pretty universal." Might a sleeping fruit fly be digesting the memory of a rotten banana it ate for dinner? Fruit flies and humans share many of what scientists call the "essential features" of sleep. Both species sleep for many hours at night, for instance, says Ravi Allada, one of the other neuroscientists involved in the study. With flies, too, as Allada explains, "the longer they're asleep, the harder you have to poke them to get them to wake up." If you deprive them of sleep, flies will try to catch up on sleep the next day. And fly sleep patterns respond to some drugs in the same way we do: antihistamines make them drowsy and caffeine keeps them awake. This all suggests that "the mechanism of sleep is very similar" in fruit flies and humans, says Allada. Though the similarities between fly sleep and human sleep were well-established a few years ago, no one had studied the specific fly brain regions involved in sleeping until now. The latest Northwestern study, published in Nature on June 7, sought to figure out which part of the brain—if any—could be isolated for sleep studies. © 2005 Discover Media LLC.

Keyword: Sleep
Link ID: 9021 - Posted: 06.24.2010

Bruce Bower A mental disorder that encompasses a wide range of recurring, hostile outbursts, including domestic violence and road rage, characterizes considerably more people than previous data had indicated, a national survey finds. At some point in their lives, between 5.4 percent and 7.3 percent of U.S. adults qualify for a diagnosis of intermittent explosive disorder, concludes a team led by sociologist Ronald C. Kessler of Harvard Medical School in Boston. Those percentages, which depend on whether the syndrome is narrowly or broadly defined, correspond to between 11.5 million and 16 million people, respectively. In any given year, intermittent explosive disorder affects between 2.7 percent and 3.9 percent of adults, or from 5.9 million to 8.5 million people, Kessler and his coworkers report. "We never thought we'd find such high prevalence rates for this condition," Kessler says. In contrast, a 2004 study of 253 Baltimore residents estimated a lifetime prevalence of 4 percent for intermittent explosive disorder. Intermittent explosive disorder features tirades, grossly disproportionate to the triggering circumstances, during which a person destroys property, tries to hurt or actually hurts someone, or threatens to do so. The expression of rage elicits a sense of relief, followed by remorse for the incident. The syndrome doesn't include outbursts that stem from other mental disorders or from alcohol or drug effects. ©2006 Science Service.

Keyword: Emotions; Aggression
Link ID: 9020 - Posted: 06.24.2010

New therapies for stroke patients may soon be possible, thanks to a discovery made by a team of University of British Columbia neuroscience researchers who have found a new stroke death channel -- the conduit through which key chemicals are lost from brain cells during stroke, causing the cell death that disables stroke victims. The findings were published recently in Science and will be the subject of an editorial in next month’s issue of Nature Reviews Neuroscience. “We’ve known for 40 years about chemicals flowing out of cells after stroke, but nobody knew the exact process -- so we went looking for the death channel. And we found it,” says Roger Thompson, a UBC Psychiatry post-doctoral Fellow who made the discovery, along with graduate student Ning Zhou and Psychiatry Prof. Brian MacVicar, all members of the Brain Research Centre at UBC Hospital and of Vancouver Coastal Health Research Institute. The researchers found, in animal models, that brain cell membranes were disrupted at the site of gap junction hemichannels. Gap junctions are connections that allow molecules and ions to flow between cells. Junctions are composed of two hemichannels that bridge the intercellular space. Until now, scientists believed the disruption to occur at the site of glutamate channels. Glutamate is one of the brain’s most abundant chemical messengers. However, therapeutic strategies targeted at glutamate channels failed to prevent brain cell death. © Copyright The University of British Columbia

Keyword: Stroke
Link ID: 9019 - Posted: 06.24.2010

Roxanne Khamsi The next time you listen to the Beatles sing “Michelle” you can thank an area of your brain called the left caudate. It could be what enables you to follow the lyrics as they switch from English to French, claim researchers at University College London in the UK. Previous brain-scan research into how the brain flips from one language to another has failed to identify any one region responsible, suggesting that the neural circuits for different languages are highly overlapping in the brain. Now Cathy Price and her colleagues have combined brain scans with behavioural tests and discovered that the left caudate becomes more active as people shift from thinking in one language to another. This area is thought to influence how we articulate words in association with another brain structure known as the thalamus. The research team recruited 35 bilingual people – 25 spoke German and English, 10 spoke Japanese and English. The participants viewed pairs of words while undergoing brain scans using either positron emission tomography (PET) or functional magnetic resonance (fMRI) imaging. When volunteers read two words with the same meaning but in different languages, or two words in the same language with unrelated meanings, the left caudate region in their brains became more active than when they read two words from the same language with a similar theme. This held true across both language groups. © Copyright Reed Business Information Ltd.

Keyword: Language
Link ID: 9018 - Posted: 06.24.2010

A federally funded team of researchers including several from Johns Hopkins have identified six regions of the human genome that might play a role in susceptibility to obsessive compulsive disorder, or OCD. The study was published online June 6 in Molecular Psychiatry. "OCD once was thought to be primarily psychological in origin," says Yin Yao Shugart, Ph.D., statistical geneticist and associate professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health. "But now there is growing evidence that there is a genetic basis behind OCD, which will help us better understand the condition," she says. OCD is characterized by intrusive and senseless thoughts and impulses that together are defined as obsessions, as well as repetitive and intentional behaviors, referred to as compulsions. OCD is estimated to affect up to 3 percent of the American population. In what the research team describes as the first whole-genome scan to look for genetic "markers" or similarities in the genomes of people with OCD, results identified six potentially significant regions in the genome, which lie on five different chromosomes that appear "linked" to OCD. It's likely that any genes directly associated OCD are to be found in these regions. "We've long suspected that, rather than being caused by a single gene, OCD has multiple genetic associations," says Jack Samuels, Ph.D., an epidemiologist and assistant professor of psychiatry at the Johns Hopkins School of Medicine.

Keyword: OCD - Obsessive Compulsive Disorder; Genes & Behavior
Link ID: 9017 - Posted: 06.10.2006

In a new study published in the latest issue of Ethology researchers show that female songbirds can alter the size of eggs and possibly the sex of their chicks according to how they perceive their mate's quality. The researchers played back attractive ("sexy") songs and less attractive control songs of male canaries to female domesticated canaries. When the females started egg-laying they varied the size of their eggs in the nest according to the attractiveness of the male's song. That is, the more attractive the song, the larger the eggs. However it is remarkable that while larger eggs were more likely to contain male offspring in natural environments, in the experiment there was no difference in brood sex ratio between the different songs played to the females, which suggests different levels of female control. Male birdsong has long been known to attract females and influence mate choice decisions and even induce an alteration in the offspring's sex ratio. This study by Leitner et al. now shows experimentally that hearing attractive song also has a selective impact on female physiology. 45 female domesticated canaries participated in this study that was a collaboration of Royal Holloway, University of London and the Max Planck Institute for Ornithology in Seewiesen and Radolfzell in Germany. The birds were kept in large aviaries where their daily behaviour was monitored in a colony before they were tested in the song experiments. The females showed a remarkable consistency in their behavioural and reproductive performance and the song stimuli alone were sufficient to elicit a profound physiological change. This study further highlights the importance of behavioural stimuli for reproductive physiology. Bathroom Pavarottis beware.

Keyword: Sexual Behavior; Animal Communication
Link ID: 9016 - Posted: 06.10.2006

With help from some drowsy fruit flies, a team of researchers from the Howard Hughes Medical Institute (HHMI) at the University of Pennsylvania School of Medicine has identified a region of the fruit fly's brain that is crucial to controlling sleep. The finding, reported in the June 8, 2006, issue of the journal Nature, is important because it identifies a new role for brain structures, called mushroom bodies, which have now been shown to control fruit fly slumber. Mushroom bodies were known to be involved in processing sensory information and memory. Thus, the new studies lend support to the idea that sleep helps the brain consolidate learning and memory. “We spend one-third of our lives sleeping, but we know very little about sleep and how it is regulated,” explained Amita Sehgal, the senior author of the new Nature paper and an HHMI investigator at the University of Pennsylvania School of Medicine. “It's really pretty amazing that we know so little.” Sleep, in fact, is such a mystery that scientists are not even sure why animals require it. No purpose or underlying mechanism for the phenomenon has ever been proven. And while the new Nature report does not delve directly into the mysteries of why animals snooze, the findings support the idea that one of sleep's essential roles is to limit sensory input so the brain can organize and crystallize the day's memories for storage and future retrieval. © 2006 Howard Hughes Medical Institute.

Keyword: Sleep
Link ID: 9015 - Posted: 06.24.2010