By ABBY ELLIN LIKE almost every dieter in America, Wendy Bassett has used all sorts of weight-loss products. Nothing worked, she said, until she tried Sensa: granules she scatters on almost everything she eats, and which are supposed to make dieters less hungry by enhancing the smell and taste of food. “Every time I touch a piece of food, I pour it on,” said Ms. Bassett, 34, an accountant in Tyler, Tex. She has been using Sensa since February. So far, she said, she has lost 30 pounds. The maker of Sensa claims that its effectiveness is largely related to smell: the heightened scent and flavor of food that has been sprinkled with Sensa stimulate the olfactory bulb — the organ that transmits smell from the nose to the brain — to signal the “satiety center” of the hypothalamus. Hormones that suppress appetite are then released. But can the manipulation of smell really lead to weight loss? A handful of niche products would have you believe just that. In addition to Sensa, which has been available since last summer, there is SlimScents, aromatherapy diet pens filled with fruity or minty odors; a peppermint spray called Happy Scent; and the vanilla-doused Aroma Patch, which you wear on your hand, wrist or chest. Last month, Compellis Pharmaceuticals of Cambridge, Mass., began human trials on a nasal spray designed to do the opposite of what Sensa does: to curb the appetite by blocking rather than enhancing smell. Copyright 2009 The New York Times Company

Keyword: Obesity; Chemical Senses (Smell & Taste)
Link ID: 12956 - Posted: 06.24.2010

By Bruce Bower The last thing depression investigators need is another dead-end research downer. Efforts to find genes that directly contribute to depression have come up empty. And a research team now concludes, after a closer inspection of accumulated research, that a gene variant initially tagged as a depression promoter when accompanied by stressful experiences actually has no such effect. By showing that follow-up studies collectively don’t support the study that launched this line of research, two new analyses debunk the proposed pathway to depression. The chances of becoming depressed rise as stressful events mount, regardless of genetic makeup, report statistical geneticist Neil Risch of the University of California, San Francisco, and his colleagues. The new studies, published together in the June 17 Journal of the American Medical Association, also demonstrate the difficulty of replicating reports of any gene variants that appear to work with environmental triggers to foster psychiatric disorders. Individual studies typically lack the statistical power to detect gene-by-environment interactions correctly because most candidate genes and stressful events exert modest effects on mental ailments at best, the scientists say. “I’m supportive of looking for gene-by-environment risk factors, but we’ll need much larger samples to find interactions that can be independently replicated,” Risch says. In his view, statistically rigorous studies will need tens of thousands of participants. © Society for Science & the Public 2000 - 2009

Keyword: Depression; Genes & Behavior
Link ID: 12955 - Posted: 06.24.2010

Heidi Ledford A compound that stimulates the production of certain steroids in the brain may one day soothe the troubled nerves of people with anxiety disorders, according to results from a small clinical trial. The compound boosts the activity of a 'translocator' protein inside cells that helps transport cholesterol molecules and allows some to be turned into steroids that act in the brain. These 'neurosteroids' regulate the effect of a relaxation-promoting molecule called GABA, and are associated with reduced anxiety. Levels of the neurosteroids plummet during panic attacks. The compound has so far been tested only in a small clinical trial, but if it survives further testing, it could fill a need for better anxiety treatments. Patients with anxiety disorders have a range of symptoms, from recurrent and debilitating panic attacks to a more general sense of social anxiety. And some people use medication to quell acute phobias, such as a fear of flying or of public speaking. "It's not that we don't have treatments, but the available treatments suffer from undesirable adverse effects," says Jerrold Rosenbaum, chief of psychiatry at Massachusetts General Hospital in Boston. One class of drugs, called benzodiazepines, act quickly and are highly effective, but can cause drowsiness. Some users also develop a tolerance to them, and the withdrawal symptoms can be worse than the disorder itself, explains Rosenbaum. "A drug that worked nearly as well as the benzodiazepines without their unwanted side effects would be quite a big winner." © 2009 Nature Publishing Group

Keyword: Emotions; Hormones & Behavior
Link ID: 12954 - Posted: 06.24.2010

U.S. federal health regulators are urging parents to keep their children on attention deficit drugs like Ritalin and Adderall despite new evidence from a government-backed study that the stimulants can increase the risk of sudden death. Published Monday in the American Journal of Psychiatry, the study suggests a link between use of the stimulant drugs and sudden death in children and adolescents. The drugs, used to treat attention deficit and hyperactivity disorder, already carry warnings about risks of heart attack and stroke in children with underlying heart conditions, but researchers have questioned whether they pose the same risks to children without those problems. Healthy children taking the medications were more likely to die suddenly for unexplained reasons than those not taking the drugs, according to the study from the National Institute of Mental Health. The study was partially funded by the Food and Drug Administration, but agency experts said its methods — which relied on interviews with parents and physicians years after the children's deaths — may have caused errors. "Since the deaths occurred a long time ago, all of this depended on the memory of people, relatives and physicians, involved with the victims," said Dr. Robert Temple, the FDA's director of drug review. © The Canadian Press, 2009

Keyword: ADHD
Link ID: 12953 - Posted: 06.24.2010

By Judy Foreman For centuries, love has been celebrated - and probed - mostly by poets, artists, and balladeers. But now, its mysteries are also yielding to the tools of science, including modern brain scanning machines. Social psychologist Arthur Aron of SUNY-Stony Brook, a coauthor of the brain scanning studies and other research on love relationships, stresses the value of marriage workshops and couples counseling to enhance relationships. Also, to make a marriage really good, he says: Keep novelty and excitement going. Have a "date night" every week or so. Do novel things - take a course together, travel, join a new group of friends. (Get that dopamine system, which loves novelty, going again.) Capitalize on the good stuff. If something good happens to your partner, get sincerely excited about it so you can both enjoy the good fortune. It's not clear yet which brain circuits are at play here, says Aron, but associating your partner with good times is clearly a plus. At a university in Stony Brook, N.Y., a handful of young people who had just fallen madly in love volunteered to have their brains scanned to see what areas were active when they looked at a picture of their sweetheart. The brain areas that "lit up" were precisely those known to be rich in a powerful "feel good" chemical, dopamine -- the substance that brain cells release in response to cocaine and nicotine. Dopamine is the key chemical in the brain's "reward system," a network of cells associated with pleasure -- and addiction. © 2009 NY Times Co.

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 12952 - Posted: 06.24.2010

By RONI CARYN RABIN By now, it is a familiar litany. Study after study suggests that alcohol in moderation may promote heart health and even ward off diabetes and dementia. The evidence is so plentiful that some experts consider moderate drinking — about one drink a day for women, about two for men — a central component of a healthy lifestyle. For some scientists, the question will not go away. No study, these critics say, has ever proved a causal relationship between moderate drinking and lower risk of death — only that the two often go together. It may be that moderate drinking is just something healthy people tend to do, not something that makes people healthy. “The moderate drinkers tend to do everything right — they exercise, they don’t smoke, they eat right and they drink moderately,” said Kaye Middleton Fillmore, a retired sociologist from the University of California, San Francisco, who has criticized the research. “It’s very hard to disentangle all of that, and that’s a real problem.” Some researchers say they are haunted by the mistakes made in studies about hormone replacement therapy, which was widely prescribed for years on the basis of observational studies similar to the kind done on alcohol. Questions have also been raised about the financial relationships that have sprung up between the alcoholic beverage industry and many academic centers, which have accepted industry money to pay for research, train students and promote their findings. Copyright 2009 The New York Times Company

Keyword: Drug Abuse
Link ID: 12951 - Posted: 06.24.2010

By Valerie Strauss Sleeping used to be one of my favorite activities -- until I got lousy at it. I started having trouble with it last year when I found myself feeling more tired when I woke up than when I went to sleep. I practically fell asleep at my desk. (Okay, I did fall asleep on my keyboard.) My once respectable memory took a precipitous decline into the "I can't remember my own telephone number" range. And then there was the problem, for my husband and anyone within a three-room radius, of the snoring. So I asked some doctors to tell me why I was so exhausted. One said I was super-anxious and should get massages. (I didn't feel anxious.) Another said I was depressed. (I wasn't.) A third said that it could be hormonal. (What isn't?) Or not. Finally I decided to figure it out myself. After investigating possible causes for all my symptoms, I began to suspect I had apnea. Sleep apnea, it turns out, is a common disorder in which you momentarily stop breathing, or take very short breaths, while you are sleeping. The number of times your breathing is interrupted per hour determines the degree of your apnea. (A mild case is marked by five to 15 episodes; a severe case involves more than 30.) © 2009 The Washington Post Company

Keyword: Sleep
Link ID: 12950 - Posted: 06.24.2010

Alcohol-related deaths among U.S. college students rose from 1,440 deaths in 1998 to 1,825 in 2005, along with increases in heavy drinking and drunk driving, according to an article in the July supplement of the Journal of Studies on Alcohol and Drugs. The special issue describes the results of a broad array of research-based programs to reduce and prevent alcohol-related problems at campuses across the country. These studies resulted from the Rapid Response to College Drinking Problems Initiative, a grant program supported by the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the National Institutes of Health. Reviewing the magnitude of the college alcohol problem, Ralph W. Hingson, Sc.D, M.P.H., director of NIAAA’s Division of Epidemiology and Prevention Research, and colleagues analyzed data from the Centers for Disease Control and Prevention and other government sources. They found that serious problems persist, as indicated by the increase in drinking-related accidental deaths among 18- to 24-year-old students, which resulted mainly from traffic-related incidents. In addition, the researchers found the proportion of students who reported recent heavy episodic drinking — sometimes called binge drinking, defined as five or more alcoholic drinks on any occasion in the past 30 days— rose from roughly 42 percent to 45 percent, and the proportion who admitted to drinking and driving in the past year increased from 26.5 percent to 29 percent.

Keyword: Drug Abuse
Link ID: 12949 - Posted: 06.24.2010

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

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

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

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

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

Keyword: Alzheimers
Link ID: 12946 - Posted: 06.24.2010

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

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

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

Keyword: Stress
Link ID: 12944 - Posted: 06.24.2010

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

Keyword: Prions
Link ID: 12943 - Posted: 06.24.2010

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

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

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

Keyword: Evolution
Link ID: 12941 - Posted: 06.24.2010

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

Keyword: Emotions
Link ID: 12940 - Posted: 06.24.2010

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

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

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

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

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

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