By Gregg Easterbrook Last month, I speculated in Slate that the mounting incidence of childhood autism may be related to increased television viewing among the very young. The autism rise began around 1980, about the same time cable television and VCRs became common, allowing children to watch television aimed at them any time. Since the brain is organizing during the first years of life and since human beings evolved responding to three-dimensional stimuli, I wondered if exposing toddlers to lots of colorful two-dimensional stimulation could be harmful to brain development. This was sheer speculation, since I knew of no researchers pursuing the question. Today, Cornell University researchers are reporting what appears to be a statistically significant relationship between autism rates and television watching by children under the age of 3. The researchers studied autism incidence in California, Oregon, Pennsylvania, and Washington state. They found that as cable television became common in California and Pennsylvania beginning around 1980, childhood autism rose more in the counties that had cable than in the counties that did not. They further found that in all the Western states, the more time toddlers spent in front of the television, the more likely they were to exhibit symptoms of autism disorders. The Cornell study represents a potential bombshell in the autism debate. "We are not saying we have found the cause of autism, we're saying we have found a critical piece of evidence," Cornell researcher Michael Waldman told me. Because autism rates are increasing broadly across the country and across income and ethnic groups, it seems logical that the trigger is something to which children are broadly exposed. 2006 Washington Post.Newsweek Interactive Co. LLC

Keyword: Autism
Link ID: 9496 - Posted: 10.18.2006

To a cognitive neuroscientist, success in life depends largely on how well your brain shapes actions to fit both your goals and the context in which you act. If you need to cross the street, first check the traffic. If you're feeding your new in-laws, serve better wine--and different jokes --than you do for your poker buddies. Such context-driven "cognitive control," thought to reside in the brain's prefrontal cortex, has lately become one of neuroscience's hottest topics, inspiring hundreds of papers regarding its role in everything from academic and sports performance to depression and gambling. Yet it remains unclear just how the prefrontal cortex exerts this control. Researchers have explored models emphasizing (not necessarily to mutual exclusion) attentional control, conversations between the prefrontal cortex and limbic areas, and the prefrontal cortex's sensitivity to context. On Monday at the Society for Neuroscience conference in Atlanta, David Badre, a post-doc at the University of California, Berkeley, described an experiment bolstering another emerging model, that of a "hierarchy" of control. In this view, Badre says, "we respond to increasing cognitive challenges not on a continuum, but in leaps as different areas of the prefrontal cortex activate." That is, we throw more light on a problem not by sliding a dimmer switch, but by flipping a series of toggles that successively activate chunks of the prefrontal cortex from back to front. Recognizing this is an important early step in understanding how cognition works, and it could help lead to better treatment for patients who have suffered strokes or other injury to the prefrontal cortex. © 1996-2006 Scientific American, Inc.

Keyword: Attention
Link ID: 9495 - Posted: 06.24.2010

By Prashant Nair Scientists have found a way to suppress epileptic seizures in rats by inhibiting the animals' ability to break down sugars. If the approach works in humans, it could herald a novel class of antiepileptic drugs. Epilepsy arises when brain neurons fire in an uncontrolled frenzy, causing seizures. Most current treatments are aimed at decreasing neuronal activity, but these approaches have side-effects, such as drowsiness and cognitive difficulties. Neurobiologists Thomas Sutula and Avtar Roopra at the University of Wisconsin, Madison, decided to tackle epileptic seizures from a different angle. Scientists have long known that seizures can sometimes be kept at bay when people with epilepsy steer clear of sugars and other carbohydrates--the so-called ketogenic diet. In addition, removing glucose from slices of the hippocampus--the brain region activated in epilepsy--leads to a dip in neuronal firing in animal studies. Sutula and Roopra focused on an inhibitor of sugar breakdown--or glycolysis--known as 2DG. When rats predisposed to epileptic seizures were given 2DG, the amount of electric current needed to set off a seizure in these animals was significantly higher than that in animals not given the drug. Furthermore, treated rats required twice as many electric discharges than untreated ones to produce seizures. An analysis of the hippocampus of treated rats revealed that 2DG was blocking the action of a protein complex that drives the expression of seizure-related genes. The activity of this complex is dependent on the end products of glycolysis, the team reports in the October issue of Nature Neuroscience. © 2006 American Association for the Advancement of Science.

Keyword: Epilepsy
Link ID: 9494 - Posted: 06.24.2010

Dartmouth researchers have found areas in the brain that indicate bilingualism. The finding sheds new light on decades of debate about how the human brain's language centers may actually be enhanced when faced with two or more languages as opposed to only one. The study was presented at the Society for Neuroscience's annual meeting on October 14-18 in Atlanta, Ga. The researchers used an optical imaging technology called Near Infrared Spectroscopy (or NIRS) as a new "microscope" into the human brain's higher cognitive capacities, and they are among the first to take advantage of this technology in this way. NIRS has been used in the detection of, for example, breast tumors and heart blood flow. The Dartmouth team used NIRS to measure changes in the brain's oxygen levels while people performed specific language and cognitive tasks. Authors of the study are Mark Shalinsky, former post-doctoral fellow at Dartmouth now a research fellow at Massachusetts General Hospital; Ioulia Kovelman, formerly a Dartmouth graduate student currently a post-doctoral fellow at MIT; Melody Berens, currently a post-doctoral fellow at Dartmouth; and Laura-Ann Petitto, the study's senior scientific director, and professor and chair of the Department of Education at Dartmouth. "NIRS provides much the same information as functional magnetic resonance imaging or 'fMRI,' but has several advantages over fMRI," says Shalinsky, the study's electro-neurophysiologist who created the analysis programs to use NIRS technology in this new way. NIRS technology is quiet, small and portable. It's only about the size of a desktop computer. It's child friendly, and it tolerates a participant's body movements, which makes it ideal for studying language where participants move their mouths to speak." Copyright © 2006 Trustees of Dartmouth College

Keyword: Language; Brain imaging
Link ID: 9493 - Posted: 06.24.2010

A version of a gene has been linked to autism in families that have more than one child with the disorder. Inheriting two copies of this version more than doubled a child's risk of developing an autism spectrum disorder, scientists supported by the National Institutes of Health's (NIH) National Institute of Mental Health (NIMH) National Institute on Child Health and Human Development (NICHD) have discovered. In a large sample totaling 1,231 cases, they traced the connection to a tiny variation in the part of the gene that turns it on and off. People with autism spectrum disorders were more likely than others to have inherited this version, which cuts gene expression by half, likely impairing development of parts of the brain implicated in the disorder, report Drs. Daniel Campbell, Pat Levitt, Vanderbilt Kennedy Center at Vanderbilt University, and colleagues, online during the week of the October 16, 2006 in the Proceedings of the National Academy of Sciences. "This common gene variant likely predisposes for autism in combination with other genes and environmental factors," said Levitt. "It exerts the strongest effect detected thus far among autism candidate genes." Autism is one of the most heritable mental disorders. If one identical twin has it, so will the other in nearly 9 out of 10 cases. If one sibling has the disorder, the other siblings run a 35-fold greater-than-normal risk of having it. Still, scientists have so far had only mixed success in identifying the genes involved.

Keyword: Autism; Genes & Behavior
Link ID: 9492 - Posted: 10.18.2006

Heidi Ledford It is essentially a 'nature versus nurture' argument about how different languages divide colours into categories. For instance, in English, there is a word for red and a word for purple, but is that the case in every language? Some say that the underlying biological basis for how we perceive and categorize colour rules all. These are the 'universalists'. In the other corner, a handful of anthropologists believe that cultural needs shape how we define colours. These are the 'relativists'. Throughout the 1940s to 1960s, the textbook view was that every language chops up the colour spectrum in a different way, says Paul Kay, a linguistics professor emeritus at the University of California, Berkeley. When Kay and his colleagues published a 20-language survey of residents of the San Francisco Bay area in 1969, that predominant view changed. "Since then, there has been a continuing parade of papers that show that the ways people cut up colour space in different languages is not random," says Kay. But as is the case in nearly any debate, many researchers fall somewhere in between, and the argument rages on. Isn't there a way to work this out? ©2006 Nature Publishing Group

Keyword: Vision
Link ID: 9491 - Posted: 06.24.2010

Roxanne Khamsi, Atlanta Initial results from the first human clinical trial of gene therapy treatment for Parkinson’s disease suggest the approach can significantly reduce symptoms of the disease. After a year, the 12 patients in the trial showed an average 25% improvement in motor control. The researchers say the new treatment shows no signs of reducing immunity – gene therapy for other illnesses has caused fatal immune-system complications. There is currently no cure for Parkinson’s disease, a fatal degenerative brain condition that causes tremors, speech difficulties and progressive loss of mobility, among many other symptoms. Sufferers can take medications such as levodopa, which helps by elevating levels of the chemical messenger dopamine in the brain. But people respond less to the drug over time and can experience side effects such as jerky movements. Researchers hoping to develop a cure for Parkinson’s have now turned to gene therapy. They developed the treatment by engineering a harmless virus to carry genes that encode a protein called glutamic acid decarboxylase, or GAD. The protein helps make a key nerve signalling chemical called GABA (gamma aminobutyric acid), which inhibits a brain region known as the subthalamic nucleus. This is important because the subthalamic nucleus is typically overactive in Parkinson’s disease due to a loss of dopamine-producing cells elsewhere in the brain. © Copyright Reed Business Information Ltd.

Keyword: Parkinsons
Link ID: 9490 - Posted: 06.24.2010

Stem cells show potential for treating the debilitating nerve condition motor neurone disease, research suggests. A US team found injecting rats with stem cells delayed the onset of MND. Writing in the Transplantation, the researchers from Johns Hopkins Medical Institutions warned clinical use of stem cells was still a long way off. But they said their findings would help scientists to better understand how stem cells behaved when they were transplanted into the body. Motor neurone disease (MND) affects about 5,000 people in the UK. It is a progressive disorder caused by the break-down of the nerve cells, called motor neurones, which control the muscle activity. It is characterised by muscle-wasting, loss of mobility, and difficulties with speech, swallowing and breathing. To investigate whether stem cells - cells that can transform into any type of cell in the body - could help MND sufferers, scientists injected rats, bred to carry the most common form of MND, amyotrophic lateral sclerosis (AMS), with live human stem cells into their lower spines. They found that 70% of the transplanted cells developed into new nerve cells, and many of them had grown new endings connecting with other cells in the rats' spinal cords. The onset of the disease, marked by weight loss, was also delayed. It began on average at 59 days, in the rats injected with live stem cells, compared with 52 days for control rats that had been injected with dead, and therefore inactive, stem cells. They also discovered the rats with live stem cells grew weaker more slowly and lived longer than those that had received dead stem cell transplants. (C)BBC

Keyword: ALS-Lou Gehrig's Disease ; Stem Cells
Link ID: 9489 - Posted: 10.17.2006

By Sally Squires Anyone who has tried to lose weight knows that trimming pounds is the easy (or easier) part. Keeping them off is the challenge, as boredom, tempting food and sedentary living erode your resolve. Yet surprisingly few studies have examined how best to maintain weight loss, leaving a missing piece in the anti-obesity puzzle. Now a Brown Medical School study published last week in the New England Journal of Medicine suggests that the bathroom scale, an emergency diet toolbox and cues from a stoplight might hold the keys to success. The study took a lesson from the National Weight Control Registry, a group of more than 5,000 "successful losers" who have shed at least 30 pounds and kept them off for at least a year. Registry members have trimmed their waistlines in a variety of ways, from cutting calories and boosting exercise on their own to joining groups such as Weight Watchers. One habit they share: regular weigh-ins and then adjustment of food and exercise when pounds start to creep back on. (Successful losers also rarely miss breakfast and get at least an hour a day of physical activity, such as brisk walking.) © 2006 The Washington Post Company

Keyword: Obesity
Link ID: 9488 - Posted: 06.24.2010

PORTLAND, Ore. - Older women on hormone therapy are more sensitive to negative events, confirming speculation that age-related estrogen loss affects the brain's ability to process emotion, an Oregon Health & Science University study shows. But that sensitivity to negative emotional events, such as viewing a photograph of a dead person, doesn't necessarily mean women taking estrogen remember those events any better. In the study by researchers in the Cognition & Aging Laboratory at the OHSU School of Medicine's Department of Behavioral Neuroscience, hormone therapy in women appears to reverse the age-related loss of arousal to negative emotional events experienced by the elderly. It also points to specific changes in the brain's arousal system, in the regions that process emotion, and intensification of negative emotions. The results were presented today at Neuroscience 2006, the Society for Neuroscience's 36th annual meeting at the Georgia World Congress Center in Atlanta. Scientists have suspected a link between sex hormones and emotion. Strengthening this theory is the fact that brain regions tuned for processing emotion and storing emotional memory - the amygdala and hippocampus - also respond to sex hormones and contain hormone receptors. Thus, changes in "emotional enhancement" people experience as they age, including a reduction in the ability to remember negative events, may be modified by age-related loss of sex hormones or hormone therapy.

Keyword: Hormones & Behavior; Emotions
Link ID: 9487 - Posted: 10.17.2006

About a third of the women who take Prozac and other selective serotonin reuptake inhibitors (SSRI) find that the antidepressants dull sexual desire and pleasure. The side effects lead some patients to stop taking the drug. Alternatives to SSRIs, such as those that modulate the neurotransmitters dopamine and norepinephrine instead of serotonin, may avoid the sexual problems. But the few studies done on these drugs, chief among them bupropion (Wellbutrin), have generated conflicting results--some found they boosted sexual interest, whereas others found they lowered it. Now the first animal study on bupropion has weighed in, and it suggests that acute doses do not dampen libido. "Given how big a deal all this is, we were surprised to find no animal studies on it," says Skidmore College senior Gabriel Wurzel. "So we did one." Working with Hassan Lopez, professor of psychology at Skidmore, and junior Benjamin Ragen, Wurzel presented a poster session on their study October 15 at the Society for Neuroscience meeting in Atlanta. "This is, of course, a first study, and it doesn't address long-term effects," Lopez says of the team's work on rats. "But at least for acute use, it seems to suggest bupropion has a fairly neutral effect." To test the rats' amorous interest, the team used a "runway apparatus." A female test rat was let into one end of a five-foot-long walled runway that ended in a "goal box"--a circular area about 18 inches across with a Plexiglas wall across its middle. © 1996-2006 Scientific American, Inc.

Keyword: Sexual Behavior; Depression
Link ID: 9486 - Posted: 06.24.2010

By Anna Salleh, ABC Science Online — Older people accused of being 'blunt' can blame their deteriorating brain for their straight talking, an Australian researcher suggests. Associate Professor Bill von Hippel, a psychologist at the University of New South Wales, says this deterioration means the brain can't properly inhibit older people from saying inappropriate things. "Older adults tend to be more likely to ask about private or personal issues in public than younger adults are," said von Hippel. "And we have suggestive evidence that this is brought about by declines in frontal lobe functioning." He was recently awarded an Australian Research Council grant to investigate the theory and the implications for older people's health. Von Hippel says the stereotype is that people over the age of 65 are more likely to speak their mind because they have earned the right to, and because they are often seen as a source of wisdom. But he says they can lose friends as it can be socially inappropriate. "If I'm asking you about your hemorrhoids in public, even if I don't mean to be mean by doing it, I'm nevertheless humiliating you and I'm not providing you with positive emotional support," he says. Copyright © 2006 Discovery Communications Inc.

Keyword: Emotions
Link ID: 9485 - Posted: 06.24.2010

John Pickrell Dung beetle research may be about to boost the cliché about men with flashy sports cars. According to new study, male beetles with the most dramatic and ostentatious sets of horns apparently pay for that with smaller testicles. The research is the first to experimentally demonstrate that investing energy in one mating advantage may come at the expense of another, the researchers claim. Male dung beetles of the genus Onthophagus are noted for the size and diversity of their horns. In some species, these make up 40% of males’ body length. These iridescent beetles use their flashy ornaments to battle against one another and block access to tunnels where they mate with females. The competition does not end there, however, as females often mate with more than one male. In these species, once inside the female, one male's sperm must compete with other males' sperm to fertilise eggs. It is generally thought that the males that produce the most sperm are more likely to achieve a fertilisation so, besides the horns, testicle capacity is important in competition between males too, says Douglas Emlen, who led the research at the University of Montana in Missoula, US. © Copyright Reed Business Information Ltd

Keyword: Sexual Behavior
Link ID: 9483 - Posted: 06.24.2010

Roxanne Khamsi Brief periods of stress can cause a rapid rise in the brain proteins linked to Alzheimer’s disease, according to a study in mice. Just three days of stress caused an abrupt 42% increase in brain proteins thought to cause the disease. The study helps to shed light on why people who experience great stress and anxiety appear more prone to this illness, experts say. Researchers placed four-month-old mice in isolation within small spaces one-third the size of normal cages. The mice stayed in the confined setting – which causes rodents great stress – for three days or as long as three months. During the course of the experiment the animals wore a special headset device, known as a micro-dialysis probe, that periodically extracted brain fluid for analysis. David Holtzman at Washington University in St Louis, Missouri, US, and colleagues focused their attention on one molecule in particular: amyloid beta peptide. This molecule is known to contribute to the formation of the amyloid protein tangles and plaques that are the hallmarks of Alzheimer’s disease. Previous research has linked higher levels of amyloid beta peptide with increased risk of dementia in humans. The team found that mice housed in the confined space for three months had nearly twice as much amyloid beta peptide in their brain fluid than the control mice that stayed in regular cages. © Copyright Reed Business Information Ltd.

Keyword: Alzheimers; Stress
Link ID: 9482 - Posted: 06.24.2010

Anisa Abid Has anyone ever told you that you have the same expressions as your siblings or parents? You might think you picked that up by hanging around with your family too long. But scientists now say that such family 'signatures' may be genetic. To separate the impact of mimicry from genetic inheritance, scientists at the University of Haifa, Israel, looked at people who were born blind. The authors note that their blind subjects considered it to be a common public misconception that they can learn expressions by touch. The participants said that without a mental model of what a face looks like, it is hard to translate expressions felt through the hands to expressions on their own face. Eviatar Nevo and his colleagues asked their 21 blind participants, along with 30 relatives of these people, to reflect on a particular memory or idea that evoked emotion, and filmed the results. By the end of the interviews they had catalogued 43 different types of facial expressions (several being sequences of expressions), some of which were shared between people. The researchers then had a computer crunch through the facial expressions and attempt to match them up. But because there were so few participants in the trial, they did this in a complex way to improve their statistics. For a given blind person, they divided the remaining participants into two groups at random, and looked to see whether the blind volunteer's facial expression better matched group 1 or group 2. They did this over and over again, dividing the participants into two groups using every possible combination. ©2006 Nature Publishing Group

Keyword: Emotions; Genes & Behavior
Link ID: 9481 - Posted: 06.24.2010

Jim Giles There is growing evidence that suicidal behaviour is a condition is its own right and not just a consequence of other psychiatric disorders, say brain researchers. People who commit suicide show distinct changes in their brain that are independent of any mental illness they may be suffering from, according to studies presented on 15 October at the annual meeting of the Society for Neuroscience in Atlanta, Georgia. Such work could lead to new tests for suicide risk, say some of those behind the research. They speculate it may also help to explain why a small minority of patients on SSRIs, a common form of anti-depressant that boosts serotonin levels, are more likely to commit suicide. "There is an assumption that people get depressed, get depressed, get depressed....and then finally end it," says Mihran Bakalian of the New York State Psychiatric Institute. "But that is not borne out by the biochemical or psychiatric studies." Bakalian says the idea is becoming firmly established among groups such as his that study suicide, but has yet to filter down to many medical doctors. Data from researchers such as Stella Dracheva, who is based at the Bronx Veterans Affairs Medical Center in New York, are beginning to change that. ©2006 Nature Publishing Group

Keyword: Depression
Link ID: 9480 - Posted: 06.24.2010

By Tina Hesman Saey ATLANTA — Some people have chocolate on the brain. A new study of people who crave chocolate shows that eating chocolate, or even just looking at a picture of it, turns on pleasure centers in the brains of cravers far more than in people who don't crave the confection. Viewing pictures of chocolate also activates an area of the brain known to be involved in drug addiction. The study, by Ciara McCabe and Edmund Rolls of Oxford University in England, was one of more than 14,000 presentations slated for the annual meeting of the Society for Neuroscience this week. The meeting draws more than 35,000 brain scientists and doctors each year, making it one of the world's largest scientific gatherings. McCabe gathered seven chocolate cravers and eight non-cravers for her experiment. All of the subjects completed a survey to confirm their chocolate-craving status. The differences were clear. Some people really don't crave chocolate, a fact McCabe — an admitted chocolate craver — finds incredible. She placed the volunteers in a functional magnetic-resonance imaging (fMRI) machine, a scanner that measures activity in the brain. McCabe then gave them a taste of liquid chocolate. The cravers and non-cravers registered the taste to the same degree in parts of the brain involved in detecting taste. But people who crave chocolate perceived the taste as more pleasant than did the non-cravers. The difference showed up in the brain scan and in the volunteers' ratings of the experience. Copyright © 2006 The Seattle Times Company

Keyword: Obesity; Drug Abuse
Link ID: 9479 - Posted: 06.24.2010

By Rob Stein Doctors yesterday reported the first evidence that targeted electrical brain stimulation may help head-trauma victims stuck in a state of semiconsciousness, after an experiment apparently restored some of one patient's abilities to function and communicate. Although the technique has been tried on only one patient, the experiment marks an unprecedented step that could lead to a new way to try to coax thousands of patients mired in similar states back toward more awareness, enabling them to function more and interact better with their families and others. "It sounds promising," said James L. Bernat, a neurologist at Dartmouth Medical School who was not involved in the research. "If it turns out to be helpful for other patients, then it certainly would be an important therapy." Thousands of Americans are left unconscious or semiconscious by brain damage. Many go into a coma, in which they are alive but completely unconscious. Some eventually emerge into a vegetative state, in which their eyes open and close but they show no signs of conscious awareness or ability to interact with their environment. The most famous recent example of this was Terri Schiavo, whose case triggered a national debate over the right-to-die issue. © 2006 The Washington Post Company

Keyword: Brain Injury/Concussion
Link ID: 9478 - Posted: 06.24.2010

By Vilayanur S. Ramachandran and Lindsay M. Oberman At first glance you might not notice anything odd on meeting a young boy with autism. But if you try to talk to him, it will quickly become obvious that something is seriously wrong. He may not make eye contact with you; instead he may avoid your gaze and fidget, rock his body to and fro, or bang his head against the wall. More disconcerting, he may not be able to conduct anything remotely resembling a normal conversation. Even though he can experience emotions such as fear, rage and pleasure, he may lack genuine empathy for other people and be oblivious to subtle social cues that most children would pick up effortlessly. In the 1940s two physicians--American psychiatrist Leo Kanner and Austrian pediatrician Hans Asperger--independently discovered this developmental disorder, which afflicts about 0.5 percent of American children. Neither researcher had any knowledge of the other's work, and yet by an uncanny coincidence each gave the syndrome the same name: autism, which derives from the Greek word autos, meaning "self." The name is apt, because the most conspicuous feature of the disorder is a withdrawal from social interaction. More recently, doctors have adopted the term "autism spectrum disorder" to make it clear that the illness has many related variants that range widely in severity but share some characteristic symptoms. Ever since autism was identified, researchers have struggled to determine what causes it. Scientists know that susceptibility to autism is inherited, although environmental risk factors also seem to play a role. Starting in the late 1990s, investigators in our laboratory at the University of California, San Diego, set out to explore whether there was a connection between autism and a newly discovered class of nerve cells in the brain called mirror neurons. © 1996-2006 Scientific American, Inc.

Keyword: Autism
Link ID: 9477 - Posted: 06.24.2010

ATLANTA, GA -- People addicted to cocaine have an impaired ability to perceive rewards and exercise control due to disruptions in the brain's reward and control circuits, according to a series of brain-mapping studies and neuropsychological tests conducted at the U.S. Department of Energy's Brookhaven National Laboratory. "Our findings provide the first evidence that the brain's threshold for responding to monetary rewards is modified in drug-addicted people, and is directly linked to changes in the responsiveness of the prefrontal cortex, a part of the brain essential for monitoring and controlling behavior," said Rita Goldstein, a psychologist at Brookhaven Lab. "These results also attest to the benefit of using sophisticated brain-imaging tools combined with sensitive behavioral, cognitive, and emotional probes to optimize the study of drug addiction, a psychopathology that these tools have helped to identify as a disorder of the brain." Goldstein's experiments were designed to test a theoretical model, called the Impaired Response Inhibition and Salience Attribution (I-RISA) model, which postulates that drug-addicted individuals disproportionately attribute salience, or value, to their drug of choice at the expense of other potentially but no-longer-rewarding stimuli -- with a concomitant decrease in the ability to inhibit maladaptive drug use.

Keyword: Drug Abuse
Link ID: 9476 - Posted: 10.16.2006