Celeste Biever A man paralysed from the neck down by knife injuries sustained five years ago can now check his email, control a robot arm and even play computer games using the power of thought alone. Matt Nagle's extraordinary abilities were first reported in March 2005. Now details of the technology that lets him perform these tasks are published in the journal Nature. Another study in the same issue reveals a technique that could dramatically improve the speed with which such implants work. Electrodes implanted in Nagle's brain measure the neural signals generated when he concentrates on trying to move one of his paralysed limbs. Software trained to recognise different patterns of neural activity then translates imagined gestures into the movement of an on-screen cursor or a robotic arm at Nagle's side. "The fundamental findings are that you can record activity from the brain years after injury, that thinking about movement is sufficient to activate the brain, and that we can decode the signal," says John Donoghue of Brown University in New York, who led the work. "Even though only one person was studied, the findings are impressive, especially as you can use the system while talking," says Maria Stokes a neurologist at the University of Southampton, UK. © Copyright Reed Business Information Ltd.

Keyword: Robotics
Link ID: 9131 - Posted: 06.24.2010

Helen Philips, Vienna Stress experienced by a pregnant female can alter the structure of her offspring’s brain, particularly regions vital for emotional development, scientists have discovered. Furthermore, in rodents at least, the effects differ in male and female offspring. That might help explain the different susceptibilities of men and women to emotional and psychiatric disorders, says Katharina Braun, from the University of Magdeburg, in Germany. Braun presented the work at the Federation of European Neuroscience Societies' annual meeting in Vienna, Austria, on Tuesday. Braun and colleagues at the University of Jerusalem in Israel studied the effects of stress on pregnant rats. If they become stressed in the last trimester of pregnancy, their offspring developed fewer nerve connections in two brain regions that control emotions – the cingulate cortex and orbitofrontal cortex. In addition, the nerve cells in several other regions show different branching patterns to normal, with different effects on males and females. In the hippocampus, an important region that controls memory and emotion, males show an increase in branching while females show a decrease. In the prefrontal cortex, the males develop shorter nerve branches, while the females do not. Braun has not yet tested the behavioural effects of these changes on adult rats, but the results could reveal a possible mechanism for the development of emotional disorders seen in humans. © Copyright Reed Business Information Ltd.

Keyword: Stress; Development of the Brain
Link ID: 9130 - Posted: 06.24.2010

Researchers have found in two studies that autism may involve a lack of connections and coordination in separate areas of the brain. In people with autism, the brain areas that perform complex analysis appear less likely to work together during problem solving tasks than in people who do not have the disorder, report researchers working in a network funded by the National Institutes of Health. The researchers found that communications between these higher-order centers in the brains of people with autism appear to be directly related to the thickness of the anatomical connections between them. In a separate report, the same research team found that, in people with autism, brain areas normally associated with visual tasks also appear to be active during language-related tasks, providing evidence to explain a bias towards visual thinking common in autism. “These findings provide support to a new theory that views autism as a failure of brain regions to communicate with each other,” said Duane Alexander, M.D., Director of NIH’s National Institute of Child Health and Human Development. “The findings may one day provide the basis for improved treatments for autism that stimulate communication between brain areas.” People with autism often have difficulty communicating and interacting socially with other people. The saying "unable to see the forest for the trees" describes how people with autism frequently excel at details, yet struggle to comprehend the larger picture.

Keyword: Autism
Link ID: 9129 - Posted: 06.24.2010

An experimental drug probably does not stop the progression of the brain disease vCJD, experts have concluded. However, the Medical Research Council said further large scale tests on animals should be carried out. The MRC monitored the effect of Pentosan Polysulphate (PPS) on seven patients with vCJD or other degenerative prion diseases. It conceded that the drug had appeared to help several people live longer than expected. Several patients have taken the drug, including Jonathan Simms, now the UK's longest-surviving vCJD patient. There is no cure for vCJD and the majority of people who have developed the disease have died. So far 111 people are known to have died from the disease in the UK, with another 45 probable fatalities. It is thought that five Britons are currently living with vCJD. The MRC did not originally include PPS in a trial of possible treatments on the advice of the Committee on the Safety of Medicines. However, the Simms family, from Belfast, won permission from the High Court to give Jonathan the drug in December 2002. Since then it has been given to others, including Holly Mills from North Yorkshire, who started treatment within weeks of being diagnosed with vCJD in October 2003. Her condition has been stable for 18 months. The drug must be surgically administered directly into the ventricles of the patient's brain. Lead researcher Professor Ian Bone accepted that his findings were not conclusive, as they were based on a small number of patients who were treated in different ways. However, he said any clear benefits of the drug would have been revealed by the study. (C)BBC

Keyword: Prions
Link ID: 9128 - Posted: 07.12.2006

Ernest Hartmann, a professor of psychiatry at Tufts University School of Medicine and the director of the Sleep Disorders Center at Newton Wellesley Hospital in Boston, Mass., explains. The questions, "Why do we dream?" or "What is the function of dreaming?" are easy to ask but very difficult to answer. The most honest answer is that we do not yet know the function or functions of dreaming. This ignorance should not be surprising because despite many theories we still do not fully understand the purpose of sleep, nor do we know the functions of REM (rapid eye movement) sleep, which is when most dreaming occurs. And these two biological states are much easier to study scientifically than the somewhat elusive phenomenon of dreaming. Some scientists take the position that dreaming probably has no function. They feel that sleep, and within it REM sleep, have biological functions (though these are not totally established) and that dreaming is simply an epiphenomenon that is the mental activity that occurs during REM sleep. I do not believe this is the most fruitful approach to the study of dreaming. Would we be satisfied with the view that thinking has no function and is simply an epiphenomenon--the kind of mental activity that occurs when the brain is in the waking state? © 1996-2006 Scientific American, Inc

Keyword: Sleep
Link ID: 9127 - Posted: 06.24.2010

WINSTON-SALEM, N.C. – Using positron emission tomography (PET), researchers have established a firm connection between a particular brain chemistry trait and the tendency of an individual to abuse cocaine and possibly become addicted, suggesting potential treatment options. The research, in animals, shows a significant correlation between the number of receptors in part of the brain for the neurotransmitter dopamine – measured before cocaine use begins – and the rate at which the animal will later self-administer the drug. The research was conducted in rhesus monkeys, which are considered an excellent model of human drug users. Generally the lower the initial number of dopamine receptors, the higher the rate of cocaine use, the researchers found. The research was led by Michael A. Nader, Ph.D., professor of physiology and pharmacology at Wake Forest University School of Medicine. It was already known that cocaine abusers had lower levels of a particular dopamine receptor known as D2, in both human and animal subjects, compared to non-users. But it was not known whether that was a pre-existing trait that predisposed individuals to cocaine abuse or was a result of cocaine use. "The present findings in monkeys suggest that both factors are likely to be true," Nader and colleagues write in a study published online this week in the journal Nature Neuroscience.

Keyword: Drug Abuse; Brain imaging
Link ID: 9126 - Posted: 06.24.2010

Alison Abbott Strokes often change a person's character, depending on where the damage hits. Some may become more impulsive, others depressed. Now researchers have shown that damage to a small but very specific brain area can wipe out an addiction to smoking. Antoine Bechera, of the University of Iowa in Iowa City, has identified 14 patients who all stopped smoking immediately after having a stroke that damaged their insular cortex. This seems to be not because they were concerned about their health, but because they had lost all interest in cigarettes, he told the Federation of Neuroscience Societies in Vienna this week. "One or two had even forgotten that they used to smoke," says Bechera. The insular cortex is a relatively primitive part of the brain whose functions include providing an emotional context for experiences, such as drug taking, along with some higher-level, decision-making functions involved, for example, in forming memories. The seemingly huge impact of switching off this area could have implications for addiction research in general, according to Bechera. Throwing off an addiction for good is tough because cues in the environment — a whiff of tobacco smoke, or the room where you used to shoot up — automatically invokes the emotion associated with the last fix. ©2006 Nature Publishing Group

Keyword: Drug Abuse; Stroke
Link ID: 9125 - Posted: 06.24.2010

By reshaping the cornea, Lasik surgery can correct the eye's ability to focus light onto the cornea.

Keyword: Vision
Link ID: 9124 - Posted: 07.11.2006

By ERIC NAGOURNEY Many people think they don’t get enough sleep. It may be even worse than they realize. Researchers who asked people to wear sleep-measuring devices found that the period of sleep was much shorter than the study subjects believed. The report appears in the July 1 issue of The American Journal of Epidemiology. The researchers, led by Diane Lauderdale of the University of Chicago, found that the people studied had spent an average of seven and a half hours in bed, but just over six hours asleep. They also found significant differences in sleep patterns between men and women and whites and blacks, and among different income groups. The findings suggest that people get less sleep than earlier studies have shown. It also raises questions about the reliability of sleep estimates that people provide to researchers. The 669 volunteers were asked to keep a diary of their sleep over three days, and were given motion-detecting devices worn on the wrist that helped the researchers determine how much they actually slept. The study took into account the normal movements that occur during sleep, Dr. Lauderdale said. Copyright 2006 The New York Times Company

Keyword: Sleep
Link ID: 9123 - Posted: 06.24.2010

A drug that harnesses the power of deadly sea snail venom has been launched in Britain. Prialt is a strong painkiller designed for patients suffering from chronic pain who cannot tolerate treatments like morphine. It is based on a toxin produced by a species of snail from the Philippines. The snail uses venom to paralyze passing fish, but scientists found chemicals in the poison could also block pain signals in the human brain. Conus magus, or the magician's cone snail, is one of about 500 species of cone snail. It hunts by harpooning its prey and injecting it with venom before swallowing now-immobile fish whole. About 25 years ago, scientists at the University of Utah, in the US, managed to isolate a molecule from the venom that also had painkilling properties in humans. The molecule works by preventing nerve cells from sending pain signals to the brain. Now researchers have created a synthetic version of the compound with similar pain-killing effects, and it forms the basis of this new drug, Prialt. Prialt is injected directly into the fluid surrounding the spinal cord through a small pump worn by the patient. (C)BBC

Keyword: Pain & Touch
Link ID: 9122 - Posted: 07.11.2006

By Sandra G. Boodman A major long-term study of girls diagnosed with attention-deficit hyperactivity disorder (ADHD) in elementary school has found they are at greater risk for substance abuse, emotional problems and academic difficulties in adolescence than their peers who don't have the common neurobehavioral condition. The results, experts say, should help dispel the myth that the disorder, which affects an estimated 4.4 million American children, poses less of a risk to girls than to boys, on whom most research has focused. The federally funded study by researchers at the University of California, Berkeley, involves more than 200 girls who have been followed since 1997, when they were 6 to 12. The broadly focused study is designed to measure the ways ADHD, a disorder characterized by pervasive inattention and impulsivity, affects peer relationships, impairs school performance and is linked to substance abuse and psychological problems. "Can you believe it's 2006" and the first long-term prospective study of girls with ADHD is just being published, asked psychologist William Pelham, an ADHD expert at the State University of New York at Buffalo. Girls, Pelham said, have been under-diagnosed and overlooked in large part because their behavior tends to be less disruptive -- although their problems may be just as severe. © 2006 The Washington Post Company

Keyword: ADHD
Link ID: 9121 - Posted: 06.24.2010

Serge Bloch Everybody has limits. I draw the line at women in gorilla suits. I’m not talking about romance. I’m talking about reality as we know it, or think we know it. Except on MTV, the real world has become harder and harder to find. Physics tells us that what we think of as reality is just a particular version of quantum mush or tangled strings cooked up by our limited senses. Cognitive science tells us we’re not even getting the straight dope from our ears and eyes because our brain is concocting a good story from the input. (For the moment let’s not worry about who “we” are. Let’s assume that we know who “we” are.) I can live with that. I imagine the brain as a writer dealing with raw information. You can’t give the reader just the facts, with no transitions or metaphors or narrative structure. So you create a story, or, perhaps, a column. The woman in the gorilla suit is something else again. I’m referring, of course, to the 1999 video known (to those in the know) as the “opaque gorilla video,” which is used in numerous studies of how people fail to see what is right in front of them. It is only 75 seconds long. Copyright 2006 The New York Times Company

Keyword: Attention
Link ID: 9120 - Posted: 06.24.2010

Sleep aids memory. Whether tested in animals or humans, studies have shown that sense memories--such as learning a certain sequence of dance steps--take root more solidly when paired with adequate rest. Now new research shows that so-called declarative memories--such as a sequence of facts--also benefit from slumber, especially when subjects are challenged with subsequent, competing information. Jeffrey Ellenbogen of Harvard Medical School and his colleagues recruited 60 healthy subjects--excluding night owls, the restless and the lethargic--and asked them to memorize 20 pairs of random words, such as blanket and village. The participants were assigned to one of five groups of 12 and had unlimited time to learn the pairings. Two of the groups began learning at 9 A.M and returned for testing at 9 P.M. that evening--with no naps allowed--and two of the groups began learning at 9 P.M. and returned for testing at 9 A.M. the following morning after a night’s sleep. The sleepers barely outperformed their sleepless peers in the first comparison: 94 percent of sleepers accurately recalled the pairings compared to 82 percent of their peers. But when the researchers added a twist--forcing subjects in two of the groups to learn a new set of word pairs 12 minutes prior to testing--the well-rested radically outperformed the sleepy; 76 percent of sleepers accurately recalled the initial pair compared to just 32 percent of their peers who had gone without shut-eye. © 1996-2006 Scientific American, Inc.

Keyword: Sleep; Learning & Memory
Link ID: 9119 - Posted: 06.24.2010

By Briahna Gray A mosquito's hum may drive humans crazy, but to other mosquitoes it's love at first buzz. Now, scientists have discovered that the sound frequencies generated by the insects' beating wings help mosquitoes of the opposite sex coordinate a romantic rendezvous. Finding a mate is tough, especially if your vision isn't very good. Male mosquitoes seem to solve the problem by homing in on the approaching buzz of a potential partner. But how do they tell the guys from the girls? And do females play an active role in this auditory courtship given their smaller and less sensitive antennae? Those have been tough questions to answer, says Gabriella Gibson, a behavioral entomologist at the University of Greenwich in Kent, United Kingdom, particularly because recording the sounds of flying insects is a logistical nightmare. Still, Gibson's team decided to give it a try. Using a dab of beeswax, the researchers separately tethered a male and female mosquito to small clamps via a thin metal wire. They then set up a tiny microphone near each insect. When the female was encouraged to fly, a curious symphony ensued. The male let loose with a flurry of rapid wing beats, creating a higher-frequency buzz than that emitted by the female. In response, the female slightly increased her wing beat frequency to try to match the buzz of the male, with the male slowing his hum frequency dramatically to match hers. Within a second, the buzzes of the two insects were in perfect harmony. © 2006 American Association for the Advancement of Science

Keyword: Sexual Behavior; Hearing
Link ID: 9118 - Posted: 06.24.2010

Experience, as the old saying goes, is the best teacher. And experience seems to play an important early role in how infants learn to understand and produce language. Using new technology that measures the magnetic field generated by the activation of neurons in the brain, researchers tracked what appears to be a link between the listening and speaking areas of the brain in newborn, 6-month-old and one-year-old infants, before infants can speak. The study, which appears in this month's issue of the journal NeuroReport, shows that Broca's area, located in the front of the left hemisphere of the brain, is gradually activated during an infant's initial year of life, according to Toshiaki Imada, lead author of the paper and a research professor at the University of Washington's Institute for Brain and Learning Sciences. Broca's area has long been identified as the seat of speech production and, more recently, as that of social cognition and is critical to language and reading, according to Patricia Kuhl, co-author of the study and co-director of the UW's Institute for Brain and Learning Sciences. "Magnetoencephalography is perfectly non-invasive and measures the magnetic field generated by neurons in the brain responding to sensory information that then 'leaks' through the skull," said Imada, one of the world's experts in the uses of magnetoencephalography to study the brain.

Keyword: Language; Development of the Brain
Link ID: 9117 - Posted: 07.11.2006

David Briscoe, Associated Press —The Navy said it will use active sonar during warfare exercises off Hawaii as early as this weekend, after reaching an agreement with environmentalists who claimed the practice poses a threat to whales and other marine life. The settlement, reached Friday, prevents the Navy from using sonar within 25 miles of the newly established Northwestern Hawaiian Islands Marine National Monument. The agreement also imposes a variety of methods to watch for and report the presence of marine mammals. Navy officials have said the value of training to detect stealthy submarines would have been severely diminished without sonar, which bounces sound off objects in the ocean. "We want to ensure that the U.S. Navy and its partner navies get the benefit of this opportunity to train in anti-submarine warfare," said Rear Adm. James Symonds, director of environmental readiness. The Navy hadn't been allowed to activate sonar under a temporary restraining order issued Monday by U.S. District Court Judge Florence-Marie Cooper in Los Angeles. She lifted the order after the settlement was reached between the environmentalists, the Navy and several federal agencies. © 2006 Discovery Communications Inc.

Keyword: Hearing; Animal Communication
Link ID: 9116 - Posted: 06.24.2010

Roxanne Khamsi “Magic” mushrooms really do have a spiritual effect on people, according to the most rigorous look yet at this aspect of the fungus's active ingredient. About one-third of volunteers in the carefully controlled new study had a “complete” mystical experience after taking psilocybin, with half of them describing their encounter as the single most spiritually significant experience in their lifetimes. However, psilocybin use has been associated with side effects such as severe paranoia, nervousness and unwanted flashbacks and so experts warn against experimentation. “Once you’ve started down the path, you might not like where it ends,” comments Herbert Kleber, a psychiatrist at Columbia University in New York, US. “These are powerful agents that are just as likely to do harm as to do good.” Psilocybin is found in mushrooms such as the liberty cap (Psilocybe semilanceata and about 186 other species. Hippies embraced the compound during the 1960s, after its mind-altering potential was touted by Timothy Leary, then a researcher at Harvard University in Cambridge, Massachusetts. But as its use grew, US lawmakers took action. It is now generally illegal to sell or possess psilocybin drugs in the US. But Roland Griffiths, of Johns Hopkins University School of Medicine in Baltimore, Maryland, US, and his colleagues believe there is a need to revisit the biological effects of psilocybin, which have been virtually ignored by the scientific community for about 40 years. “It so traumatised our society that we’ve demonised this compound,” he says. © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse
Link ID: 9115 - Posted: 06.24.2010

Helen Phillips A hormone treatment used as a "morning-after" drug to induce abortion could provide a rapid-acting treatment for depression. The drug, called RU486, was one of two new rapid treatment strategies, revealed on Sunday at the Federation of European Neurosciences Society's Annual Forum in Vienna, Austria. Most antidepressants are thought to work by raising levels of the signalling chemical serotonin, which acts in the brain. But these drugs can take several weeks to take effect. The new treatments could be effective within days or even hours. The hormone treatment is based on earlier findings that stress plays a major part in triggering and prolonging depression. Stress hormones appear to damage a part of the brain called the hippocampus. The region is susceptible because it is particularly rich in hormone receptors, allowing it to regulate ongoing hormone release. In experiments on rats, Paul Lucassen from the University of Amsterdam in the Netherlands discovered that stress hormones seemed to be interfering with the birth of new neurons in the region. “The whole turnover of cells is affected,” he reported. © Copyright Reed Business Information Ltd.

Keyword: Depression; Hormones & Behavior
Link ID: 9114 - Posted: 06.24.2010

A blood test to detect the human form of mad cow disease before it causes symptoms is a step closer, say experts. Spanish and US scientists have found a way to detect infection in hamsters before the animal shows signs of illness. More work is needed before a similar test could be used in humans, but the findings offer hope of a screening test for vCJD, Science reports. Currently, it is only possible to confirm vCJD infection after death. A test for vCJD is badly needed, especially now that some cases appear to have been transmitted by blood transfusions, say Dr Paula Saa and colleagues from the University of Texas. In the UK, there have been three reported cases of variant-CJD associated with a blood transfusion to date. The first of these was identified in December 2003. Since then the Department of Health has asked all recipients of blood transfusions not to donate blood as a precautionary measure to protect the blood supply from vCJD. This is because it has not yet been possible to screen donated blood for vCJD, unlike some other infections. The test developed by Dr Saa's team detects prion proteins - the infectious agents that are thought to be responsible for vCJD. Normally, prion concentrations are only high enough to be detectable in the brain and some lymphoid tissue at a time close to they symptomatic stage of the disease. To get round this, the scientists used a technique called protein misfolding cyclic amplification (PCMA) which amplifies the quantity of prion proteins in any sample taken from the body. (C)BBC

Keyword: Prions
Link ID: 9113 - Posted: 07.10.2006

By BENEDICT CAREY WHEN a war crime doesn't look quite like a war crime — when it seems cold and deliberate like a serial murder, rather than an impulsive act of vengeance — it can be especially disturbing, as United States Army officials have learned over the past week. According to federal prosecutors, an Army private and several comrades attacked an Iraqi family last March, raping and killing a young woman after executing her parents and her younger sister in their home. The men disguised themselves for the attack and worked as a team, the prosecutors said. Iraqi leaders are in an uproar, as are American officials in and out of the military. The accused ringleader, Steven D. Green, 21, who was discharged in May, pleaded not guilty after his arrest June 30, and details of the crime were still emerging last week. The Army has said it discharged Mr. Green for a "personality disorder." Which raises a question: How does someone with a personality disorder — a significant, disabling, and dangerous condition — manage the stress of combat? Wouldn't a person with a serious mental problem drop out, or be identified and quickly discharged? Copyright 2006 The New York Times Company

Keyword: Aggression
Link ID: 9112 - Posted: 06.24.2010