HANOVER, NH – A Dartmouth research group has found a new and unexpected way our attention can be grabbed – by grabbable objects. Their study, which appears in the March 17 advance online issue of Nature Neuroscience, demonstrates that objects we typically associate with grasping, such as screwdrivers, forks or pens, automatically attract our visual attention, especially if these items are on a person's right-hand side. In the brain, there are two primary visual pathways, one for identifying objects (perception) and one to guide your arms and legs based on what you see (action). To better understand how these two systems may interact, the Dartmouth team studied whether visual perception, specifically peripheral visual attention, influences motor systems in the brain. "People have studied peripheral vision and how it helps perception, but nobody really talked about it in terms of helping action," says Todd C. Handy, the lead author and a research assistant professor at the Center for Cognitive Neuroscience at Dartmouth. "There are certain things that we all know attract our attention, like flashing lights and loud noises. Yet, think about how often we grab things without directly looking at them. Now here's evidence that, to help us do this, grabbable objects can literally grab our attention. There's a clear association."

Keyword: Vision; Attention
Link ID: 3566 - Posted: 06.24.2010

Taking just one ecstasy tablet is enough to make you depressed, a study suggests. Researchers at London Metropolitan University have found that people who take ecstasy are more likely to suffer depression compared to non-users and even people who use other drugs. Their study also indicates that heavy users of the drug are at risk of becoming clinically depressed. The researchers believe ecstasy has a long-lasting impact on key chemicals in the brain, which regulate mood. The findings are based on a study of almost 600 working professionals. They each filled out a form detailing previous drug use and overall mood. The researchers split these people into three different groups - those who had only taken ecstasy; those who took other drugs; and those who have never taken drugs. (C) BBC

Keyword: Drug Abuse; Depression
Link ID: 3565 - Posted: 03.16.2003

By GRETCHEN REYNOLDS Wendell Johnson was a tall, knobby 20-year-old farm boy when he arrived at the University of Iowa in Iowa City to study English in 1926. The class president and valedictorian of his tiny high school in Roxbury, Kan., Johnson was engaging, ''quite a clown'' in the estimation of the folks back home. He also stuttered grotesquely, often rendered speechless by the impediment. His inability to express himself nudged him toward writing and literature, and he developed a penchant for antic humor, which kept him popular despite his silence. It also propelled him to U. Iowa, the most famous center for stuttering research in the world. Around the country, speech pathology was fighting to be recognized as a science, and Iowa was the new discipline's polestar. Dozens of experiments were under way when Johnson arrived, and he enthusiastically threw himself into the invigorating work, switching to psychology for his master's study. ''I became a speech pathologist because I needed one,'' he'd later say. Many of his fellow graduate students stuttered almost as painfully as he did, and they'd use one another as guinea pigs. They'd draw blood, hook themselves to electrodes, strike their knees to test reflexes, whip out notebooks in midstride and transcribe their own and others' faltering speech. They'd administer electroshock and shoot guns off near each other's ears to see if being startled affected stuttering. (It didn't, although the same experiment performed on normal speakers did affect their speech.) They'd also put casts on one another's arms, since it was hoped that immobilizing a person's dominant hand somehow would untangle confused brain signals. At one point, about 30 stutterers, including Johnson, wandered the Iowa campus with their arms wrapped in plaster, sometimes playing wrong-handed badminton. ''We knew that we were working on something central in the life of a human being,'' one of Johnson's contemporaries told an Iowa historian. ''We weren't just puttering around on the fringes.'' At the time, physiology had become the favored explanation at Iowa for stuttering. The department's lead professors were certain that the disorder originated in misdirected brain signals. They had used a new device called an electromyograph to study neuromus-cular activity in stutterers, nonstutterers and, in one experiment, people who were drunk (students who, solely in the interests of science, had become soused; the researchers skirted Prohibition by requisitioning alcohol from the university hospital.) The readouts from the booze-tinged subjects showed, to no one's surprise, impair-ment. Intriguingly, more comprehensive experiments showed that stutterers had subtle neuromuscular responses different from those of their nonstuttering peers. Copyright 2003 The New York Times Company

Keyword: Language; Development of the Brain
Link ID: 3564 - Posted: 03.16.2003

By RICHARD PÉREZ-PEÑA In state capitols, universities, charitable foundations, hospitals and companies around the country, a scattershot movement is under way to counteract President Bush's 2001 order sharply limiting federal money for embryonic stem cell research. Lawmakers in New York, Maryland, Rhode Island, Tennessee, Washington and Massachusetts are considering bills authorizing embryonic stem cell research, according to advocates of the research and the National Conference of State Legislatures. Some bills go further, as one passed in California did last year when it authorized the use of state money to support research using embryonic stem cells, which scientists contend could eventually yield treatments for diabetes, Parkinson's, Alzheimer's, heart disease, cancer and other ailments. Mr. Bush and others who oppose such research say it is immoral because human embryos are destroyed when the cells are extracted. Copyright 2003 The New York Times Company

Keyword: Stem Cells
Link ID: 3563 - Posted: 03.16.2003

Anti-depressant may help treat Alzheimer's disease. HELEN R. PILCHER Lithium, the standard drug for manic depression, might also help to treat other brain conditions such as stroke and Alzheimer's disease, new research suggests1. The simple salt stimulates stem cells growing in a dish to multiply faster, hinting that it could prompt stem cells in the brain to produce new cells to replace those damaged by disease. "We have underestimated the effects of lithium," says De-Maw Chuang of the Mood and Anxiety Disorder Program at the National Institutes of Health in Bethesda, Maryland. © Nature News Service / Macmillan Magazines Ltd 2003

Keyword: Depression; Stem Cells
Link ID: 3562 - Posted: 06.24.2010

There is little truth in the widely held idea that pregnancy reduces a woman's mental firepower, research has found. Many people - including some midwives - believe that pregnancy has a damaging impact on memory and concentration. A team of psychologists from the University of Sunderland asked pregnant women for their views - and found that many subscribed to the popular view. But when the same women performed a series of mental tests they actually performed no worse than women who were not carrying a child. The researchers, led by Dr Ros Crawley, compared the performance of 15 pregnant women an 14 who were not. They conducted tests twice during pregnancy and at six months and 12 months after birth. (C) BBC

Keyword: Hormones & Behavior; Learning & Memory
Link ID: 3561 - Posted: 03.15.2003

COLUMBUS, Ohio – A new study strongly indicates that the primary cause of nearsightedness is heredity. The study also suggests that the amount of time a child spends studying or reading plays a minor role in the development of myopia, or nearsightedness. The researchers found that, per week, myopic children spent more time studying and reading for pleasure and less time playing sports than non-myopic children. Myopic children also scored higher on a test of basic reading and language skills than did children with normal vision. The nearsighted children spent about the same amount of time watching television and playing video games in a week as did children with normal vision, said Donald Mutti, the study’s lead author and an associate professor of optometry at Ohio State University.

Keyword: Vision; Genes & Behavior
Link ID: 3560 - Posted: 06.24.2010

Blocking or eliminating a specific potassium channel in a small group of brain cells may improve or prevent the symptoms of Parkinson's disease, a debilitating and progressive neurodegenerative disease that afflicts over 1 million people in the United States. In Parkinson's disease, neurons that release dopamine die. The loss of dopamine causes an array of debilitating symptoms that include resting tremor, muscle rigidity and slowed movement. Although the cause of the disease remains uncertain, James Surmeier and colleagues at Northwestern University have discovered a way of potentially lessening the symptoms and progression of the disease. The investigators describe their findings in the March issue of Nature Neuroscience.

Keyword: Parkinsons; Stem Cells
Link ID: 3559 - Posted: 03.15.2003

* Alcohol abuse can lead to Korsakoff's syndrome, a severe mental disorder characterized by memory loss and disorientation. * Individuals with Korsakoff's syndrome tend to have olfactory deficits: dysfunctions in odor identification, discrimination, memory, sensitivity, and intensity. * New research has found that alcoholics without amnesia or dementia also have olfactory deficits. Researchers know that alcohol abuse can lead to Korsakoff's syndrome, a severe mental disorder characterized by memory loss and disorientation. Studies dating back to the end of the 1970s have shown that Korsakoff's syndrome, in turn, is associated with olfactory deficits, specifically, dysfunctions in odor identification, discrimination, memory, sensitivity, and intensity. A study in the March issue of Alcoholism: Clinical & Experimental Research has found that "uncomplicated" alcoholics, those without amnesia or dementia, also have impaired olfactory functioning.

Keyword: Drug Abuse; Chemical Senses (Smell & Taste)
Link ID: 3558 - Posted: 03.15.2003

PHILADELPHIA -- Scientists at the University of Pennsylvania and the Monell Chemical Senses Center in Philadelphia have found that exposure to male perspiration has marked psychological and physiological effects on women: It can brighten women's moods, reducing tension and increasing relaxation, and also has a direct effect on the release of luteinizing hormone, which affects the length and timing of the menstrual cycle. The results will be published in June in the journal Biology of Reproduction and currently appear on the journal's Web site. "It has long been recognized that female pheromones can affect the menstrual cycles of other women," said George Preti, a member of the Monell Center and adjunct professor of dermatology in Penn's School of Medicine. "These findings are the first to document mood and neuroendocrine effects of male pheromones on females."

Keyword: Chemical Senses (Smell & Taste); Stress
Link ID: 3557 - Posted: 03.15.2003

Scientists at Rockefeller University and Weill Medical College of Cornell University have discovered how estrogen initiates physical changes in rodent brain cells that lead to increased learning and memory -- a finding, the researchers contend, that illustrates the likely value of the hormone to enhance brain functioning in women. Their study, published in the March 15 issue of The Journal of Neuroscience, describes for the first time a chain of molecular events that is activated in the brain's primary memory center, called the hippocampus, when estrogen bathes neurons (nerve cells). The study details how these nerve cells "grow in complexity" when exposed to estrogen, increasing connections among nerve cells in an area of the brain needed to store new memories, retrieve older ones and even recall location of an object or event in space.

Keyword: Hormones & Behavior; Learning & Memory
Link ID: 3556 - Posted: 03.15.2003

A once-plentiful species of antelope could be wiped out after wholesale poaching triggered a dramatic change in mating behaviour. Researchers from Kazakhstan, Russia and the UK are deeply concerned about the future of the saiga antelope (Saiga tatarica tatarica) after surveys from the air suggested numbers had fallen by 95% since the 1970s. The antelope has now been rushed into the list of critically endangered species held by the World Conservation Union (IUCN). The break-up of the Soviet Union has been blamed for the decline, as the removal of collective farming threw rural economies into chaos, forcing locals to rely on saiga meat to survive. It also opened the border into China, where the horn of the male saiga is prized as an ingredient of Chinese medicine. However, some of the most dramatic falls have happened in the last five years, even though less hunting of the saiga is thought to be taking place. (C) BBC

Keyword: Sexual Behavior
Link ID: 3555 - Posted: 03.13.2003

In a study on the effects of sleep deprivation, investigators at the University of Pennsylvania found that subjects who slept four to six hours a night for fourteen consecutive nights showed significant deficits in cognitive performance equivalent to going without sleep for up to three days in a row. Yet these subjects reported feeling only slightly sleepy and were unaware of how impaired they were. The research article, "The Cumulative Cost of Additional Wakefulness: Dose-Response Effects on Neurobehavioral Functions and Sleep Physiology From Chronic Sleep Restriction and Total Sleep Deprivation," appears in the March issue of the journal SLEEP. According to Principal Investigator David Dinges, "This is the first systematic study to look at the prolonged cognitive effects of chronic sleep restriction lasting for more than a week. The results provide a clearer picture of possible dangers to people who typically are awake longer on a regular basis," he explained, "including members of the military, medical and surgical residents, and shift workers. Reduced cognitive abilities can occur even with a moderate reduction in sleep." Cognitive performance deficits included reduced ability to pay attention and react to a stimulus, such as when driving, or monitoring at airports. Other deficits involved impairment of the ability to think quickly and not make mistakes, and a reduced ability to multi-task — to hold thoughts in the brain in some order while doing something else.

Keyword: Sleep
Link ID: 3554 - Posted: 06.24.2010

By SANDRA BLAKESLEE Christopher Reeve, the actor who has been paralyzed and on a respirator since breaking his neck in a riding accident eight years ago, has had electrodes implanted in his diaphragm in an effort to restore his ability to breathe naturally. The results are extremely promising, said Dr. Raymond Onders, who performed outpatient surgery on Mr. Reeve at University Hospitals of Cleveland on Feb. 28. He can breathe without the respirator for more than two hours at a stretch compared with 10 minutes before the operation, Dr. Onders said. As his diaphragm muscles regain strength over the next couple of months, Mr. Reeve may be able to wean himself permanently from the respirator. While breathing on his own, he is regaining the ability to talk normally. And when he is breathing more normally — not through the ventilator's hole in his throat — he can smell odors for the first time since his accident. Copyright 2003 The New York Times Company

Keyword: Robotics; Regeneration
Link ID: 3553 - Posted: 06.24.2010

It's common knowledge that things aren't always as they appear, but a new study shows our brains are complicit in our vision errors even at the earliest point in the brain's visual processing system. In an article to be featured in an upcoming issue of Nature Neuroscience, David Ress of Stanford University and David Heeger of NYU report that activity in the brain's visual cortex corresponds to what the subjects perceive, rather than what they actually see. The scientists based their findings on experiments using functional magnetic resonance imaging (fMRI) to measure activity in carefully circumscribed regions of the visual cortex of the brain while human subjects performed a challenging visual discrimination task. Subjects attempted to detect the presence of slight contrast increments added to a background pattern. Behavioral responses were recorded so that the corresponding cortical activity could be grouped into four categories: "hits", when subjects correctly identified the image shown as the higher contrast image; "false alarms", when subjects misidentified the lower-contrast image as the higher contrast image; "misses", when subjects presented with the higher contrast image misidentified it as the lower contrast image; and "correct rejects", when subjects correctly identified the lower contrast image. Hits and false alarms produced significantly more cortical activity than misses, indicating that activity in the visual cortex corresponded to the subjects' precepts, rather than to the physically presented stimulus.

Keyword: Vision
Link ID: 3552 - Posted: 06.24.2010

-- Hormones and neurotransmitters secreted from cells via bubble-like vesicles are released using age-related criteria, with the youngest vesicles getting first shot at releasing their contents, according to research led by a University of Southern California (USC) physiologist. This is a "complete reverse" from what had previously been presumed to be the process behind hormone secretion, notes Robert Chow, M.D., Ph.D., associate professor of physiology and biophysics at the Keck School of Medicine of USC, the study's principal investigator. In addition, he says, it now seems likely that upsetting this process may play a role in the development or progression of diseases of secretory cells, such as diabetes. The research will be published as the cover story in the March 13 issue of the journal Nature, which will feature an image from the research paper representing the movement of a single vesicle over time, from docking at the cell membrane to release of its neurotransmitter. The typical secretory cell-endocrine cells like those found in the adrenal gland or in the pancreas, as well as nerve cells that secrete neurotransmitters-is filled with tens of thousands of bubble-like vesicles. The vesicles form by budding off from the cell's golgi apparatus, an organelle found deep in the cell's cytoplasm.

Keyword: Hormones & Behavior
Link ID: 3551 - Posted: 03.13.2003

Exclusive from New Scientist Print Edition The world's first brain prosthesis - an artificial hippocampus - is about to be tested in California. Unlike devices like cochlear implants, which merely stimulate brain activity, this silicon chip implant will perform the same processes as the damaged part of the brain it is replacing. The prosthesis will first be tested on tissue from rats' brains, and then on live animals. If all goes well, it will then be tested as a way to help people who have suffered brain damage due to stroke, epilepsy or Alzheimer's disease. Any device that mimics the brain clearly raises ethical issues. The brain not only affects memory, but your mood, awareness and consciousness - parts of your fundamental identity, says ethicist Joel Anderson at Washington University in St Louis, Missouri. © Copyright Reed Business Information Ltd.

Keyword: Robotics; Learning & Memory
Link ID: 3550 - Posted: 06.24.2010

Exclusive from New Scientist Print Edition Using gene therapy to switch off genes instead of adding new ones could slow down or prevent the fatal brain disorder Huntington's disease. The method, which exploits a mechanism called RNA interference, might also help treat a wide range of other inherited diseases. "When I first heard of this work, it just took my breath away," says Nancy Wexler of Columbia University Medical School, who is president of the Hereditary Disease Foundation in New York. Though the gene-silencing technique has yet to be tried in people, she says it is the most promising potential treatment so far for Huntington's. It involves a natural defence mechanism against viruses, in which short pieces of double-stranded RNA (short interfering RNAs, or siRNAs) trigger the degradation of any other RNA in the cell with a matching sequence. If an siRNA is chosen to match the RNA copied from a particular gene, it will stop production of the protein the gene codes for (see graphic). © Copyright Reed Business Information Ltd.

Keyword: Huntingtons
Link ID: 3549 - Posted: 06.24.2010

- A University of Alberta professor of psychology has learned men tend to overestimate the number of sexual partners they've had, and he's come up with some interesting theories explain why they do this. Psychology professor Dr. Norman Brown said while some people might conclude this happens because "men are pigs," there is in fact, important information to be gathered from his survey of approximately 1,100 Albertans, who were asked to recall how many sexual partners they had had during their lives. "Some would say men overestimate the number of partners they have had because they are pigs and like to boast and brag about their conquests," Brown said.

Keyword: Sexual Behavior
Link ID: 3548 - Posted: 03.13.2003

Cocaine and amphetamine drug users struggle with the residual effects for up to a year after going cold turkey, research suggests. Previous studies have shown that former cocaine-users show impaired concentration, memory and learning skills up to six months after kicking the habit. But new research has found that the effects last for up to twice as long. Scientists from Massachusetts General Hospital in Boston studied 50 sets of twins, in which one had previously used cocaine or amphetamines, and the other had not. They found that people who had used drugs showed diminished concentration and motor skills in comparison with their sibling a year after quitting. (C) BBC

Keyword: Drug Abuse
Link ID: 3547 - Posted: 03.12.2003