By LAURA BEIL Witness testimony has been the gold standard of the criminal justice system, revered in courtrooms and crime dramas as the evidence that clinches a case. Yet scientists have long cautioned that the brain is not a filing cabinet, storing memories in a way that they can be pulled out, consulted and returned intact. Memory is not so much a record of the past as a rough sketch that can be modified even by the simple act of telling the story. For scientists, memory has been on trial for decades, and courts and public opinion are only now catching up with the verdict. It has come as little surprise to researchers that about 75 percent of DNA-based exonerations have come in cases where witnesses got it wrong. This month, the Supreme Court heard its first oral arguments in more than three decades that question the validity of using witness testimony, in a case involving a New Hampshire man convicted of theft, accused by a woman who saw him from a distance in the dead of night. And in August the New Jersey Supreme Court set new rules to cope with failings in witness accounts, during an appeal by a man picked from a photo lineup, and convicted of manslaughter and weapons possession in a 2003 fatal shooting. Rather than the centerpiece of prosecution, witness testimony should be viewed more like trace evidence, scientists say, with the same fragility and vulnerability to contamination. © 2011 The New York Times Company

Keyword: Learning & Memory
Link ID: 16088 - Posted: 11.29.2011

By CARL ZIMMER CAMBRIDGE, Mass. — Steven Pinker was a 15-year-old anarchist. He didn’t think people needed a police force to keep the peace. Governments caused the very problems they were supposed to solve. Besides, it was 1969, said Dr. Pinker, who is now a 57-year-old psychologist at Harvard. “If you weren’t an anarchist,” he said, “you couldn’t get a date.” At the dinner table, he argued with his parents about human nature. “They said, ‘What would happen if there were no police?’ ” he recalled. “I said: ‘What would we do? Would we rob banks? Of course not. Police make no difference.’ ” This was in Montreal, “a city that prided itself on civility and low rates of crime,” he said. Then, on Oct. 17, 1969, police officers and firefighters went on strike, and he had a chance to test his first hypothesis about human nature. “All hell broke loose,” Dr. Pinker recalled. “Within a few hours there was looting. There were riots. There was arson. There were two murders. And this was in the morning that they called the strike.” The ’60s changed the lives of many people and, in Dr. Pinker’s case, left him deeply curious about how humans work. That curiosity turned into a career as a leading expert on language, and then as a leading advocate of evolutionary psychology. In a series of best-selling books, he has argued that our mental faculties — from emotions to decision-making to visual cognition — were forged by natural selection. © 2011 The New York Times Company

Keyword: Aggression
Link ID: 16087 - Posted: 11.29.2011

A new report shows that female Grade 8 students are outperforming their male counterparts in Canada on reading and science, with no discernable difference between the two genders in math skills. The report, released Monday, outlines the results of the 2010 Pan-Canadian Assessment Program (PCAP) from the Council of Ministers of Education in Canada. It's based on test results from 32,000 Grade 8 students from more than 1,600 schools across the country, providing a national report card. Girls scored better than boys in both science and reading, lending credence to the view that boys need a push in several subjects. Break-down by province Students in Quebec and Ontario scored above the national average on math. They scored near the national average in Alberta, and below the average in all other provinces and territories tested. When it comes to science, students in Alberta and Ontario scored above the national average. They scored near the national average in British Columbia and Prince Edward Island, and below the average in all other provinces and territories tested. On the reading portion, students in Ontario and Alberta scored above the national average. They scored near the national average in British Columbia, and below the average in all other provinces and territories tested. © CBC 2011

Keyword: Sexual Behavior
Link ID: 16086 - Posted: 11.29.2011

Cells taken from people with a rare syndrome linked to autism could help explain the origins of the condition, scientists suggest. The Stanford University team turned skin cells from people with "Timothy syndrome" into fully-fledged brain cells. The abnormal activity found in these cells could be partially corrected using an experimental drug, Nature Medicine reports. UK researchers warned the findings might not apply to everyone with autism. Compared with the hundreds of thousands of people worldwide thought to show characteristics of autism, "Timothy syndrome" is vanishingly rare, affecting an estimated 20 people across the planet. People who have the syndrome frequently display autistic behaviour, such as problems with social development and communication. Because it is caused by a single gene defect rather than a combination of small genetic flaws, each making a tiny contribution, it presents a useful target for scientists looking to examine what goes wrong in the developing brain of a child with autism. The US researchers used a technique developed recently to generate brain cells called neurons from only a sample of the patient's skin. BBC © 2011

Keyword: Autism; Genes & Behavior
Link ID: 16085 - Posted: 11.29.2011

by Greg Miller Immature neurons transplanted into the brains of obesity-prone mice can prevent the animals from becoming so fat, according to a new study. The researchers caution that their experiment was never intended as a step toward treating obesity in humans, but they say it provides an important proof of principle that transplanted fetal cells can integrate themselves into an abnormal neural circuit and help restore its function. Other researchers say the work highlights both the promise and the challenges of developing cell therapies for complex brain disorders. The road to fetal or stem cell therapies for the nervous system has been rocky. Despite early promise, recent trials of fetal cell transplants for Parkinson's disease have yielded disappointing results, for example, and last week the California biotechnology company Geron pulled the plug on a closely watched trial of a stem cell therapy for spinal injury. It also announced that, for financial reasons, it would abandon further stem cell work. Yet basic neuroscience research has been more encouraging. In the past decade, scientists overturned century-old dogma by showing that some parts of the human brain produce new neurons throughout life. There is evidence that these new neurons get wired into existing neural circuits and may help maintain or enhance brain function, suggesting that transplanted cells may be able to do the same. In the new study, reported online today in Science, Harvard University neuroscientist Jeffrey Macklis and colleagues investigated whether fetal neurons transplanted into a part of the mouse brain that does not normally produce new neurons of its own could repair an abnormal neural circuit. © 2010 American Association for the Advancement of Science.

Keyword: Obesity
Link ID: 16084 - Posted: 11.26.2011

By Nathan Seppa By screening people who have died with full-body computed tomography or magnetic resonance imaging, doctors can often determine the cause of death without an autopsy, British researchers report November 22 in the Lancet. Further combining a CT scan with a quick heart test might result in a solid determination of cause of death in up to half of cases referred for autopsy, says study coauthor Ian Roberts, a pathologist at the University of Oxford. Autopsies are invasive and sometimes inconclusive, and some people object to the procedure on cultural or religions grounds. The new data suggest that imaging may provide an alternative in some cases, adding to post-mortem accuracy and easing the burden of grieving survivors, says Roberts. Whether imaging would save money is unknown, he says. At their essence, autopsies have changed little in the past century but remain the gold standard post-mortem exam. In recent years, some coroners and medical examiners have considered the use of medical imaging with MRI or CT scans, but few labs or hospitals have adopted the technologies because little research data existed to document their utility in this setting. For the new study, Roberts and his colleagues examined 182 deceased people whose cause of death wasn’t known. All underwent a CT scan and MRI. Radiologists analyzed those results separately and combined, arriving at a cause of death from each set of images. The radiologists also ranked how much confidence they had in each cause-of-death conclusion — definite, probable, possible or uncertain. Pathologists then performed autopsies on all of the bodies. © Society for Science & the Public 2000 - 2011

Keyword: Brain imaging
Link ID: 16083 - Posted: 11.26.2011

By Tina Hesman Saey Scientists have deciphered the complete genetic instruction book of monarch butterflies. It is the first butterfly genome completed and the first of a long-distance migrating insect. Within the butterfly’s genetic archive, neurobiologist Steven Reppert of the University of Massachusetts Medical School in Worcester and his colleagues found genes that may help the insects sense the position of the sun and navigate to fir trees in Mexico, where they spend the winter. Reporting in the Nov. 23 Cell, the team also notes that monarchs make more of certain small genetic molecules, called microRNAs, that are involved in building muscle, regulating temperature sensitivity and storing fat when in migration mode. The 273 million DNA units that make up the monarch genome also include a complete set of genes for producing juvenile hormone, which summer butterflies use to kick-start reproduction. Migrating male monarchs use different strategies than females do to turn off the hormone, the team discovered. Monarchs have genes similar to ones that silk moths use to sense mating chemicals called pheromones. Those genes may aid social interactions between monarchs in their wintering grounds, Reppert says. The scientists also unearthed from the genome a gear previously thought to be missing from the butterfly’s daily, or circadian, clock, which helps the monarchs maintain a straight path. © Society for Science & the Public 2000 - 2011

Keyword: Animal Migration; Biological Rhythms
Link ID: 16082 - Posted: 11.26.2011

By BENEDICT CAREY ATHENS, Ohio — She was gone for good, and no amount of meditation could resolve the grief, even out here in the deep quiet of the woods. “When I began to see the delusions in the context of things that were happening in my real life, they finally made some sense," Milt Greek said. "And understanding the story of my psychosis helped me see what I needed to stay well.” Milt Greek pushed to his feet. It was Mother’s Day 2006, not long after his mother’s funeral, and he headed back home knowing that he needed help. A change in the medication for his schizophrenia, for sure. A change in focus, too; time with his family, to forget himself. And, oh yes, he had to act on an urge expressed in his psychotic delusions: to save the world. So after cleaning the yard around his house — a big job, a gift to his wife — in the coming days he sat down and wrote a letter to the editor of the local newspaper, supporting a noise-pollution ordinance. Small things, maybe, but Mr. Greek has learned to live with his diagnosis in part by understanding and acting on its underlying messages, and along the way has built something exceptional: a full life, complete with a family and a career. He is one of a small number of successful people with a severe psychiatric diagnosis who have chosen to tell their story publicly. In doing so, they are contributing to a deeper understanding of mental illness — and setting an example that can help others recover. © 2011 The New York Times Company

Keyword: Schizophrenia
Link ID: 16081 - Posted: 11.26.2011

By Emily Main Redheads may be stereotyped as having fiery tempers, but those tempers may turn to fear and loathing when they walk through the door of a dentist’s office, according to research published in the Journal of the American Dental Association. The study shows that people with a specific gene that often occurs in redheads tend to experience heightened anxiety when they pop in for a regular teeth cleaning. The details: The study’s authors recruited 144 people for the study, 67 of whom were natural redheads, and 77 who were dark-haired. The participants answered survey questions about any fears or anxieties related to dental visits, and the researchers took blood samples that they later tested for specific gene variants common in people with red hair. People with one specific gene, MC1R, were more than twice as likely to report that they avoided dental appointments because of fear and anxiety than people without that gene. Of the 85 people in the study with MC1R, 65 were redheads. What it means: It’s possible, say the researchers, that redheads with the gene in question tend to be resistant to certain pain medications. This could mean redheads are more prone than most to experience a difficult dental visit, affecting their expectations about future appointments. Redheaded or not, most of us have probably had reservations about going to the dentist at some point in our lives. But don’t let fear prevent you from getting your twice-yearly checkups. Recent studies have linked periodontal disease to a wide variety of chronic diseases, including heart disease, strokes, and type 2 diabetes. If it’s been a while since you’ve visited the dentist, you might be pleasantly surprised at the experience. “Things don’t hurt anymore,” says Kimberly A. Harms, DDS, consumer advisor for the American Dental Association. Anesthesia has become much more effective, she says, and patients don’t have to experience the pain that used to be common in dental procedures. © 2011 msnbc.com

Keyword: Pain & Touch; Genes & Behavior
Link ID: 16080 - Posted: 11.26.2011

Ewen Callaway Put two young mice in a cage and they will politely sniff one another. Two rat pups, by contrast, quickly become a blur of fur as they begin some “really rough-and-tumble play”, says Richard Paylor, a neuroscientist at Baylor College of Medicine in Houston, Texas. Such behaviour makes rats an ideal animal model for studying autism spectrum disorder, given that children who have the disorder are often less interested in play than children without it. Paylor is one of the first scientists to use transgenic rats to study neurodevelopmental diseases such as autism, and presented his team’s work at the Society for Neuroscience meeting in Washington DC last week. Transgenic rats, Paylor and others say, are a better proxy than mice for the behavioural and cognitive problems experienced by people with autism. And because rats are a preferred model for the pharmaceutical industry, their use in basic research may speed new treatments. “I think they’re the future,” says Joseph Buxbaum, a neuroscientist at the Seaver Autism Center at Mount Sinai School of Medicine in New York. “I could name 20 high-complexity behavioural tests that you can do in a rat that nobody’s ever done in a mouse.” At the meeting, he debuted his lab’s own transgenic rat strain, which is missing a working copy of a gene called Shank3. People with this same mutation usually develop a neurodevelopmental condition, often autism. © 2011 Nature Publishing Group,

Keyword: Autism; Genes & Behavior
Link ID: 16079 - Posted: 11.26.2011

Sandrine Ceurstemont, New Scientist TV Feeling sleepy after your Thanksgiving dinner? You may have heard that turkey consumption is to blame since it contains a natural sedative called tryptophan. But now an animation produced by the American Chemical Society debunks this common myth and identifies what food in your feast is most likely responsible for your drowsiness. © Copyright Reed Business Information Ltd.

Keyword: Sleep
Link ID: 16078 - Posted: 11.26.2011

by Jessica Hamzelou BRAIN shrinkage in people with Alzheimer's disease can be reversed in some cases - by jolting the degenerating tissue with electrical impulses. Moreover, doing so reduces the cognitive decline associated with the disease. "In Alzheimer's disease it is known that the brain shrinks, particularly the hippocampus," says Andres Lozano at Toronto Western Hospital in Ontario, Canada. What's more, brain scans show that the temporal lobe, which contains the hippocampus, and another region called the posterior cingulate use less glucose than normal, suggesting they have shut down. Both regions play an important role in memory. To try to reverse these degenerative effects, Lozano and his team turned to deep brain stimulation - sending electrical impulses to the brain via implanted electrodes. The group inserted electrodes into the brains of six people who had been diagnosed with Alzheimer's at least a year earlier. They placed the electrodes next to the fornix - a bundle of neurons that carries signals to and from the hippocampus - and left them there, delivering tiny pulses of electricity 130 times per second. Follow-up tests a year later showed that the reduced use of glucose by the temporal lobe and posterior cingulate had been reversed in all six people (Annals of Neurology, DOI: 10.1002/ana.22089). © Copyright Reed Business Information Ltd.

Keyword: Alzheimers
Link ID: 16077 - Posted: 11.26.2011

By R. Douglas Fields WASHINGTON, D.C.—One of the most difficult tasks to teach Air Force pilots who guide unmanned attack drones is how to pick out targets in complex radar images. Pilot training is currently one of the biggest bottlenecks in deploying these new, deadly weapons. So Air Force researchers were delighted recently to learn that they could cut training time in half by delivering a mild electrical current (two milliamperes of direct current for 30 minutes) to pilot's brains during training sessions on video simulators. The current is delivered through EEG (electroencephalographic) electrodes placed on the scalp. Biomedical engineer Andy McKinley and colleagues at the Air Force Research Laboratory at Wright–Patterson Air Force Base, reported their finding on this so-called transcranial direct current stimulation (TDCS) here at the Society for Neuroscience annual meeting on November 13. "I don't know of anything that would be comparable," McKinley said, contrasting the cognitive boost of TDCS with, for example, caffeine or other stimulants that have been tested as enhancements to learning. TDCS not only accelerated learning, pilot accuracy was sustained in trials lasting up to 40 minutes. Typically accuracy in identifying threats declines steadily after 20 minutes. Beyond accelerating pilot training, TDCS could have many medical applications in the military and beyond by accelerating retraining and recovery after brain injury or disease. The question for the Air Force and others interested in transcranial stimulation is whether these findings will hold up over time or will land in the dustbin of pseudoscience. © 2011 Scientific American,

Keyword: Learning & Memory
Link ID: 16076 - Posted: 11.26.2011

by Chelsea Whyte Name an animal that is most active during the full moon, and even those of us untouched by the charms of the Twilight movies might think werewolf. Our subject today is no mythical beast, however. The Barau's petrel is one of a handful of tropical birds that uses the moon as a kind of alarm clock. During breeding season, the bird travels to mating sites on the aptly named Reunion Island off the shore of Madagascar to meet its mate. The monogamous birds synchronise their journeys using the full moon as a kind of Bat-Signal to indicate that it's time to mate. "First arrival at the colony is crucial in the mating system of colonial animals like seabirds," writes Patrick Pinet of the University of Réunion, France. It's not uncommon for birds to take cues from the intensity of sunlight or the length of the day to determine the seasons for migration and mating. Circadian clocks are influenced by melatonin secretions, which reflect the amount and intensity of daylight. But the Barau's petrel migrates longitudinally – that is, parallel to the equator – so there isn't much difference between the hours of sunrise and sunset in winter and summer. Still, the slight changes in daylight do affect the petrels. Daily and seasonal changes in melatonin secretion indicate time of day and the time of the year for these birds. But to migrate at the right time to ensure they meet their partners, they need something that varies more reliably. © Copyright Reed Business Information Ltd.

Keyword: Biological Rhythms; Sexual Behavior
Link ID: 16075 - Posted: 11.26.2011

Chelsea Whyte, contributor A 27-year-old woman has lost her place the London 2012 Paralympic Games in what appear to be the most unusual of circumstances: Monique van der Vorst, formerly paralysed from the waist down, has regained her ability to walk. Perhaps surprisingly, though, neuroscientists say her experience is not unprecedented. van der Vorst was a handcyclist with national and international titles to her name. She has now traded her handbike for a bicycle - and has just been given one of 11 spots on the Dutch women's professional cycling team, Rabobank, according to IoL News. When she was 13, van der Vorst lost the use of her right leg after routine ankle surgery damaged her nerves. She took up handcycling, but in 2008, while she was training for the Beijing Olympics, she was hit by a car. Her spinal cord was damaged, leaving her paralysed from the waist down, yet she still entered the Olympics later that year - and won two silver medals. Last year, she was involved in another accident, this time with a cyclist. The accident left her legs tingling, and after a spell in hospital and some rehabilitation, she was able to walk again. Although van der Vorst's recovery remain unexplained, that's largely because of the speed of her recovery, according to IoL News. In fact, regaining the use of paralysed limbs is more common than we realise, according to Geoff Raisman, a neurologist at University College London. © Copyright Reed Business Information Ltd.

Keyword: Regeneration
Link ID: 16074 - Posted: 11.26.2011

By Rick Nauert PhD Senior News Editor Researchers have learned that a psychopaths brain structure is significantly different from others. University of Wisconsin-Madison researchers discovered the variance studying images of prisoners’ brains. The results could help explain the callous and impulsive anti-social behavior exhibited by some psychopaths. The study showed that psychopaths have reduced connections between the ventromedial prefrontal cortex (vmPFC), the part of the brain responsible for sentiments such as empathy and guilt, and the amygdala, which reconciles fear and anxiety. Structural changes in the brain were confirmed using two different types of brain images. Diffusion tensor images (DTI) showed reduced structural integrity in the white matter fibers connecting the two areas, while a second type of image that maps brain activity, a functional magnetic resonance image (fMRI), showed less coordinated activity between the vmPFC and the amygdala. “This is the first study to show both structural and functional differences in the brains of people diagnosed with psychopathy,” says Michael Koenigs. “Those two structures in the brain, which are believed to regulate emotion and social behavior, seem to not be communicating as they should.” © 1992-2011 Psych Central

Keyword: Aggression; Brain imaging
Link ID: 16073 - Posted: 11.26.2011

By Katherine Harmon Weakening eyesight can be sharpened with lenses, and impaired hearing can be improved with aids. What about a failing sense of smell? Detecting and distinguishing the floral bouquet of fresh honey or the miasma of bad lunchmeat might not seem quite as critical for day-to-day existence as sight or hearing. But what the nose knows is clearly important for quality of life. Research has linked this diminution, which is common in people over the age of 60 and can be exacerbated by smoking and some diseases, to loss of appetite and even to depression. Now sufferers might not have to give in to an odorless future, according to a new study, published online Sunday in Nature Neuroscience. Researchers at the New York University Langone Medical Center have found that, with some simple training, over time lab rats could actually improve their brain’s ability to distinguish smells. Without any practice rats could tell when one scent—in a mélange of 10—had been switched for another. (Researchers figured this out by waiting until the rodents were thirsty, then training them to look for water in one of a selection of holes based on what odor combination they had detected.) But their powers of discrimination were not perfect. If a scent was missing from the mix, the rats did not seem to be able to discern it from a full 10-scent combination. Other rats, however, were trained to become extra-familiar with the different combinations through repeated exposures and rewards. “We made them connoisseurs,” co-author Donald Wilson, a professor of psychiatry at NYU Langone, said in a prepared statement. © 2011 Scientific American,

Keyword: Chemical Senses (Smell & Taste)
Link ID: 16072 - Posted: 11.22.2011

By Eric Niiler Pepper spray, also known as oleoresin capsicum or OC, is made from the same naturally-occurring chemical that makes chili peppers hot, but at concentrations much higher. Its effects include temporary blindness, coughing and skin irritation. To make the spray used by law enforcement officers and police to control crowds, manufacturers take a concentrated oil made from chili peppers and combine it with water, glycol (a chemical used in shaving creams and liquid soaps) and a propellent such as nitrogen, according to Bob Nance, vice president of operations at Security Equipment Corp.,which makes pepper spray and other irritants at its Fenton, Mo., headquarters under the Sabre brand name. "We get it in a red, oily viscous syrup,” Nance said. “It’s the same thing you will find in hot sauce, but in higher concentrations." Interest in pepper spray was piqued after a video of campus police spraying peaceful protesters at the University of California, Davis, made the rounds on the internet this weekend, the university suspended its police chief and two officers. The video shows an officer spraying protesters in the face as they are sitting on the ground. "It causes your eyes to shut and makes breathing difficult," Nance said. "It can cause coughing and choking, and a severe burning sensation on your face. But it’s temporary, usually it lasts from 30 to 45 minutes." © 2011 Discovery Communications, LLC.

Keyword: Pain & Touch
Link ID: 16071 - Posted: 11.22.2011

By Laura Sanders Most caffeine addicts would tell you that coffee sharpens the mind. It turns out that in rodents, a single dose of caffeine does indeed strengthen brain cell connections in an underappreciated part of the brain, scientists report online November 20 in Nature Neuroscience. A clearer idea of caffeine’s effect on the brain could allow scientists to take advantage of its stimulating effects and perhaps even alleviate some symptoms of brain disorders. “Caffeine is something people are very interested in,” says neuroscientist Susan Masino of Trinity College in Hartford, Conn., who was not involved in the study. So far, most of caffeine’s effects have been illuminated by studies using doses much higher than an average person’s morning cup of joe, says study coauthor Serena Dudek of the National Institute of Environmental Health Sciences in Research Triangle Park, N.C. Dudek and her team looked at the effects of smaller hits of caffeine on a small part of the hippocampus. In humans, this seahorse-shaped structure is buried deep in the brain behind the ears. After feeding rats the equivalent of two human cups of coffee (two milligrams of caffeine per kilogram of body weight), the team measured the strength of nerve cells’ electrical messages in slices of brain tissue. Nerve cells in this particular nook — a brain region called CA2 — got a major jolt from caffeine, showing a bigger burst of electrical activity when researchers stimulated the cells. Nerve cells in a neighboring part of the hippocampus didn’t show this sensitivity. © Society for Science & the Public 2000 - 2011

Keyword: Drug Abuse; Sleep
Link ID: 16070 - Posted: 11.22.2011

By SINDYA N. BHANOO Grapheme-color synesthesia is a peculiar neurological condition in which people involuntarily experience colors when thinking about letters, numbers or words. They might, for instance, always see the color green along with the number four, or blue with the letter A. Neuroscientists from the University of Oxford in England are trying to determine what exactly is different about the brains of those with this type of synesthesia. In a new study, they report that people with the condition experience heightened activity in the brain region associated with vision. The study appears in the journal Current Biology. The researchers stimulated their subjects’ visual cortex using a method called transcranial magnetic stimulation. Compared with normal subjects, people with the synesthesia required only one-third the stimulation to experience phosphenes, or transient flashes of light. “We all have different thresholds in the brain, and synesthetes have a lower threshold,” said the study’s lead author, Devin Blair Terhune, a neuroscientist at Oxford. © 2011 The New York Times Company

Keyword: Vision
Link ID: 16069 - Posted: 11.22.2011