Jordan Lite Men have more willpower than women when it comes to resisting food, a small new study suggests. "We didn’t expect such striking differences between males and females," study co-author Nora Volkow, director of the National Institute on Drug Abuse, tells ScientificAmerican.com. "Men were able to inhibit their desire for food . . . and women weren’t able to do so." Scientists had 13 women and 10 men who had fasted overnight look at, smell and taste – but not dig into — goodies like pizza, burgers and cake. They then told the subjects to practice "cognitive inhibition" (read: to try to convince themselves they weren't really hungry) and measured their brain activity using positron emission tomography (PET) scanning. (PET scans measure increases in blood flow linked to brain activity.) Both sexes reported they felt less hungry when they were trying not to be, according to results published in this week’s Proceedings of the National Academy of Sciences. But the scans suggested that only the guys were able to control their desire to eat. On average, the men showed less activity in the limbic system (the brain’s emotional center that controls the drive to eat) when told to inhibit their craving for food than they did when they weren't told to control their hunger. There was no difference, however, in the women's brain activity. © 1996-2009 Scientific American Inc.

Keyword: Obesity; Sexual Behavior
Link ID: 12472 - Posted: 06.24.2010

By Richard Black A synthetic "chemical sex smell" could help rid North America's Great Lakes of a devastating pest, scientists say. US researchers deployed a laboratory version of a male sea lamprey pheromone to trick ovulating females into swimming upstream into traps. The sea lamprey, sometimes dubbed the "vampire fish", has parasitised native species of the Great Lakes since its accidental introduction in the 1800s. The work is reported in Proceedings of the National Academy of Sciences. The Great Lakes on the US-Canada border support recreational fishing worth billions of dollars a year, which the lampreys would wreck but for a control programme costing about £20m annually. This is thought to be the first time that pheromones have been shown to be the basis of a possible way of controlling animal pests other than insects. "There's been extensive study of pheromones in animals and even in humans," said lead researcher Weiming Li from Michigan State University in East Lansing, US. "But most researchers have presumed that as animals get more complex, their behaviour is regulated in a more complex way, not by just one pheromone," he told BBC News. Professor Li's team released the synthetic version of a lamprey hormone from a trap placed in a stream where lampreys come to breed. Females scenting it would swim vigorously upstream until they found the source, some becoming trapped in the process. The sea lamprey's natural life cycle takes it from birth in a stream to adulthood in the ocean, where it gains its vampirical appellation. Circular jaws lock on to another, larger fish, and a sharp tongue carves through its scales. From then on the lamprey feeds on the blood and body fluids of its temporary host, often killing it in the process. (C)BBC

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 12471 - Posted: 01.20.2009

People who socialize and are more laid back may be less likely to develop dementia, a new study suggests. In Tuesday's issue of the medical journal Neurology, Swedish researchers said people who were not socially active but calm and relaxed had a 50 per cent lower risk of developing dementia compared with people who were isolated and prone to distress. "In the past, studies have shown that chronic distress can affect parts of the brain, such as the hippocampus, possibly leading to dementia," said Hui-Xin Wang, of the Karolinska Institute in Sweden, who led the study. "But our findings suggest that having a calm and outgoing personality in combination with a socially active lifestyle may decrease the risk of developing dementia even further." The study involved 506 older people who did not have dementia when the study began. Participants were given questionnaires to identify personal traits and lifestyles, such as the richness of their social networks. After an average of six years, 144 subjects developed dementia. The dementia risk was also found to be 50 per cent lower among people who were outgoing and calm compared with those prone to distress or a high degree of neuroticism, the researchers said. © CBC 2009

Keyword: Alzheimers; Stress
Link ID: 12470 - Posted: 06.24.2010

By JANE E. BRODY Rochelle and Ian Yankwitt were thrilled when their son, Casey, was born seven years ago, 19 months after the birth of their daughter. But their delight was short-lived. At 7 months, this otherwise happy infant failed to respond to his name or any attempt to engage him with words, his mother recalled in an interview. “I thought he was deaf,” Ms. Yankwitt said, but tests showed nothing wrong with his hearing. Instead, at 14 months, Casey received a diagnosis of autism. His parents, both lawyers, wasted no time in setting up early intervention treatments — speech and occupational therapy and special education — as provided by New York State for developmentally disabled children. Ms. Yankwitt, who described Casey as “pretty seriously affected,” left her job to coordinate his endless rounds of treatment. If not for speech therapy five or more days a week for six years, Ms. Yankwitt is convinced Casey would not have the limited language skills he now has, which enable him to speak in short sentences, make his needs known and share things that excite him. But, she added, “there is no mistaking Casey for a normal child. He is in constant motion, flaps his arms, is easily frustrated and makes strange noises.” Ms. Yankwitt read many books and articles by parents claiming that this, that or the other treatment had cured their child’s autism, all anecdotal and based on theories and therapies unproved by scientific study. Copyright 2009 The New York Times Company

Keyword: Autism
Link ID: 12469 - Posted: 06.24.2010

By Carey Goldberg You're sitting at a dull meeting and your attention drifts. You're waiting in a check-out line, thinking of nothing in particular. You're lying in bed, having just turned off the television. At such times, your conscious mind is on "idle," but your brain is not. In such situations, the brain's "default system" takes over, a pattern of spontaneous activity that is fast becoming one of the hottest areas in neuroscience research, one that may cast light on mental illness. Yesterday, researchers from the Massachusetts Institute of Technology, Harvard, and elsewhere reported that the brain's default functions look strikingly hyperactive in people with schizophrenia and their relatives. And the more overactive the default system is, they found, the worse the symptoms tend to be. The findings are so strong that they raise hopes that brain scans of the default network could be used to diagnose schizophrenia before its symptoms appear, or predict how patients will respond to various treatments, researchers John Gabrieli and Susan Whitfield-Gabrieli said. "The really exciting thing is that, probably in a year or two, for many, many diseases we'll have a huge amount of evidence about what the situation is in that disease for the default system," said Gabrieli, a professor at MIT's McGovern Institute for Brain Research. © 2009 NY Times Co

Keyword: Schizophrenia; Attention
Link ID: 12468 - Posted: 06.24.2010

By LAURAN NEERGAARD WASHINGTON -- Space shuttle science may soon come to an eye doctor near you: Researchers are using a NASA gadget to finally tell if a cataract is brewing before someone's vision clouds over. It's a story of shot-in-the-dark science that paid off with a noninvasive test that tells when eyes are losing the natural compound that keeps cataracts at bay. That brings the potential to fight the world's leading cause of vision loss. Knowing their eyes are vulnerable could spur people to take common-sense steps to reduce that risk, like avoiding cigarette smoke, wearing sunglasses and improving diet. More intriguing, the device allows easier testing of whether certain medications might prevent or slow cataract formation. Studies involving astronauts _ whose space flights put them at extra risk _ and civilians could begin later this year. Don't call the eye clinic yet: The government has only a few prototypes of the device and no commercial manufacturer lined up. But already, doctors at Baltimore's Johns Hopkins University have begun experimental use to see how the exam might fit into the care of a variety of eye patients. "It's like an early alarm system," says Dr. Manuel Datiles III of the National Eye Institute, who led a study of 235 people that found the laser light technique can work. © 2009 The Associated Press

Keyword: Vision
Link ID: 12467 - Posted: 06.24.2010

by Andy Coghlan A UK company has received the go-ahead to start the world's first trial using stem cells to repair brain damage in stroke victims. ReNeuron, based in Guildford, hopes to start the trials within the next six months on 12 patients. Although six children with a rare, inherited brain condition called Batten's disease were treated with stem cells in 2006, the newly approved trial will be the first to treat a common killer. "We're absolutely delighted," says John Sinden, the company's chief scientific officer. "It's a milestone internationally, and sets the road map for what you have to do to get a stem-cell therapy into the clinic." Stroke victims will receive injections of neural stem cells through holes drilled into the skull to allow access to the worst-affected regions of their brains with a fine syringe. "Ultimately, we hope these cells will be able to differentiate into brain tissue, neurons and supporting tissue, and will re-institute connections lost through the stroke," says Keith Muir, a neurologist at the Southern General Hospital in Glasgow, where he is principle investigator for the trial. "It may be that the cells themselves, or something they produce, will help to trigger repairs." © Copyright Reed Business Information Ltd

Keyword: Stroke; Stem Cells
Link ID: 12466 - Posted: 06.24.2010

WASHINGTON - Faced with their favorite foods, women are less able than men to suppress their hunger, a discovery that may help explain the higher obesity rate for females, a new study suggests. Researchers trying to understand the brain's mechanisms for controlling food intake were surprised at the difference between the sexes in brain response. Gene-Jack Wang of Brookhaven National Laboratory and his colleagues were trying to figure out why some people overeat and gain weight and others don't. They performed brain scans on 13 women and 10 men, who had fasted overnight, to determine how their brains responded to the sight of their favorite foods. They report their findings in today's Proceedings of the National Academy of Sciences. "There is something going on in the female," Wang said in a telephone interview, "the signal is so much different." In the study, participants were quizzed about their favorite foods. Then they were asked to fast overnight. The next day they underwent brain scans while being presented with their favorite foods. In addition, they used a technique called cognitive inhibition to suppress thoughts of hunger. © Copyright 2009 Globe Newspaper Company.

Keyword: Obesity; Sexual Behavior
Link ID: 12465 - Posted: 06.24.2010

By RICHARD A. FRIEDMAN, M.D. As everyone knows, sex feels good. Or does it? In recent years, I’ve come across several patients for whom sex is not just unpleasurable; it actually seems to cause harm. One patient, a young man in his mid-20s, described it this way: “After sex, I feel literally achy and depressed for about a day.” Otherwise, he had a clean bill of health, both medical and psychiatric: well adjusted, hard-working, lots of friends and a close-knit family. Believe me, I could have cooked up an explanation very easily. He had hidden conflicts about sex, or he had ambivalent feelings about his partner. Who doesn’t? But search as I could for a good explanation, I could find none. Though his symptoms and distress were quite real, I told him he did not have a major psychiatric problem that required treatment. He was clearly disappointed leaving my office. I didn’t think much about his case until some time later, when I met another patient with a similar complaint. She was a 32-year-old woman who experienced a four- to six-hour period of intense depression and irritability after an orgasm, either alone or with a partner. It was so unpleasant that she was starting to avoid sex. Recently, a psychoanalyst colleague — a man known for his skill in uncovering psychopathology — called me about yet another case. He was puzzled about a 24-year-old man whom he viewed as psychiatrically healthy except for intense depression that lasted for several hours after sex. Copyright 2009 The New York Times Company

Keyword: Sexual Behavior; Depression
Link ID: 12464 - Posted: 06.24.2010

Mark Easton A year ago, the late, great John Mortimer announced to the world that, at the age of 84, he was going to start smoking. "I'm not particularly keen on smoking", he confessed. "I used to smoke and then I gave it up, partly because I don't like dirty ashtrays. But I forced myself to take it up again when the government said it would ban smoking in public places" . Politicians struggle to change our behaviour. The more they urge us to go out and shop for Britain, the more we are likely to squirrel our money under the mattress. If government insists that we eat our greens or that we wear helmets on motorbikes, some will delight in devouring doughnuts as they zip about on a scooter sporting a sombrero. Distrust of and disdain for authority explain the attitude of many to those who Mortimer described as the "busy control freaks". People don't like being bossed about. Nevertheless, making society function well does require control. We tend to expect government to do more than make the trains run on time and keep the drains clear. For instance, many think it is the job of politicians to sort out the drugs problem. Drugs present a particular conundrum, however. Passing legislation (lots of it) is said to have had virtually no effect other than to criminalise millions. You may recall last summer's post in which I quoted a report from the UK Drugs Policy Commission saying that "law enforcement efforts have had little adverse effect on the availability of illicit drugs in the UK". (C)BBC

Keyword: Drug Abuse
Link ID: 12463 - Posted: 01.19.2009

By Carey Goldberg In the world of therapy, Dr. Aaron T. Beck is a rock star. Considered the father of cognitive behavioral therapy, a form of psychological treatment that has swept the country in recent decades, he has been so famous for so long that some are surprised to find out that he is still, at 87, hard at work. Beck has recently come out with a new, overarching theory of depression, the mood darkness that in any given year afflicts an estimated 5 percent of Americans (and probably a higher percentage this year). More than a generation ago, Beck helped overturn the classical idea that depression was "anger turned inward," a form of self-punishment. Instead, back then he put forth a cognitive model of depression - that it is a problem of negative bias and habits of thought. Any failure means "I am a loser." A rejection means "Nobody loves me." Now, he has updated his cognitive model with the latest advances in brain science and genetics, and published it in the American Journal of Psychiatry. Beck, a professor of psychiatry at the University of Pennsylvania, cautions that much of the research he cites is still preliminary. But he sketches out a coherent overview of converging psychology and biology that goes roughly like this: Begin with genes. Beck and others used to speculate about a "blue gene." Researchers are now beginning to identify specific genes that could make the brain "hyperreactive to negative experiences," leading to depression, he writes. © 2009 NY Times Co.

Keyword: Depression
Link ID: 12462 - Posted: 06.24.2010

By Colin Nickerson Men are red, women are green, the nose may be key to "reading" a face, and ordinary eyebrows may be what makes a face recognizable, rather than, say, provocatively bee-stung lips or baby blues. Those insights into how we "see" faces are part of the growing field of facial recognition, one of the hottest realms in psychology and neural science. "It's very controversial: How do we see a face?" said Pawan Sinha, professor of vision and computational neuroscience at the Massachusetts Institute of Technology. Among the fiercely debated topics, he said, "is whether we learn to recognize faces or whether we come prewired with dedicated brainware for recognizing faces. The disagreement is deep - and rather sharp." The focus on faces at universities and other research centers is far from purely academic. In the age of terrorism, police and intelligence agencies are clamoring for new technologies that can scan and accurately identify faces - winnow a "wanted" individual from the anonymous airport crowd, or a terrorist scoping out public buildings. "Understanding how the brain works is the greatest mystery facing us in this century," said Garrison W. Cottrell, professor of computer science at the University of California in San Diego's Jacobs School of Engineering. "And facial recognition is among the greatest challenges to understanding the brain." In pursuit of answers, psychologists and brain scientists have come up with some unexpected data. © 2009 NY Times Co

Keyword: Emotions
Link ID: 12461 - Posted: 06.24.2010

By Frances Stead Sellers Focused though the world is on the youthful athleticism of the 47-year-old who will take the oath of office tomorrow, it's tempting to ask what impact his new job will have on President-elect Barack Obama over his four -- or eight -- years in office. The battle lines of two or more wars may by then have furrowed his brow; a sagging economy put bags under his eyes; and as-yet-untold worries stolen the spring from his jump shot. That's unless another trait, the calm with which Obama apparently responds to stress, allows him to transcend the unique demands of leading the free world. If looks are anything to go by -- and science suggests they may be -- the cares of the world weigh heavily on our leaders. Witness the graying of Bill Clinton and the wizening of George W. Bush. Presidents undergo a process of accelerated aging, according to Michael Roizen, who has accumulated facts and figures on presidential health dating back to the 1920s and speculates that "presidents get two years older for every year they're in office." If Roizen's right, eight years from now Obama may look more 63 than 55, more Clarence Thomas than Denzel Washington. There's no single theory of aging, or senescence, to explain why some people age more quickly than others. Most agree, though, that our bodies reach their peak in our mid-20s, and it's almost all downhill from there -- and slow going, given that life expectancy in the United States now extends about a decade beyond the proverbial three score years and 10. © 2009 The Washington Post Company

Keyword: Stress; Neuroimmunology
Link ID: 12460 - Posted: 06.24.2010

By PAM BELLUCK Even before his son was born, Pawan Sinha saw unique potential. At a birthing class, Dr. Sinha, a neuroscience professor at the Massachusetts Institute of Technology, stunned everyone, including his wife, by saying he was excited about the baby’s birth “because I really want to study him and do experiments with him.” He did, too, strapping a camera on baby Darius’s head, recording what he looked at. Dr. Sinha is among a new crop of scientists using their children as research subjects. Other researchers have studied their own children in the past, but sophisticated technology allows modern-day scientists to collect new and more detailed data. The scientists also say that studying their children allows for more in-depth research and that the children make reliable participants in an era of scarce research financing. “You need subjects, and they’re hard to get,” said Deborah Linebarger, a developmental psychologist who directs the Children’s Media Lab at the University of Pennsylvania, who has involved her four children in her studies of the effect of media on children. Arthur Toga, a neurology professor at the medical school at the University of California, Los Angeles, studying brain change, scanned his three children’s brains using magnetic resonance imaging. Copyright 2009 The New York Times Company

Keyword: Development of the Brain
Link ID: 12459 - Posted: 06.24.2010

By Bruce Bower People diagnosed with the mental ailment known as borderline personality disorder hemorrhage emotion. Real or perceived rejections, losses or even minor slights trigger depression and other volatile reactions that can lead to suicide. New brain-imaging research suggests that in people with borderline personality disorder, specific neural circuits foster extreme emotional oversensitivity and an inability to conceive of other people as having both positive and negative qualities. Psychiatrist Harold Koenigsberg of Mount Sinai School of Medicine in New York City described his team’s results January 17 in New York City at the winter meeting of the American Psychoanalytic Association. “I suspect that in social situations, people with this disorder activate the brain in unique ways,” Koenigsberg says. Koenigsberg’s findings unveil brain networks that may underlie the “faulty brakes” that borderline personality patients attempt to apply to their emotional reactions, remarks psychiatrist John Oldham of Baylor College of Medicine in Houston. It’s not yet clear whether the types of brain activity observed in the new study also occur in any of a handful of other personality disorders, Oldham adds. Borderline personality disorder affects one in five psychiatric patients. It most frequently affects women, especially those who are also depressed, and men who also display violent and criminal tendencies classed as antisocial personality disorder. About one in 10 people with borderline personality disorder commit suicide. This condition is extremely difficult to treat, Koenigsberg notes. © Society for Science & the Public 2000 - 2009

Keyword: Emotions
Link ID: 12458 - Posted: 06.24.2010

By Tina Hesman Saey Tattoos on the skin can say a lot about person. On a deeper level, chemical tattoos on a person’s DNA are just as distinctive and individual — and say far more about a person’s life history. A pair of reports published online January 18 in Nature Genetics show just how important one type of DNA tattoo, called methylation, can be. Researchers at Johns Hopkins University report the unexpected finding that most DNA methylation — a chemical alteration that turns off genes — occurs most often near, but not precisely within, the DNA regions on which scientists have typically focused their studies. The other report, from researchers at the Universityof Toronto and collaborators, suggests that identical twins owe their similarity not only to having the same genetic make-up, but also to certain methylation patterns established in the fertilized egg. Methylation is just one of many epigenetic signals — chemical changes to DNA and its associated proteins — that modify gene activity without altering the genetic information in the genes. Methylation and other epigenetic signals help guide stem cells as they develop into other type of cells. Scientists have long suspected that mishandling methylation and other epigenetic flags could lead to cancer. The Johns Hopkins group has now shown that DNA methylation is more common at what they call “CpG island shores” instead of at the CpG islands that most researchers have been studying. CpG islands are short stretches of DNA rich in the bases cytosine and guanine, also known as C and G in the genetic alphabet. (Adenine (A) and thymine (T) are the other DNA bases.) CpG islands are located near the start site of genes and help control a gene’s activity. Planting a chemical flag called a methyl group on an island declares the gene off-limits, blocking activity. © Society for Science & the Public 2000 - 2009

Keyword: Genes & Behavior; Development of the Brain
Link ID: 12457 - Posted: 06.24.2010

A virtual "body double" system has been developed to help people regain movement after a stroke by highlighting the muscles they are using. Pioneered by Dutch researchers, the system displays an image of the person training and the force at which they are using their muscles on a screen. The Human Body Model is being tested at the Sheba Hospital in Tel Aviv, Israel, reports the New Scientist. It is the latest in a series of virtual reality physiotherapy treatments. The user must don a suit which has 47 reflective markers pointing to specific muscles. They then undertake exercise such as running or walking on a treadmill or pushing weights while infrared lights and cameras are used to track the markers. Sensors on the floor are also used to measure the force applied to the ground by the user's feet. This information is then fed into a computer and the results projected onto a screen. "It allows you to see the muscle groups you are using in real time, and even the forces they are creating, which are usually invisible," says Oshri Even-Zohar, who developed the system. But he conceded it could not show every muscle at work. "There is no tool in medical science that allows you to measure all the muscle forces in motion." (C)BBC

Keyword: Stroke; Movement Disorders
Link ID: 12456 - Posted: 01.17.2009

People who drink too much coffee could start seeing ghosts or hearing strange voices, UK research has suggested. People who drank more than seven cups of instant coffee a day were three times more likely to hallucinate than those who took just one, a study found. A Durham University team questioned 200 students about their caffeine intake, the journal Personality and Individual Differences reported. However, academics say the findings do not prove a "causal link". They also stress that experiencing hallucinations is not a definite sign of mental illness and that about 3% of people regularly hear voices. "This is the first step toward looking at the wider factors associated with hallucinations," said psychology PhD student Simon Jones, who led the study. He said previous research had suggested factors such as childhood trauma could be linked to hallucinations. When under stress, the body releases a hormone called cortisol which is produced in greater quantities after consuming caffeine. The extra cortisol boost could be what causes a person to hallucinate. Therefore, Mr James added, it made sense to examine the link between caffeine and mood. Besides coffee, sources such as tea, chocolate, "pep" pills and energy drinks contain caffeine. After asking the students about their typical intake, the research team assessed their susceptibility to hallucinatory experiences and stress levels. (C)BBC

Keyword: Drug Abuse
Link ID: 12455 - Posted: 01.17.2009

By Claudia Kalb Science is rich with happy flukes. Remember the story of penicillin? Alexander Fleming discovered the bacteria-destroying mold by accident when he left a culture dish uncovered in his lab in 1928. Eight decades later, here's another one: a Googlesoftware program called SketchUp, which was intended largely for architects and design professionals, has found a very unexpected and welcome fan base—children with autism. SketchUp is not only entertaining kids with autism spectrum disorders, it's providing them with skills that might one day help them as they age out of school and into the workforce. It all started when Google's Tom Wyman and Chris Cronin started getting enthusiastic calls and e-mails from architects who had children on the spectrum. Their kids, the parents reported, had discovered the software program and loved it. All they needed was their creativity and a computer mouse and they could design entire neighborhoods. It turns out that SketchUp, which was acquired by Google from a small Colorado-based startup in 2006, allows people with autism to express their ideas in a visual way—a welcome release for kids who have trouble communicating through speech or writing. "After the second or third call, you begin to think there may be something here," says Wyman. So he contacted his local chapter of the Autism Society of America (ASA) in Boulder. "What gives?" he asked. What gives is that many people with autism excel at visual thinking. Studies show they perform exceptionally well on the Block Design Task, part of a standard IQ test, which assesses an individual's ability to recreate a complicated red and white pattern using a set of red and white blocks. "They're able to mentally segment the design into its component parts so they can see where each block would go," says Ellen Winner, a professor of psychology at Boston College, something non-autistic kids have trouble doing. © 2009 Newsweek, Inc.

Keyword: Autism
Link ID: 12454 - Posted: 06.24.2010

It started when Levi Barron's right hand curled into a claw shortly after his 13th birthday. Always laid-back, he told his mom that he'd just learn to write with the other hand and not to worry. But the debilitating stiffness crept to his other hand, and soon the athletic hockey player was having trouble walking and even fell a few times. It took four doctors and a stint in hospital, paralyzed from the waist down and so dizzy he couldn't open his eyes without vomiting, for Levi to finally get a diagnosis of multiple sclerosis. "I remember just being so frightened and upset that I didn't know that kids got MS," says Karen Barron, Levi's mom. Once thought of as a young adult disease striking people in their 20s or 30s, it is increasingly being recognized that multiple sclerosis can actually emerge much earlier, says Jon Temme, vice-president of client services and research for the Multiple Sclerosis Society of Canada. "Certainly the likelihood of a child being diagnosed accurately is much greater now than it would have been a decade ago." © CBC 2009

Keyword: Multiple Sclerosis; Development of the Brain
Link ID: 12453 - Posted: 06.24.2010