They say you never escape high school. And for better or worse, science is lending some credibility to that old saw. Thanks to sophisticated imaging technology and a raft of longitudinal studies, we’re learning that the teen years are a period of crucial brain development subject to a host of environmental and genetic factors. This emerging research sheds light not only on why teenagers act they way they do, but how the experiences of adolescence—from rejection to binge drinking—can affect who we become as adults, how we handle stress, and the way we bond with others. One of the most important discoveries in this area of study, says Dr. Frances Jensen, a neuroscientist at Harvard, is that our brains are not finished maturing by adolescence, as was previously thought. Adolescent brains “are only about 80 percent of the way to maturity,” she said at the annual meeting of the Society for Neuroscience in November. It takes until the mid-20s, and possibly later, for a brain to become fully developed. An excess of gray matter (the stuff that does the processing) at the beginning of adolescence makes us particularly brilliant at learning—the reason we’re so good at picking up new languages starting in early childhood—but also particularly sensitive to the influences of our environment, both emotional and physical. Our brains’ processing centers haven’t been fully linked yet, particularly the parts responsible for helping to check our impulses and considering the long-term repercussions of our actions. “It’s like a brain that’s all revved up not knowing where it needs to go,” says Jensen. © 2010 Harman Newsweek LLC

Keyword: Development of the Brain; Emotions
Link ID: 14795 - Posted: 12.18.2010

By MALCOLM RITTER, NEW YORK – Meet SM, a 44-year-old woman who literally knows no fear. She's not afraid to handle snakes. She's not afraid of the "The Blair Witch Project," "The Shining," or "Arachnophobia." When she visited a haunted house, it was a monster who was afraid of her. SM isn't some cold-blooded psychopath or a hero with a tight rein on her emotions. She's an ordinary mother of three with a specific psychological impairment, the result of a very rare genetic disease that damaged a brain structure called the amygdala (uh-MIG'-duh-luh). Her case shows that the amygdala plays a key role in making people feel afraid in threatening situations, researchers say. Her life history also shows that living without fear can be dangerous, they said. A study of her fearlessness was published online Thursday in the journal Current Biology by University of Iowa researcher Justin Feinstein and colleagues. As is typical, the paper identifies her only as "SM." Feinstein declined to make SM available for an interview with The Associated Press, citing laboratory policy about confidentiality. An expert unconnected with the study cautioned against drawing conclusions about the amygdala, noting that her own work with a similarly brain-damaged woman found no such impairment. But another expert said the new finding made sense. © 2010 The Associated Press.

Keyword: Emotions
Link ID: 14794 - Posted: 12.18.2010

By Helen Briggs Fighter pilots may owe their ability to perform under pressure to the way their brains are wired-up, scans suggest. The study found differences in the white matter and connections of the brain's right hemisphere, compared with healthy volunteers who were not pilots. It is not clear whether pilots are born like that, or develop the differences as a result of their training. The research by University College London (UCL) is published in the Journal of Neuroscience. Royal Air Force fighter pilots are trained to fly at supersonic speeds at low altitude, requiring fine control with very little room for error. The discipline is considered to be at the limits of human cognitive performance, prompting doctors at UCL to study their brain function. The research team looked at how 11 front-line RAF Tornado fighter pilots performed in two standard visual cognitive tests to assess their powers of thought. Their test scores were compared with healthy people of the same age and sex who had no experience of piloting aircraft. The subjects were also given MRI scans to look at the structure of their brains. BBC © MMX

Keyword: Attention; Brain imaging
Link ID: 14793 - Posted: 12.16.2010

By Jason Palmer The free will that humans enjoy is similar to that exercised by animals as simple as flies, a scientist has said. The idea may simply require "free will" to be redefined, but tests show that animal behaviour is neither completely constrained nor completely free. The paper, in Proceedings of the Royal Society B, suggests animals always have a range of options available to them. "Choices" actually fit a complex probability but, at least in humans, are perceived as conscious decisions. The idea tackles one of history's great philosophical debates, and Bjoern Brembs of the Berlin Free University brings the latest thinking from neurobiology to bear on the question. What has been long established is that "deterministic behaviour" - the idea that an animal poked in just such a way will react with the same response every time - is not a complete description of behaviour. "Even the simple animals are not the predictable automatons that they are often portrayed to be," Dr Brembs told BBC News. However, the absence of determinism does not suggest completely random behaviour either. BBC © MMX

Keyword: Attention
Link ID: 14792 - Posted: 12.16.2010

By Jason Castro The voicemail rant. The overheard insult. The lonely moral slip when your chips were down. Despite their sting, these unkind memories eventually slacken their grip. We manage, move on, shrug it off, and go about the business of filling our heads with thoughts of a better tomorrow. But for war veterans and victims of violent crime, the persistence of traumatic memories can mean a life of disability. Even when emotional demons are quieted with therapy or drugs, they are prone to return. A whispered reminder in an unfamiliar setting is sometimes all it takes. Frustrated with these grim facts, scientists have been looking for biologically based therapies that may some day help troubled minds forget debilitating fears. The most recent of these studies, by Drs. Roger Clem and Richard Huganir at Johns Hopkins, gives a spectacularly detailed view of how fear is learned, and points out fear’s Achilles Heel. The very molecular machinery that implants fear in the brain may also hold the key to its undoing. We already understand a good deal about how specific fears come to be thanks to classical neuroscience experiments, many done by Joseph LeDoux and his colleagues at New York University. Fear lives in a small almond-shaped pair of brain structures, called the amgydalae, that control your body’s panic buttons. Each amygdala receives two basic kinds of inputs: streaming images from our senses, as well as incoming alerts conveying threats, danger, or pain. When one of these alert signals – say the pain of a shock or cut – is detected together with a sensory image (such as a particular face or the sound of a gunshot), neurons in the amygdala take notice. © 2010 Scientific American,

Keyword: Emotions; Learning & Memory
Link ID: 14791 - Posted: 12.16.2010

By Ferris Jabr Your brain is electric. Tiny impulses constantly race among billions of interconnected neurons, generating an electric field that surrounds the brain like an invisible cloud. A new study published online July 15 in Neuron suggests that the brain’s electric field is not a passive by-product of its neural activity, as scientists once thought. The field may actively help regulate how the brain functions, especially during deep sleep. Although scientists have long known that external sources of electricity (such as electroshock therapy) can alter brain function, this is the first direct evidence that the brain’s native electric field changes the way the brain behaves. In the study, Yale University neurobiologists David McCormick and Flavio Fröhlich surrounded a still-living slice of ferret brain tissue with an electric field that mimicked the field an intact ferret brain produces during slow-wave sleep. The applied field amplified and synchronized the existing neural activity in the brain slice. These results indicate that the electric field generated by the brain facilitates the same neural firing that created the field in the first place, just as the cloud of enthusiasm that envelops a cheering crowd at a sports stadium encourages the crowd to keep cheering. In other words, the brain’s electric field is not a by-product; it is a feedback loop. Although researchers knew that periods of highly synchronized neural activity (such as that of deep sleep) are crucial for maintaining normal brain function, exactly how these stable phases are coordinated—and why they go awry in dis­orders such as epilepsy—was never clear. The new study indicates scientists may find some answers in the surprisingly active role of the brain’s electric field. © 2010 Scientific American,

Keyword: Sleep
Link ID: 14790 - Posted: 12.16.2010

by Greg Miller Testimony on the brain activity of a convicted murderer may have saved him from the death penalty. Earlier this month, a jury in Miami rejected the death penalty and chose life in prison for Grady Nelson, who in 2005 stabbed his wife 61 times, killing her, and stabbed and raped her 11-year-old, mentally handicapped daughter. A report in The Miami Herald last weekend suggests that measurements of Nelson's brain activity may have influenced some members of the jury, who viewed the results as evidence of a brain injury that would partially explain his behavior. But some scientists are critical of the way this technology was used in the case. During the sentencing phase of the trial, the court heard testimony from Robert Thatcher, a neuroscientist and president of by Applied Neuroscience Inc. of St. Petersburg, Florida. Thatcher's company examined Nelson using a method called quantitative electroencephalography (QEEG). As in standard EEG, technicians place electrodes on the skull to record electrical activity in the brain. In QEEG, a computer program analyzes these recordings to locate regions of abnormal activity. In Nelson's case, there was an obvious abnormality in the left frontal lobe, Thatcher says. Thatcher also testified that Nelson exhibited "sharp waves" originating from this region. These large spikes in the EEG trace are typically seen in people with epilepsy. Grady is not epileptic, but he does have a history of at least three traumatic brain injuries, Thatcher said yesterday in an interview. © 2010 American Association for the Advancement of Science.

Keyword: Aggression; Epilepsy
Link ID: 14789 - Posted: 12.16.2010

by Virginia Morell As any dog owner knows, dogs pay close attention to each other's growls—and with good reason. A new study reveals that dogs can tell another canine's size simply by listening to its growl. The size information is so accurate that a dog hearing a growl can match the sound to a photograph of the growler—a complex cognitive talent previously seen only in primates. In a previous study, Péter Pongrácz, an ethologist at Eötvös Loránd University in Hungary, and colleagues showed that dogs use a specific growl ("this bone is mine") when guarding a tasty bone. The growl always causes a listening dog to stop in its tracks. In their new study, the scientists tested the responses of dogs seated next to their owners, so that the animals felt comfortable in the lab. Twenty-four of the 96 dogs were shown images of two dogs projected onto a screen in front of them (see picture). One image showed a small dog less than 52 centimeters tall; the other image was of the same dog but projected as being taller than 60 cm (a 30% increase in size). The other dogs were shown control images, either of large and small triangles or of the silhouettes of large and small cats. The researchers then played recorded food-guarding growls—from either a large or a small dog—on a speaker placed between the two projected images. The scientists filmed the dogs, recording where the canines looked as they listened to the growls. © 2010 American Association for the Advancement of Science.

Keyword: Aggression; Animal Communication
Link ID: 14788 - Posted: 12.16.2010

By PAM BELLUCK Congress has voted unanimously to create, for the first time, a national plan to combat Alzheimer’s disease with the same intensity as the attacks on AIDS and cancer. The bill, expected to be signed by President Obama, would establish a National Alzheimer’s Project within the Department of Health and Human Services, to coordinate the country’s approach to research, treatment and caregiving. Its goal, the legislation says, is to “accelerate the development of treatments that would prevent, halt or reverse the course of Alzheimer’s” and “improve the early diagnosis of Alzheimer’s disease and coordination of the care and treatment of citizens with Alzheimer’s.” The project would include an advisory council of representatives from agencies like the Centers for Disease Control and Prevention, the National Institutes of Health, the Department of Veterans Affairs, the Food and Drug Administration, the Indian Health Service and the Centers for Medicare and Medicaid Services. Scientific experts, health care providers and people caring for relatives with Alzheimer’s would also be included. “If you go to war, you have planning, planning, planning,” said Representative Christopher H. Smith, Republican of New Jersey, who co-sponsored the bill. “Well, this is a war on a dreaded disease. We need to bring all the disparate elements together for the greatest possible result.” Copyright 2010 The New York Times Company

Keyword: Alzheimers
Link ID: 14787 - Posted: 12.16.2010

By Laura Sanders Researchers are closer to understanding how a bong packed with leaves of Salvia divinorum gave Smiley Miley the giggles. Although shamans in Mexico have been chewing the leaves of the hardy mint relative for centuries (and without any prompting from an infamous YouTube video of Miley Cyrus smoking it), little is known about what the plant’s psychoactive substance, salvinorin A, actually does to humans — despite its increasing popularity as a recreational drug. A new study provides some data: The hallucinogen kicks off an unusually intense and short-lasting high, with no obvious ill effects, researchers report in an upcoming Drug and Alcohol Dependence paper. “This is a landmark paper because it’s the first paper in which authentic salvinorin A was administered to human volunteers under controlled conditions, and it was shown to be hallucinogenic,” says psychiatrist and pharmacologist Bryan Roth of the University of North Carolina at Chapel Hill, who was not involved in the research. “All we had before were anecdotal reports, where people had bought salvia extract from their local smoke shop.” While the study is small and can’t vouch for the safety of salvia, the results lend some hard science to the current legislative fray around the substance, which is criminalized in some states but not regulated federally. © Society for Science & the Public 2000 - 2010

Keyword: Drug Abuse
Link ID: 14786 - Posted: 12.16.2010

By Tina Hesman Saey PHILADELPHIA — Scientists are learning how they might stoke the body’s fat-burning furnace by turning up a molecular thermostat. Mice lacking a protein that responds to the hunger-promoting hormone ghrelin burn more energy in their brown fat than other mice, Yuxiang Sun of Baylor College of Medicine in Houston reported December 13 at the American Society for Cell Biology’s annual meeting. This revved-up brown fat helps keep mice lean and energetic into middle age. The finding could eventually lead to a way to help people fight obesity. Brown fat burns energy instead of just storing it the way white fat does. This metabolically active fat is important in helping rodents and other animals maintain their body temperature. Recently researchers learned that adult humans have brown fat, and that the amount of energy burned by brown fat decreases with age and weight. The discovery has spurred interest in learning how to turn brown fat on. Sun and her colleagues didn’t start out trying to rev up brown fat. Because the hormone ghrelin has been shown to make animals eat more, the researchers reasoned that blocking the molecule’s activity might reduce appetite and help animals and people lose weight. Sun and her colleagues genetically engineered mice to completely lack either ghrelin or the ghrelin receptor, a protein that interacts with ghrelin and sets off a series of biological reactions in cells that leads to the hormone’s effect. © Society for Science & the Public 2000 - 2010

Keyword: Obesity; Genes & Behavior
Link ID: 14785 - Posted: 12.16.2010

by Michael Marshall A NEURAL circuit has been identified that allows people to predict whether someone is going to lie to them. The finding could help to explain why some people become paranoid. Humans have "theory of mind" - the ability to imagine what others are thinking and learn from their social habits. "We're trying to find a specific circuit that performs social learning," says Matthew Rushworth at the University of Oxford, who presented his work at a Cell Press LabLinks conference in London on 3 December. Rushworth's team scanned volunteers' brains while they chose one of two boxes to win points. They were sent advice on which box to choose from a second player who was sometimes dishonest. When the volunteers suspected they were being lied to, activity levels rose in the dorsomedial prefrontal cortex (DPFC), an area near the front of the brain. If the volunteer thought the player was telling the truth the activity remained low. If their suspicions were proved wrong, the activity changed "suggesting the volunteers needed to rethink their opinion of the second player", says Rushworth. In effect, the activity was predicting how trustworthy the advice would be, then reacting to the results of that prediction (Nature, vol 456, p 245). In effect, the brain activity predicted how trustworthy the incoming advice was going to be Failures of this system could explain why those with schizophrenia are often paranoid, says Chris Frith of University College London, who was not involved in the study. "People with schizophrenia show false prediction errors: they keep thinking their predictions are wrong," he says. This leads to distrust and paranoia. © Copyright Reed Business Information Ltd.

Keyword: Emotions; Attention
Link ID: 14784 - Posted: 12.16.2010

By Hank Greely Neuroscientists have been using brain scans to learn how to read minds. This research is increasing our basic understanding of the human brain and offering hope for medical breakthroughs. We should all applaud this work. Commercial firms, however, are beginning to apply this research to lie detection, selling their services. The technology is tempting, but before we accept it, we need to think hard about it—and go slow. The trouble is not with the pace of research. Neuroscientists have been publishing articles about detecting lies with functional magnetic resonance imaging (fMRI) for nearly 10 years. About 25 published studies have found correlations between when experimental subjects were telling a lie and the pattern of blood flow in their brains. The trouble is that different studies, using different methods, have drawn conclusions based on the activity of different brain regions. And all the studies so far have taken place in the artificial environment of the laboratory, using people who knew they were taking part in an experiment and who were following instructions to lie. None of the studies examined lie detection in real-world situations. No government agency has found that this method works; no independent bodies have tested the approach. Yet people are buying lie-detection reports, wrapped in the glamour of science, to try to prove their honesty. In May two separate cases wound up in the courts. © 2010 Scientific American,

Keyword: Stress; Brain imaging
Link ID: 14783 - Posted: 12.16.2010

This project is supported by Award Number RC2GM092708 from the National Institute of General Medical Sciences (NIGMS).

Keyword: Miscellaneous
Link ID: 14782 - Posted: 12.14.2010

John Roach For many of us, the wonders of cell biology came alive when we peered through a microscope at an amoeba in science class. Today, a new online image library of cells brings that same sense of wonder and magic to anyone with an Internet connection. The library contains more than 1,000 images, videos, and animations of cells from a variety of organisms — from the Chinese hamster (Cricetulus griseus) to humans (Homo sapiens). The database aims to advance research on cellular activity with the ultimate goal of improving human health, according to the American Society for Cell Biology, which has created the database in partnership with Glencoe Software and the Open Microscopy Environment. "In our research of disease, one of the key features is to understand the mechanism of disease — and that is going to happen, in many cases, at the cellular level," David Orloff, manager of The Cell image library, told me. For example, the library will make it possible for scientists to compare different cell types online and understand the nature of specific cells and cellular processes, both normal and abnormal. This may lead to new discoveries about diseases, as well as new targets for drug development. © 2010 msnbc.com

Keyword: Miscellaneous
Link ID: 14781 - Posted: 12.14.2010

Dr Yan Wong Illusions are fascinating because of what they reveal about how our brain works. This particular one, demonstrated to a Women's Institute meeting for Bang Goes The Theory, involves your perception of rotated pictures - usually faces. Most people can still recognise an image of a face that's been rotated upside-down, and they still do even when altered in rather major ways. In particular, a distortion known as 'Thatcherization' [1] often goes unnoticed - that's where the face is upside-down but the eyes and the mouth are changed to remain the right way up [2]. If the image is then rotated into the normal position, you're in for a shock as the face suddenly looks grotesque. Try rotating the line-up of suspects below - I’m particularly happy with how awful my own Thatcherized face suddenly becomes! With photo manipulation programs, you can easily do the same to your own digital photos, but I've found some faces and expressions aren't so good. Below are the other presenters, along with a face that definitely doesn't Thatcherize well. I suspect this is because the smile takes up a good portion of the lower part of the face, approaching the edges of her cheeks. BBC © MMX

Keyword: Vision
Link ID: 14780 - Posted: 12.14.2010

By PERRI KLASS, M.D. As recently as 2002, an international group of leading neuroscientists found it necessary to publish a statement arguing passionately that attention deficit hyperactivity disorder was a real condition. In the face of “overwhelming” scientific evidence, they complained, A.D.H.D. was regularly portrayed in the media as “myth, fraud or benign condition” — an artifact of too-strict teachers, perhaps, or too much television. In recent years, it has been rarer to hear serious doubt that the disorder really exists, and the evidence explaining its neurocircuitry and genetics has become more convincing and more complex. Even so, I’ve lately read a number of articles and essays that use attention (or its lack) as a marker and a metaphor for something larger in society — for the multitasking, the electronic distractions, the sense that the nature of concentration may be changing, that people feel nibbled at, overscheduled, distracted, irritable. But A.D.H.D. is not a metaphor. It is not the restlessness and rambunctiousness that happen when grade-schoolers are deprived of recess, or the distraction of socially minded teenagers in the smartphone era. Nor is it the reason your colleagues check their e-mail in meetings and even (spare me!) conversations. Copyright 2010 The New York Times Company

Keyword: ADHD
Link ID: 14779 - Posted: 12.14.2010

Joseph Milton We all struggle to communicate after a sleepless night, let alone pull off our best dance moves, and it seems that honeybees are no different. Sleep-deprived bees are less proficient than their well-rested hive mates at indicating the location of a food source to other members of the colony by waggle dancing — the figure-of-eight dance used to communicate the quality and location of nectar supplies to the hive — according to a study published online this week in the Proceedings of the National Academy of Sciences1. Like all animals, European honeybees (Apis mellifera) rely on a sleep-like state of inactivity to survive — but sleep in insects and the effects of sleep deprivation on their behaviour are poorly understood. Barrett Klein, who led the study as a graduate student at the University of Texas at Austin, says that sleep deprivation could conceivably affect bees when hives are invaded by predators or parasites, when apiculturists transport colonies over long distances, or as an everyday consequence of the busy nature of hives. "Bees bustle around, frequently bumping into each other," he says. "It's also possible that sleep deprivation could exacerbate colony collapse disorder," he adds, referring to recent alarming declines in bee populations worldwide, "although this hasn't been tested." © 2010 Nature Publishing Group,

Keyword: Animal Communication; Sleep
Link ID: 14778 - Posted: 12.14.2010

By Garrison Keillor People keep asking about my stroke. I am okay, really--not staggering around with one arm hanging limp, or glassy-eyed or slurring my speech, flecks of spittle on my lips. And yet people still say, "How are you doing?" in that special way that means, "Tell us the painful truth and feel free to cry." Really, it was only a minor stroke, but I will tell about it one last time and then let's move on to something interesting--such as sex or sweet corn or the Rapture--and I will never discuss this again. Thank you for your patience. It happened on Labor Day, 2009, in Minneapolis, at a massage studio (the kind with the Japanese prints and the Peruvian flute music and the careful placement of the towel of modesty). I lay on my belly under the hands of the powerful Jamaican masseuse, Angelica, who was working on my neck and shoulders and telling me how good her life had been since she turned it over to the Lord Jesus Christ and let Him make all the decisions. "Including what to eat?" I asked. Yes, she said. I started to say something witty about honey and locusts and whoa my mouth was numb, my speech slurred. My brain was melting. I heisted up on my elbows. I took a deep breath. She said, "Are you okay?" I said (as I was brought up to say), "I am just fine." ©2010 Rodale Inc.

Keyword: Stroke
Link ID: 14777 - Posted: 12.14.2010

By NICHOLAS BAKALAR Everyone yawns, but no one knows why. We start when we are in the womb, and we do it through old age. Most vertebrate species, even birds and fishes, yawn too, or at least do something that looks very much like it. But its physiological mechanisms, its purpose and what survival value it might have remain a mystery. There is no shortage of theories — a recent article in the journal Neuroscience & Biobehavioral Reviews outlines many — but a dearth of experimental proof that any of them is correct. “The lack of experimental evidence is sometimes accompanied by passionate discussion,” said Dr. Adrian G. Guggisberg, the lead author. Hippocrates proposed in the fourth century B.C. that yawning got rid of “bad air,” and increased “good air” in the brain. The widely held modern view of this theory is that yawning helps increase blood oxygen levels and decrease carbon dioxide. If this were true, Dr. Guggisberg writes, then people would yawn more when they exercise. And people with lung or heart disease, who often suffer from a lack of oxygen, yawn no more than anyone else. Researchers have exposed healthy subjects to gas mixtures with high levels of carbon dioxide and found that it does not lead to increased yawning. In fact, there is no study that shows that oxygen levels in the brain are changed one way or the other by yawning. Copyright 2010 The New York Times Company

Keyword: Miscellaneous; Aggression
Link ID: 14776 - Posted: 12.14.2010