|By Melinda Wenner Moyer For most people, “fat,” particularly the kind that bulges under the skin, is a four-letter word. It makes our thighs jiggle; it lingers despite our torturous attempts to eliminate it. Too much of it increases our risk for heart disease and type 2 diabetes (the most common form of the condition). For decades researchers have looked for ways to reduce our collective stores of fat because they seemed to do more harm than good. But biology is rarely that simple. In the late 2000s several research groups independently discovered something that shattered the consensus about the absolute dangers of body fat. Scientists had long known that humans produce at least two types of fat tissue—white and brown. Each white fat cell stores energy in the form of a single large, oily droplet but is otherwise relatively inert. In contrast, brown fat cells contain many smaller droplets, as well as chestnut-colored molecular machines known as mitochondria. These organelles in turn burn up the droplets to generate heat. Babies, who have not yet developed the ability to shiver to maintain their body temperature, rely on thermogenic deposits of brown fat in the neck and around the shoulders to stay warm. Yet investigators assumed that all brown fat disappears during childhood. The new findings revealed otherwise. Adults have brown fat, too. Suddenly, people started throwing around terms like holy grail to describe the promise of brown fat to combat obesity. The idea was appealingly simple: if researchers could figure out how to incite the body to produce extra brown fat or somehow rev up existing brown fat, a larger number of calories would be converted into heat, reducing deposits of white fat in the process. © 2014 Scientific American

Keyword: Obesity
Link ID: 19953 - Posted: 08.13.2014

By GRETCHEN REYNOLDS Regular exercise may alter how a person experiences pain, according to a new study. The longer we continue to work out, the new findings suggest, the greater our tolerance for discomfort can grow. For some time, scientists have known that strenuous exercise briefly and acutely dulls pain. As muscles begin to ache during a prolonged workout, scientists have found, the body typically releases natural opiates, such as endorphins, and other substances that can slightly dampen the discomfort. This effect, which scientists refer to as exercise-induced hypoalgesia, usually begins during the workout and lingers for perhaps 20 or 30 minutes afterward. But whether exercise alters the body’s response to pain over the long term and, more pressing for most of us, whether such changes will develop if people engage in moderate, less draining workouts, have been unclear. So for the new study, which was published this month in Medicine & Science in Sports & Exercise, researchers at the University of New South Wales and Neuroscience Research Australia, both in Sydney, recruited 12 young and healthy but inactive adults who expressed interest in exercising, and another 12 who were similar in age and activity levels but preferred not to exercise. They then brought all of them into the lab to determine how they reacted to pain. Pain response is highly individual and depends on our pain threshold, which is the point at which we start to feel pain, and pain tolerance, or the amount of time that we can withstand the aching, before we cease doing whatever is causing it. © 2014 The New York Times Company

Keyword: Pain & Touch
Link ID: 19952 - Posted: 08.13.2014

|By Piercarlo Valdesolo In the summer of 2009 I tried to cure homemade sausages in my kitchen. One of the hazards of such a practice is preventing the growth of undesirable molds and diseases such as botulism. My wife was not on board with this plan, skeptical of my ability to safely execute the procedure. And so began many weeks of being peppered with warnings, relevant articles and concerned looks. When the time came for my first bite, nerves were high. My throat itched. My heart raced. My vision blurred. I had been botulized! Halfway through our walk to the hospital I regained my composure. Of course I had not been instantaneously struck by an incredibly rare disease that, by the way, takes at least 12 hours after consumption to manifest and does not share many symptoms with your garden variety anxiety attack. My experience had been shaped by my mindset. A decade of learning about the psychological power of expectations could not inoculate me from its effect. Psychologists know that beliefs about how experiences should affect us can bring about the expected outcomes. Though these “placebo effects” have primarily been studied in the context of pharmaceutical interventions (e.g. patients reporting pain relief after receiving saline they believed to be an analgesic), recent research has shown their strength in a variety of domains. Tell people that their job has exercise benefits and they will lose more weight than their coworkers who had no such belief. Convince people of a correlation between athleticism and visual acuity and they will show better vision after working out . Trick people into believing they are consuming caffeine and their vigilance and cognitive functioning increases. Some evidence shows that such interventions can even mitigate the negative effects of other experiences. For example, consuming placebo caffeine alleviates the cognitive consequences of sleep deprivation. © 2014 Scientific American

Keyword: Sleep; Attention
Link ID: 19951 - Posted: 08.13.2014

By EDWARD LARKIN and IRENE HURFORD PHILADELPHIA — A FEW months ago, a patient came to our hospital, seeking help. One of us, Edward, was on the team that treated him. He was pleasant, if slightly withdrawn, and cogent. He was a college graduate in his 20s and had recently been fired from his job as a high school math teacher, because of unexpected absences. He had come to believe that government agents were conspiring against him, and he had taken to living out of a truck and sleeping in different parking lots. By the time he came to us, he was exhausted. A diagnosis became clear: he had schizophrenia. We admitted him to the hospital, and after a few days, with his symptoms under control, we released him. Unfortunately, we prescribed a medication for him that could cause significant, permanent harm, instead of an equally effective drug with milder side effects — all because he was uninsured. Schizophrenia, which affects 1 percent of the population and emerges in the late teens to early 20s, is deeply misunderstood. People who suffer from it are often suspected of being dangerous, but this is not usually the case, and antipsychotic drugs are very effective. Our patient was exactly the kind of person who, with the right treatment, could have weakened the stigma surrounding schizophrenia. Antipsychotic drugs fall into two classes: the older ones, like Haldol, and newer ones, like Abilify and Latuda. Both classes are equally effective at treating some of the worst symptoms of schizophrenia, specifically the hallucinations, delusions and paranoia that cause social alienation. (They’re not effective for treating “negative symptoms,” like low motivation.) But the older drugs can cause a multitude of serious side effects, including a potentially devastating one called tardive dyskinesia. This condition involves unsettling, animalistic smacking and wagging of the lips and tongue. At its extreme, it can affect the entire body. It occurs in 20 percent or more of patients who take the drugs long-term, and it tends to start so mildly that patients can’t identify it in time to stop taking the drugs. It is often irreversible. © 2014 The New York Times Company

Keyword: Schizophrenia
Link ID: 19950 - Posted: 08.13.2014

Sara Reardon When the states of Colorado and Washington voted to legalize marijuana in 2012, the abrupt and unprecedented policy switch sent the US National Institute on Drug Abuse (NIDA) into what its director Nora Volkow describes as “red alarm”. Although marijuana remained illegal for people under the age of 21, the drug’s increased availability and growing public acceptance suggested that teenagers might be more likely to try it (see ‘Highs and lows’). Almost nothing is known about whether or how marijuana affects the developing adolescent brain, especially when used with alcohol and other drugs. The new laws, along with advances in brain-imaging technology, convinced Volkow to accelerate the launch of an ambitious effort to follow 10,000 US adolescents for ten years in an attempt to determine whether marijuana, alcohol and nicotine use are associated with changes in brain function and behaviour. At a likely cost of more than US$300 million, it will be the largest longitudinal brain-imaging study of adolescents yet. Researchers are eager to study a poorly understood period of human development — but some question whether it is possible to design a programme that will provide useful information about the effects of drugs. “It’s definitely an idea that’s overdue,” says Deanna Barch, a psychologist at Washington University in St. Louis, Missouri. “The downside is it’s a lot of eggs in one basket.” © 2014 Nature Publishing Group,

Keyword: Development of the Brain; Drug Abuse
Link ID: 19949 - Posted: 08.13.2014

By MICHAEL CIEPLY and BROOKS BARNES LOS ANGELES — Peering through his camera at Robin Williams in 2012, the cinematographer John Bailey thought he glimpsed something not previously evident in the comedian’s work. They were shooting the independent film “The Angriest Man in Brooklyn,” and Mr. Williams was playing a New York lawyer who, facing death, goes on a rant against the injustice and banality of life. His performance, Mr. Bailey said Tuesday, was a window into the “Swiftian darkness of Robin’s heart.” The actor, like his character, was raging against the storm. That defiance gave way on Monday to the personal demons that had long tormented Mr. Williams. With his suicide at age 63, Mr. Williams forever shut the window on a complicated soul that was rarely visible through the cracks of an astonishingly intact career. Given his well-publicized troubles with depression, addiction, alcoholism and a significant heart surgery in 2009, Mr. Williams should have had a résumé filled with mysterious gaps. Instead, he worked nonstop. At the very least — if his life had followed the familiar script of troubled actors — there would have been whispers of on-set antics: lateness, forgotten lines, the occasional flared temper. Not so with Mr. Williams. “He was ready to work, he was the first one on the set,” said Mr. Bailey, speaking of Mr. Williams’s contribution to “The Angriest Man in Brooklyn,” of which he was the star. “Robin was always 1,000 percent reliable,” said a senior movie agent, speaking on the condition of anonymity to conform to the wishes of Mr. Williams’s family. “He was almost impossibly high functioning.” As Hollywood struggled on Tuesday to understand how Mr. Williams — effervescent in the extreme — could take his own life, authorities released details of his death. A clothed Mr. Williams hanged himself with a belt from a door frame in his bedroom in Tiburon, Calif., according to Lt. Keith Boyd, assistant deputy chief coroner for Marin County. © 2014 The New York Times Company

Keyword: Depression
Link ID: 19948 - Posted: 08.13.2014

By Lenny Bernstein, Lena H. Sun and Sandhya Somashekhar Suicides are the 10th-leading cause of death in the United States and eighth among people in the 55- to 64-year-old age group. Comedian Robin Williams, who died Monday of an apparent suicide, was 63. In 2010, 38,364 people died this way. Many suicides are the result of undiagnosed or untreated depression, often masked by self-medicating behaviors such as alcohol and drug use. Though we don’t yet know the exact circumstances of Williams’s death, we do know that he long battled addictions to cocaine and alcohol and, according to his publicist, was struggling with “severe depression.” But unlike many people, Williams had the resources and the motivation to seek treatment, at least for his addictions. According to this report, he had undergone rehab at the famed Hazelden Addiction Treatment Center in Minnesota two months ago, and had sought treatment in 2006 when he began drinking again after 20 years of sobriety. How, then, do we explain the death of someone who appeared to recognize the danger he faced and was trying to address it? Here are some thoughts: • Suicides are often impulsive acts: People who kill themselves are not thinking clearly, have trouble solving problems and weigh risks differently from us, Jill Harkavy-Friedman, vice president of research for the American Foundation for Suicide Prevention, told To Your Health in March. If thwarted in their first attempt, they often do not try again immediately, she said.

Keyword: Depression; Drug Abuse
Link ID: 19947 - Posted: 08.13.2014

Jia You Premature babies are more likely to produce piercing cries than their full-term peers are, researchers report online today in Biology Letters. Scientists have studied infant crying as a noninvasive way to assess how well a baby’s nervous system develops. Previous research of full-term babies indicates that an abnormally high pitch is associated with disturbances in an infant’s metabolism and neurological development. The team recorded spontaneous crying in preterm babies and full-term babies of the same age and compared the pitch of their sobs. They found that preterm babies whimper in a shriller voice, but not because they are smaller in size or grew at a slower rate in their mothers’ wombs. Instead, the researchers suspect the high pitch could reflect lower levels of activities in a premature baby’s vagal nerve, which extends from the brain stem to the abdomen. Vagal nerve activities are believed to decrease tension in the vocal cords, thus producing a lower pitch. Previous studies show that giving preterm babies massage therapies can stimulate their vagal activities, improve their ingestion, and help them gain weight. © 2014 American Association for the Advancement of Science

Keyword: Development of the Brain
Link ID: 19946 - Posted: 08.13.2014

James Gorman Deep in the mouse brain, scientists recently found that a very small network of cells, a few thousand at most, turns appetite on and off. They used the most sophisticated of modern techniques, but as has often happened in science — witness penicillin, Velcro and Viagra — the researchers discovered something they weren’t looking for. “This was an accidental discovery,” said David Anderson, of the California Institute of Technology, the senior scientist on the team that reported the finding, in Nature Neuroscience. The discovery may eventually lead to a better understanding and treatment of eating disorders. The surprise and drama of the finding are immediately clear, however, in lab videos. A mouse busily munches lab chow until a light signal is sent to its brain, and the mouse wanders off, no longer interested in food. His lab had previously studied this small group of neurons, in a part of the brain called the amygdala. That earlier research was on fear, an emotion strongly associated with the amygdala in both mice and humans. As a technique called optogenetics became more and more refined, he said, it seemed worth revisiting the neurons with this new tool. Optogenetics requires genetic manipulation of specific cells to make them sensitive to light in a certain wavelength, in this case blue light. Then fiber-optic cables are inserted into the brain, and when the light is turned on, neurons can be activated or turned off. Researchers in Dr. Anderson’s lab, including Haijiang Cai, a postdoctoral researcher and a co-author of the report, prepared the mice and conducted the experiment with the entirely unexpected result. © 2014 The New York Times Company

Keyword: Obesity
Link ID: 19945 - Posted: 08.12.2014

By Rachel Feltman Bioengineers have created the most realistic fake brain tissue ever – and it’s built like a jelly doughnut. The 3-D tissue, described in a paper published Monday in Proceedings of the National Academy of Sciences, is so structurally similar to a real rat brain (a common substitute for human brains in the lab) that it could help scientists answer longstanding questions about brain injuries and disease. Currently, the best way to study brain tissue is to grow neurons in a petri dish, but those neurons can only be grown flat. A real brain contains a complicated structure of 3-D tissue. Simply giving the neurons room to grow in three dimensions didn’t prove successful: While neurons will grow into more complicated structures in the right kind of gel, they don’t survive very long or mimic the structure of a real brain. Led by David Kaplan, the director of the Tissue Engineering Resource Center at Tufts University, researchers developed a new combination of materials to mimic the gray and white matter of the brain. The new model relies on a doughnut-shaped, spongy scaffold made of silk proteins with a collagen-based gel at the center. The outer scaffold layer, which is filled with rat neurons, acts as the grey matter of the brain. As the neurons grew networks throughout the scaffold, they sent branches out across the gel-filled center to connect with neurons on the other side. And that configuration is about as brain-like as lab-grown tissue can get. The basic structure can be reconfigured, too.

Keyword: Robotics; Development of the Brain
Link ID: 19944 - Posted: 08.12.2014

By PAM BELLUCK The 40-year-old man showed up in Dr. Mary Malloy’s clinic with sadly disfiguring symptoms. His hands, elbows, ears and feet were blemished with protruding pustules and tuber-like welts, some so painful it was hard for him to walk. He suffered from a rare genetic condition called dysbetalipoproteinemia, which caused his cholesterol levels to soar so high that pools of fatty tissue seemed to bubble up under his skin. But there was something else about this patient. He was missing a gene that, when present in one form, greatly increases the risk of developing Alzheimer’s disease. Dr. Malloy, who co-directs the Adult Lipid Clinic at the University of California, San Francisco, and her colleagues saw an opportunity to answer an important neurological riddle: Does the absence of the gene — named apolipoprotein E, or APOE, after the protein it encodes — hurt the brain? If a person with this rare condition were found to be functioning normally, that would suggest support for a new direction in Alzheimer’s treatment. It would mean that efforts — already being explored by dementia experts — to prevent Alzheimer’s by reducing, eliminating or neutralizing the effects of the most dangerous version of APOE might succeed without causing other problems in the brain. The researchers, who reported their findings on Monday in the journal JAMA Neurology, discovered exactly that. They ran a battery of tests, including cognitive assessments, brain imaging and cerebrospinal fluid analyses. The man’s levels of beta-amyloid and tau proteins, which are markers of Alzheimer’s, gave no indication of neurological disease. His brain size was unaffected, and the white matter was healthy. His thinking and memory skills were generally normal. “This particular case tells us you can actually live without any APOE in the brain,” said Dr. Joachim Herz, a neuroscientist and molecular geneticist at University of Texas Southwestern Medical Center, who was not involved in the research. “So if they were to develop anti-APOE therapies for Alzheimer’s, we would not have to worry about serious neurological side effects.” © 2014 The New York Times Company

Keyword: Alzheimers
Link ID: 19943 - Posted: 08.12.2014

|By Nathan Collins Time zips by when you're having fun and passes slowly when you're not—except when you are depressed, in which case your time-gauging abilities are pretty accurate. Reporting in PLOS ONE, researchers in England and Ireland asked 39 students—18 with mild depression—to estimate the duration of tones lasting between two and 65 seconds and to produce tones of specified lengths of time. Happier students overestimated intervals by 16 percent and produced tones that were short by 13 percent, compared with depressed students' 3 percent underestimation and 8 percent overproduction. The results suggest that depressive realism, a phenomenon in which depressed people perceive themselves more accurately (and less positively) than typical individuals, may extend to aspects of thought beyond self-perception—in this case, time. They speculate that mindfulness treatments may be effective for depression, partly because they help depressed people focus on the moment, rather than its passing. © 2014 Scientific American

Keyword: Depression; Attention
Link ID: 19942 - Posted: 08.12.2014

By NATALIE ANGIER SOUTH LUANGWA NATIONAL PARK, ZAMBIA — We saw the impala first, a young buck with a proud set of ridged and twisted horns, like helical rebar, bounding across the open plain at full, desperate gallop. But why? A moment later somebody in our vehicle gasped, and the answer became clear. Rising up behind the antelope, as though conjured on movie cue from the aubergine glow of the late afternoon, were six African wild dogs, running in single file. They moved with military grace and precision, their steps synchronized, their radio-dish ears cocked forward, their long, puppet-stick legs barely skimming the ground. Still, the impala had such a jump on them that the dogs couldn’t possibly catch up — could they? We gunned the engine and followed. The pace quickened. The dogs’ discipline held steady. They were closing the gap and oh, no, did I really want to watch the kill? To my embarrassed relief, the violence was taken off-screen, when prey and predators suddenly dashed up a hill and into obscuring bushes. By the time we reached the site, the dogs were well into their communal feast, their dark muzzles glazed with bright red blood, their white-tipped tails wagging in furious joy. “They are the most enthusiastic animals,” said Rosie Woodroffe of the Institute of Zoology in London, who has studied wild dogs for the last 20 years. “Other predators may be bigger and fiercer, but I would argue that there is nothing so enthusiastic as a wild dog,” she said. “They live the life domestic dogs wish they could live.” In 1997, while devising an action plan to help save the wild dog species, Lycaon pictus, Dr. Woodroffe felt anything but exuberant. Wild dogs were considered among the most endangered of Africa’s mammals; Dr. Woodroffe had yet to see one in the wild, and she feared she never would. © 2014 The New York Times Company

Keyword: Aggression; Animal Communication
Link ID: 19941 - Posted: 08.12.2014

Helen Shen Most people gradually recover from trauma, but a small fraction of individuals develop post-traumatic stress disorder (PTSD) — prompting scientists to look for the biological underpinnings of this extreme response to traumatic situations such as warfare, car accidents and natural disasters. Research published on 11 August in Proceedings of the National Academy of Sciences identifies up to 334 genes that may be involved in vulnerability to post-traumatic stress in rats1. Most animal studies of stress use intense stimuli such as electric shocks, designed to produce large, group differences between exposed and unexposed animals. But Nikolaos Daskalakis and his colleagues tried a subtler approach to elicit a wide range of individual responses in rats that had all experienced the same trauma — more closely mimicking the variability of human responses to disturbing events. "We wanted to capture the differences between a susceptible individual and one that is not susceptible to the same experience," says Daskalakis, a neuroendocrinologist at the Icahn School of Medicine at Mount Sinai in New York. The researchers exposed around 100 rats to soiled cat litter — which evokes a feared predator — and tested the animals one week later for lingering effects of the trauma. About one-quarter of the exposed animals were classified as 'extreme' responders, showing high levels of anxiety and startling easily on hearing loud noises. Another quarter of the animals were 'minimal' responders, and exhibited anxiety levels similar to those of non-exposed rats. © 2014 Nature Publishing Group

Keyword: Stress; Genes & Behavior
Link ID: 19940 - Posted: 08.12.2014

By Gary Stix A gamma wave is a rapid, electrical oscillation in the brain. A scan of the academic literature shows that gamma waves may be involved with learning memory and attention—and, when perturbed, may play a part in schizophrenia, epilepsy Alzheimer’s, autism and ADHD. Quite a list and one of the reasons that these brainwaves, cycling at 25 to 80 times per second, persist as an object of fascination to neuroscientists. Despite lingering interest, much remains elusive when trying to figure out how gamma waves are produced by specific molecules within neurons—and what the oscillations do to facilitate communication along the brains’ trillions and trillions of connections. A group of researchers at the Salk Institute in La Jolla, California has looked beyond the preeminent brain cell—the neuron— to achieve new insights about gamma waves. At one time, neuroscience textbooks depicted astrocytes as a kind of pit crew for neurons, providing metabolic support and other functions for the brain’s rapid-firing information-processing components. In recent years, that picture has changed as new studies have found that astrocytes, like neurons, also have an alternate identity as information processors. This research demonstrates astrocytes’ ability to spritz chemicals known as neurotransmitters that communicate with other brain cells. Given that both neurons and astrocytes perform some of the same functions, it has been difficult to tease out what specifically astrocytes are up to. Hard evidence for what these nominal cellular support players might contribute in forming memories or focusing attention has been lacking. © 2014 Scientific American

Keyword: Attention; Glia
Link ID: 19939 - Posted: 08.12.2014

By Smitha Mundasad Health reporter, BBC News Human brains grow most rapidly just after birth and reach half their adult size within three months, according to a study in JAMA Neurology. Using advanced scanning techniques, researchers found male brains grew more quickly than those of female infants. Areas involved in movement developed at the fastest pace. Those associated with memory grew more slowly. Scientists say collating this data may help them identify early signs of developmental disorders such as autism. For centuries doctors have estimated brain growth using measuring tape to chart a baby's head circumference over time. Any changes to normal growth patterns are monitored closely as they can suggest problems with development. But as head shapes vary, these tape measurements are not always accurate. Led by scientists at the University of California, researchers scanned the brains of 87 healthy babies from birth to three months. They saw the most rapid changes immediately after birth - newborn brains grew at an average rate of 1% a day. This slowed to 0.4% per day at the end of the 90-day period. Researchers say recording the normal growth trajectory of individual parts of the brain might help them better understand how early disorders arise. They found the cerebellum, an area of the brain involved in the control of movement, had the highest rate of growth - doubling in size over the 90-day period. BBC © 2014

Keyword: Development of the Brain; Brain imaging
Link ID: 19938 - Posted: 08.12.2014

By ZACH SCHONBRUN EAST RUTHERFORD, N.J. — Victor Cruz dumped a bucket of ice water on his head at home on Sunday and then stepped out on thin ice himself — challenging the Giants’ co-owners to do the same. Taking part in the Ice Bucket Challenge — a social media craze that raises awareness for Lou Gehrig’s disease (amyotrophic lateral sclerosis) — Cruz, a wide receiver, posted the video on his Twitter feed. “That water was cold, man,” Cruz said Monday. The Ice Bucket Challenge was started by friends and family members of Pete Frates, a 29-year-old from Beverly, Mass., who played baseball at Boston College and was found to have A.L.S., a neurodegenerative condition, in 2012. As a reward for withstanding the icy punishment, the participant gets to nominate another person, who has 24 hours to complete the task. Cruz aimed high, calling out the co-owners John Mara and Steve Tisch to step under the bucket themselves. Just before practice on Monday, the 59-year-old Mara, wearing a white Giants T-shirt and black shorts, allowed Cruz to dump a Gatorade tub filled with ice water over his head. Before doing so, Mara nominated the Jets’ owner, Woody Johnson; the Patriots’ owner, Robert K. Kraft; and Patriots Coach Bill Belichick to do the same. “Feels good,” a smiling Mara said in a video posted on the Giants’ team website. It is unclear if Tisch will follow suit. Those who fail to complete the task within 24 hours are asked to donate to A.L.S. research. © 2014 The New York Times Company

Keyword: ALS-Lou Gehrig's Disease
Link ID: 19937 - Posted: 08.12.2014

By DANIEL J. LEVITIN THIS month, many Americans will take time off from work to go on vacation, catch up on household projects and simply be with family and friends. And many of us will feel guilty for doing so. We will worry about all of the emails piling up at work, and in many cases continue to compulsively check email during our precious time off. But beware the false break. Make sure you have a real one. The summer vacation is more than a quaint tradition. Along with family time, mealtime and weekends, it is an important way that we can make the most of our beautiful brains. Every day we’re assaulted with facts, pseudofacts, news feeds and jibber-jabber, coming from all directions. According to a 2011 study, on a typical day, we take in the equivalent of about 174 newspapers’ worth of information, five times as much as we did in 1986. As the world’s 21,274 television stations produce some 85,000 hours of original programming every day (by 2003 figures), we watch an average of five hours of television per day. For every hour of YouTube video you watch, there are 5,999 hours of new video just posted! If you’re feeling overwhelmed, there’s a reason: The processing capacity of the conscious mind is limited. This is a result of how the brain’s attentional system evolved. Our brains have two dominant modes of attention: the task-positive network and the task-negative network (they’re called networks because they comprise distributed networks of neurons, like electrical circuits within the brain). The task-positive network is active when you’re actively engaged in a task, focused on it, and undistracted; neuroscientists have taken to calling it the central executive. The task-negative network is active when your mind is wandering; this is the daydreaming mode. These two attentional networks operate like a seesaw in the brain: when one is active the other is not. © 2014 The New York Times Company

Keyword: Attention; Stress
Link ID: 19936 - Posted: 08.11.2014

By KATHARINE Q. SEELYE SPARTA, N.J. — When Gail Morris came home late one night after taking her daughter to college, she saw her teenage son, Alex, asleep on the sofa in the family room. Nothing seemed amiss. An unfinished glass of apple juice sat on the table. She tucked him in under a blanket and went to bed. The next morning, he would not wake up. He was stiff and was hardly breathing. Over the next several hours, Ms. Morris was shocked to learn that her son had overdosed on heroin. She was told he would not survive. He did survive, but barely. He was in a coma for six weeks. He went blind and had no function in his arms or legs. He could not speak or swallow. Hospitalized for 14 months, Alex, who is 6-foot-1, dropped to 90 pounds. One of his doctors said that Alex had come as close to dying as anyone he knew who had not actually died. Most people who overdose on heroin either die or fully recover. But Alex plunged into a state that was neither dead nor functional. There are no national statistics on how often opioid overdose leads to cases like Alex’s, but doctors say they worry that with the dramatic increase in heroin abuse and overdoses, they will see more such outcomes. “I would expect that we will,” said Dr. Nora Volkow, director of the National Institute on Drug Abuse. “They are starting to report isolated cases like this. And I would not be surprised if you have more intermediate cases with more subtle impairment.” More than 660,000 Americans used heroin in 2012, the federal government says, double the number of five years earlier. Officials attribute much of the increase to a crackdown on prescription painkillers, prompting many users to turn to heroin, which is cheaper and easier to get than other opioids. © 2014 The New York Times Company

Keyword: Consciousness; Drug Abuse
Link ID: 19935 - Posted: 08.11.2014

|By William Skaggs One of the most frustrating and mysterious medical conditions affecting the mind is impaired consciousness, as can occur with brain damage. Patients in a coma or a vegetative or minimally conscious state sometimes spontaneously recover to varying degrees, but in most cases there is little that doctors can do to help. Now a rigorous study by a group at Liège University Hospital Center in Belgium has found that a simple treatment called transcranial direct-current stimulation (tDCS) can temporarily raise awareness in minimally conscious patients. In tDCS, electrodes are glued to the scalp, and a weak electric current is passed through them to stimulate the underlying brain tissue. Scientists led by neurologist Steven Laureys applied the electric current for 20 minutes to patients' left prefrontal cortex, an area known to be involved in attentiveness and working memory. Afterward, the effects on consciousness were measured by doctors who did not know whether the patient had received real tDCS or a sham treatment, in which the apparatus ran, but no current was delivered. For patients in a vegetative state, who display no communication or purposeful behavior, the stimulation might have led to improvement in two patients, but no statistically compelling evidence emerged. Yet 13 of 30 patients in a minimally conscious state—defined by occasional moments of low-level awareness—showed measurable gains in their responses to questions and sensory stimuli. Some had only recently been injured, but others had been minimally conscious for months. © 2014 Scientific American

Keyword: Consciousness
Link ID: 19934 - Posted: 08.11.2014