By Erin Wayman BOSTON — The taste for alcohol may be an ancient craving. The ability to metabolize ethanol — the alcohol in beer, wine and spirits — might have originated in the common ancestor of chimpanzees, gorillas and humans roughly 10 million years ago, perhaps when this ancestor became more terrestrial and started eating fruits fermenting on the ground. Chemist Steven Benner of the Foundation for Applied Molecular Evolution in Gainesville, Fla., reached that conclusion by “resurrecting” the alcohol-metabolizing enzymes of extinct primates. Benner and his colleagues estimated the enzymes’ genetic code, built the enzymes in the lab and then analyzed how they work to understand how they changed over time. “It’s like a courtroom re-enactment,” said biochemist Romas Kazlauskas of the University of Minnesota in Minneapolis. Benner “can re-enact what happened in evolution.” Benner proposed the idea February 15 at the annual meeting of the American Association for the Advancement of Science. Today, humans rely on an enzyme called alcohol dehydrogenase 4, or ADH4, to break down ethanol. The enzyme is common throughout the esophagus, stomach and intestines, and is the first alcohol-metabolizing enzyme that comes into contact with what a person drinks. Among primates, not all ADH4s are the same — some can’t effectively metabolize ethanol. © Society for Science & the Public 2000 - 2013

Keyword: Drug Abuse; Evolution
Link ID: 17819 - Posted: 02.19.2013

By Erin Wayman BOSTON — “Birdbrain” may not be much of an insult: Humans and songbirds share genetic changes affecting parts of the brain related to singing and speaking, new research shows. The finding may help scientists better understand how human language evolved, as well as unravel the causes of speech impairments. Neurobiologist Erich Jarvis of Duke University Medical Center in Durham, N.C., and colleagues discovered roughly 80 genes that turn on and off in similar ways in the brains of humans and songbirds such as zebra finches and parakeets. This gene activity, which occurs in brain regions involved in the ability to imitate sounds and to speak and sing, is not present in birds that can’t learn songs or mimic sounds. Jarvis described the work February 15 at the annual meeting of the American Association for the Advancement of Science. Songbirds are good models for language because the birds are born not knowing the songs they will sing as adults. Like human infants learning a specific language, the birds have to observe and imitate others to pick up the tunes they croon. The ancestors of humans and songbirds split some 300 million years ago, suggesting the two groups independently acquired a similar capacity for song. With the new results and other recent research, Jarvis said, “I feel more comfortable that we can link structures in songbird brains to analogous structures in human brains due to convergent evolution.” © Society for Science & the Public 2000 - 2013

Keyword: Language; Genes & Behavior
Link ID: 17818 - Posted: 02.18.2013

By JANE E. BRODY The title of a recent report on smoking and health might well have paraphrased the popular ad campaign for Virginia Slims, introduced in 1968 by Philip Morris and aimed at young professional women: “You’ve come a long way, baby.” Today that slogan should include: “…toward a shorter life.” Ten years shorter, in fact. The new report is one of two rather shocking analyses of the hazards of smoking and the benefits of quitting published last month in The New England Journal of Medicine. The data show that “women who smoke like men die like men who smoke,” Dr. Steven A. Schroeder, a professor of health and health care at the University of California, San Francisco, wrote in an accompanying editorial. That was not always the case. Half a century ago, the risk of death from lung cancer among men who smoked was five times higher than that among women smokers. But by the first decade of this century, that risk had equalized: for both men and women who smoked, the risk of death from lung cancer was 25 times greater than for nonsmokers, Dr. Michael J. Thun of the American Cancer Society and his colleagues reported. Today, women who smoke are even more likely than men who smoke to die of lung cancer. According to a second study in the same journal, women smokers face a 17.8 times greater risk of dying of lung cancer than women who do not smoke; men who smoke are at 14.6 times greater risk to die of lung cancer than men who don’t. Women who smoke now face a risk of death from lung cancer that is 50 percent higher than the estimates reported in the 1980s, according to Dr. Prabhat Jha of the Center for Global Health Research in Toronto and his colleagues. After controlling for age, body weight, education level and alcohol use, the new analysis found something else: men and women who continue to smoke die on average 10 years sooner than those who never smoked. Copyright 2013 The New York Times Company

Keyword: Drug Abuse; Sexual Behavior
Link ID: 17817 - Posted: 02.18.2013

By Alan Boyle, Science Editor, NBC News BOSTON — Neuroscientists are following through on the promise of artificially enhanced bodies by creating the ability to "feel" flashes of light in invisible wavelengths, or building an entire virtual body that can be controlled via brain waves. "Things that we used to think were hoaxes or science fiction are fast becoming reality," said Todd Coleman, a bioengineering professor at the University of California at San Diego. Coleman and other researchers surveyed the rapidly developing field of neuroprosthetics in Boston this weekend at the annual meeting of the American Association for the Advancement of Science. One advance came to light just in the past week, when researchers reported that they successfully wired up rats to sense infrared light and move toward the signals to get a reward. "This was the first attempt … not to restore a function but to augment the range of sensory experience," said Duke University neurobiologist Miguel Nicolelis, the research team's leader. The project, detailed in the journal Nature Communications, involved training rats to recognize a visible light source and poke at the source with its nose to get a sip of water. Then electrodes were implanted in a region of the rats' brains that is associated with whisker-touching. The electrodes were connected to an infrared sensor on the rats' heads, which stimulated the target neurons when the rat was facing the source of an infrared beam. Then the visible lights in the test cage were replaced by infrared lights. © 2013 NBCNews.com

Keyword: Pain & Touch; Robotics
Link ID: 17816 - Posted: 02.18.2013

Changing the channel on what TV children watch could improve their behaviour, but watching too much regular programming may have harmful long-term consequences, new research suggests. In Monday's issue of the journal Pediatrics, researchers reported that preschoolers spent less time watching violent programming when they were randomly assigned to participate in a program that encouraged aggression-filled shows to be replaced with educational or empathy-building viewing compared with a control group. Muppets Bert, left, and Ernie, from the children's program Sesame Street, were created to teach preschoolers that people can be good friends with those who are very different from themselves, which builds empathy. "We demonstrated that an intervention to modify the viewing habits of preschool-aged children can significantly enhance their overall social and emotional competence and that low-income boys may derive the greatest benefit," Dr. Dimitri Christakis of Seattle Children's Research Institute and his co-authors concluded. "Although television is frequently implicated as a cause of many problems in children, our research indicates that it may also be part of the solution." There was no difference in total viewing time between the 820 families involved in the study. The educational or "prosocial" programs included Sesame Street, Dora the Explorer and Super Why. A second category of shows also promoted co-operative problem-solving and non-violent conflict resolution but inconsistently, such as on Mickey Mouse Clubhouse. © CBC 2013

Keyword: Aggression; Development of the Brain
Link ID: 17815 - Posted: 02.18.2013

By Pallab Ghosh Science correspondent, BBC News, Boston Scientists are set to release the first batch of data from a project designed to create the first map of the human brain. The project could help shed light on why some people are naturally scientific, musical or artistic. Some of the first images were shown at the American Association for the Advancement of Science meeting in Boston. I found out how researchers are developing new brain imaging techniques for the project by having my own brain scanned. Scientists at Massachusetts General Hospital are pushing brain imaging to its limit using a purpose built scanner. It is one of the most powerful scanners in the world. The scanner's magnets need 22MW of electricity - enough to power a nuclear submarine. The researchers invited me to have my brain scanned. I was asked if I wanted "the 10-minute job or the 45-minute 'full monty'" which would give one of the most detailed scans of the brain ever carried out. Only 50 such scans have ever been done. I went for the full monty. It was a pleasant experience enclosed in the scanner's vast twin magnets. Powerful and rapidly changing magnetic fields were looking to see tiny particles of water travelling along the larger nerve fibres. By following the droplets, the scientists in the adjoining cubicle are able to trace the major connections within my brain. Arcs of understanding The result was a 3D computer image that revealed the important pathways of my brain in vivid colour. One of the lead researchers, Professor Van Wedeen, gave me a guided tour of the inside of my head. BBC © 2013

Keyword: Brain imaging
Link ID: 17814 - Posted: 02.18.2013

By JOHN MARKOFF The Obama administration is planning a decade-long scientific effort to examine the workings of the human brain and build a comprehensive map of its activity, seeking to do for the brain what the Human Genome Project did for genetics. The project, which the administration has been looking to unveil as early as March, will include federal agencies, private foundations and teams of neuroscientists and nanoscientists in a concerted effort to advance the knowledge of the brain’s billions of neurons and gain greater insights into perception, actions and, ultimately, consciousness. Scientists with the highest hopes for the project also see it as a way to develop the technology essential to understanding diseases like Alzheimer’s and Parkinson’s, as well as to find new therapies for a variety of mental illnesses. Moreover, the project holds the potential of paving the way for advances in artificial intelligence. The project, which could ultimately cost billions of dollars, is expected to be part of the president’s budget proposal next month. And, four scientists and representatives of research institutions said they had participated in planning for what is being called the Brain Activity Map project. The details are not final, and it is not clear how much federal money would be proposed or approved for the project in a time of fiscal constraint or how far the research would be able to get without significant federal financing. © 2013 The New York Times Company

Keyword: Brain imaging
Link ID: 17813 - Posted: 02.18.2013

By Jason Bittel Bears hibernate. They spend all year eating salmon, blueberries, and picnic baskets and then, sometime around baseball playoffs, they all wander off to a cave full of treasure and explorers’ skulls where they curl up in a big furry ball and snore away the winter. Everybody knows this! Even small children too young to attend to their own biological functions know how these wild animals make it through a period of harsh weather and food shortage. But beyond the fact that bears den up in winter, what do we really know of these lumbering slumber beasts and the secrets they keep beneath the ice and snow? Let’s start with this bit of housekeeping—cursory Googling of bears and hibernation will lead you to all sorts of trash talk saying bears aren’t “true hibernators.” True hibernators, such as Arctic ground squirrels, are capable of dropping their body temperatures below the freezing point of water, conditions so cold that neurons in the brain’s cortex are physically incapable of firing. Not to mention you can do all sorts of awful things to true hibernators while they slumber—like, oh, I don’t know, locking marmots in airtight jars filled with carbonic acid and hydrogen. (Easy, PETA. We’re talking 1832.) I know what you’re thinking: First Lance Armstrong, then Manti Te’o, and now this. But before you sit the kids down and blow their fragile little minds with the message that bears may not be true hibernators, consider that science is something of a moving target. The more we learn, the more questions we raise. © 2013 The Slate Group, LLC

Keyword: Miscellaneous
Link ID: 17812 - Posted: 02.18.2013

by Emily Underwood BOSTON—Dude, check out these European perch. After swimming in water laced with a common antianxiety medication, the red-finned fish lose their inhibitions and gobble up prey at a much faster rate, according to a new study presented here today at the annual meeting of the American Association for the Advancement of Science (publisher of ScienceNOW). The animals act strangely even after being exposed to low concentrations of the medication found in rivers worldwide, suggesting that the drug and others like it could affect fish behavior and ecology even in small doses. Hundreds of different pharmaceuticals are able to slip past conventional wastewater treatment plants and into our waterways, says Jerker Fick, a toxicologist at Umeå University in Sweden and co-author of the new study. "They don't mysteriously go away after we excrete them." Scientists have known for a long time that many pharmaceuticals can persist in rivers and streams, and have behavioral effects on aquatic species in high doses, he says; however, determining whether more dilute concentrations have an effect is harder to establish. Several years ago, Fick and his colleagues discovered a common psychoactive medication called oxazepam in water samples from the River Fyris, which flows through Uppsala, the fourth largest city in Sweden. Oxazepam belongs to a class of drugs that make neurons less excitable and slower to transmit signals throughout the brain and is an "essential" treatment for panic attacks and other severe anxiety disorders, Fick says. Although the authors describe the concentration of the drug—0.58 micrograms per liter-1—as "unusually high," they also say it is comparable to levels found in rivers in other countries; however, there isn't enough research to know for sure how widespread the drug is. "This is not a particularly Swedish problem," says lead author Tomas Brodin of Umeå University. © 2010 American Association for the Advancement of Science

Keyword: Emotions; Drug Abuse
Link ID: 17811 - Posted: 02.16.2013

By Laura Sanders An element of surprise may be the key to whitewashing a painful memory. People who encountered something unexpected were better able to shake a troubling association, a new laboratory study finds. The results, published in the Feb. 15 Science, bring scientists closer to being able to weaken traumatic memories with help from a drug. Understanding how the brain forms and reforms traumatic memories might lead to treatments that would help people who suffer from post-traumatic stress disorder and other anxiety disorders. “The idea that an original memory could have the sting taken out of it — that’s been very appealing,” says psychiatrist Roger Pitman of Harvard Medical School and Massachusetts General Hospital, who was not involved in the research. Memories are not written in neural stone. Recent results in animals and humans have shown that once called to mind, painful memories’ emotional edges can be blunted. Experiments have used certain drugs to weaken associations between a memory and a negative response. But the details of how and why those drugs work haven’t been clear. The new result may have uncovered a previously underappreciated step in that weakening process: In order for the emotional response tied to a memory to wither, something unexpected must happen while the person is recalling the memory. This mismatch between what a person expects and what actually happens — called a prediction error — puts a memory into a wobbly, vulnerable form that can be washed out, says study coauthor Merel Kindt of the University of Amsterdam. © Society for Science & the Public 2000 - 2013

Keyword: Learning & Memory; Emotions
Link ID: 17810 - Posted: 02.16.2013

Mo Costandi Prions are best known as the infectious agents that cause ‘mad cow’ disease and the human versions of it, such as variant Creutzfeldt–Jakob Disease. But the proteins also have at least one known useful function, in the cells that insulate nerves, and are suspected to have more. Now researchers have provided the first direct evidence that the proteins play an important role in neurons themselves. The team reports in the Journal of Neuroscience1 that prions are involved in developmental plasticity, the process by which the structure and function of neurons in the growing brain is shaped by experience. Prions come in two main forms: the normal version and the misfolded, infectious version. The normal version, known as cellular prion protein (or PrPC), is present in every cell of the body and helps to maintain the myelin sheath in the cells that protect the nerves2. But the molecule is abundant in neurons themselves, especially during development. Because it is tethered to the membrane, it is widely assumed to be involved in signalling between nerve cells, but little direct evidence has been found for this. Neurobiologist Enrico Cherubini of the International School for Advanced Studies in Trieste, Italy, and his colleagues therefore decided to look at the effects of electrical stimulation on slices of tissue from the hippocampus of healthy 3–7-day-old mice and of animals genetically engineered to lack the gene that encodes the prion protein. They used electrodes to stimulate individual cells at the same time as the networks of young neurons showed bursts of spontaneous electrical activity, or to simultaneously stimulate pairs of cells that are connected to each other. © 2013 Nature Publishing Group

Keyword: Prions; Development of the Brain
Link ID: 17809 - Posted: 02.16.2013

by Gisela Telis A stint in the dark may be just what the doctor ordered—at least if you have "lazy eye." Researchers report that kittens with the disorder, a visual impairment medically known as amblyopia that leads to poor sight or blindness in one eye, can completely recover their vision by simply spending 10 days in total darkness. "It's a remarkable study, with real potential to change how we think about recovery from amblyopia," says neuroscientist Frank Sengpiel of Cardiff University in the United Kingdom who was not involved in the work. Amblyopia affects about 4% of the human population. It's thought to start with an imbalance in vision early in life: If one eye doesn't see as well as the other—because, for example, of a cataract or astigmatism—the brain reroutes most of the connections needed for visual processing to the "good" eye. Doctors often treat the condition by patching the good eye and forcing the brain to rely on the other eye, but the treatment risks damaging vision in the good eye, and if it doesn't succeed or occur early enough in a child's visual development, the vision loss in the impaired eye can be permanent. Earlier studies with cats, whose complex visual systems are good stand-ins for human vision, showed that neurons in the brain's visual centers shrink when the brain decides to disconnect from the bad eye, but that they grow again when the cats are placed in darkness. So neuroscientists Kevin Duffy and Donald Mitchell of Dalhousie University in Halifax, Canada, set out to test darkness itself as a treatment. © 2010 American Association for the Advancement of Science

Keyword: Vision; Development of the Brain
Link ID: 17808 - Posted: 02.16.2013

By PAM BELLUCK The device allows people with a certain type of blindness to detect crosswalks on the street, the presence of people or cars, and sometimes even large numbers or letters. The approval of the system marks a milestone in a new frontier in vision research, a field in which scientists are making strides with gene therapy, optogenetics, stem cells and other strategies. “This is just the beginning,” said Grace Shen, a director of the retinal diseases program at the National Eye Institute, which helped finance the artificial retina research and is supporting many other blindness therapy projects. “We have a lot of exciting things sitting in the wings.” The artificial retina is a sheet of electrodes implanted in the eye. The patient is also given glasses with an attached camera and a portable video processor. This system, called Argus II, allows visual signals to bypass the damaged portion of the retina and be transmitted to the brain. With the artificial retina or retinal prosthesis, a blind person cannot see in the conventional sense, but can identify outlines and boundaries of objects, especially when there is contrast between light and dark — fireworks against a night sky or black socks mixed with white ones. “Without the system, I wouldn’t be able to see anything at all, and if you were in front of me and you moved left and right, I’m not going to realize any of this,” said Elias Konstantopolous, 74, a retired electrician in Baltimore, one of about 50 Americans and Europeans who have been using the device in clinical trials. He said it helps him differentiate curbs from roads, and detect contours of objects and people. “When you have nothing, this is something. It’s a lot.” The F.D.A. approved Argus II, made by Second Sight Medical Products, to treat people with severe retinitis pigmentosa, in which photoreceptor cells, which take in light, deteriorate. © 2013 The New York Times Company

Keyword: Vision; Robotics
Link ID: 17807 - Posted: 02.16.2013

by Hal Hodson CAN YOU imagine feeling Earth's magnetic field on the tip of your tongue? Strangely, this is now possible, using a device that converts the tongue into a "display" for output from environmental sensors. Gershon Dublon of the Massachusetts Institute of Technology devised a small pad containing electrodes in a 5 × 5 grid. Users put the pad, which Gershon calls Tongueduino, on their tongue. When hooked up to an electronic sensor, the pad converts signals from the sensor into small pulses of electric current across the grid, which the tongue "reads" as a pattern of tingles. Dublon says the brain quickly adapts to new stimuli on the tongue and integrates them into our senses. For example, if Tongueduino is attached to a sensor that detects Earth's magnetic field, users can learn to use their tongue as a compass. "You might not have to train much," he says. "You could just put this on and start to perceive." Dublon has been testing Tongueduino on himself for the past year using a range of environmental sensors. He will now try the device out on 12 volunteers. Blair MacIntyre at the Georgia Institute of Technology in Atlanta says a wireless version of Tongueduino could prove useful in augmented reality applications that deliver information to users inconspicuously, without interfering with their vision or hearing. "There's a need for forms of awareness that aren't socially intrusive," he says. Even Google's much-publicised Project Glass will involve wearing a headset, he points out. © Copyright Reed Business Information Ltd.

Keyword: Chemical Senses (Smell & Taste); Pain & Touch
Link ID: 17806 - Posted: 02.16.2013

The latest bionic superhero is a rat: its brain hooked up to an infrared detector, it's become the first animal to be given a sixth sense. Developed by Miguel Nicolelis and colleagues at Duke University in Durham, North Carolina, the system connects a head-mounted sensor to a brain region that normally processes touch sensations from whiskers. As shown in this video, the rat's brain is tricked when infrared light is detected, giving it a new sense organ. "Instead of seeing, the rats learned how to touch the light," says Nicolelis. Even though the touch-processing brain area acquires a new role, the team found that it continues to process touch sensations from whiskers, somehow dividing its time between both types of signal. "The adult brain is a lot more plastic than we thought," says Nicolelis. The finding could lead to new brain prostheses that restore sight in humans with a damaged visual cortex. By bypassing the damaged part of the brain altogether, it might be possible to wire up a video camera to a part of the brain that processes touch, letting people "touch" what the camera sees. According to Nicolelis, it could also lead to superhero powers for humans. "It could be X-rays, radio waves, anything," he says. "Superman probably had a prosthetic device that nobody knew of." © Copyright Reed Business Information Ltd.

Keyword: Vision; Robotics
Link ID: 17805 - Posted: 02.14.2013

By Emily Chung, CBC News Among musicians who learned to play an instrument before the age of seven, earlier training was linked to more connections in the area of the brain that co-ordinates both hands.Among musicians who learned to play an instrument before the age of seven, earlier training was linked to more connections in the area of the brain that co-ordinates both hands. (Jorge Silva/Reuters) Starting piano or violin lessons before the age of seven appears to cause permanent changes to the brain that are linked to better motor skills. Those changes in brain development don't occur in people who learn to play an instrument when they are older, a new study has found. "What we think is that it doesn't mean you can't be an amazing musician if you start later — just that if you start earlier it may give you some of these specific abilities that are helpful," said Virginia Penhune, a Concordia University psychologist who co-authored the research with two of her doctoral students and McGill University neuropsychologist Robert Zatorre. The Montreal researchers gave a test of motor skills to and scanned the brains of 36 musicians who were either enrolled in a university music program or performed professionally, and who had an average of 16 years experience playing musical instruments. Half of them began their musical training between age three and seven, while the other half started between the ages of eight and 18, but both groups had a comparable level of experience. The study also tested 17 non-musicians. © CBC 2013

Keyword: Development of the Brain; Hearing
Link ID: 17804 - Posted: 02.14.2013

by Lizzie Wade When a male wasp decides it's time to settle down and start a family, he releases a chemical calling card in the form of pheromones, broadcasting his location, his availability, and, most importantly, his identity. Most other kinds of insects will either ignore his signal or be repelled by it, but female wasps of his own species will buzz over and get down to business. But how and why did different pheromone blends—and the species that prefer them—evolve in the first place? A new study offers a possible solution to this long-standing evolutionary mystery, suggesting that new sex pheromones may evolve through genetic mutation before potential mates develop the ability to detect them. Scientists have long been impressed by the perfect harmony of chemical communication among insects, especially when it comes to choosing mates by detecting and responding to the sex pheromones of only their own species. But scientists were puzzled by how such a delicate system evolved. If female wasps respond to only a specific blend of pheromones, males that produce even a subtly different blend shouldn't have much luck mating and passing on their mutant genes. It seemed that in order for males to evolve new pheromones, the female insects would need some preexisting adaptation that would cause them to prefer the new chemical blend. But how could they evolve a preference for something they had never encountered and should, logic suggests, find off-putting? In essence, the question is which came first, a new species or its sex pheromone? In order to answer this question, a team of researchers in Germany turned to the Nasonia vitripennis wasp, a species famous for its propensity to lay its parasitic eggs on doomed fly pupae. When the scientists analyzed the N. vitripennis male sex pheromone, they found it contained two important chemicals, which they call RS and RR. RS also turns up in the male sex pheromones of another species of wasp, N. giraulti, whereas RR appears to be unique. © 2010 American Association for the Advancement of Science.

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 17803 - Posted: 02.14.2013

By Laura Sanders Before you can run, you have to walk, and before you can walk well, you have to walk like a brand-new baby. A new study uncovers the logistics of newborns’ herky-jerky, Frankensteinian stepping action and how this early reflex morphs into refined adult locomotion. In the study, electrodes on infants’ chubby legs picked up signals from neurons that tell muscles to fire, revealing that three-day old babies tense up many of their leg muscles all at once. Toddlers, preschoolers and adults, by contrast, showed a progressively more sophisticated, selective pattern of neuron activity. From birth to adulthood, motor neurons in the spine get an overhaul as neurons in different locations along the spine become specialized for various aspects of walking, such as foot position, balance and direction, Yuri Ivanenko of the Santa Lucia Foundation in Rome and colleagues conclude in the Feb. 13 Journal of Neuroscience. © Society for Science & the Public 2000 - 2013

Keyword: Development of the Brain
Link ID: 17802 - Posted: 02.14.2013

By Melinda Wenner Moyer On the night of my 32nd birthday, my husband and I enjoyed a delicious dinner while on vacation in Orvieto, Italy. To complement my pasta, I drank a single glass of red wine, my first since learning I was pregnant four months earlier. Even now my indulgence that evening inspires periodic pangs of guilt: Did I stunt my son's potential by sipping that Sangiovese? Nobody questions the notion that heavy drinking during pregnancy is harmful. It can cause facial abnormalities, central nervous system problems and stunted growth. But evidence regarding the effects of light or occasional drinking is mixed. In five epidemiological studies published in 2012, medical psychologist Erik Mortensen of the University of Copenhagen and his colleagues found that five-year-old children born to women who had one to four drinks a week during pregnancy displayed no deficits in general intelligence, attention or other types of higher-order thinking. On the other hand, in 2011 psychiatrist Nancy Day of the University of Pittsburgh and her colleagues reported that teens born to women who averaged more than one drink a week during pregnancy were twice as likely as those born to nondrinkers to have conduct disorder, a condition characterized by theft, deceit or violence. The truth is hard to discern because research on the issue is fraught with problems. The ideal type of experiment is not ethical: scientists cannot randomly assign one group of women to drink during pregnancy and compare the outcome with those instructed to abstain. As a result, they must compare what happens to women who choose to drink during pregnancy with those who do not, and these women often differ in important ways. All things considered, having an occasional drink during those nine months—say, one or two a week—probably poses little, if any, harm. Still, some experts warn, light or sporadic drinking may have effects we do not know how to measure. © 2013 Scientific American

Keyword: Drug Abuse; Development of the Brain
Link ID: 17801 - Posted: 02.14.2013

by Kelli Whitlock Burton Having a conversation in a noisy restaurant can be difficult. For many elderly adults, it's often impossible. But with a little practice, the brain can learn to hear above the din, a new study suggests. Age-related hearing loss can involve multiple components, such as the disappearance of sensory cells in the inner ear. But scientists say that part of the problem may stem from our brains. As we get older, our brains slow down—a natural part of aging called neural slowing. One side effect of this sluggishness is the inability to process the fast-moving parts of speech, particularly consonants at the beginning of words that sound alike, such as "b," "p," "g," and "d." Add background noise to the mix and "bad" may sound like "dad," says Nina Kraus, director of the Auditory Neuroscience Laboratory at Northwestern University in Evanston, Illinois. "Neural slowing especially affects our ability to hear in a noisy background because the sounds we need to hear are acoustically less salient and because noise also taxes our ability to remember what we hear." Building on animal studies that pointed to an increase in neural speed following auditory training, Kraus and colleagues enrolled 67 people aged 55 to 70 years old with no hearing loss or dementia in an experiment. Half the group completed about 2 months of exercises with Brain Fitness, a commercially available auditory training program by Posit Science. (The team has no connection to the company.) The exercises helped participants better identify different speech sounds and distinguish between similar-sounding syllables, such as "ba" or "ta." © 2010 American Association for the Advancement of Science

Keyword: Hearing; Development of the Brain
Link ID: 17800 - Posted: 02.14.2013