Chapter 19. Language and Hemispheric Asymmetry
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Young people who sustain brain injuries are more likely to commit crimes and end up in prison, research suggests. The University of Exeter study says such injuries can lead maturing brains to "misfire", affecting judgement and the ability to control impulses. It calls for greater monitoring and treatment to prevent later problems. The findings echo a separate report by the Children's Commissioner for England on the impact of injuries on maturing brains and the social consequences. In the report, Repairing Shattered Lives, Professor Huw Williams from the University of Exeter's Centre for Clinical Neuropsychology Research, describes traumatic brain injury as a "silent epidemic". It is said to occur most frequently among children and young people who have fallen over or been playing sport, as well as those involved in fights or road accidents. The consequences can include loss of memory, with the report citing international research which indicates the level of brain injuries among offenders is much higher than in the general population. A survey of 200 adult male prisoners in Britain found 60% claimed to have suffered a head injury, it notes. The report acknowledges there may be underlying risk factors for brain injury and offending behaviour but says improving treatment and introducing screening for young offenders would deliver significant benefits in terms of reducing crime and saving public money. BBC © 2012
Results of a new study presented at Neuroscience 2012, the annual meeting of the Society of Neuroscience, has suggested the right hemisphere of the brain performs important tasks during its resting state, implying different end results for left-handed people and right-handed people, who use the right and left sides of their brains differently. Findings showed that when resting, the right hemisphere of the brain communicates more with itself and the left side of the brain, than when the left hemisphere talks to itself and communicates to the right side of the brain, regardless of participants' dominant hand. Neuroscientists did note that right-handed people used their left hemisphere at a higher rate, and vice versa. The authors of this study say that during rest, the right hemisphere is "doing important things, we don't yet understand." The activities that are being processed by the right hemisphere could be storing and processing acquired information, daydreaming, or similar creative tasks. Andrei Medvedev, Ph.D., an assistant professor in the Center for Functional and Molecular Imaging at Georgetown explains: The researchers had 15 participants connect to near-infrared spectroscopy (NIRS) equipment. This inexpensive and moveable technology uses light to calculate changes in oxygenated hemoglobin inside the body. Participants wore a hat that contained optical fibers delivering infrared light to the outermost layers of the brain and then assessed the light that bounced back. Through this method, the device could see which parts of the brain are active and communicate at the highest rate, based on heightened use of oxygen in the blood and elevated simultaneous occurrence of their activities.
by Sara Reardon, New Orleans, Louisiana Does beer make you shlur your wordsh? You're not alone: drunk zebra finches (Taeniopygia guttata) sing songs that are blurrier and more disordered than those of their sober counterparts. What's more, binge drinking may permanently impair juvenile finches' ability to learn new songs – which could have implications for our understanding of the effect of heavy drinking on adolescents. Having a unique and interesting song is important for zebra finches to mate, and each male develops his own signature tune as he matures, says Christopher Olson of Oregon Health and Science University in Portland. Because zebra finch song is so well studied, Olson and colleagues decided to find out how alcohol would affect it. First, they had to find out whether finches are even interested in alcohol. When they gave a group of adult finches 6 per cent ethanol in their water bottles, the birds drank enough of it that their blood alcohol content sometimes reached 0.8 per cent: the legal limit for drivers in many places. The birds were also happy to sing while drunk. Using audio analysis software, the researchers determined the degree of "white noise", or disorganised sounds, in their songs. The drunk birds' songs were significantly more broken and disorganised. "It's their husky bar voice," says Olson. © Copyright Reed Business Information Ltd.
by Moheb Costandi NEW ORLEANS, LOUISIANA—Books and educational toys can make a child smarter, but they also influence how the brain grows, according to new research presented here on Sunday at the annual meeting of the Society for Neuroscience. The findings point to a "sensitive period" early in life during which the developing brain is strongly influenced by environmental factors. Studies comparing identical and nonidentical twins show that genes play an important role in the development of the cerebral cortex, the thin, folded structure that supports higher mental functions. But less is known about how early life experiences influence how the cortex grows. To investigate, neuroscientist Martha Farah of the University of Pennsylvania and her colleagues recruited 64 children from a low income background and followed them from birth through to late adolescence. They visited the children's homes at 4 and 8 years of age to evaluate their environment, noting factors such as the number of books and educational toys in their houses, and how much warmth and support they received from their parents. More than 10 years after the second home visit, the researchers used MRI to obtain detailed images of the participants' brains. They found that the level of mental stimulation a child receives in the home at age 4 predicted the thickness of two regions of the cortex in late adolescence, such that more stimulation was associated with a thinner cortex. One region, the lateral inferior temporal gyrus, is involved in complex visual skills such as word recognition. © 2010 American Association for the Advancement of Science
By Nathan Seppa Men with high blood levels of lycopene — the compound that makes tomatoes red — are about half as likely to have a stroke as those low on lycopene, researchers in Finland report October 9 in Neurology. Some evidence suggests that lycopene quells inflammation, limits cholesterol production and inhibits blood clotting. But first and foremost, lycopene is a carotenoid, an antioxidant that sops up unstable molecules in the body called free radicals —agents that can induce DNA damage, kill cells, attack proteins and contribute to blood vessel disease. Lycopene’s direct effect on stroke risk is less clear. Studies have found that a diet rich in fruits and vegetables, meaning plenty of carotenoids, seems to reduce the risk of heart disease and stroke. But few studies have analyzed lycopene’s effect specifically on stroke risk over time, the researchers note. Jouni Karppi and colleagues at the University of Eastern Finland in Kuopio used blood tests to determine the lycopene levels of 1,031 men ages 46 to 65. Afterward, the men were monitored for a median of 12 years. The researchers tallied 67 strokes in the men over that span. Men with the lowest lycopene levels at the outset were more than twice as likely to have a stroke later as were those with the highest. “This is a very good study, and I’m really surprised they were able to find this relationship with only 67 strokes,” says Lyn Steffen, a nutritional epidemiologist at the University of Minnesota. © Society for Science & the Public 2000 - 2012
Link ID: 17363 - Posted: 10.13.2012
Strokes are occurring at a younger age, say researchers who call the trend concerning. Researchers looked at strokes occurring in people aged 20 to 54 in the Greater Cincinnati and Northern Kentucky regions. "We found trends toward increasing stroke incidence at younger ages," study author Dr. Brett Kissela of the University of Cincinnati College of Medicine in Ohio and his co-authors concluded in Wednesday's online issue of the journal Neurology. A rise in risk factors such as obesity, Type 2 diabetes and high cholesterol are potential reasons for the trend, Kissela said. Better diagnosis from MRI could also be contributing. "Regardless, the rising trend found in our study is of great concern for public health because strokes in younger people translate to greater lifetime disability," he said in a release. In the study, researchers looked at first strokes that occurred during three, separate year-long periods between 1993 and 2005. What's behind stroke trend? The average age of people who experienced stroke fell from 71 years in 1993 and 1994 to 69 years in 2005, the researchers found. Among the young stroke patients, more coronary heart disease was found in 1999 and 2005 compared with the first year. The prevalence of heart disease among the general population didn't change. © CBC 2012
Mo Costandi The growth pattern of long-range connections in the brain predicts how a child’s reading skills will develop, according to research published today in Proceedings of the National Academy of Sciences1. Literacy requires the integration of activity in brain areas involved in vision, hearing and language. These areas are distributed throughout the brain, so efficient communication between them is essential for proficient reading. Jason Yeatman, a neuroscientist at Stanford University in California, and his colleagues studied how the development of reading ability relates to growth in the brain’s white-matter tracts, the bundles of nerve fibres that connect distant regions of the brain. They tested how the reading skills of 55 children aged between 7 and 12 years old developed over a three-year period. There were big differences in reading ability between the children, and these differences persisted — the children who were weak readers relative to their peers at the beginning of the study were still weak three years later. The researchers also scanned the brains of 39 of the children at least three times during the same period, to visualize the growth of two major white-matter tracts: the arcuate fasciculus, which conects the brain's language centres, and the inferior longitudinal fasciculus, which links the language centres with the parts of the brain that process visual information. © 2012 Nature Publishing Group,
It may be possible to use a drug to prevent some of the lasting and crippling damage caused by a stroke, according to doctors in the US and Canada. A safety trial, published in the Lancet Neurology medical journal, suggested the chemical NA-1 was safe to use. The study on 185 people also hinted that patients given the drug developed fewer regions of damaged brain tissue. The Stroke Association said that it was promising, but needed more research. Tests in primates had suggested NA-1 prevented brain cells dying when a stroke starved them of oxygen. A small trial was set up at 14 hospitals in the US and Canada. Patients who took part were having an operation to repair a brain aneurysm, a weakened blood vessel which could rupture, are at increased risk of a stroke. Ninety-two people had the drug injected into a vein, while another 93 were injected with salty water. The doctors concluded that NA-1 was safe, with only two patients having mild side effects. However, brain scans also showed that fewer brain lesions, damaged areas of tissue, formed in patients given the drug. BBC © 2012
Link ID: 17344 - Posted: 10.08.2012
By Susan Milius A patch over a male Gouldian finch’s right eye works like beer goggles, though the bird doesn’t need booze to flirt unwisely. If limited to using his left eye when checking out possible mates, he risks making really stupid choices. Gouldian finches have caps of black, red or yellow feathers on their heads. In nature, the birds prefer to mate with partners with the same cap color. Yet black-headed males rendered temporarily left-eyed by a tiny removable eye patch flirted as readily with red-heads as with black-heads, says cognitive ecologist Jennifer Templeton of Knox College in Galesburg, Ill. That’s not smart because daughters typically fail to survive when Gouldian finches mate outside their cap color. Also the male himself “becomes less attractive,” Templeton says. When the bird’s right eye was covered, he sang, bowed and posed less during his attempts at courtship. Some left-eyed males didn’t manage to make up their minds at all, but “just hopped around randomly,” Templeton says. Moving the eye patch to the right eye, however, restored male Gouldian finches to their senses. Males then spent more time perching near same-cap-color females and flirting with them. “Beauty is in the right eye of the beholder,” Templeton and her colleagues conclude online October 3 in Biology Letters. Birds make fine subjects for comparing eye biases because many species’ eyes sit on opposite sides of their skulls with very different fields of view. A bird’s right eye connects to the left hemisphere of its brain, and the left eye to the right hemisphere. Unlike mammals, birds don’t have a high-speed connection between hemispheres. © Society for Science & the Public 2000 - 2012
By Susan Milius Let’s take a minute to turn faces upside down. Pick any face. Ignore beards, glasses, hairdos or lack of any hair to do, and upend the facial features of Charles Darwin, Ray Charles or anyone named Charlotte who reads Science News. People who normally remember or match a face perfectly well have trouble when it is standing on its head. But before there’s a chorus of “well, obviously,” let’s try turning dogs upside down, too. Most people who don’t breed dogs or judge shows don’t recognize an individual dog nearly as well as a person’s face to begin with. And when pictures of poodles and Irish setters flip upside down in quizzes of learning and memory, people struggle a bit more than they do with the natural versions. But scores drop only modestly with these flipped-dog pics, compared with the dramatic drop for facial flips. The disproportionate decline in remembering inverted faces has shown up in a variety of recall tests, with comparison groups from dogs to bridges, airplanes, stick figures, even clothing from 17th and 18th century paintings. Upside-down faces are where quiz scores really slump, and researchers view that slump as one of the signs that test-takers are actually experts at face perception. A dog is a dog in any orientation. Same for other organisms and objects. But right-side-up faces apparently are so compelling that people have become especially masterful at recognizing the human visage. Know-it-at-a-glance holistic techniques behind this mastery fail when the world turns upside down. access © Society for Science & the Public 2000 - 2012
by Virginia Morell Bumblebees foraging in flowers for nectar are like salesmen traveling between towns: Both seek the optimal route to minimize their travel costs. Mathematicians call this the "traveling salesman problem," in which scientists try to calculate the shortest possible route given a theoretical arrangement of cities. Bumblebees, however, take the brute-force approach: For them, it's simply a matter of experience, plus trial and error, scientists report in the current issue of PLoS Biology. The study, the first to track the movements of bumblebees in the field, also suggests that bumblebees aren't using cognitive maps—mental recreations of their environments—as some scientists have suggested, but rather are learning and remembering the distances and directions that need to be flown to find their way from nest to field to home again. A team of researchers from Queen Mary, University of London outfitted seven bumblebees with tiny radar transponders, which they stuck on the bees' backs with double-sided tape. They trained the bees to forage nectar from five blue artificial flowers (see video). Each artificial flower had a yellow landing platform and a single drop of sucrose, just enough to fill one-fifth of a bumblebee's tank capacity, to ensure that the bees would visit all five flowers on each foraging bout. The scientists placed the flowers in a field at Rothamsted Research, a biological research station north of London, in October—a time of year when there are few natural sources of nectar and pollen and the bees are more likely to focus on the artificial flowers. They arranged the flowers in a pentagon and spaced them 50 meters apart; that distance is more than three times as far as bumblebees can see, so the bees must actively fly around to locate their next target. A motion-triggered Webcam was attached to each flower to record the bees' visits. Then, every day for a month, each bee was freed to forage for 7 hours. © 2010 American Association for the Advancement of Science
By Frances Stead Sellers Carolyn McCaskill remembers exactly when she discovered that she couldn’t understand white people. It was 1968, she was 15 years old, and she and nine other deaf black students had just enrolled in an integrated school for the deaf in Talledega, Ala. When the teacher got up to address the class, McCaskill was lost. “I was dumbfounded,” McCaskill recalls through an interpreter. “I was like, ‘What in the world is going on?’ ” The teacher’s quicksilver hand movements looked little like the sign language McCaskill had grown up using at home with her two deaf siblings and had practiced at the Alabama School for the Negro Deaf and Blind, just a few miles away. It wasn’t a simple matter of people at the new school using unfamiliar vocabularly; they made hand movements for everyday words that looked foreign to McCaskill and her fellow black students. So, McCaskill says, “I put my signs aside.” She learned entirely new signs for such common nouns as “shoe” and “school.” She began to communicate words such as “why” and “don’t know” with one hand instead of two as she and her black friends had always done. She copied the white students who lowered their hands to make the signs for “what for” and “know” closer to their chins than to their foreheads. And she imitated the way white students mouthed words at the same time as they made manual signs for them. Whenever she went home, McCaskill carefully switched back to her old way of communicating. © 1996-2012 The Washington Post
Link ID: 17271 - Posted: 09.18.2012
By Laura Sanders A single four-month deployment to Afghanistan is associated with brain changes and diminished attention, Dutch scientists report. Most changes went away a year and a half after returning from combat, suggesting that the brain can largely heal itself — and that longer breaks between combat tours might be a good idea. The study, which focused on healthy Dutch soldiers, reveals how the brain responds to stress outside of a laboratory, says clinical neuroscientist Rajita Sinha of the Yale University School of Medicine. “It’s a nice way to start looking at natural high levels of stress we experience as humans,” she says. Although the soldiers came back mentally and physically healthy, in Afghanistan they had fought, come under enemy fire and seen their fellow soldiers and civilians wounded or dead. Researchers led by Guido van Wingen of the University of Amsterdam conducted brain scans while the soldiers performed a lab test that required them to hold several numbers in their memory simultaneously. Initially, the researchers found no brain differences between 33 soldiers who were about to be deployed for the first time and 26 who were still in training. Nor were there differences in a lab task that required intense concentration for several minutes. But the story changed after some soldiers experienced combat, the team reports online September 4 in the Proceedings of the National Academy of Sciences. © Society for Science & the Public 2000 - 2012
By Mollie Bloudoff-Indelicato | The doctors told her she needed surgery — brain surgery. Operations on such a complex organ are never simple, but this procedure was exceptionally difficult. There was a high risk of complications, of debilitation, of post-op problems. Alvarez might wake up paralyzed. She might wake up legally blind. Worse still, there was a chance she might not wake up at all. Her mad dash to the emergency room had all begun with a walk in the park four days earlier. It was December 20, 2010, in Sunnyvale, Calif., a town that lives up to its name. The West Coast winter, not as long or as harsh as seasons in the East, gave her the opportunity to take her youngest child out for an afternoon stroll. In the fading light of dusk, Alvarez, too, began to fade. She lost the feeling in her right leg. Her right foot followed suit. She couldn’t lift or move her right hand. She was weak, and her body was numb. There was fear then, too. At 10:15 p.m., Alvarez says her husband drove her to Redwood City. That night she became a patient at Kaiser Permanente Redwood City Hospital. She says the doctors batted diagnoses back and forth. It was a tumor. No, it was cancer. It was Christmas, and Alvarez’s children cried and prayed, terrified that an unknown affliction would steal their mother away. Finally a CT scan revealed the malady. Alvarez had neurocysticercosis — a calcified tapeworm lodged in her brain. © 2012 Scientific American,
Link ID: 17229 - Posted: 09.07.2012
Jeannine Stamatakis psychologist John Watson, the founder of behaviorism, once said, “Give me a dozen healthy infants, well formed, and my own specified world to bring them up in, and I'll guarantee to take any one at random and train him to become any type of specialist I might select.” If we take Watson's logic one step further, it may be possible to mold someone into a psychopath. Psychopathy, also called sociopathy, is defined by a lack of empathy, deceitfulness and complete selfishness. Current thinking is that although certain genes may predispose people toward psychopathy, their environment seems to provide the ultimate catalyst. Thus, a person who possesses the particular genes associated with this malady and is brought up in an abusive or neglectful household will be at a higher risk of exhibiting the traits associated with this disorder. Severe trauma to specific regions of the brain can cause a person to undergo marked personality changes, such as in the famous case of Phineas Gage. While working as a railroad construction foreman in Vermont in 1848, he survived an accident in which a large iron rod was driven through his head, damaging much of his brain's left frontal lobe. Although he did not become a sociopath, the reported effects on his personality and behavior were so profound that friends saw him as “no longer Gage.” An incident two decades ago supports the idea that brain trauma can lead to psychopathic behaviors. In 1991 convicted sex offender Phillip Garrido kidnapped 11-year-old Jaycee Dugard and kept her as a prisoner in his home for 18 years. Experts believe that Garrido experienced severe brain damage after a serious motorcycle accident as a teenager, which was compounded by intense drug use. Garrido's father said that his son had been a “good boy” as a child but that he had changed radically after the accident and had become unstable. © 2012 Scientific American,
By ANNE EISENBERG FOOTBALL teams of the future — even high school squads on limited budgets — may someday have a new tool to check players for brain injuries. It’s a special form of headgear, packed with sensors that read the brain waves of athletes after they come off the field, thus detecting changes caused by the trauma of hard knocks. The compact, portable sensors decipher neural activity by measuring changes in the brain’s tiny magnetic field. These small magnetometers — still in the laboratory and in prototype — have yet to be tried on athletes. But their potential is enormous for brain imaging and for inexpensive monitoring of brain diseases, as well as for many other applications like the control of prosthetics, said Dr. José Luis Contreras-Vidal, a professor of electrical and computer engineering at the University of Houston. Dr. Contreras-Vidal’s research includes work on a system that will use brain signals to control prosthetic legs. “This is a transformative technology” that could make brain interfaces available at a small cost, he said. “We could potentially use these devices to record in real time brain waves that could be analyzed for specific diseases such as Alzheimer’s, or the progression of these diseases.” The research is occurring at a time of growing concern about collisions and subsequent brain injuries in sports — and the dire effects that may show up only many years later. But an inexpensive system for spotting changes in brain behavior could play an important safety role one day in boxing, football and many other sports. © 2012 The New York Times Company
Keyword: Brain Injury/Concussion
Link ID: 17207 - Posted: 08.27.2012
By James Gallagher Health and science reporter, BBC News Using small nets to extract blood clots from patients' brains may be the future of stroke care, according to two studies. Clots block blood vessels, starving parts of the brain of oxygen, which leads to symptoms such as paralysis and loss of speech. Two studies, presented in the Lancet medical journal, suggest extracting clots with nets could improve recovery. The Stroke Association said it was very excited by the treatment's potential. There are already techniques for reopening blocked blood vessels in people's brains. Some patients will be given "clot-busting" drugs, but this needs to be in the hours just after the stroke and is not suitable for everyone. Other techniques have been developed to extract the clot. Some procedures pass a tube up through the groin to the brain. There the wire passes through the clot, forming a coil on the far side and then pulling the clot out. However, this is far from routine practice. The latest methods involve a tiny wire cage instead of a coil. This pushes the clot up against the walls of the artery and enmeshes the clot in the wires, allowing doctors to pull the clot back out of the groin. BBC © 2012
Link ID: 17204 - Posted: 08.27.2012
By Bruce Bower Indo-European languages range throughout Europe and South Asia and even into Iran, yet the roots of this widespread family of tongues have long been controversial. A new study adds support to the proposal that the language family expanded out of Anatolia — what’s now Turkey — between 8,000 and 9,500 years ago, as early farmers sought new land to cultivate. A team led by psychologist Quentin Atkinson of the University of Auckland in New Zealand came to that conclusion by using a mathematical method to calculate the most likely starting point and pattern of geographic spread for a large set of Indo-European languages. The new investigation, published in the Aug. 24 Science, rejects a decades-old idea that Kurgan warriors riding horses and driving chariots out of West Asia’s steppes 5,000 to 6,000 years ago triggered the rise of Indo-European speakers. “Our analysis finds decisive support for an Anatolian origin over a steppe origin of Indo-European languages,” Atkinson says. He and his colleagues generated likely family trees for Indo-European languages, much as geneticists use DNA from different individuals to reconstruct humankind’s genetic evolution. Many linguists, who compare various features of languages to establish their historical connections, consider Atkinson’s statistical approach unreliable (SN: 11/19/11, p. 22). © Society for Science & the Public 2000 - 2012
Analysis by Sheila Eldred Behavioral control and decision-making take part in different regions of the brain's frontal lobe, new research shows The study effectively created a map of the frontal lobes, making it possible for patients with brain injuries to get an accurate prognosis early in treatment. "That knowledge will be tremendously useful for prognosis after brain injury," Ralph Adolphs, Bren Professor of Psychology and Neuroscience at Caltech and a coauthor of the study published in this week's issue of the Proceedings of the National Academy of Sciences (PNAS), said in a press release. "Many people suffer injury to their frontal lobes -- for instance, after a head injury during an automobile accident -- but the precise pattern of the damage will determine their eventual impairment," he added. When you're making a decision, several different parts of the brain might be activated. How a person functions after a brain injury depends on precisely where a brain injury occurs. Other parts of the brain might compensate, allowing the person to function typically, or the person might be left with a lifelong hardship in making decisions. "We can use our lesion maps and compare the location of damaged brain areas in new patients," Jan Glascher, lead author of the study and a visiting associate in psychology at Caltech, said in an email interview. "This way we can predict what impairments these new patients will likely have. This can facilitate medical diagnoses and spark ideas for treatment strategies." © 2012 Discovery Communications, LLC.
Link ID: 17192 - Posted: 08.22.2012
by Hannah Krakauer Kanzi the bonobo continues to impress. Not content with learning sign language or making up "words" for things like banana or juice, he now seems capable of making stone tools on a par with the efforts of early humans. Eviatar Nevo of the University of Haifa in Israel and his colleagues sealed food inside a log to mimic marrow locked inside long bones, and watched Kanzi, a 30-year-old male bonobo chimp, try to extract it. While a companion bonobo attempted the problem a handful of times, and succeeded only by smashing the log on the ground, Kanzi took a longer and arguably more sophisticated approach. Both had been taught to knap flint flakes in the 1990s, holding a stone core in one hand and using another as a hammer. Kanzi used the tools he created to come at the log in a variety of ways: inserting sticks into seams in the log, throwing projectiles at it, and employing stone flints as choppers, drills, and scrapers. In the end, he got food out of 24 logs, while his companion managed just two. Perhaps most remarkable about the tools Kanzi created is their resemblance to early hominid tools. Both bonobos made and used tools to obtain food – either by extracting it from logs or by digging it out of the ground. But only Kanzi's met the criteria for both tool groups made by early Homo: wedges and choppers, and scrapers and drills. © Copyright Reed Business Information Ltd.