Chapter 15. Language and Our Divided Brain
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Smart, successful, and well-connected: a good description of Albert Einstein … and his brain. The father of relativity theory didn’t live to see modern brain imaging techniques, but after his death his brain was sliced into sections and photographed. Now, scientists have used those cross-sectional photos to reveal a larger-than-average corpus callosum—the bundle of nerve fibers connecting the brain’s two hemispheres. Researchers measured the thickness of the famous noggin’s corpus callosum (the lighter-colored, downward-curving region at the center of each hemisphere, above) at various points along its length, and compared it to MRIs from 15 elderly men and 52 young, healthy ones. The thickness of Einstein’s corpus callosum was greater than the average for both the elderly and the young subjects, the team reported online last week in the journal Brain. The authors posit that in Einstein’s brain, more nerve fibers connected key regions such as the two sides of the prefrontal cortex, which are responsible for complex thought and decision-making. Combined with previous evidence that parts of the physicist’s brain were unusually large and intricately folded, the researchers suggest that this feature helps account for his extraordinary gifts. © 2013 American Association for the Advancement of Science
By Lenny Bernstein, Joanna Leigh describes her life in black and white, before and after. Before the Boston Marathon bombing, she says, she had “just embarked on a really beautiful future” with a new doctoral degree in international development and a career as a consultant. Today, she says, she can’t work or drive and often gets lost, sometimes on her own block. Her vision is blurry, her hearing is diminished and her ears ring constantly. She struggles to cook dinner, do her laundry, fill out a form. Mostly, she sleeps. The cause of her difficulties, according to the physician who examined her, was a traumatic brain injury on April 15. But because Leigh, 39, walked home that day after she was knocked unconscious by the second bomb and never went to a hospital, she received just $8,000 from the One Fund charity for survivors. She said her medical and other expenses have reached $70,000. She is applying for disability payments and food stamps. One Fund payouts to everyone except 16 amputees and the families of the four people who were killed were based on the number of nights spent in the hospital. A single night was worth $125,000; 32 nights qualified victims for $948,000. The 143 people who were treated as outpatients received $8,000 each. In coming days, Leigh and four other attack survivors will petition the One Fund to develop a new plan for distributing the millions of dollars in donations the charity has received since the first payout. They are seeking a formula that takes into account injuries that were slow to reveal themselves. © 1996-2013 The Washington Post
Keyword: Brain Injury/Concussion
Link ID: 18736 - Posted: 10.03.2013
By KEN BELSON Football players as young as 7 sustain hits to the head comparable in magnitude to those absorbed by high school and adult players, and most of the hits are sustained in practices, not games, according to research to be released Wednesday. The findings, which may influence how youth football organizations handle training methods and rules, were included in four studies published by researchers at the Virginia Tech-Wake Forest University School of Biomedical Engineering and Sciences. The research, though limited, is considered by experts to be a step in the effort to address the relatively shallow understanding of the potential long-term effects of head trauma on young players. More than 25,000 football players from 8 to 19 years old are taken to emergency rooms seeking treatment for concussions every year, but most of the research on head injuries in football has focused on professional and college players. The new research, which was presented at the annual Biomedical Engineering Society conference this week, tracked about 120 players in Virginia and North Carolina from 7 to 18 over two seasons. Each young athlete wore six devices, known as accelerometers, in their helmets to measure the force, position and direction of the hits, and every practice and game was videotaped to determine how they occurred. To help determine any changes in brain structure and function, many of the players received magnetic resonance imaging brain scans before and after the season, and after they sustained a concussion. Some players also received magnetoencephalography scans, or MEG scans, to map their brain activity. © 2013 The New York Times Company
By Melissa Hogenboom Science reporter, BBC News Moving in time to a steady beat is closely linked to better language skills, a study suggests. People who performed better on rhythmic tests also showed enhanced neural responses to speech sounds. The researchers suggest that practising music could improve other skills, particularly speech. In the Journal of Neuroscience, the authors argue that rhythm is an integral part of language. "We know that moving to a steady beat is a fundamental skill not only for music performance but one that has been linked to language skills," said Nina Kraus, of the Auditory Neuroscience Laboratory at Northwestern University in Illinois. More than 100 teenagers were asked to tap their fingers along to a beat. Their accuracy was measured by how closely their responses matched the timing of a metronome. Next, in order to understand the biological basis of rhythmic ability, the team also measured the brainwaves of their participants with electrodes, a technique called electroencephalography. This was to observe the electrical activity in the brain in response to sound. Using this biological approach, the researchers found that those who had better musical training also had enhanced neural responses to speech sounds. In poorer readers this response was diminished. BBC © 2013
By Joshua K. Hartshorne There are two striking features of language that any scientific theory of this quintessentially human behavior must account for. The first is that we do not all speak the same language. This would be a shocking observation were not so commonplace. Communication systems and other animals tend to be universal, with any animal of the species able to communicate with any other. Likewise, many other fundamental human attributes show much less variation. Barring genetic or environmental mishap, we all have two eyes, one mouth, and four limbs. Around the world, we cry when we are sad, smile when we are happy, and laugh when something is funny, but the languages we use to describe this are different. The second striking feature of language is that when you consider the space of possible languages, most languages are clustered in a few tiny bands. That is, most languages are much, much more similar to one another than random variation would have predicted. Starting with pioneering work by Joseph Greenberg, scholars have cataloged over two thousand linguistic universals (facts true of all languages) and biases (facts true of most languages). For instance, in languages with fixed word order, the subject almost always comes before the object. If the verb describes a caused event, the entity that caused the event is the subject ("John broke the vase") not the object (for example, "The vase shbroke John" meaning "John broke the vase"). In languages like English where the verb agrees with one of its subjects or objects, it typically agrees with the subject (compare "the child eats the carrots" with "the children eat the carrots") and not with its object (this would look like "the child eats the carrot" vs. "the child eat the carrots"), though in some languages, like Hungarian, the ending of the verb changes to match both the subject and object. © 2013 Scientific American
Link ID: 18664 - Posted: 09.18.2013
By Tina Hesman Saey About 10 percent of people prefer using their left hand. That ratio is found in every population in the world and scientists have long suspected that genetics controls hand preference. But finding the genes has been no simple task, says Chris McManus, a neuropsychologist at University College London who studies handedness but was not involved in the new research. “There’s no single gene for the direction of handedness. That’s clear,” McManus says. Dozens of genes are probably involved, he says, which means that one person’s left-handedness might be caused by a variant in one gene, while another lefty might carry variants in an entirely different gene. To find handedness genes, William Brandler, a geneticist at the University of Oxford, and colleagues conducted a statistical sweep of DNA from 3,394 people. Statistical searches such as this are known as genome-wide association studies; scientists often do such studies to uncover genes that contribute to complex diseases or traits such as diabetes and height. The people in this study had taken tests involving moving pegs on a board. The difference in the amount of time they took with one hand versus the other reflected how strongly left- or right-handed they were. A variant in a gene called PCSK6 was most tightly linked with strong hand preference, the researchers report in the Sept. 12 PLOS Genetics.. The gene has been implicated in handedness before, including in a 2011 study by the same research group. PCSK6 is involved in the asymmetrical positioning of internal organs in organisms from snails to vertebrates. © Society for Science & the Public 2000 - 2013
Associated Press It's the ape equivalent of Google Maps and Facebook. The night before a big trip, Arno the orangutan plots his journey and lets others know where he is going with a long, whooping call. What he and his orangutan buddies do in the forests of Sumatra tells scientists that advance trip planning and social networking aren't just human traits. A new study of 15 wild male orangutans finds that they routinely plot out their next-day treks and share their plans in long calls, so females can come by or track them, and competitive males can steer clear. The researchers closely followed the males as they traveled on 320 days during the 1990s. The results were published Wednesday in the journal PLoS One. Typically, an orangutan would turn and face in the direction of his route and let out a whoop, sometimes for as long as four minutes. Then he'd go to sleep and 12 hours later set on the heralded path, said study author Carel van Schaik, director of the Anthropological Institute at the University of Zurich. "This guy basically thinks ahead," van Schaik said. "They're continuously updating their Google Maps, so to speak. Based on that, they're planning what to do next." The apes didn't just call once - they kept at it, calling more than 1,100 times over the 320 days. © 2013 The Hearst Corporation
Ed Yong Listen very carefully in the rainforests of Brazil and you might hear a series of quiet, high-pitched squeaks. These are the alarm calls of the black-fronted titi (Callicebus nigrifrons), a monkey with a rusty-brown tail that lives in small family units. The cries are loaded with information. Cristiane Cäsar, a biologist at the University of St Andrews, UK, and her colleagues report that the titis mix and match two distinct calls to tell each other about the type of predator that endangers them, as well as the location of the threat. Her results are published in Biology Letters1. Cäsar's team worked with five groups of titis that live in a private nature reserve in the Minas Gerais region of Brazil. When the researchers placed a stuffed caracara — a bird of prey — in the treetops, the titis gave out A-calls, which have a rising pitch. When the animals saw a ground-based threat — represented by an oncilla, a small spotted cat — they produced B-calls, sounds with a falling pitch. However, when the team moved the predator models around, the monkeys tweaked their calls. If the caracara was on the ground, the monkeys started with at least four A-calls before adding B-calls into the mix. If the oncilla was in a tree, the monkeys made a single introductory A-call before switching to B-calls. “A single call doesn’t really tell the recipient what’s happening, but they can infer the type of predator and its location by listening to the first five or six calls,” says co-author Klaus Zuberbühler of the University of Neuchâtel in Switzerland. “The five different groups were almost unanimous in their response. There was no deviation.” © 2013 Nature Publishing Group
By Jason G. Goldman One of the key differences between humans and non-human animals, it is thought, is the ability to flexibly communicate our thoughts to others. The consensus has long been that animal communication, such as the food call of a chimpanzee or the alarm call of a lemur, is the result of an automatic reflex guided primarily by the inner physiological state of the animal. Chimpanzees, for example, can’t “lie” by producing a food call when there’s no food around and, it is thought, they can’t not emit a food call in an effort to hoard it all for themselves. By contrast, human communication via language is far more flexible and intentional. But recent research from across the animal kingdom has cast some doubt on the idea that animal communication always operates below the level of conscious control. Male chickens, for example, call more when females are around, and male Thomas langurs (a monkey native to Indonesia) continue shrieking their alarm calls until all females in their group have responded. Similarly, vervet monkeys are more likely sound their alarm calls when their are other vervet monkeys around, and less likely when they’re alone. The same goes for meerkats. And possibly chimps, as well. Still, these sorts of “audience effects” can be explained by lower-level physiological factors. In yellow-bellied marmots, small ground squirrels native to the western US and southwestern Canada, the production of an alarm call correlates with glucocorticoid production, a physiological measurement of stress. And when researchers experimentally altered the synthesis of glucocorticoids in rhesus macaques, they found a change in the probability of alarm call production. © 2013 Scientific American
by Nancy Shute It was hard to ignore those headlines saying that people with migraine have brain damage, even if you're not among the 12 percent or so who do suffer from these painful, recurring headaches. Don't panic, says the neurologist whose work sparked those alarming headlines. "It's still not something to stay up nights worrying about," says Dr. Richard Lipton, director of the Montefiore Headache Center in New York. But knowing about the brain anomalies that Lipton and his colleagues found might help people reduce their stroke risk. Some people who get do have a slightly . And some of the brain changes identified in the study look like mini-strokes. "On the MRI they look like very tiny strokes," Lipton tells Shots. But the people aren't having any stroke symptoms. Still, Lipton is convinced that the process is the same. "We now know it's a risk factor for these very small silent strokes," he says. The scientists evaluated data from 19 studies in which people with migraine headaches got MRI scans of their brains. Just about everybody is going to have some abnormalities show up in a scan. But the people who had migraines were more likely to have two common abnormalities: white matter abnormalities and infarct-like lesions. The were published in the journal Neurology. ©2013 NPR
by Jacob Aron DOES your brain work like a dictionary? A mathematical analysis of the connections between definitions of English words has uncovered hidden structures that may resemble the way words and their meanings are represented in our heads. "We want to know how the mental lexicon is represented in the brain," says Stevan Harnad of the University of Quebec in Montreal, Canada. As every word in a dictionary is defined in terms of others, the knowledge needed to understand the entire lexicon is there, as long as you first know the meanings of an initial set of starter, or "grounding", words. Harnad's team reasoned that finding this minimal set of words and pinning down its structure might shed light on how human brains put language together. The team converted each of four different English dictionaries into a mathematical structure of linked nodes known as a graph. Each node in this graph represents a word, which is linked to the other words used to define it – so "banana" might be connected to "long", "bendy", "yellow" and "fruit". These words then link to others that define them. This enabled the team to remove all the words that don't define any others, leaving what they call a kernel. The kernel formed roughly 10 per cent of the full dictionary – though the exact percentages depended on the particular dictionary. In other words, 90 per cent of the dictionary can be defined using just the other 10 per cent. © Copyright Reed Business Information Ltd.
Link ID: 18587 - Posted: 08.31.2013
Beth Skwarecki Be careful what you say around a pregnant woman. As a fetus grows inside a mother's belly, it can hear sounds from the outside world—and can understand them well enough to retain memories of them after birth, according to new research. It may seem implausible that fetuses can listen to speech within the womb, but the sound-processing parts of their brain become active in the last trimester of pregnancy, and sound carries fairly well through the mother's abdomen. "If you put your hand over your mouth and speak, that's very similar to the situation the fetus is in," says cognitive neuroscientist Eino Partanen of the University of Helsinki. "You can hear the rhythm of speech, rhythm of music, and so on." A 1988 study suggested that newborns recognize the theme song from their mother's favorite soap opera. More recent studies have expanded on the idea of fetal learning, indicating that newborns already familiarized themselves with sounds of their parent’s native language; one showed that American newborns seem to perceive Swedish vowel sounds as unfamiliar, sucking on a high-tech pacifier to hear more of the new sounds. Swedish infants showed the same response to English vowels. But those studies were based on babies' behaviors, which can be tricky to test. Partanen and his team decided instead to outfit babies with EEG sensors to look for neural traces of memories from the womb. "Once we learn a sound, if it's repeated to us often enough, we form a memory of it, which is activated when we hear the sound again," he explains. This memory speeds up recognition of sounds in the learner's native language and can be detected as a pattern of brain waves, even in a sleeping baby. © 2012 American Association for the Advancement of Science.
Virginia Morell A wolf’s howl is one of the most iconic sounds of nature, yet biologists aren’t sure why the animals do it. They’re not even sure if wolves howl voluntarily or if it’s some sort of reflex, perhaps caused by stress. Now, scientists working with captive North American timber wolves in Austria report that they’ve solved part of the mystery. Almost 50 years ago, wildlife biologists suggested that a wolf’s howls were a way of reestablishing contact with other pack members after the animals became separated, which often happens during hunts. Yet, observers of captive wolves have also noted that the pattern of howls differs depending on the size of the pack and whether the dominant, breeding wolf is present, suggesting that the canids’ calls are not necessarily automatic responses. Friederike Range, a cognitive ethologist at the University of Veterinary Medicine in Vienna, was in a unique position to explore the conundrum. Since 2008, she and her colleagues have hand-raised nine wolves at the Wolf Science Center in Ernstbrunn, which she co-directs. “We started taking our wolves for walks when they were 6 weeks old, and as soon as we took one out, the others would start to howl,” she says. “So immediately we became interested in why they howl.” Although the center’s wolves don’t hunt, they do howl differently in different situations, Range says. “So we also wanted to understand these variations in their howling.” © 2012 American Association for the Advancement of Science.
JoNel Aleccia TODAY When doctors told Pete and Michelle Gallagher that they wanted to remove half of their 3-year-old son’s brain, the Attica, Ohio, parents were horrified. But a new study shows the extreme procedure may offer some kids their best shot at a normal life. “We panicked,” said Pete Gallagher, recalling their reaction seven years ago. The couple also knew that the dramatic surgery known as a hemispherectomy might be the only workable option to stop the severe seizures, more than a dozen a day, that were robbing Aiden of his ability to function – and to learn. “He had forgotten his alphabet. He had forgotten how to count. It was all slipping,” the father said. Today, Aiden is a healthy, red-haired fifth-grader who goes to regular school and loves to play baseball and basketball. He hasn’t had a seizure since the rare operation, making the boy a poster child for new research that finds the procedure offers real-world success for children suffering from devastating epilepsy. “The brain has an amazing capacity to work around the function that it has lost,” said Dr. Ajay Gupta, head of pediatric epilepsy at the Cleveland Clinic. In the first large-scale study to look at the everyday capabilities of kids who undergo hemispherectomy, Gupta and his colleagues reviewed 186 operations performed at their center between 1997 and 2009 and took a close look at 115 patients. They confirmed what doctors knew, but had little practical data to support: That removing the diseased hemisphere of a seizure-prone brain allows sufferers to learn and grow and, in some cases, lead normal lives.
By Scott Barry Kaufman So yea, you know how the left brain is really realistic, analytical, practical, organized, and logical, and the right brain is so darn creative, passionate, sensual, tasteful, colorful, vivid, and poetic? No. Just no. Stop it. Please. Thoughtful cognitive neuroscientists such as Rex Jung, Darya Zabelina, Andreas Fink, John Kounios, Mark Beeman, Kalina Christoff, Oshin Vartanian, Jeremy Gray, Hikaru Takeuchi and others are on the forefront of investigating what actually happens in the brain during the creative process. And their findings are overturning conventional notions surrounding the neuroscience of creativity. The latest findings from the real neuroscience of creativity suggest that the right brain/left brain distinction is not the right one when it comes to understanding how creativity is implemented in the brain. Creativity does not involve a single brain region or single side of the brain. Instead, the entire creative process– from the initial burst of inspiration to the final polished product– consists of many interacting cognitive processes and emotions. Depending on the stage of the creative process, and what you’re actually attempting to create, different brain regions are recruited to handle the task. Importantly, many of these brain regions work as a team to get the job done, and many recruit structures from both the left and right side of the brain. In recent years, evidence has accumulated suggesting that “cognition results from the dynamic interactions of distributed brain areas operating in large-scale networks.” © 2013 Scientific American
By GRETCHEN REYNOLDS The start this month of high school and college football seasons across the country renews concerns about the issue of repeated head impacts and how to manage or, preferably, avoid concussions. Unfortunately, the resources to deal with the problem remain limited. Newly released, state-of-the-art football helmets, for instance, may measure how much force each player’s head is absorbing and relay that data via telemetry to trainers on the sidelines, but at $1,500 or so per helmet, they are unattainable for most teams. Which is why a study published recently in The British Journal of Sports Medicine is so appealing. Eminently practical, it offers a means by which any team, no matter how small or cash-strapped, can assess the likelihood of one of its players having sustained an on-field concussion. It also celebrates a nifty, D.I.Y., MacGyver-ish sensibility rarely seen in our technology-obsessed times. The study’s authors began with the simple idea that, to manage sports-related concussions, “you need to be able to quickly and easily assess” whether a given player has actually sustained one, said Steven P. Broglio, director of the University of Michigan’s NeuroSport Research Laboratory and co-author of the study. Not every head impact results in a concussion. One means of assessing concussion status, Dr. Broglio continued, is to look at a player’s reaction time, since it is known to increase immediately after a concussion. A variety of scientifically validated tools exist to measure players’ reaction times, but most require a computer and sophisticated software, and are not practicable on the sidelines or in the budgets of many teams. Copyright 2013 The New York Times Company
by Sara Reardon It's a case of hear no object, see no object. Hearing the name of an object appears to influence whether or not we see it, suggesting that hearing and vision might be even more intertwined than previously thought. Studies of how the brain files away concepts suggest that words and images are tightly coupled. What is not clear, says Gary Lupyan of the University of Wisconsin in Madison, is whether language and vision work together to help you interpret what you're seeing, or whether words can actually change what you see. Lupyan and Emily Ward of Yale University used a technique called continuous flash suppression (CFS) on 20 volunteers to test whether a spoken prompt could make them detect an image that they were not consciously aware they were seeing. CFS works by displaying different images to the right and left eyes: one eye might be shown a simple shape or an animal, for example, while the other is shown visual "noise" in the form of bright, randomly flickering shapes. The noise monopolises the brain, leaving so little processing power for the other image that the person does not consciously register it, making it effectively invisible. Wheels of perception In a series of CFS experiments, the researchers asked volunteers whether or not they could see a specific object, such as a dog. Sometimes it was displayed, sometimes not. When it was not displayed or when the image was of another animal such as a zebra or kangaroo, the volunteers typically reported seeing nothing. But when a dog was displayed and the question mentioned a dog, the volunteers were significantly more likely to become aware of it. "If you hear a word, that greases the wheels of perception," says Lupyan: the visual system becomes primed for anything to do with dogs. © Copyright Reed Business Information Ltd.
By Michelle Roberts Health editor, BBC News online Brain scans may allow detection of dyslexia in pre-school children even before they start to read, say researchers. A US team found tell-tale signs on scans that have already been seen in adults with the condition. And these brain differences could be a cause rather than a consequence of dyslexia - something unknown until now - the Journal of Neuroscience reports. Scans could allow early diagnosis and intervention, experts hope. The part of the brain affected is called the arcuate fasciculus. Among the 40 school-entry children they studied they found some had shrinkage of this brain region, which processes word sounds and language. They asked the same children to do several different types of pre-reading tests, such as trying out different sounds in words. Those children with a smaller arcuate fasciculus had lower scores. It is too early to say if the structural brain differences found in the study are a marker of dyslexia. The researchers plan to follow up groups of children as they progress through school to determine this. Lead researcher Prof John Gabrieli said: "We don't know yet how it plays out over time, and that's the big question. BBC © 2013
Roger Dobson Older male nightingales have perfected an art that would be the envy of men having a mid-life crisis: a trick that makes them more attractive to females than their younger male competitors. Their mastery of successful courtship is achieved with a dazzling array of up to 100 trills a second, far more than their younger competitors can manage, and more than any other investigated bird, according to new research. That ability, backed up by a sophisticated playlist of about 200 songs, means that they are probably seen as better mates by young trill-seeking females. Singing so many trills at peak frequency requires a lot of physical effort and, as a result, it has evolved as a sign on fitness, say the researchers. "Females could assess the age of the male singer by the trill rate, and mate preferably with older ones," says the zoologist Dr Valentin Amrhein, who led the study at the University of Basel, Switzerland. "This makes sense for the females because older males have more experience with defending their territory or with raising young, and therefore have a better reproductive performance." The research, being published in the Journal of Avian Biology, shows that older birds can come up with 100 trills a second, making them the fastest singers. They also performed about 200 different song types, but the researchers think it is the immediate impact of the trills that is attracting the females. It would take more than an hour for the male to go through his whole song list. "Since the performance of these sounds is very demanding, the rate at which they can be repeated is limited. Trying to sing rapidly increasing sounds in fast repetition is very hard for us humans as well," says Dr Amrhein. "Singing rapid broadband trills comes at a certain price for the male nightingale, so trilling is a good indicator for mate quality." © independent.co.uk
Jason Bruck Ever been at a party where you recognize everyone’s faces but can’t think of their names? That wouldn’t happen if you were a bottlenose dolphin (Tursiops truncatus). The marine mammals can remember each other’s signature contact whistles—calls that function as names—for more than 20 years, the longest social memory ever recorded for a nonhuman animal, according to a new study. “The ability to remember individuals is thought to be extremely important to the ‘social brain,’ ” says Janet Mann, a marine mammal biologist at Georgetown University in Washington, D.C., who was not involved in the research. Yet, she notes, no one has succeeded in designing a test for this talent in the great apes—our closest kin—let alone in dolphins. Dolphins use their signature whistles to stay in touch. Each has its own unique whistle, and they learn and can repeat the whistles of other dolphins. A dolphin will answer when another dolphin mimics its whistle—just as we reply when someone calls our name. The calls enable the marine mammals to communicate over long distances—which is necessary because they live in “fission-fusion” societies, meaning that dolphins in one group split off to join other groups and later return. By whistling, they’re able to find each other again. Scientists don’t know how long dolphins are separated in the wild, but they do know the animals can live almost 50 years. So how long do the dolphins remember the calls of their friends? To find out, Jason Bruck, a cognitive ethologist at the University of Chicago in Illinois, spent 5 years collecting 71 whistles from 43 dolphins at six captive facilities, including Brookfield Zoo near Chicago and Dolphin Quest in Bermuda. The six sites belong to a consortium that rotates the marine mammals for breeding and has decades-long records of which dolphins have lived together. © 2012 American Association for the Advancement of Science