Chapter 15. Language and Our Divided Brain
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By Ling Xin For many, the hardest part of learning to speak Chinese is mastering its complex tonal variations. Now, new research suggests a surprising explanation for how those tones arose: a humid climate. By examining the correlation between humidity and the role of tone in more than 3700 languages, scientists found that tonal languages are remarkably rare in arid regions like Central Europe, whereas languages with complex tone pitches are prevalent in relatively humid regions such as the tropics, subtropical Asia, and Central Africa. Humidity keeps the voice box moist and elastic, allowing it to produce correct and complex tones, the scientists explain online this month in the Proceedings of the National Academy of Sciences. “If the United Kingdom had been a humid jungle, English may also have developed into a tonal language,” they claim. So, next time you go to your Chinese class, don’t forget to wet your whistle! © 2015 American Association for the Advancement of Science.
Link ID: 20517 - Posted: 01.26.2015
By Amy Ellis Nutt Scientists have discovered what a traumatic brain injury, or TBI, suffered by a quarter-million combat veterans of Iraq and Afghanistan looks like, and it’s unlike anything they’ve seen before: a honeycomb pattern of broken connections, primarily in the frontal lobes, our emotional control center and the seat of our personality. “In some ways it’s a 100-year-old problem,” said Vassilis Koliatsos, a Johns Hopkins pathologist and neuropsychiatrist. He was referring to the shell-shock victims of World War I, tens of thousands of soldiers who returned home physically sound but mentally wounded, haunted by their experiences and unable to fully resume their lives. “When we started shelling each other on the Western Front of World War I, it created a lot of sick people . . . . [In a way,] we’ve gone back to the Western Front and created veterans who come back and do poorly, and we’re back to the Battle of the Somme,” he said. “They have mood changes, commit suicide, substance abuse, just like in World War I, and they really do poorly and can’t function. It’s a huge problem.” Many of the lingering symptoms of shell shock, or what today is known as neurotrauma, are the same as they were a century ago. Only the nature of the blast has changed, from artillery to improvised explosive devices. Koliatsos and colleagues, who published their findings in the journal Acta Neuropathologica Communications in November, examined the brains of five recent U.S. combat veterans, all of whom suffered a traumatic brain injury from an IED but died of unrelated causes back home. Their controls included the brains of people with a history of auto accidents and of those with no history of auto accidents or TBI. Koliatsos says he was prompted to do this study because he is both a pathologist and a neuropsychiatrist, and he sees many TBI cases, both in veterans and in young people with sports concussions.
// by Jennifer Viegas Researchers eavesdropping on wild chimpanzees determined that the primates communicate about at least two things: their favorite yummy fruits, and the trees where these fruits can be found. Of particular interest to the chimps is the size of trees bearing the fruits that they relish most, such that the chimps yell out that information, according to a new study published in the journal Animal Behaviour. The study is the first to find that information about tree size and available fruit amounts are included in chimp calls, in addition to assessments about food quality. "Chimpanzees definitely have a very complex communication system that includes a variety of vocalizations, but also facial expressions and gestures," project leader Ammie Kalan of the Max Planck Institute for Evolutionary Anthropology told Discovery News. "How much it resembles human language is still a matter of debate," she added, "but at the very least, research shows that chimpanzees use vocalizations in a sophisticated manner, taking into account their social and environmental surroundings." Kalan and colleagues Roger Mundry and Christophe Boesch spent over 750 hours observing chimps and analyzing their food calls in the Ivory Coast's Taï Forest. The Wild Chimpanzee Foundation in West Africa is working hard to try and protect this population of chimps, which is one of the last wild populations of our primate cousins. © 2015 Discovery Communications, LLC
by Ashley Yeager The brain's got its own set of pipes for flushing waste. The plumbing is delicate, however — a finding that may complicate scientists' attempts to create a blood test to diagnose traumatic brain injuries. Bumps to the head can knock proteins out of brain cells. The brain's plumbing system is supposed to wash these proteins away from the damaged area and eventually into the blood. But new research in mice shows that slight alterations to the brain's self-cleaning system, even from treating head injuries, can change the levels of proteins flushed into the blood. As a result, the proteins are unreliable markers of injury, researchers report January 14 in the Journal of Neuroscience. © Society for Science & the Public 2000 - 2015.
By Michael Balter If there’s one thing that distinguishes humans from other animals, it’s our ability to use language. But when and why did this trait evolve? A new study concludes that the art of conversation may have arisen early in human evolution, because it made it easier for our ancestors to teach each other how to make stone tools—a skill that was crucial for the spectacular success of our lineage. Researchers have long debated when humans starting talking to each other. Estimates range wildly, from as late as 50,000 years ago to as early as the beginning of the human genus more than 2 million years ago. But words leave no traces in the archaeological record. So researchers have used proxy indicators for symbolic abilities, such as early art or sophisticated toolmaking skills. Yet these indirect approaches have failed to resolve arguments about language origins. Now, a team led by Thomas Morgan, a psychologist at the University of California, Berkeley, has attacked the problem in a very different way. Rather than considering toolmaking as a proxy for language ability, he and his colleagues explored the way that language may helps modern humans learn to make such tools. The researchers recruited 184 students from the University of St. Andrews in the United Kingdom, where some members of the team were based, and organized them into five groups. The first person in each group was taught by archaeologists how to make artifacts called Oldowan tools, which include fairly simple stone flakes that were manufactured by early humans beginning about 2.5 million years ago. This technology, named after the famous Olduvai Gorge in Tanzania where archaeologists Louis and Mary Leakey discovered the implements in the 1930s, consists of hitting a stone “core” with a stone “hammer” in such a way that a flake sharp enough to butcher an animal is struck off. Producing a useful flake requires hitting the core at just the right place and angle. © 2015 American Association for the Advancement of Science.
|By Matthew H. Schneps Many of the etchings by artist M. C. Escher appeal because they depict scenes that defy logic. His famous “Waterfall” shows a waterwheel powered by a cascade pouring down from a brick flume. Water turns the wheel and is redirected uphill back to the mouth of the flume, where it can once again pour over the wheel in an endless cycle. The drawing shows us an impossible situation that violates nearly every law of physics. In 2003 a team of psychologists led by Catya von Károlyi of the University of Wisconsin–Eau Claire made a discovery using such images. When the researchers asked people to pick out impossible figures from similarly drawn illustrations, they found that participants with dyslexia were among the fastest at this task. Dyslexia is often called a learning disability. And it can indeed present learning challenges. Although its effects vary widely, some children with dyslexia read so slowly that it would typically take them months to read the same number of words that their peers read in a day. Therefore, the fact that people with this difficulty were so adept at rapidly picking out the impossible figures puzzled von Károlyi. The researchers had stumbled on a potential upside to dyslexia, one that investigators have just begun to understand. Scientists had long suspected dyslexia might be linked to creativity, but laboratory evidence for this was rare. In the years to follow, sociologist Julie Logan of Cass Business School in London showed that there is a higher incidence of dyslexia among entrepreneurs than in the general population. Meanwhile cognitive scientist Gadi Geiger of the Massachusetts Institute of Technology found that people with dyslexia could attend to multiple auditory inputs at once. © 2015 Scientific American
by Clare Wilson Could a lopsided gap help set us apart from our primate cousins? Our brains and chimps' are built differently in the areas that give us our social skills and language. The human brain has a 4.5-centimetre-long groove running deeper along the right side than the left. Chimp brains lack this asymmetry, as François Leroy of the French National Institute of Health and Medical Research in Saclay, and colleagues, have discovered. The groove's function is unknown, but its location suggests it played a role in the evolution of our communication abilities. "One day this will help us understand what makes us tick," says Colin Renfrew of the University of Cambridge, who was not involved in the study. Although our brain is about three times the size of a chimp's, anatomical features that only the human brain possesses are surprisingly hard to find. One known difference is in a region called Broca's area, which is also involved in speech and is larger in humans than chimps. The asymmetrical groove in humans was also known, but the new study, in which 177 people and 73 chimps had brain scans, revealed it is almost completely absent in the other primates. In humans, the deeper groove in the right brain lies in the region that controls voice and face recognition and working out what other people are thinking – our so-called theory of mind. The shallower groove on the left is at the heart of the areas associated with language. The lack of symmetry could signify that tissue layers in the right brain have been reorganised, says Leroy. © Copyright Reed Business Information Ltd.
By DOUGLAS QUENQUA A sparrow’s song may sound simple, consisting of little more than whistles and trills. But to the sparrows, those few noises can take on vastly different meanings depending on small variations in context and repetition, researchers have found. In humans, the ability to extract nearly endless meanings from a finite number of sounds, known as partial phonemic overlapping, was key to the development of language. To see whether sparrows shared this ability, researchers at Duke University recorded and analyzed the songs of more than 200 Pennsylvania swamp sparrows. They found that the sparrows’ whistles could be divided into three lengths: short, intermediate and long. The researchers then played the sparrows two versions of the songs — the original and a slightly altered one. They found that replacing a single short whistle with an intermediate one, for example, could significantly alter a bird’s reaction, but only if it came at the right moment in the song. “Identical sounds seemed to belong to a different category depending on the context,” said Robert F. Lachlan, a biologist now with Queen Mary University of London and the lead author of the study. The findings, which were published in Proceedings of the National Academy of Sciences, are part of a larger effort to better understand how human language evolved. If even birds rely on phonemic overlapping to communicate, Dr. Lachlan said, it could indicate that such features “developed independently of higher aspects of language.” © 2015 The New York Times Company
Christopher Dean Hopkins If you've ever listened to karaoke at a bar, you know that drinking can affect how well someone can sing. Christopher Olson and his colleagues at Oregon Health and Science University recently set out to find if the same was true for birds, specifically zebra finches. "We just showed up in the morning and mixed a little bit of juice with 6 percent alcohol, and put it in their water bottles and put it in the cages," Olson told All Things Considered's Arun Rath. "At first we were thinking that they wouldn't drink on their own because, you know, a lot of animals just won't touch the stuff. But they seem to tolerate it pretty well and be somewhat willing to consume it." The finches long have been used as a model to study human vocal learning, or how people learn to communicate using language, Olson said. Obviously, alcohol affects human speech, so Olson and his team checked for similar problems with the birds. The blood alcohol levels achieved — .05 to .08 percent — would be laughed off by many college students, but because birds metabolize alcohol differently it was plenty to produce the effects the scientists were looking for. Listen to the audio, and you'll hear that the finches' song gets a bit quieter and just a little slurred, or as Olson puts it, "a bit less organized in their sound production" — like a roommate calling from a bar to get a ride home. © 2014 NPR
by Lisa Seachrist Chiu Just before winter break, my fifth grader came home from school, opened her mouth and produced what sounded to me like a stuttering mess of gibberish. After complaining that when she spends the entire day immersed in Chinese, she sometimes can’t figure out what language to use, she carried on speaking flawless English to me and Chinese to a friend while they did their homework. Quite honestly, I had been eagerly anticipating this very day for a long time. Having worked several years to establish the Chinese language immersion elementary school my daughter attends, I could barely contain my excitement at this demonstration that she truly grasps a second language. Early language programs are hot, in no small part because, when it comes to language, kids under the age of 7 are geniuses. Like many parents, I wanted my child to be fluent in as many languages as possible so she can communicate with more people and because it gives her a prime tool to explore different cultures. Turns out, it may also benefit her brain. With the help of advanced imaging tools that reveal neural processes in specific brain structures, researchers are coalescing around the idea that fluency in more than one language heightens executive function — the ability to regulate and control cognitive processes. It’s a radical shift from just a few decades ago when psychologists routinely warned against raising children who speak two languages, lest they become confused and suffer delays in learning. © Society for Science & the Public 2000 - 2014
Link ID: 20448 - Posted: 01.01.2015
|By Joshua A. Krisch There is a mystery on Tiwai Island. A large wildlife sanctuary in Sierra Leone, the island is home to pygmy hippopotamuses, hundreds of bird species and several species of primates, including Campbell’s monkeys. These monkeys communicate via an advanced language that primatologists and linguists have been studying for decades. Over time, experts nearly cracked the code behind monkey vocabulary. And then came krak. In the Ivory Coast’s Tai Forest Campbell’s monkeys (Cercopithecus campbelli) use the term krak to indicate that a leopard is nearby and the term hok to warn of an eagle circling overheard. Primatologists indexed their monkey lexicon accordingly. But on Tiwai Island they found that those same monkeys used krak as a general alarm call—one that, occasionally, even referred to eagles. “Why on Earth were they producing krak when they heard an eagle,” asks co-author Philippe Schlenker, a linguist at France’s National Center for Scientific Research and professor at New York University. “For some reason krak, which is a leopard in the Tai Forest, seems to be recycled as a general alarm call on Tiwai Island.” In a paper published in the November 28 Linguistics and Philosophy Schlenker and his team applied logic and human linguistics to crack the krak code. Their findings imply that some monkey dialects can be just as sophisticated as human language. In 2009 a team of scientists travelled to Tai Forest with one mission—to terrify Campbell’s monkeys. Prior studies had collected monkey calls and then parsed vague meanings based on events that were already happening on the forest floor. But these primatologists set up realistic model leopards and played recordings of eagle screeches over loudspeakers. Their field experiments resulted in some of the best data available about how monkeys verbally respond to predators. © 2014 Scientific American
By GINA KOLATA After three decades of failure, researchers have found a treatment that greatly improves the prognosis for people having the most severe and disabling strokes. By directly removing large blood clots blocking blood vessels in the brain, they can save brain tissue that would have otherwise died, enabling many to return to an independent life. The study, published online Wednesday in The New England Journal of Medicine and conducted by researchers in the Netherlands, is being met with an outpouring of excitement. One reason the treatment worked, researchers suspect, is that doctors used a new type of snare to grab the clots. It is a stent, basically a small wire cage, on the end of a catheter that is inserted in the groin and threaded through an artery to the brain. When the tip of the catheter reaches the clot, the stent is opened and pushed into the clot. It snags the clot, allowing the doctor to withdraw the catheter and pull out the stent with the clot attached. About 630,000 Americans each year have strokes caused by clots blocking blood vessels in the brain. In about a third to half, the clot is in a large vessel, which has potentially devastating consequences. People with smaller clots are helped by the lifesaving drug tPA, which dissolves them. But for those with big clots, tPA often does not help. Until now, no other treatments had been shown to work. One in five patients who had tPA alone recovered enough to return to living independently. But one in three who also had their clot removed directly were able to take care of themselves after their stroke. And that, said Dr. Larry B. Goldstein, director of the Duke Stroke Center, is “a significant and meaningful improvement in what people are able to do.” © 2014 The New York Times Company
Link ID: 20429 - Posted: 12.18.2014
Jason G Goldman We humans don’t typically agree on all that much, but there is at least one thing that an impressive amount of us accept: which hand is easiest to control. If you use one hand for writing, you probably use the same one for eating as well, and most of us – around 85% of our species – prefer our right hands. In fact, "there has never been any report of a human population in which left-handed individuals predominate", according to archaeologist Natalie Uomini at the University of Liverpool in the UK. Lateralisation of limb use – that is, a bias towards one side or the other – usually begins in the brain. We know that some tasks are largely controlled by brain activity in the left hemisphere, while the right hemisphere governs other tasks. Confusingly, there is some crossing of nerves between the body and the brain, which means it’s actually the left side of the brain that has more control over the right side of the body and vice versa. In other words, the brain’s left hemisphere helps control the operation of the right hand, eye, leg and so on. Some argue that this division of neurological labour has been a feature of animals for half a billion years. Perhaps it evolved because it is more efficient to allow the two hemispheres to carry out different computations at the same time. The left side of the brain, for instance, might have evolved to carry out routine operations – things like foraging for food – while the right side was kept free to detect and react rapidly to unexpected challenges in the environment – an approaching predator, for instance. This can be seen in various fish, toads and birds, which are all more likely to attack prey seen in the right eye. © 2014 BBC.
|By Marissa Fessenden Songbirds stutter, babble when young, become mute if parts of their brains are damaged, learn how to sing from their elders and can even be "bilingual"—in other words, songbirds' vocalizations share a lot of traits with human speech. However, that similarity goes beyond behavior, researchers have found. Even though humans and birds are separated by millions of years of evolution, the genes that give us our ability to learn speech have much in common with those that lend birds their warble. A four-year long effort involving more than 100 researchers around the world put the power of nine supercomputers into analyzing the genomes of 48 species of birds. The results, published this week in a package of eight articles in Science and 20 papers in other journals, provides the most complete picture of the bird family tree thus far. The project has also uncovered genetic signatures in song-learning bird brains that have surprising similarities to the genetics of speech in humans, a finding that could help scientists study human speech. The analysis suggests that most modern birds arose in an impressive speciation event, a "big bang" of avian diversification, in the 10 million years immediately following the extinction of dinosaurs. This period is more recent than posited in previous genetic analyses, but it lines up with the fossil record. By delving deeper into the rich data set, research groups identified when birds lost their teeth, investigated the relatively slow evolution of crocodiles and outlined the similarities between birds' and humans' vocal learning ability, among other findings. © 2014 Scientific American,
|By Ingrid Wickelgren Confusion is one symptom of a concussion. But confusion may also characterize decisions about how soon to let an athlete play after taking a hit to the head. Sizing up symptoms such as dizziness and nausea is subjective, after all. Now a study suggests that a blood test could objectively determine whether or not the damage is bad enough to put a player on the bench. The work is in the Journal of Neurotrauma. [Robert Siman et al, Serum SNTF Increases in Concussed Professional Ice Hockey Players and Relates to the Severity of Post Concussion Symptoms] A strong blow to the head causes chemical changes within nerve cells that damage their structural proteins. Among the debris is a protein fragment called SNTF—which in more severe cases, spills into the bloodstream. The new study followed 20 professional hockey players who got concussions with symptoms that lasted six days or more. And blood levels of SNTF were much higher one hour to six days later than were levels of the protein fragment in eight other athletes who had gotten concussions that cleared up within five days. Levels were also low in 45 non-concussed players tested during the pre-season. A blood test for SNTF might thus forecast recovery time from a head injury. Combined with other neurological tests, levels of this molecule could help doctors tell athletes when it’s safe to suit up again. © 2014 Scientific American
Keyword: Brain Injury/Concussion
Link ID: 20419 - Posted: 12.16.2014
by Colin Barras It's not just great minds that think alike. Dozens of the genes involved in the vocal learning that underpins human speech are also active in some songbirds. And knowing this suggests that birds could become a standard model for investigating the genetics of speech production – and speech disorders. Complex language is a uniquely human trait, but vocal learning – the ability to pick up new sounds by imitating others – is not. Some mammals, including whales, dolphins and elephants, share our ability to learn new vocalisations. So do three groups of birds: the songbirds, parrots and hummingbirds. The similarities between vocal learning in humans and birds are not just superficial. We know, for instance, that songbirds have specialised vocal learning brain circuits that are similar to those that mediate human speech. What's more, a decade ago we learned that FOXP2, a gene known to be involved in human language, is also active in "area X" of the songbird brain – one of the brain regions involved in those specialised vocal learning circuits. Andreas Pfenning at the Massachusetts Institute of Technology and his colleagues have now built on these discoveries. They compared maps of genetic activity – transcriptomes – in brain tissue taken from the zebra finch, budgerigar and Anna's hummingbird, representing the three groups of vocal-learning birds. © Copyright Reed Business Information Ltd.
By JOHN McWHORTER “TELL me, why should we care?” he asks. It’s a question I can expect whenever I do a lecture about the looming extinction of most of the world’s 6,000 languages, a great many of which are spoken by small groups of indigenous people. For some reason the question is almost always posed by a man seated in a row somewhere near the back. Asked to elaborate, he says that if indigenous people want to give up their ancestral language to join the modern world, why should we consider it a tragedy? Languages have always died as time has passed. What’s so special about a language? The answer I’m supposed to give is that each language, in the way it applies words to things and in the way its grammar works, is a unique window on the world. In Russian there’s no word just for blue; you have to specify whether you mean dark or light blue. In Chinese, you don’t say next week and last week but the week below and the week above. If a language dies, a fascinating way of thinking dies along with it. I used to say something like that, but lately I have changed my answer. Certainly, experiments do show that a language can have a fascinating effect on how its speakers think. Russian speakers are on average 124 milliseconds faster than English speakers at identifying when dark blue shades into light blue. A French person is a tad more likely than an Anglophone to imagine a table as having a high voice if it were a cartoon character, because the word is marked as feminine in his language. This is cool stuff. But the question is whether such infinitesimal differences, perceptible only in a laboratory, qualify as worldviews — cultural standpoints or ways of thinking that we consider important. I think the answer is no. Furthermore, extrapolating cognitive implications from language differences is a delicate business. In Mandarin Chinese, for example, you can express If you had seen my sister, you’d have known she was pregnant with the same sentence you would use to express the more basic If you see my sister, you know she’s pregnant. One psychologist argued some decades ago that this meant that Chinese makes a person less sensitive to such distinctions, which, let’s face it, is discomfitingly close to saying Chinese people aren’t as quick on the uptake as the rest of us. The truth is more mundane: Hypotheticality and counterfactuality are established more by context in Chinese than in English. © 2014 The New York Times Company
Link ID: 20401 - Posted: 12.08.2014
| By Carolyn Gregoire When reading about Harry Potter's adventures fighting Lord Voldemort or flying around the Quidditch field on his broomstick, we can become so absorbed in the story that the characters and events start to feel real. And according to neuroscientists, there's a good reason for this. Researchers in the Machine Learning Department at Carnegie Mellon University scanned the brains of Harry Potter readers, and found that reading about Harry's adventures activates the same brain regions used to perceive people's intentions and actions in the real world. The researchers performed fMRI scans on a group of eight study participants while they read chapter nine of Harry Potter and the Sorcerer's Stone, which describes Harry's first flying lesson. Then, they analyzed the scans, one cubic millimeter at a time, for four-word segments of the chapter in order to build the first integrated computational model of reading. The researchers created a technique such that for each two-second fMRI scan, the readers would see four words. And for each word, the researchers identified 195 detailed features that the brain would process. Then, an algorithm was applied to analyze the activation of each millimeter of the brain for each two-second scan, associating various word features with different regions of the brain. Using the model, the researchers were able to predict which of two passages the subjects were reading with a 74 percent accuracy rate. ©2014 TheHuffingtonPost.com, Inc
By Gabe Bergado It's not news that reading has countless benefits: Poetry stimulates parts of the brain linked to memory and sparks self-reflection; kids who read the Harry Potter books tend to be better people. But what about people who only read newspapers? Or people who scan Twitter all day? Are those readers' brains different from literary junkies who peruse the pages of 19th century fictional classics? Short answer: Yes — reading enhances connectivity in the brain. But readers of fiction? They're a special breed. The study: A 2013 Emory University study looked at the brains of fiction readers. Researchers compared the brains of people after they read to the brains of people who didn't read. The brains of the readers — they read Robert Harris' Pompeii over a nine-day period at night — showed more activity in certain areas than those who didn't read. Specifically, researchers found heightened connectivity in the left temporal cortex, part of the brain typically associated with understanding language. The researchers also found increased connectivity in the central sulcus of the brain, the primary sensory region, which helps the brain visualize movement. When you visualize yourself scoring a touchdown while playing football, you can actually somewhat feel yourself in the action. A similar process happens when you envision yourself as a character in a book: You can take on the emotions they are feeling. It may sound hooey hooey, but it's true: Fiction readers make great friends as they tend to be more aware of others' emotions. Copyright © Mic Network Inc.
Some teenagers appear to show changes in their brains after one season of playing American football, a small study suggests. Even though players were not concussed during the season, researchers found abnormalities similar to the effects of mild traumatic brain injury. Twenty-four players aged between 16 and 18 were studied and devices on their helmets measured head impacts. The study was presented to the Radiological Society of North America. In recent years, a number of reports have expressed concern about the potential effects on young, developing brains of playing contact sports. These studies have tended to focus on brain changes as a result of concussion. But this study focused on the effects of head impacts on the brain, even when players did not suffer concussion at any point during the season. Using detailed scans of the players' brains before the season began and then again after it ended, the researchers were able to identify slight changes to the white matter of the brain. White matter contains millions of nerve fibres which act as communication cables between the brain's regions. Those players who were hit harder and hit more often were more likely to show these changes in post-season brain scans. Dr Alex Powers, co-author and paediatric neurosurgeon at Wake Forest Baptist Medical Centre in North Carolina, said the changes were a direct result of the hits received by the young players during their football season. BBC © 2014