Chapter 19. Language and Hemispheric Asymmetry

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by Sarah Zielinski When you get a phone call or a text from a friend or acquaintance, how fast you respond — or whether you even bother to pick up your phone — often depends on the quality of the relationship you have with that person. If it’s your best friend or mom, you probably pick up right away. If it’s that annoying coworker contacting you on Sunday morning, you might ignore it. Ring-tailed lemurs, it seems, are even pickier in who they choose to respond to. They only respond to calls from close buddies, a new study finds. These aren’t phone calls but contact calls. Ring-tailed lemurs live in female-dominated groups of 11 to 16, and up to 25, animals, and when the group is on the move, it’s common for one member to yell out a “meow!” and for other members to “meow!” back. A lemur may also make the call if it gets lost. The calls serve to keep the group together. The main way ring-tailed lemurs (and many other primates) build friendships, though, is through grooming. Grooming helps maintain health and hygiene and, more importantly, bonds between members. It’s a time-consuming endeavor, and animals have to be picky about who they bother to groom. Ipek Kulahci and colleagues at Princeton University wanted to see if there was a link between relationships built through grooming and vocal exchanges among ring-tailed lemurs. Contact calls don’t require nearly as much time or effort as grooming sessions, so it is possible that animals could be less discriminating when they respond to calls. But, the researchers reasoned, if the vocalizations were a way of maintaining the relationships built through painstaking grooming sessions, then the lemurs would be as picky in their responses as in their grooming partners. © Society for Science & the Public 2000 - 2015.

Keyword: Animal Communication; Language
Link ID: 21727 - Posted: 12.29.2015

By KEN BELSON Researchers at several universities and research institutes were awarded almost $16 million Tuesday to find a way to diagnose, while victims are alive, chronic traumatic encephalopathy, a degenerative brain disease linked to repeated head hits in contact sports. The National Institutes of Health and the National Institute of Neurological Disorders and Stroke issued the seven-year grant as part of a long-term study of brain disease in former N.F.L. and college football players, many of whom sustained multiple concussions on the field. Despite the implications that the research may have on football players and the N.F.L., no league money will be used to help pay for the grant. For years, researchers have been able to diagnose C.T.E. only by examining the brains of players who died and whose families agreed to donate the organ, a limitation that has slowed efforts to determine who is susceptible to having the disease. The new study, considered among the most ambitious in the field of sports-related brain injury, aims to develop ways to spot the disease in the living and figure out why certain players get it and others do not. A more comprehensive understanding of the disease, the researchers said, may lead to ways to prevent it. “There are so many critical unanswered questions about C.T.E.,” Dr. Robert Stern, the lead principal investigator and a professor at Boston University School of Medicine, said in a statement. “We are optimistic that this project will lead to many of these answers, by developing accurate methods of detecting and diagnosing C.T.E. during life, and by examining genetic and other risk factors for this disease.” © 2015 The New York Times Company

Keyword: Brain Injury/Concussion
Link ID: 21723 - Posted: 12.24.2015

Scientists hunting for a drug that speeds stroke recovery might find one in the bedside cabinets of millions of Americans. Mice treated with small doses of the sleeping pill Ambien recovered more quickly from strokes than those given a placebo. Ambien is the best-known incarnation of the drug zolpidem, which was prescribed 40 million times in the US in 2011. The researchers say that the finding should be replicated by other labs before proceeding with clinical trials, but it’s an intriguing result for a problem in desperate need of solutions. Strokes cut off the blood supply to part of the brain, leading to the death of oxygen-starved tissue. Some tissue repair can take place in the months afterwards, but most people never fully recover. Although physical therapy can help, there are no drugs that increase the amount of brain tissue repaired. “There are various natural mechanisms that promote a degree of normal recovery in animals and people, but it’s limited”, says Gary Steinberg of Stanford University School of Medicine, who was lead author of the study. One such mechanism may be an increase in signalling by the GABA neurotransmitter in parts of the brain that are able to rewire themselves. Because Ambien acts on GABA receptors, Steinberg and his team wondered whether they could use it to hack this mechanism to improve recovery. © Copyright Reed Business Information Ltd.

Keyword: Stroke; Sleep
Link ID: 21710 - Posted: 12.19.2015

By C. CLAIBORNE RAY Q. We know that aquatic mammals communicate with one another, but what about fish? A. Fish have long been known to communicate by several silent mechanisms, but more recently researchers have found evidence that some species also use sound. It is well known that fish communicate by gesture and motion, as in the highly regimented synchronized swimming of schools of fish. Some species use electrical pulses as signals, and some use bioluminescence, like that of the firefly. Some kinds of fish also release chemicals that can be sensed by smell or taste. In 2011, a scientist in New Zealand suggested that what might be called fish vocalization has a role, at least in some ocean fish. In the widely publicized work, done for his doctoral thesis at the University of Auckland, Shahriman Ghazali recorded reef fish in the wild and in captivity, and found two dominant vocalizations, the croak and the purr, in choruses that lasted up to three hours, as well as a previously undescribed popping sound. The sounds of one species recorded in captivity — the bigeye, or Pempheris adspersa — carried 100 feet or more, and the researcher suggested it could be used to keep a group of fish together during nocturnal foraging. Another species, the bluefin gurnard, or Chelidonichthys kumu, was also very noisy, he found. “Vocalization” is a bit of a misnomer, as the sounds these fish make are produced by contracting and vibrating the swim bladder, not by using the mouth. © 2015 The New York Times Company

Keyword: Animal Communication; Hearing
Link ID: 21697 - Posted: 12.14.2015

By SINDYA N. BHANOO Moderate levels of exercise may increase the brain’s flexibility and improve learning, a new study suggests. The visual cortex, the part of the brain that processes visual information, loses the ability to “rewire” itself with age, making it more difficult for adults to recover from injuries and illness, said Claudia Lunghi, a neuroscientist at the University of Pisa and one of the study’s authors. In a study in the journal Current Biology, she and her colleagues asked 20 adults to watch a movie with one eye patched while relaxing in a chair. Later, the participants exercised on a stationary bike for 10-minute intervals while watching a movie. When one eye is patched, the visual cortex compensates for the limited input by increasing its activity level. Dr. Lunghi and her colleagues tested the imbalance in strength between the participants’ eyes after the movie — a measure of changeability in the visual cortex. © 2015 The New York Times Company

Keyword: Regeneration
Link ID: 21681 - Posted: 12.08.2015

Helen Thompson Just after dawn, barbershop quartets of male howler monkeys echo over the canopy of Mexico’s forests. Jake Dunn remembers them well from his early fieldwork in Veracruz. “Most people who don’t know what they’re listening to assume it’s a jaguar,” says Dunn, a primatologist at the University of Cambridge. The calls serve as a warning to male competitors and an alluring pickup line for females. While studying primates in Mexico, Dunn heard drastic differences between resident howler monkeys. He and his colleagues decided to pin down the origin and evolution of this well-known variation among species. After reading a 1949 paper that classified howlers based on a vocal tract bone called the hyoid, Dunn paired up with Lauren Halenar of the American Museum of Natural History in New York City, who was studying the hyoid’s role in howler biology. Scouring collections at museums and zoos in the United States and Europe, the team used laser scanners to create 3-D models of hyoids from nine howler species. The work required a lot of digging through cupboards for skeletons. “Some of these specimens are hundreds of years old,” says Dunn, who recalls imagining “the early naturalists hunting these animals and bringing back the collections.” Real pay dirt came from the National Museums of Scotland, which had preserved the remains of two howlers that had died of natural causes in zoos. CT and MRI scans of the two specimens provided a rare peek at the howler vocal system’s layout. © Society for Science & the Public 2000 - 2015.

Keyword: Sexual Behavior; Animal Communication
Link ID: 21666 - Posted: 12.01.2015

By Karen Russell In late October, when the Apple TV was relaunched, Bandit’s Shark Showdown was among the first apps designed for the platform. The game stars a young dolphin with anime-huge eyes, who battles hammerhead sharks with bolts of ruby light. There is a thrilling realism to the undulance of the sea: each movement a player makes in its midnight-blue canyons unleashes a web of fluming consequences. Bandit’s tail is whiplash-fast, and the sharks’ shadows glide smoothly over rocks. Every shark, fish, and dolphin is rigged with an invisible skeleton, their cartoonish looks belied by the programming that drives them—coding deeply informed by the neurobiology of action. The game’s design seems suspiciously sophisticated when compared with that of apps like Candy Crush Soda Saga and Dude Perfect 2. Bandit’s Shark Showdown’s creators, Omar Ahmad, Kat McNally, and Promit Roy, work for the Johns Hopkins School of Medicine, and made the game in conjunction with a neuroscientist and neurologist, John Krakauer, who is trying to radically change the way we approach stroke rehabilitation. Ahmad told me that their group has two ambitions: to create a successful commercial game and to build “artistic technologies to help heal John’s patients.” A sister version of the game is currently being played by stroke patients with impaired arms. Using a robotic sling, patients learn to sync the movements of their arms to the leaping, diving dolphin; that motoric empathy, Krakauer hopes, will keep patients engaged in the immersive world of the game for hours, contracting their real muscles to move the virtual dolphin.

Keyword: Stroke; Robotics
Link ID: 21635 - Posted: 11.17.2015

Angus Chen English bursts with consonants. We have words that string one after another, like angst, diphthong and catchphrase. But other languages keep more vowels and open sounds. And that variability might be because they evolved in different habitats. Consonant-heavy syllables don't carry very well in places like windy mountain ranges or dense rainforests, researchers say. "If you have a lot of tree cover, for example, [sound] will reflect off the surface of leaves and trunks. That will break up the coherence of the transmitted sound," says Ian Maddieson, a linguist at the University of New Mexico. That can be a real problem for complicated consonant-rich sounds like "spl" in "splice" because of the series of high-frequency noises. In this case, there's a hiss, a sudden stop and then a pop. Where a simple, steady vowel sound like "e" or "a" can cut through thick foliage or the cacophony of wildlife, these consonant-heavy sounds tend to get scrambled. Hot climates might wreck a word's coherence as well, since sunny days create pockets of warm air that can punch into a sound wave. "You disrupt the way it was originally produced, and it becomes much harder to recognize what sound it was," Maddieson says. "In a more open, temperate landscape, prairies in the Midwest of the United States [or in Georgia] for example, you wouldn't have that. So the sound would be transmitted with fewer modifications." © 2015 npr

Keyword: Language; Evolution
Link ID: 21616 - Posted: 11.07.2015

Paul Ibbotson and Michael Tomasello The natural world is full of wondrous adaptations such as camouflage, migration and echolocation. In one sense, the quintessentially human ability to use language is no more remarkable than these other talents. However, unlike these other adaptations, language seems to have evolved just once, in one out of 8.7 million species on earth today. The hunt is on to explain the foundations of this ability and what makes us different from other animals. The intellectual most closely associated with trying to pin down that capacity is Noam Chomsky. He proposed a universal grammatical blueprint that was unique to humans. This blueprint operated like a computer program. Instead of running Windows or Excel, this program performed “operations” on language – any language. Regardless of which of the 6000+ human languages that this code could be exposed to, it would guide the learner to the correct adult grammar. It was a bold claim: despite the surface variations we hear between Swahili, Japanese and Latin, they are all run on the same piece of underlying software. As ever, remarkable claims require remarkable evidence, and in the 50 years since some of these ideas were laid out, history has not been kind. First, it turned out that it is really difficult to state what is “in” universal grammar in a way that does justice to the sheer diversity of human languages. Second, it looks as if kids don’t learn language in the way predicted by a universal grammar; rather, they start with small pockets of reliable patterns in the language they hear, such as Where’s the X?, I wanna X, More X, It’s a X, I’m X-ing it, Put X here, Mommy’s X-ing it, Let’s X it, Throw X, X gone, I X-ed it, Sit on the X, Open X, X here, There’s a X, X broken … and gradually build their grammar on these patterns, from the “bottom up”. © 2015 Guardian News and Media Limited

Keyword: Language
Link ID: 21607 - Posted: 11.06.2015

Nicole Fisher , We know that the brain is neuroplastic — adapts to changes in behavior, environment, thinking and emotions — and may even rewire itself in certain ways. Life experience also teaches us that the tongue is a learning tool that shapes our brain. During early development, babies test everything by placing it in their mouths. As children age they stick out their tongues when concentrating on tasks such as drawing. Even as adults we let our tongue tell us about the world around us through eating, drinking and kissing. During basketball games, some players stick out their tongues while shooting. Now, knowing that there is such a rich nerve connection to the brain, scientists and doctors are turning to the tongue as a way to possibly stimulate the brain for neural retraining and rehabilitation after traumatic injuries or disease. The team at Helius Medical Technologies believe combining physical therapy with stimulation of the tongue may improve impairment of brain function and associated symptoms of injury. “We have already seen that stimulation of various nerves can improve symptoms of a range of neurological diseases. However, we believe the tongue is a much more elegant and direct pathway for stimulating brain structures and inducing neuroplasticity. We are focused on investigating the tongue as a gateway to the brain to hopefully ease the disease of brain injury,” said Dr. Jonathan Sackier, CMO at Helius. It has been argued by some that the era of small molecule is gone. Instead, recognition that the entire body is a closed electrical circuit, is leading to new therapeutic modalities that are known in certain circles as “electroceuticals.”

Keyword: Brain Injury/Concussion; Chemical Senses (Smell & Taste)
Link ID: 21595 - Posted: 11.03.2015

Looking at brain tissue from mice, monkeys and humans, scientists have found that a molecule known as growth and differentiation factor 10 (GDF10) is a key player in repair mechanisms following stroke. The findings suggest that GDF10 may be a potential therapy for recovery after stroke. The study, published in Nature Neuroscience, was supported by the National Institute of Neurological Disorders and Stroke (NINDS), part of the National Institutes of Health. “These findings help to elucidate the mechanisms of repair following stroke. Identifying this key protein further advances our knowledge of how the brain heals itself from the devastating effects of stroke, and may help to develop new therapeutic strategies to promote recovery,” said Francesca Bosetti, Ph.D., stroke program director at NINDS. Stroke can occur when a brain blood vessel becomes blocked, preventing nearby tissue from getting essential nutrients. When brain tissue is deprived of oxygen and nutrients, it begins to die. Once this occurs, repair mechanisms, such as axonal sprouting, are activated as the brain attempts to overcome the damage. During axonal sprouting, healthy neurons send out new projections (“sprouts”) that re-establish some of the connections lost or damaged during the stroke and form new ones, resulting in partial recovery. Before this study, it was unknown what triggered axonal sprouting. Previous studies suggested that GDF10 was involved in the early stages of axonal sprouting, but its exact role in the process was unclear. S. Thomas Carmichael, M.D., Ph.D., and his colleagues at the David Geffen School of Medicine at the University of California Los Angeles took a closer look at GDF10 to identify how it may contribute to axonal sprouting.

Keyword: Stroke; Regeneration
Link ID: 21576 - Posted: 10.28.2015

By Bob Grant Scientists delving into the neurological underpinnings of traumatic brain injuries (TBI) are finding that there may be crucial differences in the long-term effects of the events that depend not only on the insult, but also on the victim. “No two brain injuries are identical,” University of Pennsylvania neuroscientist Akiva Cohen said during a press conference held at the Society for Neuroscience (SfN) annual meeting in Chicago on Monday (October 19). “Brain injury, like many pathologies these days, constitutes a spectrum.” In addition to a severity spectrum that spans mild to severe, brain injuries may differ in terms of how male and female animals respond to them, according to Ramesh Raghupathi, a neurobiologist at Drexel University. Raghupathi and his colleagues have found that young male mice suffer more depressive behaviors than female mice at both four and eight weeks after mild TBI, and females display more headache-like symptoms after similar insults, which can include concussion. “All of these animals at these times after injury are cognitively normal,” Raghupathi told reporters. “And they do not have any movement problems.” Raghupathi and his colleagues also found molecular differences that may underlie the sex differences in TBI response that they observed. “In the male mice,” he said, “there is a dramatic difference in dopamine transmission” compared to the uninjured mice.” Researchers have previously linked impaired dopamine signaling to depression. Raghupathi’s team tested for the lingering effects of TBI in mice by subjecting the animals to certain swimming tests—which are accepted as proxies for depression—and by using a thin filament to touch the faces of the rodents and recording their sensitivity as a measure of headache-like behaviors.

Keyword: Brain Injury/Concussion; Sexual Behavior
Link ID: 21558 - Posted: 10.24.2015

By Jonathan Webb Science reporter, BBC News Crocodiles can sleep with one eye open, according to a study from Australia. In doing so they join a list of animals with this ability, which includes some birds, dolphins and other reptiles. Writing in the Journal of Experimental Biology, the researchers say the crocs are probably sleeping with one brain hemisphere at a time, leaving one half of the brain active and on the lookout. Consistent with this idea, the crocs in the study were more likely to leave one eye open in the presence of a human. They also kept that single eye trained directly on the interloper, said senior author John Lesku. "They definitely monitored the human when they were in the room. But even after the human left the room, the animal still kept its open eye… directed towards the location where the human had been - suggesting that they were keeping an eye out for potential threats." The experiments were done in an aquarium lined with infrared cameras, to monitor juvenile crocodiles day and night. "These animals are not particularly amenable to handling; they are a little snippy. So we had to limit all of our work to juvenile crocodiles, about 40-50cm long," said Dr Lesku, from La Trobe University in Melbourne. As well as placing a human in the room for certain periods, the team tested the effect of having other young crocs around. Sure enough, these also tended to attract the gaze of any reptiles dozing with only one eye. This matches what is known of "unihemispheric sleep" in aquatic mammals, such as walruses and dolphins, which seem to use one eye to make sure they stick together in a group. © 2015 BBC.

Keyword: Sleep; Laterality
Link ID: 21548 - Posted: 10.22.2015

By Hanae Armitage About 70 million people worldwide stutter when they speak, and it turns out humans aren’t the only ones susceptible to verbal hiccups. Scientists at this year’s Society for Neuroscience Conference in Chicago, Illinois, show that mice, too, can stumble in their vocalizations. In humans, stuttering has long been linked to a mutation in the “housekeeping” gene Gnptab, which maintains basic levels of cellular function. To cement this curious genetic link, researchers decided to induce the Gnptab “stutter mutation” in mice. They suspected the change would trigger a mouse version of stammering. But deciphering stuttered squeaks is no easy task, so researchers set up a computerized model to register stutters through a statistical analysis of vocalizations. After applying the model to human speech, researchers boiled the verbal impediment down to two basic characteristics—fewer vocalizations in a given period of time and longer gaps in between each vocalization. For example, in 1 minute, stuttering humans made just 90 vocalizations compared with 125 for non-stutterers. Using these parameters to evaluate mouse vocalizations, researchers were able to identify stuttering mice over a 3.5-minute period. As expected, the mice carrying the mutated gene had far fewer vocalizations, with longer gaps between “speech” compared with their unmodified littermates—Gnptab mutant mice had about 80 vocalizations compared with 190 in the nonmutant mice. The findings not only supply evidence for Gnptab’s role in stuttering, but they also show that its function remains relatively consistent across multiple species. Scientists say the genetic parallel could help reveal the neural mechanisms behind stuttering, be it squeaking or speaking. © 2015 American Association for the Advancement of Science.

Keyword: Language; Genes & Behavior
Link ID: 21527 - Posted: 10.20.2015

By Christopher Intagliata "Babies come prepared to learn any of the world's languages." Alison Bruderer, a cognitive scientist at the University of British Columbia. "Which means no matter where they're growing up in the world, their brains are prepared to pick up the language they're listening to around them." And listen they do. But another key factor to discerning a language’s particular sounds may be for babies to move their tongues as they listen. Bruderer and her colleagues tested that notion by sitting 24 sixth-month-olds in front of a video screen and displaying a checkerboard pattern, while they played one of two tracks: a single, repeated "D" sound in Hindi, <> or two slightly different, alternating "D" sounds. <> The idea here is that babies have a short attention span, so novel things hold their gaze. And indeed, the babies did stare at the screen longer while the alternating "D"s played than for the single “D”—indicating they could detect the novelty. Until, that is, the researchers blocked the babies' tongue movements by having them suck on a teething device. Then the effect disappeared, with the babies unable to differentiate [single D sound] from [alternating D sounds]. And when the babies used a different teether that did not block tongue movement, they once again appeared to comprehend the difference between the Ds. The study is in the Proceedings of the National Academy of Sciences. © 2015 Scientific American

Keyword: Language; Development of the Brain
Link ID: 21517 - Posted: 10.16.2015

Music can be a transformative experience, especially for your brain. Musicians’ brains respond more symmetrically to the music they listen to. And the size of the effect depends on which instrument they play. People who learn to play musical instruments can expect their brains to change in structure and function. When people are taught to play a piece of piano music, for example, the part of their brains that represents their finger movements gets bigger. Musicians are also better at identifying pitch and speech sounds – brain imaging studies suggest that this is because their brains respond more quickly and strongly to sound. Other research has found that the corpus callosum – the strip of tissue that connects the left and right hemisphere of the brain – is also larger in musicians. Might this mean that the two halves of a musician’s brain are better at communicating with each other compared with non-musicians? To find out, Iballa Burunat at the University of Jyväskylä in Finland and her colleagues used an fMRI scanner to look at the brains of 18 musicians and 18 people who have never played professionally. The professional musicians – all of whom had a degree in music – included cellists, violinists, keyboardists and bassoon and trombone players. While they were in the scanner, all of the participants were played three different pieces of music – prog rock, an Argentinian tango and some Stravinsky. Burunat recorded how their brains responded to the music, and used software to compare the activity of the left and right hemispheres of each person’s brain. © Copyright Reed Business Information Ltd.

Keyword: Hearing; Laterality
Link ID: 21465 - Posted: 10.01.2015

Neuroscientist Dr. Charles Tator has asked the family of former NHL enforcer Todd Ewen to donate Ewen's brain so he can study it. This week, Ewan's death was ruled a suicide and Tator wants to examine his brain to determine whether it has signs of degeneration. In particular, he's interested in what Ewen's brain may have in common with the other brains of athletes he's studying as part of the Canadian Sports Concussion Project. Brent Bambury speaks with Dr. Tator about how concussions can affect athletes and what big unanswered questions remain when it comes to the links between concussions, brain injury and self-harm. This conversation has been edited for clarity and length. Brent Bambury: You and your team already have examined the brains of eighteen former professional athletes. What do you hope to learn by looking at Todd Ewen's brain? Dr. Charles Tator: Well we want to know if he had C.T.E. In other words, was this the cause of his decline in terms of depression, for example. BB: What is C.T.E. ? CT: Well C.T.E. is chronic traumatic encephalopathy which is a specific type of brain degeneration that occurs after repetitive trauma like multiple concussions. BB: Is that something that you can only determine by examining the brain from a cadaver? CT: Unfortunately, even though we are getting clues about it from other tests like M.R.I., at this point in 2015, you have to do an autopsy to be sure that it's C.T.E. So with the Todd Ewen donation, if we're fortunate enough to have that opportunity to examine his brain, we would want to see if there were any manifestations of these previous concussions that he had in his career. ©2015 CBC/Radio-Canada

Keyword: Brain Injury/Concussion
Link ID: 21450 - Posted: 09.28.2015

By Jane E. Brody Mark Hammel’s hearing was damaged in his 20s by machine gun fire when he served in the Israeli Army. But not until decades later, at 57, did he receive his first hearing aids. “It was very joyful, but also very sad, when I contemplated how much I had missed all those years,” Dr. Hammel, a psychologist in Kingston, N.Y., said in an interview. “I could hear well enough sitting face to face with someone in a quiet room, but in public, with background noise, I knew people were talking, but I had no idea what they were saying. I just stood there nodding my head and smiling. “Eventually, I stopped going to social gatherings. Even driving, I couldn’t hear what my daughter was saying in the back seat. I live in the country, and I couldn’t hear the birds singing. “People with hearing loss often don’t realize what they’re missing,” he said. “So much of what makes us human is social contact, interaction with other human beings. When that’s cut off, it comes with a very high cost.” And the price people pay is much more than social. As Dr. Hammel now realizes, “the capacity to hear is so essential to overall health.” Hearing loss is one of the most common conditions affecting adults, and the most common among older adults. An estimated 30 million to 48 million Americans have hearing loss that significantly diminishes the quality of their lives — academically, professionally and medically as well as socially. One person in three older than 60 has life-diminishing hearing loss, but most older adults wait five to 15 years before they seek help, according to a 2012 report in Healthy Hearing magazine. And the longer the delay, the more one misses of life and the harder it can be to adjust to hearing aids. © 2015 The New York Times Company

Keyword: Hearing; Language
Link ID: 21449 - Posted: 09.28.2015

Now hear this. Anthropologists have estimated the hearing abilities of early hominins – reconstructing a human ancestor’s sensory perception. Rolf Quam from Binghamton University in New York and his colleagues studied skulls and ear bones from Australopithecus africanus and Paranthropus robustus, two species that lived between 1 million and 3 million years ago, as well as modern humans and chimpanzees. Using CT scans of the bones, they built 3D reconstructions of the ear of each species. Then they fed a series of anatomical measurements into a computer model to predict their hearing abilities. The results for humans and chimpanzees fitted well with laboratory data, suggesting the model aligned well with real performance. For each species, they then estimated the frequency range they can hear best. Modern humans and chimpanzees perform similarly below 3 kilohertz, but humans have better hearing than chimps in the 3-5 kHz range. The early hominins had a similar sensitive range to chimpanzees, but shifted slightly towards that of modern humans, so they have better hearing than chimps do for 3-4 kHz sounds. Australopithecus and Paranthropus are not believed to have been capable of language, but they almost certainly communicated vocally as other primates do, says Quam. Quam thinks this shift in hearing sensitivity would have helped them communicate in open environments, such as African savannahs, where human ancestors are thought to have evolved bipedalism. © Copyright Reed Business Information Ltd.

Keyword: Evolution; Language
Link ID: 21446 - Posted: 09.26.2015

Linda Geddes Jack struggled in regular school. Diagnosed with dyslexia and the mathematical equivalent, dyscalculia, as well as the movement disorder dyspraxia, Jack (not his real name) often misbehaved and played the class clown. So the boy’s parents were relieved when he was offered a place at Fairley House in London, which specializes in helping children with learning difficulties. Fairley is also possibly the first school in the world to have offered pupils the chance to undergo electrical brain stimulation. The stimulation was done as part of an experiment in which twelve eight- to ten-year-olds, including Jack, wore an electrode-equipped cap while they played a video game. Neuroscientist Roi Cohen Kadosh of the University of Oxford, UK, who led the pilot study in 2013, is one of a handful of researchers across the world who are investigating whether small, specific areas of a child’s brain can be safely stimulated to overcome learning difficulties. “It would be great to be able to understand how to deliver effective doses of brain stimulation to kids’ brains, so that we can get ahead of developmental conditions before they really start to hold children back in their learning,” says psychologist Nick Davis of Swansea University, UK. The idea of using magnets or electric currents to treat psychiatric or learning disorders — or just to enhance cognition — has generated a flurry of excitement over the past ten years. The technique is thought to work by activating neural circuits or by making it easier for neurons to fire. The research is still in its infancy, but at least 10,000 adults have undergone such stimulation, and it seems to be safe — at least in the short term. One version of the technology, called transcranial magnetic stimulation (TMS), has been approved by the US Food and Drug Administration to treat migraine and depression in adults. © 2015 Nature Publishing Group,

Keyword: Dyslexia; Attention
Link ID: 21441 - Posted: 09.24.2015