Chapter 19. Language and Hemispheric Asymmetry
Follow us on Facebook and Twitter, or subscribe to our mailing list, to receive news updates. Learn more.
By Kate Baggaley WASHINGTON, D.C. — Adding magnets to football helmets could reduce the risk of concussions, new research suggests. When two players collide, the magnets in their helmets would repel each other, reducing the force of the collision. “All helmet design companies and manufacturers have the same approach, which is to try to disperse the impact energy after the impact’s already occurred,” neuroscientist Raymond Colello said November 15 at the annual meeting of the Society for Neuroscience. The magnets, he says, would put a brake on the impact before it happens. The idea hasn’t been tested yet in helmets with real players, said Judy Cameron, a neuroscientist at the University of Pittsburgh. “But a lot of thought has gone into it, and the data that was shown about the ability of the magnets to actually repel each other looked extremely promising.” On the field, football players can run at nearly 20 miles per hour and can experience up to 150 g’s of force upon impact. Concussions readily occur at impacts greater than 100 g’s. Every year there are 100,000 concussions at all levels of play among the nearly 1.2 million people who play football in the United States. Colello, of Virginia Commonwealth University in Richmond, is testing magnets made in China from the rare-earth element neodymium. They are the most powerful commercially available magnets and weigh about one-third of a pound each (football helmets weigh from 3.5 to 5.5 pounds). When placed one-fourth of an inch away from each other, two magnets with their same poles face-to-face exert nearly 100 pounds of repulsive force. © Society for Science & the Public 2000 - 2014
Keyword: Brain Injury/Concussion
Link ID: 20317 - Posted: 11.17.2014
by Helen Thomson As you read this, your neurons are firing – that brain activity can now be decoded to reveal the silent words in your head TALKING to yourself used to be a strictly private pastime. That's no longer the case – researchers have eavesdropped on our internal monologue for the first time. The achievement is a step towards helping people who cannot physically speak communicate with the outside world. "If you're reading text in a newspaper or a book, you hear a voice in your own head," says Brian Pasley at the University of California, Berkeley. "We're trying to decode the brain activity related to that voice to create a medical prosthesis that can allow someone who is paralysed or locked in to speak." When you hear someone speak, sound waves activate sensory neurons in your inner ear. These neurons pass information to areas of the brain where different aspects of the sound are extracted and interpreted as words. In a previous study, Pasley and his colleagues recorded brain activity in people who already had electrodes implanted in their brain to treat epilepsy, while they listened to speech. The team found that certain neurons in the brain's temporal lobe were only active in response to certain aspects of sound, such as a specific frequency. One set of neurons might only react to sound waves that had a frequency of 1000 hertz, for example, while another set only cares about those at 2000 hertz. Armed with this knowledge, the team built an algorithm that could decode the words heard based on neural activity aloneMovie Camera (PLoS Biology, doi.org/fzv269). © Copyright Reed Business Information Ltd.
GrrlScientist Since today is caturday, that wonderful day when the blogosphere takes a breather from hell-raising to celebrate pets, I thought some of my favourite animals: corvids. I ran across this lovely video created by Cornell University’s Laboratory of Ornithology (more fondly referred to as the “Lab of O”) that discusses the differences between and potential meanings of the sounds made by crows and ravens. If you watch birds, even casually, you might be confused by trying to distinguish these two large black corvid species. However, both species are quite chatty, and these birds’ sounds provide important identifying information. In this video, narrated by Kevin McGowan, an ornithologist at the Cornell Lab of O, you’ll learn how to distinguish crows and ravens on the basis of their voices alone. Both crows and ravens make loud raspy signature calls, described as “caw” and “kraa” respectively, but American crows and common ravens have large repertoires of sounds in addition to these calls. They also can learn to imitate the calls of other birds. As you’ll learn in this video, crows often make a “rattle” sound along with their territorial “caw”. They also communicate using a wide variety of other sounds including clicks and bell-like notes. Ravens, on the other hand, produce deep, throaty kraa calls.
Keyword: Animal Communication
Link ID: 20255 - Posted: 10.29.2014
By Virginia Morell Human fetuses are clever students, able to distinguish male from female voices and the voices of their mothers from those of strangers between 32 and 39 weeks after conception. Now, researchers have demonstrated that the embryos of the superb fairy-wren (Malurus cyaneus, pictured), an Australian songbird, also learn to discriminate among the calls they hear. The scientists played 1-minute recordings to 43 fairy-wren eggs collected from nests in the wild. The eggs were between days 9 and 13 of a 13- to 14-day incubation period. The sounds included white noise, a contact call of a winter wren, or a female fairy-wren’s incubation call. Those embryos that listened to the fairy-wrens’ incubation calls and the contact calls of the winter wrens lowered their heart rates, a sign that they were learning to discriminate between the calls of a different species and those of their own kind, the researchers report online today in the Proceedings of the Royal Society B. (None showed this response to the white noise.) Thus, even before hatching, these small birds’ brains are engaged in tasks requiring attention, learning, and possibly memory—the first time embryonic learning has been seen outside humans, the scientists say. The behavior is key because fairy-wren embryos must learn a password from their mothers’ incubation calls; otherwise, they’re less successful at soliciting food from their parents after hatching. © 2014 American Association for the Advancement of Science.
With the passing away of Professor Allison Doupe on Friday, October 24, of cancer, UCSF and biomedical science have lost a scholar of extraordinary intelligence and erudition and a campus leader. Allison Doupe was a psychiatrist and systems neuroscientist who became a leader of her field, the study of sensorimotor learning and its neural control. Allison was recruited to the Departments of Psychiatry and Physiology and the Neuroscience Graduate Program in 1993, rising to Professor in 2000. Her academic career has been outstanding at every stage, including First Class Honors at McGill, an MD and PhD in Neurobiology from Harvard, and a prestigious Junior Fellowship from the Harvard University Society of Fellows. Her PhD work with Professor Paul Patterson definitively established the role of particular environmental factors in the development of autonomic neurons and was important in the molecular and cellular investigations of the roles of hormones and growth factors in that system. After internship at the Massachusetts General Hospital and residency in psychiatry at UCLA, she chose to pursue a postdoctoral fellowship at Caltech, studying song learning in birds with Professor Mark Konishi as a way of combining her clinical interests in behavior and development with research in cognitive neuroscience. The development of birdsong is in many important respects similar to language development in humans. The pioneering work of Peter Marler, on song sparrows in Golden Gate Park, showed that each baby songbird learns its father’s dialect but could readily learn the dialect of any singing bird of the same species placed in the role of tutor. Many birds, including the ones studied by Allison Doupe, learn their song by listening to their father sing during a period of life in which they are not themselves singing, and they later practice and perfect their own song by comparison with their memory of the father’s (or tutor’s) song.
|By Steve Mirsky People have been leaving messages on bathroom walls for thousands of years. Just google “ancient Roman bathroom graffiti.” But we’re not the only ones to use latrines for information exchange—as two German researchers have confirmed after hundreds of hours watching lemurs pee and poop. For science. Primatologists Iris Dröscher and Peter Kappeler concentrated on seven sets of pair-bonded members of a species called white-footed sportive lemurs, at a nature reserve in southern Madagascar. Their report is in the journal Behavioral Ecology and Sociobiology. [Iris Dröscher & Peter M. Kappeler Maintenance of familiarity and social bonding via communal latrine use in a solitary primate (Lepilemur leucopus)] Many animals use the same spots repeatedly to do their business, primates in particular. For these lemurs, a specific tree becomes the urine and feces focal point. And because chemical compounds in their waste transmit information, the so-called latrine tree becomes like a bulletin board to post messages for the rest of the community. Based on their 1,097 hours of observations, the researchers conclude that urine and glandular secretions left on the tree trunk are the primary message vehicles. Feces mostly just collects on the ground. Some urine telegrams are probably signals from a particular lemur to the neighbors that he or she is around. But male lemurs upped their latrine visits when potential competitors for females came into their home area. So the frequent chemical messages left on the tree probably say in that case, “Buzz off, buddy, she’s with me.” In lemur. © 2014 Scientific American,
by Colin Barras LOCKED in but not shut out: for the first time people who have lost the ability to move or talk because of a stroke may be able to communicate with their loved ones using a brain-computer interface. Brain injuries can leave people aware but almost completely paralysed, a condition called locked-in syndrome. Brain-computer interfaces (BCIs) can help some people communicate by passing signals from electrodes attuned to their brain activity as they watch a screen displaying letters. Subtle changes in neural activity let researchers know when a person wishes to select a particular on-screen item, allowing them to spell out messages by thought alone. Until now, BCIs have only been tested on healthy volunteers and people with amyotrophic lateral sclerosis, a neurodegenerative disease that leads to muscle wasting. But no one had tested whether the technology could help people locked in after a brain stem stroke. Now Eric Sellers and his colleagues at East Tennessee State University in Johnson City have tested the technique on a 68-year-old man. After more than a year of training he learned to communicate reliably via the BCI. He took the opportunity to thank his wife for her hard work, and to give his thoughts on gift purchases for his children (Science Translational Medicine, DOI: 10.1126/scitranslmed.3007801). © Copyright Reed Business Information Ltd.
By Virginia Morell Two years ago, scientists showed that dolphins imitate the sounds of whales. Now, it seems, whales have returned the favor. Researchers analyzed the vocal repertoires of 10 captive orcas (Orcinus orca), three of which lived with bottlenose dolphins (Tursiops truncatus) and the rest with their own kind. Of the 1551 vocalizations these seven latter orcas made, more than 95% were the typical pulsed calls of killer whales. In contrast, the three orcas that had only dolphins as pals busily whistled and emitted dolphinlike click trains and terminal buzzes, the scientists report in the October issue of The Journal of the Acoustical Society of America. (Watch a video as bioacoustician and co-author Ann Bowles describes the difference between killer whale and orca whistles.) The findings make orcas one of the few species of animals that, like humans, is capable of vocal learning—a talent considered a key underpinning of language. © 2014 American Association for the Advancement of Science.
|By Tori Rodriguez The safety of football continues to be a heated topic for players and parents, with mixed evidence regarding the effect of head injuries on mental illness. Past studies on the connection have often been methodologically flawed or yielded ambiguous results. Now a paper in April in the American Journal of Psychiatry, the largest study yet to investigate the link, finds that even a single head injury indeed increases the risk of later mental illness, especially if the injury occurs during adolescence. Using Danish medical registries, researchers led by physician Sonja Orlovska of the University of Copenhagen studied 113,906 people who had been hospitalized for head injuries over a 23-year period. They discovered that in addition to cognitive symptoms caused by structural damage to the brain (such as delirium), these people were subsequently more likely than the general population to develop several psychiatric illnesses. Risk increased by 65 percent for schizophrenia and 59 percent for depression. Risk was highest in the first year postinjury but remained significantly elevated throughout the next 15 years. After the team controlled for several potential confounders, such as accident proneness and a family history of psychiatric problems, they found the strongest injury-related predictor for later onset of schizophrenia, depression and bipolar disorder was a head trauma experienced between the ages of 11 and 15. “Previous studies have shown that head injury induces inflammation in the brain, which causes several changes—for example, an increased permeability of the blood-brain barrier,” Orlovska says. Normally the barrier protects the brain from potentially harmful contents in the bloodstream, but injury-induced inflammation may allow these substances access to the brain. “For some individuals, this might initiate damaging processes in the brain,” she says. © 2014 Scientific American,
by Jason M. Breslow As the NFL nears an end to its long-running legal battle over concussions, new data from the nation’s largest brain bank focused on traumatic brain injury has found evidence of a degenerative brain disease in 76 of the 79 former players it’s examined. The findings represent a more than twofold increase in the number of cases of chronic traumatic encephalopathy, or CTE, that have been reported by the Department of Veterans Affairs’ brain repository in Bedford, Mass. Researchers there have now examined the brain tissue of 128 football players who, before their deaths, played the game professionally, semi-professionally, in college or in high school. Of that sample, 101 players, or just under 80 percent, tested positive for CTE. To be sure, players represented in the data represent a skewed population. CTE can only be definitively identified posthumously, and many of the players who have donated their brains for research suspected that they may have had the disease while still alive. For example, former Chicago Bears star Dave Duerson committed suicide in 2011 by shooting himself in the chest, reportedly to preserve his brain for examination. Nonetheless, Dr. Ann McKee, the director of the brain bank, believes the findings suggest a clear link between football and traumatic brain injury. “Obviously this high percentage of living individuals is not suffering from CTE,” said McKee, a neuropathologist who directs the brain bank as part of a collaboration between the VA and Boston University’s CTE Center. But “playing football, and the higher the level you play football and the longer you play football, the higher your risk.” ©1995-2014 WGBH Educational Foundation
Keyword: Brain Injury/Concussion
Link ID: 20146 - Posted: 10.01.2014
By Melissa Dahl If you are the sort of person who has a hard time just watching TV — if you’ve got to be simultaneously using your iPad or laptop or smartphone — here’s some bad news. New research shows a link between juggling multiple digital devices and a lower-than-usual amount of gray matter, the stuff that’s made up of brain cells, in the region of the brain associated with cognitive and emotional control. More details, via the press release: The researchers at the University of Sussex's Sackler Centre for Consciousness used functional magnetic resonance imaging (fMRI) to look at the brain structures of 75 adults, who had all answered a questionnaire regarding their use and consumption of media devices, including mobile phones and computers, as well as television and print media. They found that, independent of individual personality traits, people who used a higher number of media devices concurrently also had smaller grey matter density in the part of the brain known as the anterior cingulate cortex (ACC), the region notably responsible for cognitive and emotional control functions. But a predilection for using several devices at once isn’t necessarily causing a decrease in gray matter, the authors note — this is a purely correlational finding. As Earl Miller, a neuroscientist at MIT who was not involved in this research, wrote in an email, “It could be (in fact, is possibly more likely) that the relationship is the other way around.” In other words, the people who are least content using just one device at a time may have less gray matter in the first place.
by Helen Thomson My, what big eyes you have – you must be trying really hard. A study of how pupils dilate with physical effort could allow us to make strenuous tasks seem easier by zapping specific areas of the brain. We know pupils dilate with mental effort, when we think about a difficult maths problem, for example. To see if this was also true of physical exertion, Alexandre Zenon at the Catholic University of Louvain in Belgium, measured the pupils of 18 volunteers as they squeezed a device which reads grip strength. Sure enough, the more force they exerted, the larger their pupils. To see whether pupil size was related to actual or perceived effort, the volunteers were asked to squeeze the device with four different grip strengths. Various tests enabled the researchers to tell how much effort participants felt they used, from none at all to the most effort possible. Comparing the results from both sets of experiments suggested that pupil dilation correlated more closely with perceived effort than actual effort. The fact that both mental effort and perceived physical effort are reflected in pupil size suggests there is a common representation of effort in the brain, says Zenon. To see where in the brain this might be, the team looked at which areas were active while similar grip tasks were being performed. Zenon says they were able to identify areas within the supplementary motor cortex – which plays a role in movement – associated with how effortful a task is perceived to be. © Copyright Reed Business Information Ltd.
Link ID: 20121 - Posted: 09.27.2014
By Smitha Mundasad Health reporter, BBC News A spice commonly found in curries may boost the brain's ability to heal itself, according to a report in the journal Stem Cell Research and Therapy. The German study suggests a compound found in turmeric could encourage the growth of nerve cells thought to be part of the brain's repair kit. Scientists say this work, based in rats, may pave the way for future drugs for strokes and Alzheimer's disease. But they say more trials are needed to see whether this applies to humans. Researchers from the Institute of Neuroscience and Medicine in Julich, Germany, studied the effects of aromatic-turmerone - a compound found naturally in turmeric. Rats were injected with the compound and their brains were then scanned. Particular parts of the brain, known to be involved in nerve cell growth, were seen to be more active after the aromatic-turmerone infusion. Scientists say the compound may encourage a proliferation of brain cells. In a separate part of the trial, researchers bathed rodent neural stem cells (NSCs) in different concentrations of aromatic-tumerone extract. NSCs have the ability to transform into any type of brain cell and scientists suggest they could have a role in repair after damage or disease. Dr Maria Adele Rueger, who was part of the research team, said: "In humans and higher developed animals their abilities do not seem to be sufficient to repair the brain but in fish and smaller animals they seem to work well." Picture of the spice turmeric Turmeric belongs to the same plant family as ginger BBC © 2014
By SAM BORDEN Bellini, a Brazilian soccer star who led the team that won the 1958 World Cup and was honored with a statue outside the Estádio do Maracanã in Rio de Janeiro, had a degenerative brain disease linked to dozens of boxers and American football players when he died in March at age 83. At the time, his death was attributed to complications related to Alzheimer’s disease. But researchers now say he had an advanced case of chronic traumatic encephalopathy, or C.T.E., which is caused by repeated blows to the head and has symptoms similar to those of Alzheimer’s. C.T.E. can be diagnosed only posthumously, and few brains of former soccer players have been examined. Bellini is the second known case, according to Dr. Ann McKee, a neuropathologist at Boston University and the Veterans Affairs Medical Center in Bedford, Mass., who assisted in examining Bellini’s brain. McKee was also involved this year when researchers found C.T.E. in the brain of a 29-year-old man from New Mexico who had played soccer semiprofessionally. McKee said in an interview that she was aware of a third former soccer player who had C.T.E. but that she was not yet authorized to publicly identify the person. As C.T.E. began to gain widespread attention about six years ago, it was often thought of as an American problem. Many of the early cases of the disease, for which there is no known cure, were connected to boxers and American football players. © 2014 The New York Times Company
Keyword: Brain Injury/Concussion
Link ID: 20110 - Posted: 09.24.2014
Jia You In the future, a nurse could determine whether a baby is likely to develop a reading disorder simply by attaching a few electrodes to its scalp and watching its brain waves respond to human speech. Such is the scenario suggested by a new study, which finds a potential biological indicator of how well preschool children perceive rhythm, an ability linked to language development. “It’s really impressive to work with children this young, who are not often looked at,” says Aniruddh Patel, a cognitive neuroscientist at Tufts University in Medford, Massachusetts, who was not involved with the research. Spoken language consists of sound waves occurring over multiple timescales. A syllable, for example, takes place over a quarter of a second, while a sentence unfolds over a few seconds. To make sense of this complex auditory information, humans use rhythmic cues such as stress and pause to discern words and syllables. Adults and school-aged children with reading disorders, however, struggle to pick up on these rhythmic patterns. Scientists estimate that dyslexia and other reading disabilities plague about 5% to 10% of the population. Detecting such impairments early could lead to more effective intervention, but observing telltale signs in younger children who have not learned to read has proven a challenge. So biologist Nina Kraus of Northwestern University in Evanston, Illinois, and her colleagues looked for automatic brain responses that can track language development in preschoolers, who have not learned to read. © 2014 American Association for the Advancement of Science
2014 by Dan Jones The vast majority of people think we have free will and are the authors of our own life stories. But if neuroscientists were one day able to predict our every action based on brain scans, would people abandon this belief in droves? A new study concludes that such knowledge would not by itself be enough to shake our confidence in our own volition. Many neuroscientists, such as the late Francis Crick, have argued that our sense of free will is no more than the behaviour of a vast assembly of nerve cells. This is tied to the idea of determinism, which has it that every effect is preceded by a cause, with cause and effect connected by physical laws. This is why the behaviour of physical systems can be predicted – even the brain, in principle. As author Sam Harris puts it: "If determinism is true, the future is set – and this includes all our future states of mind and our subsequent behaviour." If people lost their belief in their own free will, that would have important consequences for how we think about moral responsibility, and even how we behave. For example, numerous studies have shown that when people are led to reject free will they are more likely to cheat, and are also less bothered about punishing other wrongdoers. For those who argue that what we know about neuroscience is incompatible with free will, predicting what our brain is about to do should reveal the illusory nature of free will, and lead people to reject it. Experimental philosopher Eddy Nahmias at Georgia State University in Atlanta dubs this view "willusionism". He recently set out to test it. © Copyright Reed Business Information Ltd.
Link ID: 20102 - Posted: 09.22.2014
2014 by Helen Thomson Shall I compare thee to... well, no one actually. A 76-year-old woman has developed an incredibly rare disorder – she has the compulsive urge to write poetry. Her brain is now being studied by scientists who want to understand more about the neurological basis for creativity. In 2013, the woman arrived at a UK hospital complaining of memory problems and a tendency to lose her way in familiar locations. For the previous two years, she had experienced occasional seizures. She was diagnosed with temporal lobe epilepsy and treated with the drug lamotrigine, which stopped her seizures. However, as they receded, a strange behaviour took hold. She began to compulsively write poetry – something she hadn't shown any interest in previously. Suddenly, the woman was writing 10 to 15 poems a day, becoming annoyed if she was disrupted. Her work rhymed but the content was banal if a touch wistful – a style her husband described as doggerel (see "Unstoppable creativity"). About six months after her seizures stopped, the desire to write became less strong, although it still persists to some extent. Doctors call the intense desire to write hypergraphia. It typically occurs alongside schizophrenia and an individual's output is usually rambling and disorganised. "It was highly unusual to see such highly structured and creative hypergraphia without any of the other behavioural disturbances," says the woman's neurologist, Jason Warren at University College London. © Copyright Reed Business Information Ltd
By Elizabeth Pennisi "What's for dinner?" The words roll off the tongue without even thinking about it—for adults, at least. But how do humans learn to speak as children? Now, a new study in mice shows how a gene, called FOXP2, implicated in a language disorder may have changed between humans and chimps to make learning to speak possible—or at least a little easier. As a uniquely human trait, language has long baffled evolutionary biologists. Not until FOXP2 was linked to a genetic disorder that caused problems in forming words could they even begin to study language’s roots in our genes. Soon after that discovery, a team at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, discovered that just two bases, the letters that make up DNA, distinguished the human and chimp versions of FOXP2. To try to determine how those changes influenced the gene's function, that group put the human version of the gene in mice. In 2009, they observed that these "humanized" mice produced more frequent and complex alarm calls, suggesting the human mutations may have been involved in the evolution of more complex speech. Another study showed that humanized mice have different activity in the part of the brain called the striatum, which is involved in learning, among other tasks. But the details of how the human FOXP2 mutations might affect real-world learning remained murky. To solve the mystery, the Max Planck researchers sent graduate student Christiane Schreiweis to work with Ann Graybiel, a neuroscientist at the Massachusetts Institute of Technology in Cambridge. She's an expert in testing mouse smarts by seeing how quickly they can learn to find rewards in mazes. © 2014 American Association for the Advancement of Science
By KEN BELSON The National Football League, which for years disputed evidence that its players had a high rate of severe brain damage, has stated in federal court documents that it expects nearly a third of retired players to develop long-term cognitive problems and that the conditions are likely to emerge at “notably younger ages” than in the general population. The findings are a result of data prepared by actuaries hired by the league and provided to the United States District Court judge presiding over the settlement between the N.F.L. and 5,000 former players who sued the league, alleging that it had hidden the dangers of concussions from them. “Thus, our assumptions result in prevalence rates by age group that are materially higher than those expected in the general population,” said the report, prepared by the Segal Group for the N.F.L. “Furthermore, the model forecasts that players will develop these diagnoses at notably younger ages than the generation population.” The statements are the league’s most unvarnished admission yet that the sport’s professional participants sustain severe brain injuries at far higher rates than the general population. They also appear to confirm what scientists have said for years: that playing football increases the risk of developing neurological conditions like chronic traumatic encephalopathy, a degenerative brain disease that can be identified only in an autopsy. “This statement clears up all the confusion and doubt manufactured over the years questioning the link between brain trauma and long-term neurological impairment,” said Chris Nowinski, the executive director of the Sports Legacy Institute, who has for many years pressured the league to acknowledge the connection between football and brain diseases. © 2014 The New York Times Company
Keyword: Brain Injury/Concussion
Link ID: 20073 - Posted: 09.13.2014
By Lesley Evans Ogden Humans are noisy creatures, our cacophony of jet engines and jackhammering drowning out the communications of other species. In response, a number of animals, including marmosets and whales, turn up their own volume to be heard above the din, a phenomenon called the Lombard effect. A new study reveals that even fish “shout.” Researchers took a close look at the blacktail shiner (Cyprinella venusta), which is common to freshwater streams of the southeastern United States and whose short-distance acoustic signals are often exposed to boat and road noise. Only male shiners make sounds; popping sounds called knocks are used aggressively toward other males, while staticky-sounding “growls” are used for courtship, both heard in the above video. When the scientists brought the fish back to the lab and cranked up white noise from an underwater amplifier, they found that shiner males emitted fewer, shorter pulses, and cranked up the volume of their acoustic signals to be heard above background noise. Published in Behavioral Ecology, it’s the first study documenting the Lombard effect in fish, suggesting that freshwater fish are another group potentially impacted by our ever-increasing hubbub. © 2014 American Association for the Advancement of Science