Chapter 19. Language and Lateralization

Follow us on Facebook or subscribe to our mailing list, to receive news updates. Learn more.


Links 901 - 920 of 2699

By Meeri Kim, Dizziness, vertigo and nausea are common symptoms of an inner-ear infection. But they can also be signs of a stroke. For doctors, especially those working in emergency rooms, quickly and accurately making the distinction is vital. But basic diagnostic tools, including the otoscope and simple eye-movement tests, are far from definitive. As a result, many doctors resort to a pricey imaging test such as a CT scan or an MRI. Nearly half of the 4 million people who visit U.S. emergency rooms each year with dizziness are given an MRI or CT scan, according to a study issued last month. Only about 3 percent of those 4 million people are actually having strokes. Why did the physical therapist’s staff push him to make more visits? Hefty insurance payments, perhaps. For the 25 percent of strokes that restrict blood flow to the back portions of the brain, CT scans are a poor diagnostic tool, according to the study’s leader, David Newman-Toker, an associate professor of neurology and otolaryngology at the Johns Hopkins University School of Medicine. “CT scans are so bad at detecting [these strokes] that they miss about 85 percent of them” in the first day after symptoms begin, he said. “That’s pretty close to useless.” Even MRIs miss almost 20 percent of strokes if the test is done within the first 24 hours. A new device offers a promising option for rooting out the cause of dizziness: eye-tracking goggles. © 1996-2013 The Washington Post

Keyword: Stroke; Hearing
Link ID: 18464 - Posted: 08.06.2013

By Michele Solis Attention training might trump language practice in treating dyslexia, and video games might provide just that, according to a recent study in Current Biology. Researchers at the University of Padua in Italy found that 10 kids with dyslexia who played an action-filled video game for nine 80-minute sessions increased their reading speed, without introducing mistakes. These reading gains lasted at least two months and outpaced gains measured in 10 children with dyslexia who played a nonaction version of the same game, as well as trumping the expected improvement that naturally occurs in a year for a child with dyslexia. Though small, the study bolsters evidence that dyslexia stems in part from problems in focusing attention onto letters and words in an orderly way. Last year the same team reported that preschoolers who struggled to quickly and accurately shift their attention—which can be thought of as a spotlight—were likely to have reading difficulties three years later. Because action video games require players to constantly redirect their attention to different targets, neuroscientist Simone Gori and his colleagues thought the video games might fine-tune that spotlight so as to avoid jumbling letters on a page. The training honed visual attention skills and reading hand in hand, and the reading improvements even exceeded those obtained in children after traditional therapies for dyslexia, which focus on building language skills. Gori does not advocate abandoning the older methods but says that training visual attention could be a vital, overlooked component. He also notes that kids are prone to quit traditional dyslexia therapies, which he says can be demanding and even boring; not a problem in his video-game experiment. “Our difficulty was in getting the kids to stop playing,” Gori says. © 2013 Scientific American

Keyword: Dyslexia
Link ID: 18450 - Posted: 08.03.2013

By Julie Hecht AFTER A LONG DAY of being a dog, no dog in existence has ever curled up on a comfy couch to settle in with a good book. Dogs just don’t roll like that. But that shouldn’t imply that human words don’t or can’t have meaning for dogs. Chaser, a Border Collie from South Carolina, first entered the news in 2011 when a Behavioral Processes paper reported she had learned and retained the distinct names of over 1,000 objects. But that’s not all. When tested on the ability to associate a novel word with an unfamiliar item, she could do that, too. She also learned that different objects fell into different categories: certain things are general “toys,” while others are the more specific “Frisbees” and, of course, there are many, many exciting “balls.” She differentiates between object labels and action commands, interpreting “fetch sock” as two separate words, not as the single phrase “fetchsock.” Fast forward two years. Chaser and her owner and trainer Dr. John Pilley, an emeritus professor of psychology at Wofford College, appeared again in a scientific journal. This time, the study highlighted Chaser’s attention to the syntactical relationships between words, for example, differentiating “to ball take Frisbee” from “to Frisbee take ball.” I’ve been keeping an eye on Chaser, and I’ve been keeping an eye on Rico, Sofia, Bailey, Paddy and Betsy, all companion dogs whose way with human language has been reported in scientific journals. Most media reports tend to focus on outcomes: what these dogs can — or can’t — do with our words. But I think these reports are missing the point. Learning the names of over 1,000 words doesn’t just happen overnight. What does the behind-the-scenes learning and training look like? How did Chaser develop this intimate relationship with human language? © 2013 Scientific American

Keyword: Learning & Memory; Language
Link ID: 18435 - Posted: 07.31.2013

By Glen Tellis, Rickson C. Mesquita, and Arjun G. Yodh Terrence Murgallis, a 20 year-old undergraduate student in the Department of Speech-Language Pathology at Misericordia University has stuttered all his life and approached us recently about conducting brain research on stuttering. His timing was perfect because our research group, in collaboration with a team led by Dr. Arjun Yodh in the Department of Physics and Astronomy at the University of Pennsylvania, had recently deployed two novel optical methods to compare blood flow and hemoglobin concentration differences in the brains of those who stutter with those who are fluent. These noninvasive methods employ diffusing near-infrared light and have been dubbed near-infrared spectroscopy (NIRS) for concentration dynamics, and diffuse correlation spectroscopy (DCS) for flow dynamics. The near-infrared light readily penetrates through intact skull to probe cortical regions of the brain. The low power light has no known side-effects and has been successfully utilized for a variety of clinical studies in infants, children, and adults. DCS measures fluctuations of scattered light due to moving targets in the tissue (mostly red blood cells). The technique measures relative changes in cerebral blood flow. NIRS uses the relative transmission of different colors of light to detect hemoglobin concentration changes in the interrogated tissues. Though there are numerous diagnostic tools available to study brain activity, including positron emission tomography (PET), magnetic resonance imaging (MRI), and magnetoencephalography (MEG), these methods are often invasive and/or expensive to administer. In the particular case of electroencephalography (EEG), its low spatial resolution is a significant limitation for investigations of verbal fluency. © 2013 Scientific American

Keyword: Language
Link ID: 18426 - Posted: 07.30.2013

By Michelle Warwicker BBC Nature Individual wild wolves can be recognised by just their howls with 100% accuracy, a study has shown. The team from Nottingham Trent University, UK, developed a computer program to analyse the vocal signatures of eastern grey wolves. Wolves roam huge home ranges, making it difficult for conservationists to track them visually. But the technology could provide a way for experts to monitor individual wolves by sound alone. "Wolves howl a lot in the wild," said PhD student Holly Root-Gutteridge, who led the research. "Now we can be sure... exactly which wolf it is that's howling." The team's findings are published in the journal Bioacoustics. Wolves use their distinctive calls to protect territory from rivals and to call to other pack members. "They enjoy it as a group activity," said Ms Root-Gutteridge, "When you get a chorus howl going they all join in." The team's computer program is unique because it analyses both volume (or amplitude) and pitch (or frequency) of wolf howls, whereas previously scientists had only examined the animals' pitch. "Think of [pitch] as the note the wolf is singing," explained Ms Root-Gutteridge. "What we've added now is the amplitude - or volume - which is basically how loud it's singing at different times." "It's a bit like language: If you put the stress in different places you form a different sound." BBC © 2013

Keyword: Language; Evolution
Link ID: 18401 - Posted: 07.23.2013

By Rebecca Morelle Science reporter, BBC World Service Scientists have found further evidence that dolphins call each other by "name". Research has revealed that the marine mammals use a unique whistle to identify each other. A team from the University of St Andrews in Scotland found that when the animals hear their own call played back to them, they respond. The study is published in the Proceedings of the National Academy of Sciences. Dr Vincent Janik, from the university's Sea Mammal Research Unit, said: "(Dolphins) live in this three-dimensional environment, offshore without any kind of landmarks and they need to stay together as a group. "These animals live in an environment where they need a very efficient system to stay in touch." It had been-long suspected that dolphins use distinctive whistles in much the same way that humans use names. Previous research found that these calls were used frequently, and dolphins in the same groups were able to learn and copy the unusual sounds. But this is the first time that the animals response to being addressed by their "name" has been studied. To investigate, researchers recorded a group of wild bottlenose dolphins, capturing each animal's signature sound. BBC © 2013

Keyword: Language; Evolution
Link ID: 18400 - Posted: 07.23.2013

The author of a new six-step plan for Canadian doctors treating concussion patients warns that many people are unaware you don't need to hit your head to get a concussion. Dr. Charles Tator of the neurosurgery division at the University of Toronto wrote in Monday's Canadian Medical Association And for doctors and other trained health professionals in remote regions who have the responsibility for diagnosing concussions, Tator's primer summarizes how to detect and assess the injury. Concussions are the most common traumatic brain injury, often occurring during vehicle collisions, work activities, sports, recreation and falls in seniors. Females may be more prone to concussion than males, said Dr. Charles Tator.Females may be more prone to concussion than males, said Dr. Charles Tator. (CBC) It's now clear concussion can occur without direct impact to the head. For instance, a blow to the chest can cause a whiplash effect on the brain that jiggles the organ. Everyone who is involved in sports should be aware of the importance of recognizing concussions, he said. The most frequent symptoms are headache, dizziness, nausea and imbalance. Only one symptom is needed for the diagnosis. "The importance of accurate and timely recognition and management stems from the consequences of misdiagnosis or faulty management that can lead to major disability or death, in both the short and long term," Tator wrote. © CBC 2013

Keyword: Brain Injury/Concussion
Link ID: 18397 - Posted: 07.23.2013

Here’s yet another reason to get off the couch: new research findings suggest that regularly breaking a sweat may lower the risk of having a stroke. A stroke can occur when a blood vessel in the brain gets blocked. As a result, nearby brain cells will die after not getting enough oxygen and other nutrients. A number of risk factors for stroke have been identified, including smoking, high blood pressure, diabetes and being inactive. For this study, published in the journal Stroke, Michelle N. McDonnell, Ph.D., from the University of South Australia, Adelaide and her colleagues obtained data from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study. REGARDS is a large, long-term study funded by the NIH National Institute of Neurological Disorders and Stroke (NINDS) to look at the reasons behind the higher rates of stroke mortality among African-Americans and other residents living in the Southeastern United States. “Epidemiological studies such as REGARDS provide an important opportunity to explore race, genetics, environmental, and lifestyle choices as stroke risk factors,” said Claudia Moy, Ph.D., program director at NINDS. Over 30,000 participants supplied their medical history over the phone. The researchers also visited them to obtain health measures such as body mass index and blood pressure. At the beginning of the study, the researchers asked participants how many times per week they exercised vigorously enough to work up a sweat. The researchers contacted participants every six months to see if they had experienced a stroke or a mini-stroke known as a transient ischemic attack (TIA). To confirm their responses, the researchers reviewed participants’ medical records.

Keyword: Stroke
Link ID: 18393 - Posted: 07.20.2013

By NICHOLAS BAKALAR There are many dying languages in the world. But at least one has recently been born, created by children living in a remote village in northern Australia. Carmel O’Shannessy, a linguist at the University of Michigan, has been studying the young people’s speech for more than a decade and has concluded that they speak neither a dialect nor the mixture of languages called a creole, but a new language with unique grammatical rules. The language, called Warlpiri rampaku, or Light Warlpiri, is spoken only by people under 35 in Lajamanu, an isolated village of about 700 people in Australia’s Northern Territory. In all, about 350 people speak the language as their native tongue. Dr. O’Shannessy has published several studies of Light Warlpiri, the most recent in the June issue of Language. “Many of the first speakers of this language are still alive,” said Mary Laughren, a research fellow in linguistics at the University of Queensland in Australia, who was not involved in the studies. One reason Dr. O’Shannessy’s research is so significant, she said, “is that she has been able to record and document a ‘new’ language in the very early period of its existence.” Everyone in Lajamanu also speaks “strong” Warlpiri, an aboriginal language unrelated to English and shared with about 4,000 people in several Australian villages. Many also speak Kriol, an English-based creole developed in the late 19th century and widely spoken in northern Australia among aboriginal people of many different native languages. Lajamanu parents are happy to have their children learn English in school for use in the wider world, but eager to preserve Warlpiri as the language of their culture. There is an elementary school in Lajamanu, but most children go to boarding school in Darwin for secondary education. The language there is English. But they continue to speak Light Warlpiri among themselves. © 2013 The New York Times Company

Keyword: Language; Evolution
Link ID: 18376 - Posted: 07.15.2013

by Helen Thomson "I told my daughter her living room TV was out of sync. Then I noticed the kitchen telly was also dubbed badly. Suddenly I noticed that her voice was out of sync too. It wasn't the TV, it was me." Ever watched an old movie, only for the sound to go out of sync with the action? Now imagine every voice you hear sounds similarly off-kilter – even your own. That's the world PH lives in. Soon after surgery for a heart problem, he began to notice that something wasn't quite right. "I was staying with my daughter and they like to have the television on in their house. I turned to my daughter and said 'you ought to get a decent telly, one where the sound and programme are synchronised'. I gave a little chuckle. But they said 'there's nothing wrong with the TV'." Puzzled, he went to the kitchen to make a cup of tea. "They've got another telly up on the wall and it was the same. I went into the lounge and I said to her 'hey you've got two TVs that need sorting!'." That was when he started to notice that his daughter's speech was out of time with her lip movements too. "It wasn't the TV, it was me. It was happening in real life." PH is the first confirmed case of someone who hears people speak before registering the movement of their lips. His situation is giving unique insights into how our brains unify what we hear and see. It's unclear why PH's problem started when it did – but it may have had something to do with having acute pericarditis, inflammation of the sac around the heart, or the surgery he had to treat it. © Copyright Reed Business Information Ltd

Keyword: Attention; Language
Link ID: 18350 - Posted: 07.06.2013

By TIM REQUARTH and MEEHAN CRIST Babies learn to speak months after they begin to understand language. As they are learning to talk, they babble, repeating the same syllable (“da-da-da”) or combining syllables into a string (“da-do-da-do”). But when babies babble, what are they actually doing? And why does it take them so long to begin speaking? Insights into these mysteries of human language acquisition are now coming from a surprising source: songbirds. Researchers who focus on infant language and those who specialize in birdsong have teamed up in a new study suggesting that learning the transitions between syllables — from “da” to “do” and “do” to “da” — is the crucial bottleneck between babbling and speaking. “We’ve discovered a previously unidentified component of vocal development,” said the lead author, Dina Lipkind, a psychology researcher at Hunter College in Manhattan. “What we’re showing is that babbling is not only to learn sounds, but also to learn transitions between sounds.” The results provide insight into language acquisition and may eventually help shed light on human speech disorders. “Every time you find out something fundamental about the way development works, you gain purchase on what happens when children are at risk for disorder,” said D. Kimbrough Oller, a language researcher at the University of Memphis, who was not involved in the study. At first, however, the scientists behind these findings weren’t studying human infants at all. They were studying birds. “When I got into this, I never believed we were going to learn about human speech,” said Ofer Tchernichovski, a birdsong researcher at Hunter and the senior author of the study, published online on May 29 in the journal Nature. © 2013 The New York Times Company

Keyword: Language; Evolution
Link ID: 18332 - Posted: 07.01.2013

by Andrew Porterfield Honey bees may have only a fraction of our neurons—just under a million versus our tens of billions—but our brains aren't so different. Take sidedness. The human brain is divided into right and left sides—our right brain controls the left side of our body and vice versa. New research reveals that something similar happens in bees. When scientists removed the right or left antenna of honey bees, those insects with intact right antennae more quickly recognized bees from the same hive, stuck out their tongues (showing willingness to feed), and fended off invaders. Bees with just their left antennae took longer to recognize bees, didn't want to feed, and mistook familiar bees for foreign ones. This suggests, the team concludes today in Scientific Reports, that bee brains have a sidedness just like ours do. The researchers also think that right antennae might control other bee behavior, like their sophisticated, mysterious "waggle dance" to indicate food. But there's no buzz for the left-antennaed. © 2010 American Association for the Advancement of Science

Keyword: Laterality; Evolution
Link ID: 18320 - Posted: 06.29.2013

By Meghan Rosen Paralyzed rats can now decide for themselves when it’s time to take a leak. Animals in a new study regained bladder control thanks to a new treatment that coaxes severed nerves to grow. Instead of dribbling out urine, the rodents squeezed out shots of pee almost as well as healthy rats do, researchers report June 25 in the Journal of Neuroscience. The study is the first to regenerate nerves that restore bladder function in animals with severely injured spinal cords. “This is a very big deal,” says neurologist John McDonald of the Kennedy Krieger Institute in Baltimore, Md. If the treatment works in people with spinal cord injuries, he says, “it would change their lives.” Unlike paralyzed rats, severely paralyzed humans can’t leak urine to relieve a full bladder. Unless injured people are fitted with a catheter, urine backs up into the kidneys. “These people get kidney failure all the time,” says study leader Jerry Silver, a neuroscientist at Case Western Reserve University in Cleveland. “It’s a terrible problem. If they didn’t have the catheter, they would die.” Some of the worst spinal cord injuries sever the bundle of nerve cells that reach from a mammal’s brain down through the vertebrae. The neurons can’t just grow back. Instead, the cells’ stumps get stuck in a gummy thicket of scar tissue that forms around the wound. © Society for Science & the Public 2000 - 2013

Keyword: Regeneration; Movement Disorders
Link ID: 18316 - Posted: 06.26.2013

The prevalence of traumatic brain injuries such as concussions among students points to a silent epidemic that demands a wake-up call from parents, coaches and other adults, Canadian neurosurgeons and psychologists say. One in five students in grades 7 to 12 said they’d had a traumatic brain injury that left them unconscious for at least five minutes or required a hospital stay overnight after symptoms, researchers said in Wednesday’s issue of the Journal of the American Medical Association. The researchers from St. Michael's Hospital and the Centre for Addiction and Mental Health in Toronto surveyed 8,915 students across Ontario in 2011 as part of one of the longest ongoing school surveys in the world. "It needs to be a wake-up call to say, look, young people are sustaining brain injuries at a very high rate,” said the study’s lead author, Dr. Michael Cusimano, a neurosurgeon at St. Michael’s Hospital. "If we want to protect future generations, because our brain really defines how we are … not just as an individual, we need to do something collectively as a society to address this problem." Of the 464 students reporting a traumatic brain injury in the past 12 months, sports injuries accounted for more than half of the cases, 56 per cent, particularly for boys. Concussions that didn't lead to loss of consciousness or a hospital stay weren't included. © CBC 2013

Keyword: Brain Injury/Concussion; Development of the Brain
Link ID: 18314 - Posted: 06.26.2013

Did that prairie dog just call you fat? Quite possibly. On The Current Friday, biologist Con Slobodchikoff described how he learned to understand what prairie dogs are saying to one another and discovered how eloquent they can be. Slobodchikoff, a professor emeritus at North Arizona University, told Erica Johnson, guest host of The Current, that he started studying prairie dog language 30 years ago after scientists reported that other ground squirrels had different alarm calls to warn each other of flying predators such as hawks and eagles, versus predators on the ground, such as coyotes or badgers. Prairie dogs, he said, were ideal animals to study because they are social animals that live in small co-operative groups within a larger colony, or "town" and they never leave their colony or territory, where they have built an elaborate underground complex of tunnels and burrows. In order to figure out what the prairie dogs were saying, Slobodchikoff and his colleagues trapped them and painted them with fur dye to identify each one. Then they recorded the animals' calls in the presence of different predators. They found that the animals make distinctive calls that can distinguish between a wide variety of animals, including coyotes, domestic dogs and humans. The patterns are so distinct, Slobodchikoff said, that human visitors that he brings to a prairie dog colony can typically learn them within two hours. But then Slobodchikoff noticed that the animals made slightly different calls when different individuals of the same species went by. © CBC 2013

Keyword: Language; Evolution
Link ID: 18300 - Posted: 06.22.2013

By Caroline Parkinson Health editor, BBC News website Patients given a clot-busting drug within six hours of a stroke are more likely to have a good quality of life 18 months afterwards, an international study suggests. However, the review of more than 3,000 patients found the drug - alteplase - offered no improvement in survival rates. The drug is increasingly being used in specialist stroke units in the UK. The Stroke Association said the Lancet Neurology research was "encouraging". Quality of life The treatment is given to patients who have had an ischaemic stroke, when the brain's blood supply is interrupted by a clot. A stroke can cause permanent damage such as paralysis and speech problems, and can be fatal. Without treatment, a third of people who suffer a stroke die, with another third left permanently dependent and disabled. This international trial, led by researchers at the University of Edinburgh, followed patients from 12 different countries - half had the alteplase treatment, which is given intravenously, and half did not. It was funded by the UK and Australian governments, the UK Stroke Association, the Medical Research Council and Health Foundation UK, with no funding from the pharmaceutical company that makes the drug. The researchers suggest that for every 1,000 patients given the drug within six hours of stroke, by 18 months, 36 more will be able to manage independently and will have less pain and discomfort than if they had not had it. However that is the average - and more of those given alteplase within the first hour or two after a stroke will see such benefits. BBC © 2013

Keyword: Stroke
Link ID: 18299 - Posted: 06.22.2013

by Emily Underwood Something odd happened when Shu Zhang was giving a presentation to her classmates at the Columbia Business School in New York City. Zhang, a Chinese native, spoke fluent English, yet in the middle of her talk, she glanced over at her Chinese professor and suddenly blurted out a word in Mandarin. "I meant to say a transition word like 'however,' but used the Chinese version instead," she says. "It really shocked me." Shortly afterward, Zhang teamed up with Columbia social psychologist Michael Morris and colleagues to figure out what had happened. In a new study, they show that reminders of one's homeland can hinder the ability to speak a new language. The findings could help explain why cultural immersion is the most effective way to learn a foreign tongue and why immigrants who settle within an ethnic enclave acculturate more slowly than those who surround themselves with friends from their new country. Previous studies have shown that cultural icons such as landmarks and celebrities act like "magnets of meaning," instantly activating a web of cultural associations in the mind and influencing our judgments and behavior, Morris says. In an earlier study, for example, he asked Chinese Americans to explain what was happening in a photograph of several fish, in which one fish swam slightly ahead of the others. Subjects first shown Chinese symbols, such as the Great Wall or a dragon, interpreted the fish as being chased. But individuals primed with American images of Marilyn Monroe or Superman, in contrast, tended to interpret the outlying fish as leading the others. This internally driven motivation is more typical of individualistic American values, some social psychologists say, whereas the more externally driven explanation of being pursued is more typical of Chinese culture. © 2010 American Association for the Advancement of Science.

Keyword: Language; Learning & Memory
Link ID: 18283 - Posted: 06.18.2013

Robert Bazell NBC News Just two years ago, Barbara Whitmarsh was a woman who seemed to have it all. She was a highly regarded scientist at the National Institutes of Health. Married for 30 years, she’d raised six children with her beloved husband, John. But then John Whitmarsh started to notice some disturbing changes in his wife, now 62. It was as if the woman he’d married and lived with all that time was slowly and inexorably fading away. “Her ability to feel empathy, her personality, it just disappeared over a period of time,” John said. “I would ask her, ‘Is there anything wrong?’ and she would say, ‘No, I love you and everything's fine,’ but she wasn't there. And she said it in that flat way.” A scientist himself, Whitmarsh knew there was, indeed, something wrong. And he was worried. He asked his wife to see a psychiatrist who eventually diagnosed her with frontotemporal dementia or FTD. It’s a dementia that generally strikes at an earlier age than Alzheimer’s disease. And its symptoms are different – at least in the beginning – from Alzheimer’s because it originates in a different part of the brain. It’s also a disease that until very recently doctors thought was rare -- but that view is changing. “We've begun to realize that frontotemporal dementia is actually more common than Alzheimer's disease in people with degenerative disorders under the age of 60,” said Dr. Bruce Miller, director of the Memory and Aging Center at the University of California, San Francisco.

Keyword: Alzheimers
Link ID: 18277 - Posted: 06.15.2013

By Nathan Seppa Soccer players who hit the ball with their head a lot don’t score as well on a memory test as players who head the ball less often, a new study finds. Frequent headers are also associated with abnormalities in the white matter of the brain, researchers report June 11 in Radiology. “These changes are subtle,” says Inga Koerte, a radiologist at Harvard Medical School and Brigham and Women’s Hospital in Boston. “But you don’t need a concussive trauma to get changes in the microstructure of your brain.” While soccer players can get concussions from colliding with goal posts, the ground or each other, concussions are uncommon from heading the ball, even though it can move at 80 kilometers per hour, says coauthor Michael Lipton, a neuroradiologist at the Albert Einstein College of Medicine in New York City. He and his colleagues took magnetic resonance imaging scans of 28 men and nine women who played amateur soccer. The players, with an average age of 31, tallied up their games and practice sessions in the previous year and estimated how many headers they had done in each. Most players headed the ball hundreds of times; some hit thousands of headers. The MRIs revealed brain abnormalities in some players, mainly in the white matter of three regions of the brain. White matter coats nerve fibers, and bundles of fibers cross and converge in the three regions. But the areas aren’t associated with a single function, Lipton says. Attention, memory, sensory inputs and visual and spatial functions could all be processed there. © Society for Science & the Public 2000 - 2013

Keyword: Brain Injury/Concussion; Learning & Memory
Link ID: 18266 - Posted: 06.13.2013

By Felicity Muth I recently came across an article entitled ‘Advantages in exploring a new environment with the left eye in lizards’ and I couldn’t help but read more. In this study, conducted in Italy, scientists caught 44 wall lizards and glued eye patches on to them (using a paper glue that is harmless to the lizards as they can shed and renew their skin). Half the lizards had their left eye covered, and half had their right eye covered. The lizards were then let into a maze for 20 minutes to see how they fared with turning left and right. The ones that were allowed to use just their left eye were much faster than those that could just use their right eye at turning both left and right. In addition to this, they made fewer stops, seeming to be less hesitant and indecisive than the right-eyed individuals. However, this was only the case when the lizard had to make a choice between turning left or right, not when they only had the choice to turn one way. Why might this be the case? Well, like a lot of vertebrates, lizards have lateralized brains. This means that the brain is divided in two halves, and some functions are specialized to one half. The classic example of this in humans is Broca’s area (associated with speech), which is found in the left hemisphere of the brain in 95% of us. Similar to how humans on the whole prefer to use their right hand, it seems that lizards generally prefer to use their left eye. As with humans, lizard optic nerve fibres are crossed over, meaning that control of the left eye comes from the right hemisphere of the brain and vice versa. As these lizards predominantly use their left eye, this indicates that in this species, something in the right side of their brain is specialised in attending to spatial cues. © 2013 Scientific American

Keyword: Laterality; Vision
Link ID: 18261 - Posted: 06.12.2013