Chapter 7. Life-Span Development of the Brain and Behavior
Follow us on Facebook and Twitter, or subscribe to our mailing list, to receive news updates. Learn more.
By Ariana Eunjung Cha Autism has always been a tricky disorder to diagnose. There’s no such thing as a blood test, cheek swap or other accepted biological marker so specialists must depend on parent and teacher reports, observations and play assessments. Figuring out a child's trajectory once he or she is diagnosed is just as challenging. The spectrum is wide and some are destined to be on the mild end and be very talkative, sometimes almost indistinguishable from those without the disorder in some settings, while others will suffer from a more severe form and have trouble being able to speak basic words. Now scientists believe that they have a way to distinguish between those paths, at least in terms of language ability, in the toddler years using brain imaging. In an article published Thursday in the journal Neuron, scientists at the University of California-San Diego have found that children with autism spectrum disorder, or ASD, with good language outcomes have strikingly distinct patterns of brain activation as compared to those with poor language outcomes and typically developing toddlers. "Why some toddlers with ASD get better and develop good language and others do not has been a mystery that is of the utmost importance to solve," Eric Courchesne, one of the study’s authors and co-director of the University of California-San Diego's Autism Center, said in a statement. The images of the children in the study -- MRIs of the brain -- were taken at 12 to 29 months while their language was assessed one to two years later at 30 to 48 months.
By Megan Griffith-Greene The idea of playing a game to make you sharper seems like a no-brainer. That's the thinking behind a billion-dollar industry selling brain training games and programs designed to boost cognitive ability. But an investigation by CBC's Marketplace reveals that brain training games such as Lumosity may not make your brain perform better in everyday life. Lumosity Brain training games, such as Lumosity, are a billion-dollar industry. Many people are worried about maintaining their brain health and want to prevent a decline in their mental abilities. (CBC) Almost 15 per cent of Canadians over the age of 65 are affected by some kind of dementia. And many people of all ages are worried about maintaining their brain health and possibly preventing a decline in their mental abilities. "I don't think there's anything to say that you can train your brain to be cognitively better in the way that we know that we can train our bodies to be physically better," neuroscientist Adrian Owen told Marketplace co-host Tom Harrington. To test how effective the games are at improving cognitive function, Marketplace partnered with Owen, who holds the Canada Excellence Research Chair in Cognitive Neuroscience and Imaging at the Brain and Mind Institute at Western University. A group of 54 adults, including Harrington, did the brain training at least three times per week for 15 minutes or more over a period of between two and a half and four weeks. The group underwent a complete cognitive assessment at the beginning and end of the training to see if there had been any change as the result of the training program. ©2015 CBC/Radio-Canada.
|By Simon Makin People can control prosthetic limbs, computer programs and even remote-controlled helicopters with their mind, all by using brain-computer interfaces. What if we could harness this technology to control things happening inside our own body? A team of bioengineers in Switzerland has taken the first step toward this cyborglike setup by combining a brain-computer interface with a synthetic biological implant, allowing a genetic switch to be operated by brain activity. It is the world's first brain-gene interface. The group started with a typical brain-computer interface, an electrode cap that can register subjects' brain activity and transmit signals to another electronic device. In this case, the device is an electromagnetic field generator; different types of brain activity cause the field to vary in strength. The next step, however, is totally new—the experimenters used the electromagnetic field to trigger protein production within human cells in an implant in mice. The implant uses a cutting-edge technology known as optogenetics. The researchers inserted bacterial genes into human kidney cells, causing them to produce light-sensitive proteins. Then they bioengineered the cells so that stimulating them with light triggers a string of molecular reactions that ultimately produces a protein called secreted alkaline phosphatase (SEAP), which is easily detectable. They then placed the human cells plus an LED light into small plastic pouches and inserted them under the skin of several mice. © 2015 Scientific American
By Jan Hoffman As adults age, vision deteriorates. One common type of decline is in contrast sensitivity, the ability to distinguish gradations of light to dark, making it possible to discern where one object ends and another begins. When an older adult descends a flight of stairs, for example, she may not tell the edge of one step from the next, so she stumbles. At night, an older driver may squint to see the edge of white road stripes on blacktop. Caught in the glare of headlights, he swerves. But new research suggests that contrast sensitivity can be improved with brain-training exercises. In a study published last month in Psychological Science, researchers at the University of California, Riverside, and Brown University showed that after just five sessions of behavioral exercises, the vision of 16 people in their 60s and 70s significantly improved. After the training, the adults could make out edges far better. And when given a standard eye chart, a task that differed from the one they were trained on, they could correctly identify more letters. “There’s an idea out there that everything falls apart as we get older, but even older brains are growing new cells,” said Allison B. Sekuler, a professor of psychology, neuroscience and behavior at McMaster University in Ontario, who was not involved in the new study. “You can teach an older brain new tricks.” The training improved contrast sensitivity in 16 young adults in the study as well, although the older subjects showed greater gains. That is partly because the younger ones, college students, already had reasonably healthy vision and there was not as much room for improvement. Before the training, the vision of each adult, young and older, was assessed. The exercises were fine-tuned at the beginning for each individual so researchers could measure improvements, said Dr.G. John Andersen, the project’s senior adviser and a psychology professor at the University of California, Riverside. © 2015 The New York Times Company
Cory Turner To survive, we humans need to be able to do a handful of things: breathe, of course. And drink and eat. Those are obvious. We're going to focus now on a less obvious — but no less vital — human function: learning. Because new research out today in the journal Science sheds light on the very building blocks of learning. Imagine an 11-month-old sitting in a high chair opposite a small stage where you might expect, say, a puppet show. Except this is a lab at Johns Hopkins University. Instead of a puppeteer, a researcher is rolling a red and blue striped ball down a ramp, toward a little wall at the bottom. Even babies seem to know the ball can't go through that wall, though not necessarily because they learned it. It's what some scientists call core knowledge — something, they say, we're born with. "Some pieces of knowledge are so fundamental in guiding regular, everyday interactions with the environment, navigating through space, reaching out and picking up an object, avoiding an oncoming object — those things are so fundamental to survival that they're really selected for by evolution," says Lisa Feigenson, a professor of psychological and brain sciences at Hopkins and one of the researchers behind this study. Which explains why the baby seems genuinely surprised when the ball rolls down the ramp and does go through the wall — thanks to some sleight of hand by the researchers: © 2015 NPR
Keyword: Development of the Brain
Link ID: 20756 - Posted: 04.04.2015
By Matt McFarland The individuals who have founded some of the most success tech companies are decidedly weird. Examine the founder of a truly innovative company and you’ll find a rebel without the usual regard for social customs. This begs the question, why? Why aren’t more “normal” people with refined social graces building tech companies that change the world? Why are only those on the periphery reaching great heights? If you ask tech investor Peter Thiel, the problem is a social environment that’s both powerful and destructive. Only individuals with traits reminiscent of Asperger’s Syndrome, which frees them from an attachment to social conventions, have the strength to create innovative businesses amid a culture that discourages daring entrepreneurship. “Many of the more successful entrepreneurs seem to be suffering from a mild form of Asperger’s where it’s like you’re missing the imitation, socialization gene,” Thiel said Tuesday at George Mason University. “We need to ask what is it about our society where those of us who do not suffer from Asperger’s are at some massive disadvantage because we will be talked out of our interesting, original, creative ideas before they’re even fully formed. Oh that’s a little bit too weird, that’s a little bit too strange and maybe I’ll just go ahead and open the restaurant that I’ve been talking about that everyone else can understand and agree with, or do something extremely safe and conventional.” An individual with Asperger’s Syndrome — a form of autism — has limited social skills, a willingness to obsess and an interest in systems. Those diagnosed with Asperger’s Syndrome tend to be unemployed or underemployed at rates that far exceed the general population. Fitting into the world is difficult.
Link ID: 20755 - Posted: 04.04.2015
Emily Hodgkin As a nation we think we understand autism. Since the first discovery of the condition just over 70 years ago awareness of autism has continued to grow. Despite this, 87 per cent of people affected by autism think the general public has a bad understanding of the condition. Many of the common myths surrounding autism have been debunked - including the perception that people with autism can’t hold a job. But only 15 per cent of adults in the UK with autism are in full-time employment, while 61 per cent of people with autism currently not in employment say they want to work. Research suggests that employers are missing out on abilities that people on the autism spectrum have in greater abundance – such as heightened abilities in pattern recognition and logical reasoning, as well as a greater attention to detail. Mark Lever, chief executive of the National Autistic Society (NAS) said: "It's remarkable that awareness has increased so much since the NAS was set up over 50 years ago, a time when people with the condition were often written off and hidden from society. But, as our supporters frequently tell us and the poll confirms, there is still a long way to go before autism is fully understood and people with the condition are able to participate fully in their community. All too often we still hear stories of families experiencing judgemental attitudes or individuals facing isolation or unemployment due to misunderstandings or myths around autism.” There are around 700,000 autistic people in the UK – more than 1 in a 100. So as it's more common than perhaps expected, what other myths still exist? © independent.co.uk
Link ID: 20754 - Posted: 04.04.2015
By LAWRENCE K. ALTMAN, M.D WASHINGTON — Even before Ronald Reagan became the oldest elected president, his mental state was a political issue. His adversaries often suggested his penchant for contradictory statements, forgetting names and seeming absent-mindedness could be linked to dementia. In 1980, Mr. Reagan told me that he would resign the presidency if White House doctors found him mentally unfit. Years later, those doctors and key aides told me they had not detected any changes in his mental abilities while in office. Now a clever new analysis has found that during his two terms in office, subtle changes in Mr. Reagan’s speaking patterns linked to the onset of dementia were apparent years before doctors diagnosed his Alzheimer’s disease in 1994. The findings, published in The Journal of Alzheimer’s Disease by researchers at Arizona State University, do not prove that Mr. Reagan exhibited signs of dementia that would have adversely affected his judgment and ability to make decisions in office. But the research does suggest that alterations in speech one day might be used to predict development of Alzheimer’s and other neurological conditions years before symptoms are clinically perceptible. Detection of dementia at the earliest stages has become a high priority. Many experts now believe that yet-to-be-developed treatments are likely to be effective at preventing or slowing progression of dementia only if it is found before it significantly damages the brain. The “highly innovative” methods used by the researchers may eventually help “to further clarify the extent to which spoken-word changes are associated with normal aging or predictive of subsequent progression to the clinical stages of Alzheimer’s disease,” said Dr. Eric Reiman, the director of the Banner Alzheimer’s Institute in Phoenix, who was not involved in the new study. © 2015 The New York Times Company
Scientists have found that a compound originally developed as a cancer therapy potentially could be used to treat Alzheimer’s disease. The team demonstrated that the drug, saracatinib, restores memory loss and reverses brain problems in mouse models of Alzheimer’s, and now the researchers are testing saracatinib’s effectiveness in humans. The study was funded by the National Institutes of Health as part of an innovative crowdsourcing initiative to repurpose experimental drugs. Researchers from the Yale University School of Medicine, New Haven, Connecticut, conducted the animal study, published for early view on March 21 in the Annals of Neurology External Web Site Policy, with support from the National Center for Advancing Translational Sciences (NCATS) through its Discovering New Therapeutic Uses for Existing Molecules (New Therapeutic Uses) program. Launched in May 2012, this program matches scientists with a selection of pharmaceutical industry assets that have undergone significant research and development by industry, including safety testing in humans, to test potential ideas for new therapeutic uses. Alzheimer’s disease is the most common form of dementia, a group of disorders that cause progressive loss of memory and other mental processes. An estimated 5 million Americans have Alzheimer’s disease, which causes clumps of amyloid beta protein to build up in the brain, and these protein clusters damage and ultimately kill brain cells (neurons). Alzheimer’s disease also leads to loss of synapses, which are the spaces between neurons through which the cells talk to each other and form memories. Current Alzheimer’s drug therapies can only ease symptoms without stopping disease progression. New treatments are needed that can halt the condition by targeting its underlying mechanisms.
Link ID: 20742 - Posted: 04.01.2015
Sara Reardon A new study finds that children's cognitive skills are linked to family income. The stress of growing up poor can hurt a child’s brain development starting before birth, research suggests — and even very small differences in income can have major effects on the brain. Researchers have long suspected that children’s behaviour and cognitive abilities are linked to their socioeconomic status, particularly for those who are very poor. The reasons have never been clear, although stressful home environments, poor nutrition, exposure to industrial chemicals such as lead and lack of access to good education are often cited as possible factors. In the largest study of its kind, published on 30 March in Nature Neuroscience1, a team led by neuroscientists Kimberly Noble from Columbia University in New York City and Elizabeth Sowell from Children's Hospital Los Angeles, California, looked into the biological underpinnings of these effects. They imaged the brains of 1,099 children, adolescents and young adults in several US cities. Because people with lower incomes in the United States are more likely to be from minority ethnic groups, the team mapped each child’s genetic ancestry and then adjusted the calculations so that the effects of poverty would not be skewed by the small differences in brain structure between ethnic groups. The brains of children from the lowest income bracket — less than US$25,000 — had up to 6% less surface area than did those of children from families making more than US$150,000, the researchers found. In children from the poorest families, income disparities of a few thousand dollars were associated with major differences in brain structure, particularly in areas associated with language and decision-making skills. Children's scores on tests measuring cognitive skills, such as reading and memory ability, also declined with parental income. © 2015 Nature Publishing Group,
by Bethany Brookshire Music displays all the harmony and discord the auditory world has to offer. The perfect pair of notes at the end of the Kyrie in Mozart’s Requiem fills churches and concert halls with a single chord of ringing, echoing consonance. Composers such as Arnold Schönberg explored the depths of dissonance — groups of notes that, played together, exist in unstable antagonism, their frequencies crashing and banging against each other. Dissonant chords are difficult to sing and often painful to hear. But they may get less painful with age. As we age, our brains may lose the clear-cut representations of these consonant and dissonant chords, a new study shows. The loss may affect how older people engage with music and shows that age-related hearing loss is more complex than just having to reach for the volume controls. The main mechanism behind age-related hearing loss is the deterioration of the outer hair cells in the cochlea, a coiled structure within our inner ear. When sound waves enter the ear, a membrane vibrates, pulling the hair cells to and fro and kicking off a series of events that produce electrical signals that will be sent onward to the brain. As we age, we lose some of these outer hair cells, and with them goes our ability to hear extremely high frequencies. In a new study, researchers tested how people perceive consonant pairs of musical notes, which are harmonious and generally pleasing, or dissonant ones, which can be harsh and tense. © Society for Science & the Public 2000 - 2015
Nicholette Zeliadt, One afternoon in October 2012, a communication therapist from Manchester visited the home of Laura and her three children. Laura sat down at a small white table in a dimly lit room to feed her 10-month-old daughter, Bethany, while the therapist set up a video camera to record the pair’s every movement. (Names of research participants have been changed to protect privacy.) Bethany sat quietly in her high chair, nibbling on macaroni and cheese. She picked up a slimy noodle with her tiny fingers, looked up at Laura and thrust out her hand. “Oh, Mommy’s going to have some, yum,” Laura said. “Clever girl!” Bethany beamed a toothy grin at her mother and let out a brief squeal of laughter, and then turned her head to peer out the window as a bus rumbled by. “Oh, you can hear the bus,” Laura said. “Can you say ‘bus?’” “Bah!” Bethany exclaimed. “Yeah, bus!” Laura said. This ordinary domestic moment, immortalized in the video, is part of the first rigorous test of a longstanding idea: that the everyday interactions between caregiver and child can shape the course of autism1. The dynamic exchanges with a caregiver are a crucial part of any child’s development. As Bethany and her mother chatter away, responding to each other’s glances and comments, for example, the little girl is learning how to combine gestures and words to communicate her thoughts. In a child with autism, however, this ‘social feedback loop’ might go awry. An infant who avoids making eye contact, pays little attention to faces and doesn’t respond to his or her name gives parents few opportunities to engage. The resulting lack of social interaction may reinforce the baby’s withdrawal, funneling into a negative feedback loop that intensifies mild symptoms into a full-blown disorder. © 2015 Guardian News and Media Limited
Link ID: 20733 - Posted: 03.30.2015
By Virginia Morell Children and parrot and songbird chicks share a rare talent: They can mimic the sounds that adults of their species make. Now, researchers have discovered this vocal learning skill in baby Egyptian fruit bats (Rousettus aegyptiacus, pictured), a highly social species found from Africa to Pakistan. Only a handful of other mammals, including cetaceans and certain insectivorous bats, are vocal learners. The adult fruit bats have a rich vocal repertoire of mouselike squeaks and chatter (listen to a recording here), and the scientists suspected the bat pups had to learn these sounds. To find out, they placed baby bats with their mothers in isolation chambers for 5 months and made video and audio recordings of each pair. Lacking any other adults to vocalize to, the mothers were silent, and their babies made only isolation calls and babbling sounds, the researchers report today in Science Advances. As a control, the team raised another group of bat pups with their mothers and fathers, who chattered to each other. Soon, the control pups’ babbling gave way to specific sounds that matched those of their mothers. But the isolated pups quickly overcame the vocal gap after the scientists united both sets of bats—suggesting that unlike many songbird species (and more like humans), the fruit bats don’t have a limited period for vocal learning. Although the bats’ vocal learning is simple compared with that of humans, it could provide a useful model for understanding the evolution of language, the scientists say. © 2015 American Association for the Advancement of Science
Carl Zimmer Scientists in Iceland have produced an unprecedented snapshot of a nation’s genetic makeup, discovering a host of previously unknown gene mutations that may play roles in ailments as diverse as Alzheimer’s disease, heart disease and gallstones. “This is amazing work, there’s no question about it,” said Daniel G. MacArthur, a geneticist at Massachusetts General Hospital who was not involved in the research. “They’ve now managed to get more genetic data on a much larger chunk of the population than in any other country in the world.” In a series of papers published on Wednesday in the journal Nature Genetics, researchers at Decode, an Icelandic genetics firm owned by Amgen, described sequencing the genomes — the complete DNA — of 2,636 Icelanders, the largest collection ever analyzed in a single human population. With this trove of genetic information, the scientists were able to accurately infer the genomes of more than 100,000 other Icelanders, or almost a third of the entire country. “From the technical point of view, these papers are a tour-de-force,” said David Reich, a geneticist at Harvard Medical School who was not involved in the research. While some diseases, like cystic fibrosis, are caused by a single genetic mutation, the most common ones are not. Instead, mutations to a number of different genes can each raise the risk of getting, say, heart disease or breast cancer. Discovering these mutations can shed light on these diseases and point to potential treatments. But many of them are rare, making it necessary to search large groups of people to find them. The wealth of data created in Iceland may enable scientists to begin doing that. In their new study, the researchers at Decode present several such revealing mutations. For example, they found eight people in Iceland who shared a mutation on a gene called MYL4. Medical records showed that they also have early onset atrial fibrillation, a type of irregular heartbeat. © 2015 The New York Times Company
Hannah Devlin, science correspondent Scientists have raised the alert about an antibiotic routinely prescribed for chest infections, after linking it to an increased risk of epilepsy and cerebral palsy in children whose mothers took the drug during pregnancy. Children of mothers who had taken macrolide antibiotics were found to be almost twice as likely to be affected by the conditions, prompting scientists to call for a review of their use during pregnancy. The study authors urged pregnant women not to stop taking prescribed antibiotics, however. The potential adverse effects are rare and, as yet, unproven, while infections during pregnancy are a well-established cause of health problems in babies. Professor Ruth Gilbert, a clinical epidemiologist who led the research at University College London, said: “The main message is for medicines regulators and whether they need to issue a warning about these drugs. For women, if you’ve got a bacterial infection, it’s more important to get on and treat it.” The study tracked the children of nearly 65,000 women who had been prescribed a variety of antibiotics for illnesses during pregnancy, including chest and throat infections and cystitis. There was no evidence that most antibiotics (including penicillin, which made up 67% of prescriptions), led to an increased risk of the baby developing cerebral palsy or epilepsy. However, when the antibiotics were compared head-to-head, the potential adverse effect of macrolide drugs emerged. Around 10 in 1,000 children whose mothers were given the drug had developed the conditions by the age of seven, compared to 6 in 1,000 children, for those who had other types of antibiotic. © 2015 Guardian News and Media Limited
Jon Hamilton Doctors are much more likely to level with patients who have cancer than patients who have Alzheimer's, according to a report released this week by the Alzheimer's Association. The report found that just 45 percent of Medicare patients who'd been diagnosed with Alzheimer's said they were informed of the diagnosis by their doctor. By contrast, more than 90 percent of Medicare patients with cancer said they were told by their doctor. "What we found is really shocking," says Beth Kallmyer, vice president of constituent services for the Alzheimer's Association. "This is reminiscent of what happened in the 1960s and 1970s with cancer," she says. "But that's changed now, and it really needs to change for Alzheimer's as well." For years, the association's help line has been receiving complaints from family members who say that doctors are reluctant to reveal an Alzheimer's diagnosis, Kallmyer says. So the association decided to investigate by studying medical records and survey results from Medicare recipients. To make sure that Alzheimer's patients hadn't simply forgotten what a doctor said, the group also looked at Medicare survey responses from family members and other caregivers. The result wasn't much better: Just 53 percent said a doctor told them of the patient's diagnosis. © 2015 NPR
Link ID: 20721 - Posted: 03.25.2015
By Siri Carpenter “I don’t look like I have a disability, do I?” Jonas Moore asks me. I shake my head. No, I say — he does not. Bundled up in a puffy green coat, Moore, 35 and sandy-haired, doesn’t stand out in the crowd seeking refuge from the winter cold in a drafty Starbucks. His handshake is firm and his blue eyes meet mine as we talk. He comes across as intelligent and thoughtful, if perhaps a bit reserved. His disability — a form of autism — is invisible. That’s part of the problem, Moore says. Like most people with an autism spectrum disorder, he finds relationships challenging. In the past, he has been quick to anger and has had what he calls meltdowns. Those who don’t know he has autism can easily misinterpret his actions. “People think that when I do misbehave I’m somehow intentionally trying to be a jerk,” Moore says. “That’s just not the case.” His difficulty managing emotions has gotten him into some trouble, and he has had a hard time holding onto jobs — an outcome he might have avoided, he says, if his co-workers and bosses had better understood his intentions. Over time, things have gotten better. Moore has held the same job for five years, vacuuming commercial buildings on a night cleaning crew. He attributes his success to getting the right amount of medication and therapy, to time’s maturing him and to the fact that he works mostly alone. Moore is fortunate. His parents help support him financially. He has access to good mental health care where he lives in Wisconsin. And he has found a job that suits him. Many adults with autism are not so lucky.
Link ID: 20711 - Posted: 03.24.2015
By ANDREW POLLACK An experimental drug for Alzheimer’s disease sharply slowed the decline in mental function in a small clinical trial, researchers reported Friday, reviving hopes for an approach to therapy that until now has experienced repeated failures. The drug, being developed by Biogen Idec, could achieve sales of billions of dollars a year if the results from the small trial are replicated in larger trials that Biogen said it hoped to begin this year. Experts say that there are no really good drugs now to treat Alzheimer’s. Biogen’s stock has risen about 50 percent since early December, when the company first announced that the drug had slowed cognitive decline in the trial, without saying by how much. Analysts and investors had been eagerly awaiting the detailed results, some of them flying to France to hear Biogen researchers present them at a neurology meeting on Friday. The drug, called aducanumab, met and in some cases greatly exceeded Wall Street expectations in terms of how much the highest dose slowed cognitive decline. However, there was a high incidence of a particular side effect that might make it difficult to use the highest dose. Still, the net impression was positive. “Out-of-the-ballpark efficacy, acceptable safety,” Ravi Mehrotra, an analyst at Credit Suisse, wrote on Friday. Shares of Biogen rose $42.33, or 10 percent, to $475.98. Alzheimer’s specialists were impressed, but they cautioned that it was difficult to read much from a small early-stage, or Phase 1, trial that was designed to look at safety, not the effect on cognition. Also, other Alzheimer’s drugs that had looked promising in early studies ended up not working in larger trials. “It’s certainly encouraging,” said Dr. Samuel Gandy, director of the Center for Cognitive Health at Mount Sinai Hospital in New York, who was not involved in the study. He said the effect of the highest dose was “pretty impressive.” © 2015 The New York Times Company
Link ID: 20709 - Posted: 03.21.2015
Elie Dolgin The southern city of Guangzhou has long held the largest eye hospital in China. But about five years ago, it became clear that the Zhongshan Ophthalmic Center needed to expand. More and more children were arriving with the blurry distance vision caused by myopia, and with so many needing eye tests and glasses, the hospital was bursting at the seams. So the centre began adding new testing rooms — and to make space, it relocated some of its doctors and researchers to a local shopping mall. Now during the summer and winter school holidays, when most diagnoses are made, “thousands and thousands of children” pour in every day, says ophthalmologist Nathan Congdon, who was one of those uprooted. “You literally can't walk through the halls because of all the children.” East Asia has been gripped by an unprecedented rise in myopia, also known as short-sightedness. Sixty years ago, 10–20% of the Chinese population was short-sighted. Today, up to 90% of teenagers and young adults are. In Seoul, a whopping 96.5% of 19-year-old men are short-sighted. Other parts of the world have also seen a dramatic increase in the condition, which now affects around half of young adults in the United States and Europe — double the prevalence of half a century ago. By some estimates, one-third of the world's population — 2.5 billion people — could be affected by short-sightedness by the end of this decade. “We are going down the path of having a myopia epidemic,” says Padmaja Sankaridurg, head of the myopia programme at the Brien Holden Vision Institute in Sydney, Australia. The condition is more than an inconvenience. Glasses, contact lenses and surgery can help to correct it, but they do not address the underlying defect: a slightly elongated eyeball, which means that the lens focuses light from far objects slightly in front of the retina, rather than directly on it. © 2015 Nature Publishing Group
Michaeleen Doucleff Malaria is one of the oldest scourges of mankind. Yet it's been a mystery how the deadliest form of the disease kills children. One doctor in Michigan has dedicated her life to figuring that out. Now she and her team report their findings in this week's issue of the New England Journal of Medicine. The key to solving the mystery was looking inside the brain. Most of the time malaria causes a bad fever and body aches. But in rare cases — often in children — the parasite gets stuck in the capillaries of the brain. The child has a seizure, goes into a coma and can die. This all happens in only two or three days, says Dr. Terrie Taylor of Michigan State University. "These are bright, happy children who are suddenly felled by a disease that quickly renders them unconscious. And quickly kills them. It's a catastrophe." The sudden death of a child devastates not just the family but the whole community, Taylor says: "Imagine the ripple effects on their friends and their siblings. Suddenly their friends are gone. Just gone." Since 1986, Taylor has been treating children with severe malaria at Queen Elizabeth Central Hospital in Blantyre, Malawi. Seeing so many families deal with these huge losses, year after year, made Taylor focus her career on one goal: Figuring out why some children die from cerebral malaria but others soon recover. © 2015 NPR
Keyword: Development of the Brain
Link ID: 20702 - Posted: 03.19.2015