Bob Holmes, contributor HUMANS are very good at language. Computers are just beginning to cope with the complexities of speech, but almost every child masters language easily. This remarkable talent has led some anthropologists and psychologists to conclude that we have an innate "language instinct" - that evolution shaped our brains into language-learning devices. In Harnessed, psychologist Mark Changizi turns this argument on its head: instead of our brains adapting to language, he claims, language has evolved to take advantage of sound-processing skills the brain already possessed. Music has done the same, adapting itself to fit our brain's pre-existing talents and borrowing - harnessing - them for a new purpose. Our prelinguistic ancestors used their ears to inform them about events in their surroundings, and we are still good at this. Close your eyes for a moment and listen: not only can you hear a person walking nearby, but you know how close they are, whether they are going up or down stairs, often who they are and what their mood is, and whether they just filled a coffee mug or a water glass. You do that by discriminating many small details of the sounds you hear - the particular "clink" of a coffee mug, the characteristic rhythm of someone's gait, and the like. Crucially, most of this discrimination takes place subliminally, before your conscious mind assembles and labels the perception. © Copyright Reed Business Information Ltd.

Keyword: Hearing; Evolution
Link ID: 15712 - Posted: 08.23.2011

by Sujata Gupta In spring last year, the number of narcolepsy cases in Beijing, China, multiplied threefold. Now, it looks like the swine flu pandemic of the previous winter was to blame. Previously, similar rises in cases of narcolepsy – a disorder that causes sleepiness at inappropriate times – have been linked to use of a swine flu vaccine. The cause was presumed to lie in the drug's adjuvants – additives that boost the immune response to the vaccine. The claim puzzled researchers who saw a concurrent rise in narcolepsy cases in China, where few people had opted to get vaccinated and those who did received a vaccine without adjuvants. Could the flu itself be to blame? To find out, Fang Han and his colleagues at Beijing University People's Hospital studied the medical profiles of 906 people who had come to the hospital with narcolepsy since 1998. The group found that, even in the years before the vaccine was introduced in October 2009, the number of narcolepsy cases followed a seasonal pattern – cases dropped significantly around November and spiked in April. The peak was higher than normal in the spring after the swine flu pandemic (Annals of Neurology, DOI: 10.1002/ana.22587). The idea that flu causes narcolepsy fits in with the theory that narcolepsy is triggered by the immune system's response to airway infections. © Copyright Reed Business Information Ltd.

Keyword: Narcolepsy
Link ID: 15711 - Posted: 08.23.2011

By SINDYA N. BHANOO Acorn woodpeckers are industrious, cooperative birds that live in family groups. Each family has several “helper” woodpeckers that do not breed. These birds devote their time to gathering acorns and other food for the young. Researchers were surprised to find that helpers are more beneficial in the spring after a good crop than in one after a poor harvest. “It makes a lot of intuitive sense that the helpers are a lot more useful when conditions are bad,” said Walter Koenig, an ornithologist at Cornell University. “But in fact it seems to be exactly the opposite.” In the spring after a good acorn crop, the average number of new offspring in a family group increased by about seven-tenths of an offspring per helper. In a bad year, helpers slightly reduced the overall reproductive success. That’s because when an acorn crop is bad, having a helper may not help much, Dr. Koenig said. In fact, helpers might be eating up food that could otherwise go to fledglings. But in a good year, helpers are able to help harvest extra food and contribute to the family’s food reserves. Helper woodpeckers are generally young adults that are actively looking for breeding opportunities, within the family group or outside of it. Until they make a match, they maintain their roles as assistants and help raise their younger siblings and other relatives. © 2011 The New York Times Company

Keyword: Sexual Behavior; Evolution
Link ID: 15710 - Posted: 08.23.2011

By AMANDA SCHAFFER For years, scientists thought they understood the skeleton. It serves as structural support for the body. It stores calcium and phosphate. It contributes to blood cell development. And it serves, indispensably, as the creepy mascot of Halloween. But as it turns out, there may be still more to bone. A few years ago, researchers at Columbia University Medical Center discovered, to everyone’s surprise, that the skeleton seems to help regulate blood sugar. Now the team, led by Dr. Gerard Karsenty, geneticist and endocrinologist at Columbia University, has found that bone may play an unexpected role in reproduction. If the work pans out, it may help to explain some cases of low fertility in men. “It’s definitely an attention-grabber,” Dr. William Crowley of Harvard Medical School, who was not involved in the research, said of the new finding regarding fertility. “I think it will turn out to be a seminal observation.” (No pun intended, presumably.) It is well known that the hormones estrogen and testosterone, produced in the ovaries and testes, help to regulate bone growth. When women reach menopause, estrogen levels decrease along with bone mass, putting them at increased risk for osteoporosis. As men age, their testosterone and estrogen levels decline, as well. Men lose bone, but much more slowly than women do. “We thought that if the sex organs talk to the skeleton, then the skeleton should talk back to the sex organs,” Dr. Karsenty said. Apparently it does. © 2011 The New York Times Company

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 15709 - Posted: 08.23.2011

by Caroline Williams A bat would probably have no trouble imagining how it is to see like a human: some species have eyesight that is at least as good as ours, and some see better than us in dim light. For us to imagine their world, though, is somewhat trickier. Insect-eating bats and some fruit-eaters get much of the detail they need to find food through echolocation: clicks, squeals and screams that they belt out at up to 120 decibels. That's the volume of a passing ambulance siren. Thankfully they do it in ultrasound, above the range of human hearing. The echoes of these sounds give them a huge amount of information about their surroundings. The time it takes for an echo to return, for example, reveals the distance of an object, and the changes in the sound's frequency as it bounces off another creature can even reveal the speed and direction of the animal's movement. The sensitivity of echolocation is phenomenal. A study published last year found that some bats can detect differences in the distance between themselves and their prey with an accuracy of between 4 and 13 millimetres (Journal of the Acoustical Society of America, vol 128, p 1467). For an insect-eating bat, that's enough to scoop up the insect with its wings before passing it to its mouth. Subtle differences in the tone of these sounds, meanwhile, reveal a bat's identity to its peers, in much the same way that we recognise someone's speaking voice (PLoS Computer Biology, vol 6, p e1000400). © Copyright Reed Business Information Ltd.

Keyword: Hearing
Link ID: 15708 - Posted: 08.23.2011

by Caroline Williams The idea that animals can navigate using their own internal compass is so startling it was once dismissed as pure fantasy. Now there is good evidence that many species - including pigeons, sea turtles, chickens, naked mole rats and possibly cattle - can detect the Earth's geomagnetic field, sometimes with astonishing accuracy. Young loggerhead turtles, for example, read the Earth's magnetic field to adjust the direction in which they swim. They seem to hatch with a set of directions, which, with the help of their magnetic sense, ensures that they always stay in warm waters during their first migration around the rim of the North Atlantic. Over time they build a more detailed magnetic map by learning to recognise variations in the strength and direction of the field lines, which are angled more steeply towards the poles and flatter at the magnetic equator. What isn't known, however, is how they sense magnetism. Part of the problem is that magnetic fields can pass through biological tissues without being altered, so the sensors could, in theory, be located in any part of the body. What's more, the detection might not need specialised structures at all, but may instead be based on a series of chemical reactions. Even so, many researchers think that magnetic receptors probably exist in the head of turtles and perhaps other animals. These might be based on crystals of magnetite, which align with the Earth's magnetic field and could pull on some kind of stretch receptor or hair-like cell as it changes polarity. The mineral has already been found in some bacteria, and in the noses of fish like salmon and rainbow trout, which also seem to track the Earth's magnetic field as they migrate. © Copyright Reed Business Information Ltd.

Keyword: Animal Migration
Link ID: 15707 - Posted: 08.23.2011

by Caroline Williams When a bee flies into your garden, it doesn't see what you and I see. Flowers leap out from much darker-looking leafy backgrounds, and they have ultraviolet-reflecting landing strips that show the way to the nectar. Some spiders might even have evolved to exploit these displays, spinning UV patterns into their webs that could work to fool a bee into thinking that it was making a beeline for a tasty treat. If the bee manages to resist the spider's trap, she finds her way back home by checking the pattern of polarised light in the sky. All this is seen through the pixellated window of mosaic vision, with each unit of the insect's compound eye providing one of the 5000 dots that make up an image. It's a world of vision that it is difficult to imagine, but we might get some clues from people with aphakia: a condition in which the lens of the eye - which normally absorbs UV light before it can reach the retina - has been removed in surgery or lost in an accident. Bill Stark, an insect-vision researcher at Saint Louis University in Missouri, lost the lens in his left eye after an accident when he was 10 years old. He says he can see UV light as a kind of "whitish blue", which he would see washing the scenery at a funfair, for example. Because the sight in his left eye is not great, however, he cannot see the subtle patterns in flowers that bees do. © Copyright Reed Business Information Ltd.

Keyword: Vision; Evolution
Link ID: 15706 - Posted: 08.23.2011

By LISA TUCKER I was in a neurologist’s office to discuss the results of my brain scan. For the past month and a half, I’d had headaches that felt as if my skull was underwater, punctuated by frequent electric jolts through the right side of my brain. Two CT scans and an M.R.I. had revealed nothing. All the drug treatments tried by my doctor had failed to change me back into myself. But the new test, magnetic resonance angiography, had uncovered something. “You have a cerebral aneurysm,” the neurologist announced. “It’s small. You’ll have to see a neurosurgeon, but it probably won’t require surgery.” He handed me a card for a specialist at a stroke and vascular center. I took the card, though I was focused on the headaches. At least we had a cause for them now, I thought — until he explained that my aneurysm was an “incidental finding.” “It has nothing to do with the pain you’ve been experiencing,” said the neurologist. He offered me another drug. Multiple Google searches later, I understood what he meant. Most experts think that small aneurysms do not cause any symptoms unless they are about to rupture. Even more surprising, given the fear the word “aneurysm” strikes in patients with new diagnoses and their families, is that many small unruptured aneurysms are not treated. © 2011 The New York Times Company

Keyword: Stroke
Link ID: 15705 - Posted: 08.23.2011

By Laura Sanders Widely used antidepressants may reduce the ominous brain plaques associated with Alzheimer’s disease, a new study in mice and humans finds. Brain scans of people who have taken antidepressants reveal fewer clumps of the protein amyloid-beta, a target of Alzheimer’s prevention strategies, when compared with people who have not taken the drugs. Many in the field voiced caution about the results. But if borne out by further study, the findings may point to a new, relatively safe way to treat and prevent Alzheimer’s disease, which is the sixth leading cause of death in the United States. “I think this is a wonderful piece of news, and I think there’s going to be a lot of excitement about this,” says internist Michael Weiner, who leads the Alzheimer’s Disease Neuroimaging Initiative at the Veterans Affairs Medical Center campus of the University of California, San Francisco. “It points the way towards a possible approach to treating Alzheimer’s disease that people have not been talking about very much.” In the study, mice genetically engineered to overproduce amyloid-beta, or A-beta, were given one of three selective serotonin reuptake inhibitors, a class of antidepressants that boost circulating levels of the chemical messenger serotonin in the brain. After a single dose of the antidepressants, A-beta levels dropped in the fluid that surrounds mouse brain cells, researchers report online the week of August 22 in the Proceedings of the National Academy of Sciences. A full day after receiving the drug, the mice’s A-beta levels fell by nearly a quarter. © Society for Science & the Public 2000 - 2011

Keyword: Alzheimers; Depression
Link ID: 15704 - Posted: 08.23.2011

By Bruce Bower LAS VEGAS — Soldiers fighting at the tip of the spear — the leading edge of combat — confront fighting, suffering and dying. But the success of those soldiers’ operations depends on a huge network of service and support personnel who themselves face considerable and often overlooked war stress, says military sociologist Wilbur Scott of the U.S. Air Force Academy in Colorado Springs. After returning from one or more deployments, National Guard combat service personnel — including clerks, truck drivers, medics and supply officers — displayed slightly less emotional resilience and described having experienced more stress while overseas and after returning home than their comrades engaged in combat, Scott reported August 20 at the annual meeting of the American Sociological Association. In particular, combat service personnel cited deployment stress triggered by exposure to danger, life-threatening situations and death. Their responses reflect the changed nature of warfare, Scott suggested. In Iraq and Afghanistan, counterinsurgency efforts have replaced conventional warfare. “While those in combat arms typically are thought of as being at the tip of the spear, this thinking applies more accurately to conventional settings rather than those encountered in Iraq and Afghanistan,” Scott said. Combat units not only fight and kill but establish relationships with local officials, head local building projects and encourage trust in local governments. Service personnel work in the midst of operations, where they can encounter guerilla attacks or roadside bombs. © Society for Science & the Public 2000 - 2011

Keyword: Stress
Link ID: 15703 - Posted: 08.23.2011

A breakdown of a recycling system in cells appears to be the underlying cause of a fatal nerve disease. Amyotrophic lateral sclerosis (ALS), the most common form of motor neuron disease, causes paralysis. A US team, writing in Nature, found the flaw in the way nerve cells in the brain recycle protein building blocks, which means cells cannot repair themselves and become damaged. Experts in the UK said that the findings were significant. ALS affects an estimated 350,000 people around the world, including children and adults, with about half of people dying within three years of its onset. The breakdown occurs in the recycling system in the nerve cells of the spinal cord and the brain. In order to function properly, the protein building blocks in the cells need to be recycled. But in ALS, that system is broken. The cell cannot repair or maintain itself and becomes severely damaged. The scientists found a protein, ubiquilin2, which should be directing the recycling process, does not work in people with ALS. BBC © 2011

Keyword: ALS-Lou Gehrig's Disease
Link ID: 15702 - Posted: 08.23.2011

By ALEXANDRA HOROWITZ and AMMON SHEA HUMANS have long been fascinated with animal intelligence. Scientific studies have asked if animals use language or tools; have culture; can imitate, cooperate, empathize or deceive. Inevitably, the results of these studies invite comparison with our own cognitive faculties. In such comparisons, humans nearly always come out on top. An impartial observer might suggest that the deck is stacked. After all, we are the ones running these tests. But if we look at some of the subtler aspects of animal behavior, the beasts begin to offer surprisingly stiff competition. A few recent research papers describe animal competence at social and cognitive tasks that humans often struggle with — mastering conversational etiquette, understanding botanical classification, competing on game shows and figuring out how to get a drink when you’re thirsty and the only glass of water is glued to the table and your hands are tied behind your back. “Aping Expressions? Chimpanzees Produce Distinct Laugh Types When Responding to Laughter of Others,” in the journal Emotion (2011). You’re at a dinner party. Your hostess regales you with a long, meandering tale of her recent back surgery. It ends with attempted humor: she laughs and glances at you. You laugh in response, trying to convey an appreciation for her humor that you don’t actually feel. Congratulations: you are now at the level of social politeness of chimpanzees. © 2011 The New York Times Company

Keyword: Evolution; Intelligence
Link ID: 15701 - Posted: 08.23.2011

By Laura Sanders A new kind of visual illusion confirms that people are not masters of perception. Observers are oblivious to peripheral visions of a woman’s face dissolving into a fountain, a stroller becoming a blob, and windows melding into trees, researchers report online August 14 in Nature Neuroscience. By studying these visual oversights, scientists hope to understand how the brain culls the flood of visual data that constantly streams into the eyes. Jeremy Freeman of New York University and Howard Hughes Medical Institute investigator Eero Simoncelli, also of NYU, started the project by developing a mathematical description of how information moves through the visual system in the brain. Their model predicted that the visual system tosses unnecessary information that comes from the periphery. “Your visual system is giving you the information that you need, and it’s throwing away information that you really don’t need,” Simoncelli says. To see whether this information loss actually happens, the team showed eight people quick flashes — a fifth of a second — of various scenes, scrambled in a way the math model predicted would be undetectable to humans. While fixating on a point in the middle, people couldn’t tell the difference between two very different van Gogh-esque scrambles of a normal scene of a crowd at Washington Square Park in New York City, for example. These scrambles went undetected even when people were allowed to stare at the images for nearly half a second, the team reports. © Society for Science & the Public 2000 - 2011

Keyword: Vision; Attention
Link ID: 15700 - Posted: 08.20.2011

By NICHOLAS WADE Sustaining the flickering hope that human aging might somehow be decelerated, researchers have found they can substantially extend the average life span of obese mice with a specially designed drug. The drug, SRT-1720, protects the mice from the usual diseases of obesity by reducing the amount of fat in the liver and increasing sensitivity to insulin. These and other positive health effects enable the obese mice to live 44 percent longer, on average, than obese mice that did not receive the drug, according to a team of researchers led by Rafael de Cabo, a gerontologist at the National Institute on Aging. Drugs closely related to SRT-1720 are now undergoing clinical trials in humans. The findings “demonstrate for the first time the feasibility of designing novel molecules that are safe and effective in promoting longevity and preventing multiple age-related diseases in mammals,” Dr. de Cabo and colleagues write in Thursday’s issue of the new journal Scientific Reports. Their conclusion supports claims that had been thrown in doubt by an earlier study that was critical of SRT-1720. A drug that makes it cost-free to be obese may seem more a moral hazard than an incentive to good health. But the rationale behind the research is somewhat different: the researchers are trying to capture the benefits that allow mice on very low-calorie diets to live longer. It just so happens that such benefits are much easier to demonstrate in mice under physiological stress like obesity than in normal mice. © 2011 The New York Times Company

Keyword: Obesity
Link ID: 15699 - Posted: 08.20.2011

by Michael Marshall IT SMELLS, it buzzes, it even dances like a honeybee. In a field in Germany, RoboBee is making its first attempts at speaking to the insects in their own language. Bees are famous for communicating using the waggle dance - walking forward while rapidly vibrating their rear. In the 1940s, biologist Karl von Frisch realised that the length and angle of the dance correlated with the distance and direction of the food source the bee had just visited. Since then, most apiologists have held that dancers tell their fellows where to find foodMovie Camera (New Scientist, 19 September 2009, p 40)Movie Camera. Now Tim Landgraf of the Free University of Berlin in Germany and colleagues have programmed their foam RoboBee, to mimic the dance. RoboBee is stuck to the end of a rod attached to a computer, which determines its "dance" moves. The rod is also connected to a belt which makes it vibrate. Like a real bee, it can spin, buzz its wings, carry scents and droplets of sugar water, and give off heat. To program RoboBee, Landgraf took high-speed video of 108 real waggle dances, and put the footage through software that analysed the dances in detail (PLoS One, DOI: 10.1371/journal.pone.0021354). The outcome is "the most detailed description so far of the waggle dance", says Christoph Grüter of the University of Sussex in Brighton, UK, who was not involved in the study. What do real bees think of RoboBee's skills? In a field outside Berlin, Landgraf trained groups of honeybees to use a feeder, which he then closed. The bees stopped foraging and stayed in their hives. There they met RoboBee, which had been programmed with Landgraf's best guess at a waggle dance pointing to another feeder, which the bees had never visited. © Copyright Reed Business Information Ltd.

Keyword: Language; Evolution
Link ID: 15698 - Posted: 08.20.2011

by Michael Marshall Anyone who has used an in-car satnav will be familiar with Jane, the calm voice that tells you to turn around because you've gone the wrong way. Many users will also be familiar with the response: yelling "Shut up, Jane!" while performing illegal turns. Bumblebees, it turns out, could give Jane a run for her money. Despite having a brain the size of a poppy seed, these insects can solve a fiendish navigational problem that modern supercomputers struggle to crack. Not so bumbling Bumblebees have been changing their name for centuries. From Shakespeare through to Darwin they were known as "humblebees", because of the humming sound they make. Then in the 20th century, for no good reason, they became "bumblebees". Like honeybees and ants they are social insects, with a queen who controls hordes of sterile workers. Among other ingenious behaviours, they keep their nests at a constant temperatureMovie Camera, avoid foraging close to homeMovie Camera for fear of leading predators to it, and become paranoid when camouflaged predators are aboutMovie Camera. Buff-tailed bumblebee workers fly from flower to flower in search of nectar and pollen. But each flight costs energy and time, so they need to minimise the distance they fly. To do that, they have to solve one of the hardest problems in mathematics: the travelling salesman problem. © Copyright Reed Business Information Ltd.

Keyword: Intelligence; Evolution
Link ID: 15697 - Posted: 08.20.2011

by Jessica Hamzelou Until now, neuroscientists have focused on identifying parts of the brain that are active during learning. "But no one has looked at the preparedness state," says John Gabrieli at the Massachusetts Institute of Technology. "The idea is to identify before the event whether the brain is prepared to be a learner." Gabrieli and his colleagues used functional MRI scanning to monitor the naturally fluctuating brain activity of 20 volunteers and investigate whether the brain enters such a learning state. While in the scanner, each person was presented with 250 images, one at a time, and asked to memorise them. The volunteers were shown the images again 2 hours later - mixed in with 250 new ones - and asked to remember which they had seen before. Looking through the results, the team was surprised to find that in the moments before individuals were shown images that they later remembered, they had low levels of activity in the parahippocampal place area - a region of the brain that is known to be highly active during learning. "Maybe the fact that this region was less active meant that the deck was cleared - that it was more open for a stimulus to provoke a response," suggests Gabrieli. To investigate further, the team attempted to boost subsequent participants' memory test scores by presenting them with images only when they showed this pattern of brain activity. "There was around a 30 per cent improvement in the memory task," Gabrieli says (NeuroImage, DOI: 10.1016/j.neuroimage.2011.07.063). © Copyright Reed Business Information Ltd.

Keyword: Learning & Memory
Link ID: 15696 - Posted: 08.20.2011

By Vilayanur S. Ramachandran and Diane Rogers-Ramachandran You probably look in a mirror every day without thinking about it. But mirrors can reveal a great deal about the brain, with implications for psychology, clinical neurology and even philosophy. They can help us explore the way the brain puts together information from different sensory channels such as vision and somatic sensations (touch, muscle and joint sense). In doing so, they can reveal a lot about our sense of self. Would a person who has never looked at his reflection—even in a pool—ever develop a sophisticated self-representation? Using two bricks, or some duct tape, prop up an 18-inch-square mirror vertically on a table. Sit so that the edge faces you. Now put your left hand on the table at the left side of the mirror (either palm up or down) and match your right-hand position on the right side. If you now look into the right side of the mirror, you will see the right hand’s reflection optically superimposed in the same place where you feel your left hand to be. (You may need to adjust the position of the left hand to achieve this sensation.) It will now look like you are viewing your own left hand, but of course you are not. Now try the following experiments. While continuing to look in the mirror on the right side and keeping your left hand perfectly still, move your right hand, wiggle its fingers or make a fist. The “left hand” in the mirror will appear to move in perfect synchrony with the right but, paradoxically, feel completely still. The conflict creates a slight jolt; it feels spooky, sometimes mildly uncomfortable. The brain abhors discrepancies. © 2011 Scientific American

Keyword: Vision; Pain & Touch
Link ID: 15695 - Posted: 08.20.2011

By WALLACE RAVVEN The parasite, a common single-celled organism called Toxoplasma gondii, infects all sorts of animals, including rats, in which it causes a strange transformation. For obvious reasons, rats normally avoid cats. In the presence of cat urine they become very timid — unless they’re infected with Toxoplasma. Research over the past 10 years has shown that infected rats drop their normal fearful “freezing” response, and instead go exploring. They even approach the cat smell. Bad news for the rats, but very good news for the parasite, because Toxoplasma reproduces sexually only in cats. Parasite infects rat. Cat eats rat. Parasite reproduces. The parasite can also infect all sorts of other animals, including humans, in which it causes toxoplasmosis — one of many good reasons to avoid contact with cat droppings. But outside of cats, its reproductive cycle cannot be completed. If this puppet-master behavior were not strange enough, scientists have now found out how the parasite may change rat behavior. Toxoplasma infection activates a part of the rat’s brain normally engaged in sexual attraction. The smell of cat urine revs up this set of neurons like the presence of a sexually receptive female rat normally would. The neurons that trigger the rat’s normal “freezing” reaction to cats continue to fire. But their message may get swamped by the overactive sexual attraction signaling, the researchers suspect. © 2011 The New York Times Company

Keyword: Emotions; Evolution
Link ID: 15694 - Posted: 08.20.2011

By Jennifer Viegas The brain-eating amoeba that killed three people this summer is an organism that thrives in warm fresh water and can be found in lakes, rivers, hot springs and soil, according to the Centers for Disease Control and Prevention. All three deaths this year occurred in the South: a 16-year-old girl in Florida, a 9-year-old boy in Virginia and a 20-year-old man in Louisiana. A brutal summer and drought make the conditions perfect for the amoeba. The threat of N. fowleri could potentially be elevated for weeks in some areas. According to the CDC, infections occur mainly in July, August and September. The microscopic amoeba, Naegleria fowleri, attacks anyone who has the misfortune of inhaling it. It enters first up the nose and then goes to the brain, usually killing its victims within two weeks. "Once forced up the nose, it can travel to the brain, where it digests brain cells," Jonathan Yoder, an epidemiologist at the Centers for Disease Control and Prevention, told Discovery News. "It's a very tragic disease that thankfully is very rare." Aside from its rarity, the amoeba "is not looking to prey upon human victims," he said. "They usually go after bacteria in water and soil." © 2011 Discovery Communications, LLC.

Keyword: Miscellaneous
Link ID: 15693 - Posted: 08.20.2011