by Paul Marks YOU are the victim of identity theft and the fraudster calls your bank to transfer money into their own account. But instead of asking them for your personal details, the bank assistant simply presses a button that causes the phone to produce a brief series of clicks in the fraudster's ear. A message immediately alerts the bank that the person is not who they are claiming to be, and the call is ended. Such a safeguard could one day be commonplace, if a new biometric technique designed to identify the person on the other end of a phone line proves successful. The concept relies on the fact that the ear not only senses sound but also makes noises of its own, albeit at a level only detectable by supersensitive microphones. If those noises prove unique to each individual, it could boost the security of call-centre and telephone-banking transactions and reduce the need for people to remember numerous identification codes. Stolen cellphones could also be rendered useless by programming them to disable themselves if they detect that the user of the phone is not the legitimate owner. Called otoacoustic emissions (OAEs), the ear-generated sounds emanate from within the spiral-shaped cochlea in the inner ear. They are thought to be produced by the motion of hair cells within the outer part of the cochlea. Typically, sounds entering the ear cause these outer hair cells to vibrate, and these vibrations are converted to electrical signals which are transmitted along the auditory nerve, allowing the sound to be sensed. Crucially, these cells also create their own sounds as they expand and contract. © Copyright Reed Business Information Ltd.

Keyword: Hearing
Link ID: 12748 - Posted: 06.24.2010

Failure to control type 2 diabetes may have a long-term impact on the brain, research has suggested. Severe hypoglycaemic episodes - hypos - occur when blood sugar levels drop dangerously low. A University of Edinburgh team found they may lead to poorer memory and diminished brain power. The study, based on 1,066 people with type 2 diabetes aged between 60 and 75, was presented at a conference of the charity Diabetes UK. The volunteers completed seven tests assessing mental abilities such as memory, logic and concentration. The 113 people who had previously experienced severe hypos scored lower than the rest of the group. They performed poorly in tests of their general mental ability, and vocabulary. There are at least 670,000 people in England aged between 60 and 75 years old who have Type 2 diabetes and around a third of them could be at risk of a hypo. Lead researcher Dr Jackie Price said: "Either hypos lead to cognitive decline, or cognitive decline makes it more difficult for people to manage their diabetes, which in turn causes more hypos. "A third explanation could be that a third unidentified factor is causing both the hypos and the cognitive decline. We are carrying out more research to establish which explanation is the most likely." Dr Iain Frame, director of research at Diabetes UK, said: "This study reinforces previous evidence which suggests that poorly controlled diabetes affects the functioning of the brain. "We already know that type 2 diabetes increases the risk of developing Alzheimer's disease, which is a type of dementia, and this research adds another piece to a very complex jigsaw puzzle. (C)BBC

Keyword: Learning & Memory; Obesity
Link ID: 12747 - Posted: 04.13.2009

Scientists say they understand more about how the body responds to pleasurable touch. A team, including scientists from the Unilever company, have identified a class of nerve fibres in the skin which specifically send pleasure messages. And people had to be stroked at a certain speed - 4-5cm per second - to activate the pleasure sensation. They say the study, published in Nature Neuroscience, could help understand how touch sustains human relationships. For many years, scientists have been trying to understand the mechanisms behind how the body experiences pain, and the nerves involved in conveying those messages to the brain. This is because people can suffer a great deal. Neuropathy, where the peripheral nervous system is damaged, can be very painful and sometimes the messaging system goes wrong a people feel pain even when there is no cause. But the researchers involved in this work were looking to understand the opposite sensation - pleasure. This research, which also involved experts at the University of Gothenburg in Sweden and at the University of North Carolina, recorded nerve responses in 20 people. They then tested how people responded to having their forearm skin stroked at a range of different speeds. They identified "C-tactile" nerve fibres as those stimulated when people said a touch had been pleasant. If the stroke was faster or slower than the optimum speed, the touch was not pleasurable and the nerve fibres were not activated. The scientists also discovered that the C-tactile nerve fibres are only present on hairy skin, and are not found on the hand. (C)BBC

Keyword: Pain & Touch
Link ID: 12746 - Posted: 04.13.2009

By LISA SANDERS, M.D. “I can’t see a doggone thing. It started off as a headache, and now I can’t see.” The middle-aged man’s face was flushed and shiny beneath a mop of prematurely white hair. His clear, blue eyes were shaded by a brow pulled together by worry. “I’d rather cut off my leg than lose my sight,” he told the slender, dark-haired doctor at his bedside. Three days ago he was at work at a local animal hospital when his head began to pound. “It was like there was someone inside my head trying to get out.” He made it to the end of the day, then went home and straight to bed. The headache was still there the next morning when he got up. He took his coffee and the Sunday newspaper to the living room and — as was his habit — turned to the obituaries. The page was a sea of gray. He couldn’t read it. He couldn’t even make out the headlines. He went to see his doctor, who sent him to an ophthalmologist. The ophthalmologist sent him to the emergency room. Hearing that his patient was being admitted to a hospital, the primary-care doctor promptly called Dr. Lydia Barakat, an infectious-disease specialist at Waterbury Hospital in Waterbury, Conn. The 58-year-old man had a high fever, he reported, and the thick optic nerves that connect the eyes to the brain were visibly swollen from some kind of increased pressure inside the skull. Barakat was worried. Infections in the brain carry a high risk of death and disability. “If you lose a nerve cell, it doesn’t come back,” she said. Infections involving the brain, she told me, were those most likely to keep her up at night. These were the infections where you couldn’t afford to miss anything. “If you’re not just a little scared when you see these patients, then you are either arrogant, indifferent or just plain ignorant.” Copyright 2009 The New York Times Company

Keyword: Vision
Link ID: 12745 - Posted: 06.24.2010

By Tina Hesman Saey Whether you like it or not, you’re a little different. If it makes you feel any better, so is everybody else. In fact, everybody is far more different than anybody had imagined. Scientists are only beginning to discover just how different humans are from each other at the genetic level and what those personal genetic attributes mean for health, history and the human evolutionary future. It’s true that people are 99.9 percent alike, if only minor spelling variations in the genetic instruction book are taken into account. In each person, about one in every 1,000 DNA bases — the chemical letters of the genetic alphabet — differs from the generic human construction and operating manual. So, on average, one person will differ from another at about 3 million of the 3 billion letters in the human genome. Researchers have recently mapped many of these single letter variations, called single 
nucleotide polymorphisms or SNPs, looking for variants that might play a role in complex diseases such as heart disease, diabetes and high blood pressure (SN: 6/21/08, p. 20). So far, SNPs have been associated with many diseases, but SNPs can also be protective. And those little spelling differences may contain information about a person’s geographic ancestry — just as whether people write color or colour is a clue about whether they hail from the United States or Great Britain. © Society for Science & the Public 2000 - 2009

Keyword: Genes & Behavior; Schizophrenia
Link ID: 12744 - Posted: 06.24.2010

By Laura Sanders As the curtain lifts at Harrah’s in Las Vegas, magician Mac King walks out on stage in a tacky plaid suit and belts out a goofy “Howdy! I’m Mac King!” He then starts bending minds with more finesse and precision than a Jedi knight. King convinces spectators that he can hook a fish out of thin air, eat it and then spit it back out — intact — into a wine glass. Such skill in manipulating people’s perceptions has earned magicians a new group of spellbound fans: Scientists seeking to learn how the eyes and brain perceive — or don’t perceive — reality. Magicians’ intuitions about human cognition have been passed down, along with their methods for entertaining, for thousands of years. “We as scientists have a lot to learn from the art world,” says Susana Martinez-Conde, of the Barrow Neurological Institute in Phoenix, who studies the neuroscience of visual systems. “If we had been paying attention to magic early on, cognitive neuroscience may have come around much faster.” In an article published in November 2008 in Nature Reviews Neuroscience, Martinez-Conde and other neuroscientists teamed up with famous magicians to argue that magic can be a powerful tool for probing how the human mind sees the world. Using cutting-edge methods to study how the brain and visual systems control perception, scientists are starting to figure out what magicians have known for ages — how your brain can play tricks on you. © Society for Science & the Public 2000 - 2009

Keyword: Attention; Vision
Link ID: 12743 - Posted: 06.24.2010

By Nikhil Swaminathan Senior moments, those pesky instances of not so total recall—forgetting where we left our keys or what we did last weekend—are a subtle but significant part of the aging process. Another effect of growing old: rising blood sugar levels, which typically take off in our late 30s or early 40s as our bodies become less adept at metabolizing glucose in the bloodstream. Now a study has linked these rising levels with momentary forgetfulness, pinpointing exactly where in the brain the aging process acts—a finding that could help the elderly ward off memory lapses. The nature of senior moments led scientists to believe they stem from disruptions in the hippocampus—an area that, among other roles, acts as the brain’s “save” button, allowing us to retain new information. Using functional MRI, researchers looked at the effects of increased blood glucose in the hippocampus of 181 subjects aged 65 or older with no history of dementia. They found that elevated levels impaired function of a section of the hippocampus called the dentate gyrus, which is a “hotspot” of age-related impairment, according to study author Scott Small, a neurologist at Columbia University. Blood glucose is not alone in selectively affecting dentate gyrus performance. A 2007 study co-authored by Small shows that exercise improves its function in both mice and humans. The newer research, he points out, suggests that these positive effects may actually result from the influence of regular exercise on the body’s ability to break down glucose. © 1996-2009 Scientific American Inc

Keyword: Learning & Memory
Link ID: 12742 - Posted: 06.24.2010

by Ewen Callaway A chemical best known for cementing the bond between a mother and her newborn child could also play a part in picking mister (or miss) right. A new study shows that men and women who inhale a whiff of the hormone oxytocin rate strangers as more attractive. When oxytocin courses through our blood, "we are more likely to see people we don't know in a more positive light," says Angeliki Theodoridou, a psychologist at the University of Bristol, UK, who led the new study. This effect adds to the hormone's known role in human relationships. One study found that oxytocin levels spike after new mothers look at or touch their newborns and may help bonding. Other work has hinted at the importance of oxytocin in social situations between adults too. People administered the hormone make overly generous offers in an economic game that measures trust, while men who got a dose of oxytocin proved better at remembering the faces of strangers a day later, compared to subjects who got a placebo. In the latest trial, Theodoridou's team tested 96 men and women in a double-blind placebo-controlled trial. After participants got either a spritz of oxytocin or a placebo, they rated pictures of 48 men and women for attractiveness and 30 for trustworthiness. Her team also tested for mood. © Copyright Reed Business Information Ltd

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 12741 - Posted: 06.24.2010

by Ewen Callaway A seven-year-old girl with a Y chromosome is providing new clues about a possible "master switch" of maleness. The girl has the normal chromosome count – 46 – and should be male. Other children who have the male sex chromosome but do not appear to be boys have been found to have gene mutations that temper the Y chromosome's effects. However this child doesn't have ambiguous gonads, shrivelled testes or other developmental defects. She instead has a normal vagina, cervix and set of ovaries. A team led by Anna Biason-Lauber, of University Children's Hospital in Zurich, Switzerland, thinks the patient's normalcy is due to mutations in a poorly understood gene on chromosome 17 called CBX2. The child's unique condition might not have been discovered were it not for tests performed before birth to check for major genetic defects, such as an extra copy of chromosome 21 that causes Down's syndrome. Those tests came up negative and indicated the child would be a boy. Gene shut-down When a girl with normal sex organs was born, doctors started scratching their heads. Most females with a Y chromosome have underdeveloped gonads that are prone to developing tumours and usually removed. However, when surgeons operated with the intention of removing the gonads they found normal-looking ovaries in the girl, and took only a tissue sample. This sample, too, looked normal. © Copyright Reed Business Information Ltd

Keyword: Sexual Behavior; Genes & Behavior
Link ID: 12740 - Posted: 06.24.2010

By Gisela Telis Stare at a waterfall long enough, and nearby stationary objects such as rocks and trees will seem to drift up. The optical illusion is called motion aftereffect, and it may trick more than just your eyes, according to a new study. When subjects watched a stationary stripe on a computer screen after a machine stroked their fingertips, the motion of the stroking created the illusion that the stripe was moving. The discovery demonstrates for the first time a two-way crosstalk between touch and vision, challenging long-held notions of how the brain organizes the senses. In 2000, neuroscientist Christopher Moore, now at the Massachusetts Institute of Technology in Cambridge, noticed that when a vibrating device buzzed a subject's fingertips, the visual motion detector in the brain fired up. But he immediately dismissed the result. At the time, researchers thought that the brain processes each sense--taste, touch, smell, sight, and hearing--separately and that it only later combines them to interpret the world. Over the past 5 years, however, further studies have challenged this picture. Experiments with blind subjects, for example, have found that reading Braille by touch can trigger activity in the brain's visual cortex (ScienceNOW, 8 November 2002). Researchers attributed the phenomenon to the brain rewiring itself to compensate for disability. But Moore and graduate student Talia Konkle wondered if the sight-touch link might lurk in everyone and if one sense might influence the other. © 2009 American Association for the Advancement of Science.

Keyword: Pain & Touch; Vision
Link ID: 12739 - Posted: 06.24.2010

By Tina Hesman Saey In the ongoing battle of the bulge, maybe it is time to fight fat with fat. Three new studies in the April 9 New England Journal of Medicine show that adult humans have brown fat, an energy-burning type of fat previously thought to be found only in animals and human babies. White fat cells store energy in the form of lipids, but brown fat cells burn energy and give off heat. Mice and human babies have pads of brown fat on their backs that help maintain body temperature. Brown fat is activated by cold temperatures. Mice keep the fat throughout life, but brown fat disappears from babies’ backs and many researchers thought adult humans didn’t have brown fat. Or if they did, that it wasn’t important. Now, the new studies demonstrate that brown fat is common in adults and may be important for regulating body weight and blood sugar. But the fat isn’t where people expected to find it. In adults, brown fat is found in the neck, above the collarbone, around the spine and in the abdomen. Ronald Kahn of the Joslin Diabetes Center and Harvard Medical School in Boston and his colleagues examined records from 1,972 people who had PET-CT scans for other reasons. The researchers found evidence of brown fat in 7.5 percent of the women and 3.1 percent of the men. Brown fat was more apparent in people younger than 50, people with healthy blood sugar levels and in lean people. Comparisons with weather records showed the fat was more evident in scans taken when the weather was colder. © Society for Science & the Public 2000 - 2009

Keyword: Obesity
Link ID: 12738 - Posted: 06.24.2010

Pregnant women who suffer from stress are more likely to have a child with asthma, according to research from Children of the 90s study. Researchers working with about 6,000 families in Bristol found anxious mums-to-be were 60% more likely to have a baby who would develop the illness. The findings show 16% of asthmatic children had mothers who reported high anxiety while pregnant. Mothers-to-be who were less stressed had a lower incidence rate. Professor John Henderson, from the Children of the 90s team, said: "Perhaps the natural response to stress which produces a variety of hormones in the body may have an influence on the developing infant and their developing immune system that manifests itself later on." The Children of the 90s study - carried out by the University of Bristol - has been following 14,000 children. They are regularly tested and monitored to see how different lifestyles affect growth, intelligence and health. The aim is to identify ways to optimise the health and development of children. Key findings to come out of the project include left-handed children do less well in tests than their right-handed peers and women who eat oily fish while pregnant have children with better visual development. (C)BBC

Keyword: Stress; Neuroimmunology
Link ID: 12737 - Posted: 04.08.2009

By Victoria Gill Chimpanzees enter into "deals" whereby they exchange meat for sex, according to researchers. Male chimps that are willing to share the proceeds of their hunting expeditions mate twice as often as their more selfish counterparts. This is a long-term exchange, so males continue to share their catch with females when they are not fertile, copulating with them when they are. The team describe their findings in the journal PLoS One. Cristina Gomes and her colleagues, from the Max Planck Institute for Evolutionary Anthropology in Germany, studied chimps in the Tai Forest reserve in Ivory Coast. She and her team observed the animals as they hunted, and monitored the number of times they copulated. "By sharing, the males increase the number of times they mate, and the females increase their intake of calories," said Dr Gomes. "What's amazing is that if a male shares with a particular female, he doubles the number of times he copulates with her, which is likely to increase the probability of fertilising that female." Meat is important for the animals' diet because it is so high in protein. Since female chimps do not usually hunt, "they have a hard time getting it on their own," explained Dr Gomes. The "meat for sex hypothesis" had already been proposed to explain why male chimps might share with females. But previous attempts to record the phenomenon failed, because researchers looked for direct exchanges, where a male shared meat with a fertile female and copulated with her right away. Dr Gomes' team took a new approach. (C)BBC

Keyword: Sexual Behavior; Evolution
Link ID: 12736 - Posted: 04.08.2009

By Stephen L. Macknik and Susana Martinez-Conde Alas! Poor Yorick. I knew him well. A fellow of infinite jest, of most excellent fancy; he hath borne me on his back a thousand times; and now, how abhorred in my afterimage he is! Well… that’s what Hamlet would have said, had he been holding the vintage Pear’s Soap advertisement bearing Yorick’s skull in the accompanying slide, rather than a dug up and rotting Danish cranium. In this antique illusion, you can stare at the X in Yorick’s left eye socket for about 10 to 30 seconds, then look away at a flat surface such as a piece of paper, wall, ceiling or sky, and you will see Yorick’s afterimage as a ghostly apparition. Afterimages such as this one help us to understand how neurons in various areas of the brain adapt to the visual environment. Adaptation, in this case, is the process by which neurons habituate and eventually cease responding to an unchanging stimulus. Once neurons have adapted, it takes a while for them to reset to their previous, unadapted state: it is during this period that we see illusory afterimages. We see afterimages every day: after briefly looking at the sun, at a bright light bulb or after being momentarily blinded by a camera flash, we perceive a temporary dark spot in our field of vision. Vision scientists believe that the adaptation effect producing poor Yorick’s afterimage largely takes place in the neurons of the retina. How can we know? Close your right eye and stare at the X again. Then look at the wall again to see the afterimage, but this time switch back-and-forth between closing one eye and the other. Only the left eye—which was open during the adaptation period—will reveal Yorick’s ghost. © 1996-2009 Scientific American Inc

Keyword: Vision
Link ID: 12735 - Posted: 06.24.2010

By Susan Milius Exposing a bottle-nosed dolphin to a couple of minutes of nearby sonar pinging could cause some temporary hearing impairment, a new test finds. What sonar does to marine mammals has become a hotly debated topic in recent years, as beaked whales and other species have stranded in shallow water and died after naval training exercises in the area. For the first time, researchers have played recordings of actual naval sonar to a marine mammal and tested its hearing after progressive step-ups in intensity over a couple of months, says Aran Mooney of the Woods Hole Oceanographic Institution in Massachusetts. Working with a bottle-nosed dolphin trained in the protocols of hearing tests, Mooney and his colleagues played a series of recordings of sonar pings, building up to an intensity that mimicked a ship some 40 meters away. (The bottle-nosed dolphin was free to swim farther away from the noise. It didn’t, but then again researchers were offering it fish.) After hearing 15 pings at 203 decibels, the animal’s threshold for detecting sounds had shifted up some six decibels, Mooney and his colleagues report online April 7 in Biology Letters. “It’s a rock-concert effect,” Mooney says. After listening to blasting music, fans may notice a cottony quality to their hearing, as if something’s blocking their ears. The effect diminishes in time. And the bottle-nosed dolphin’s hearing also returned to normal typically after about 20 minutes, Mooney reports. © Society for Science & the Public 2000 - 2009

Keyword: Hearing
Link ID: 12734 - Posted: 06.24.2010

By ERIC NAGOURNEY Stroke patients who practice tai chi may improve their balance — reducing the risk of falls, researchers say. Writing in the journal Neurorehabilitation and Neural Repair, the researchers reported improvement in volunteers after as little as six weeks of training. The lead author was Stephanie S. Y. Au-Yeung of Hong Kong Polytechnic University. In earlier research, one of the article’s co-authors, Christina W. Y. Hui-Chan, found that tai chi improved balance among healthy elderly people. For this study, the researchers wanted to see if the same effect would occur among stroke patients. They took 136 people who had a stroke six months or more earlier and divided them into two groups. Over 12 weeks, one group did general exercise, the other a modified version of tai chi. The tai chi group met once a week for an hour, and were asked to practice at home about three hours a week. While the exercise group showed little improvement in balance, the tai chi group made significant gains when they were tested on weight-shifting, reaching and how well they could maintain their stability on a platform that moved like a bus. The benefit of tai chi, the researchers said, is that once the forms are mastered, they can be done without supervision. Copyright 2009 The New York Times Company

Keyword: Stroke; Regeneration
Link ID: 12733 - Posted: 06.24.2010

By DONALD G. McNEIL Jr. Confirming the fears of Somali immigrants in Minneapolis, the Minnesota Health Department agreed Tuesday that young Somali children there appeared to have higher-than-usual rates of autism. Though health officials emphasized that their report was based on very limited data, they concluded that young Somali children appeared to be two to seven times as likely as other children to be in classes for autistic pupils. Dr. Sanne Magnan, the state health commissioner, said the finding was “consistent with the observations by parents,” who have been saying for more than a year that alarming numbers of Somali children born in this country have severe autism. Somalis began immigrating into the area in the 1990s, fleeing civil war in their homeland. The report made no effort to explain why the children had autism. Its authors did not examine children or their medical records. They accepted the diagnoses — some by doctors, some by school evaluators — that admitted children to special-education classes, and they calculated rates for different ethnic groups. They counted only 3- to 4-year-olds, only children in Minneapolis public schools, and only children born in Minnesota. They drew no comparisons with Somalis in other cities. There have been anecdotal reports of higher autism rates among Somalis in some American cities, and no formal studies. A small study in Sweden reported high rates among Somali schoolchildren in Stockholm. Copyright 2009 The New York Times Company

Keyword: Autism
Link ID: 12732 - Posted: 06.24.2010

Heightened activity in an area of the brain that deals with memory may give a subtle early warning of dementia decades later, UK research suggests. It was known that carrying a rogue version of a gene called ApoE4 raised the risk of Alzheimer's disease. Now researchers have linked the same mutation with raised activity in an area of the brain called the hippocampus in people as young as 20. The study appears in Proceedings of the National Academy of Science. The researchers, from Oxford University and Imperial College London, believe over-activity in the hippocampus may effectively wear it out, raising the risk of dementia in later life. They hope their work could be a first step towards developing a simple method to identify people at increased risk of developing dementia. They could then potentially be offered early treatment and lifestyle advice. Carrying one copy of the rogue ApoE4 gene raises the risk of Alzheimer's by up to four times the normal, two copies by up to 10 times. But not everyone with the rogue gene will develop the condition. The latest study used scans to compare brain activity in 36 volunteers aged 20 to 35. In those who carried the rogue gene activity in the hippocampus was consistently raised, even at rest. Researcher Dr Clare Mackay said: "These are exciting first steps towards a tantalising prospect: a simple test that will be able to distinguish who will go on to develop Alzheimer's." (C)BBC

Keyword: Alzheimers
Link ID: 12731 - Posted: 04.07.2009

by Helen Thomson By the time you retire, there's no doubt about it, your brain isn't what it used to be. By 65 most people will start to notice the signs: you forget people's names and the teapot occasionally turns up in the fridge. There is a good reason why our memories start to let us down. At this stage of life we are steadily losing brain cells in critical areas such as the hippocampus - the area where memories are processed. This is not too much of a problem at first; even in old age the brain is flexible enough to compensate. At some point though, the losses start to make themselves felt. Clearly not everyone ages in the same way, so what's the difference between a jolly, intelligent oldie and a forgetful, grumpy granny? And can we improve our chances of becoming the former? Exercise can certainly help. Numerous studies have shown that gentle exercise three times a week can improve concentration and abstract reasoning in older people, perhaps by stimulating the growth of new brain cells. Exercise also helps steady our blood glucose. As we age, our glucose regulation worsens, which causes spikes in blood sugar. This can affect the dentate gyrus, an area within the hippocampus that helps form memories. Since physical activity helps regulate glucose, getting out and about could reduce these peaks and, potentially, improve your memory (Annals of Neurology, vol 64, p 698). © Copyright Reed Business Information Ltd.

Keyword: Alzheimers; Development of the Brain
Link ID: 12730 - Posted: 06.24.2010

by Anil Ananthaswamy Healthy young adults carrying a gene variant that is a major risk factor for the disease seem to have extra activity in brain regions related to memory, even when their brains are at rest. The gene APOE codes for a protein thought to help create, maintain and repair neuronal connections. One variant, epsilon 4, is considered the biggest risk factor for getting Alzheimer's, increasing your risk by up to 4 times if you have one copy and up to 12 if you have two. It is not known exactly how epsilon 4 ups the risk, but in people who carry it and have developed Alzheimer's, the hippocampus, which is involved in memory functions, is usually smaller. To figure out if epsilon 4 influences brain function earlier on in life, Clare Mackay of the University of Oxford and colleagues at Imperial College London scanned the brains of 18 healthy adults with epsilon 4 and 18 controls who did not have the variant. In the scanner, the volunteers spent time performing memory tests and also doing nothing. During the memory task, the epsilon 4 carriers had more activity in the hippocampus compared with controls, even though there was no difference in their performance on the tests, suggesting that their hippocampuses expend more energy to achieve the same result. © Copyright Reed Business Information Ltd.

Keyword: Alzheimers
Link ID: 12729 - Posted: 06.24.2010