Chapter 5. The Sensorimotor System
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By MARY ROACH WAGENINGEN, THE NETHERLANDS — When I told people I was traveling to Food Valley, I described it as the Silicon Valley of eating. At this cluster of universities and research facilities, nearly 15,000 scientists are dedicated to improving — or, depending on your sentiments about processed food, compromising — the quality of our meals. At the time I made the Silicon Valley comparison, I did not expect to be served actual silicone. But here I am, in the Restaurant of the Future, a cafeteria at Wageningen University where hidden cameras record diners as they make decisions about what to eat. And here it is, a bowl of rubbery white cubes the size of salad croutons. Andries van der Bilt has brought them from his lab in the brusquely named Department of Head and Neck, at the nearby University Medical Center Utrecht. “You chew them,” he said. The cubes are made of a trademarked product called Comfort Putty, more typically used in its unhardened form for taking dental impressions. Dr. Van der Bilt isn’t a dentist, however. He is an oral physiologist, and he likely knows more about chewing than anyone else in the world. He uses the cubes to quantify “masticatory performance” — how effectively a person chews. I take a cube from the bowl. If you ever, as a child, chewed on a whimsical pencil eraser in the shape of, say, an animal or a piece of fruit, then you have tasted this dish. “I’m sorry.” Dr. Van der Bilt winces. “It’s quite old.” As though fresh silicone might be better. © 2013 The New York Times Company
Keyword: Chemical Senses (Smell & Taste)
Link ID: 17949 - Posted: 03.26.2013
By Sandra G. Boodman, A year after her daughter’s stomach problems began, Margaret Kaplow began having pains of her own. When she sat down to dinner with her family, Kaplow’s gut would clench involuntarily as she waited to see if this was one of the nights Madeline would eat a few bites before putting down her fork, pushing away from the table and announcing, “I don’t feel good.” For nearly six years, Maddie Kaplow’s severe, recurrent abdominal pain, which began shortly before her 13th birthday, was attributed to a host of ailments. Specialists in the District, Maryland and Virginia decided at various times that she had a gluten intolerance, a ruptured ovarian cyst, a diseased appendix or irritable bowel syndrome (IBS). Some were convinced that her problem was psychological and that she was a high-strung teenaged girl seeking attention. “It was a freaking nightmare,” Kaplow recalled of those years. She said she never believed her daughter was exaggerating or faking her symptoms. And each time a new diagnosis was made, Kaplow said, she felt elated that a doctor had figured out the cause of Maddie’s pain, which would turn into crushing disappointment when it recurred. It was only after she landed in a college infirmary 400 miles from her Northern Virginia home that doctors finally determined what was wrong and treated Maddie for the illness that dominated her adolescence. © 1996-2013 The Washington Post
Keyword: Pain & Touch
Link ID: 17948 - Posted: 03.26.2013
A compact, self-contained sensor recorded and transmitted brain activity data wirelessly for more than a year in early stage animal tests, according to a study funded by the National Institutes of Health. In addition to allowing for more natural studies of brain activity in moving subjects, this implantable device represents a potential major step toward cord-free control of advanced prosthetics that move with the power of thought. The report is in the April 2013 issue of the Journal of Neural Engineering. “For people who have sustained paralysis or limb amputation, rehabilitation can be slow and frustrating because they have to learn a new way of doing things that the rest of us do without actively thinking about it,” said Grace Peng, Ph.D., who oversees the Rehabilitation Engineering Program of the National Institute of Biomedical Imaging and Bioengineering (NIBIB), part of NIH. “Brain-computer interfaces harness existing brain circuitry, which may offer a more intuitive rehab experience, and ultimately, a better quality of life for people who have already faced serious challenges.” Recent advances in brain-computer interfaces (BCI) have shown that it is possible for a person to control a robotic arm through implanted brain sensors linked to powerful external computers. However, such devices have relied on wired connections, which pose infection risks and restrict movement, or were wireless but had very limited computing power. Building on this line of research, David Borton, Ph.D., and Ming Yin, Ph.D., of Brown University, Providence, R.I., and colleagues surmounted several major barriers in developing their sensor. To be fully implantable within the brain, the device needed to be very small and completely sealed off to protect the delicate machinery inside the device and the even more delicate tissue surrounding it. At the same time, it had to be powerful enough to convert the brain’s subtle electrical activity into digital signals that could be used by a computer, and then boost those signals to a level that could be detected by a wireless receiver located some distance outside the body. Like all cordless machines, the device had to be rechargeable, but in the case of an implanted brain sensor, recharging must also be done wirelessly.
Link ID: 17923 - Posted: 03.20.2013
by Audrey Carlsen Plenty of us got our fill of green-colored food on St. Patrick's Day. (Green beer, anyone?) But for some people, associating taste with color is more than just a once-a-year experience. These people have synesthesia — a neurological condition in which stimulation of one sense (e.g., taste) produces experiences in a totally different sense (e.g., sight). According to researcher Sean Day, approximately one in 27 people has some form of synesthesia. We've covered this phenomenon in the past. And I'm a synesthete myself — I see letters and numbers in color, and associate sounds with shapes and textures. But only a very few people — maybe only 1 percent of synesthetes — have sensory crossovers that affect their relationship with food and drink. Jaime Smith is one of those people. He's a sommelier by trade, and he has a rare gift: He smells in colors and shapes. For Smith, who lives in Las Vegas, a white wine like Nosiola has a "beautiful aquamarine, flowy, kind of wavy color to it." Other smells also elicit three-dimensional textures and colors on what he describes as a "projector" in his mind's eye. This "added dimension," Smith says, enhances his ability to appraise and analyze wines. "I feel that I have an advantage over a lot of people, particularly in a field where you're judged on how good of a smeller you are," he says. ©2013 NPR
By LAURIE EDWARDS TO the list of differences between men and women, we can add one more: the drug-dose gender gap. Doctors and researchers increasingly understand that there can be striking variations in the way men and women respond to drugs, many of which are tested almost exclusively on males. Early this year, for instance, the Food and Drug Administration announced that it was cutting in half the prescribed dose of Ambien for women, who remained drowsy for longer than men after taking the drug. Women have hormonal cycles, smaller organs, higher body fat composition — all of which are thought to play a role in how drugs affect our bodies. We also have basic differences in gene expression, which can make differences in the way we metabolize drugs. For example, men metabolize caffeine more quickly, while women metabolize certain antibiotics and anxiety medications more quickly. In some cases, drugs work less effectively depending on sex; women are less responsive to anesthesia and ibuprofen for instance. In other cases, women are at more risk for adverse — even lethal — side effects. These differences are particularly important for the millions of women living with chronic pain. An estimated 25 percent of Americans experience chronic pain, and a disproportionate number of them are women. A review published in the Journal of Pain in 2009 found that women faced a substantially greater risk of developing pain conditions. They are twice as likely to have multiple sclerosis, two to three times more likely to develop rheumatoid arthritis and four times more likely to have chronic fatigue syndrome than men. As a whole, autoimmune diseases, which often include debilitating pain, strike women three times more frequently than men. © 2013 The New York Times Company
By Stephani Sutherland Treating the brain with magnets went mainstream a few years ago, when the technique proved successful at relieving major depression. Now the procedure, repetitive transcranial magnetic stimulation (rTMS), shows promise for another mysterious, hard-to-treat disorder: chronic pain. Until now, pain seemed out of reach for rTMS because the regions involved in pain perception lie very deep within the brain. The other disorders helped by rTMS all involve brain areas close to the skull. To treat depression, for example, a single magnetic coil directs a magnetic field at the dorsolateral prefrontal cortex, a region of the brain's outer folds. When aimed at different areas of these outer folds, rTMS improves the motor symptoms of Parkinson's disease, staves off the damage of stroke, lessens the discomfort that follows nerve injury and treats obsessive-compulsive disorder. The magnetic field affects the electrical signaling used by neurons to communicate, but how exactly it improves symptoms is unclear—scientists suspect rTMS may redirect the activity of select cells or even entire brain circuits. To extend the technique's reach, David Yeomans, a neuroscientist at Stanford University, and his colleagues used four magnets rather than one and employed high-level math to steer the resulting complex fields. Their target was an area called the anterior cingulate cortex (ACC), an area active in the experience of all types of pain, regardless of its source or nature. © 2013 Scientific American
Keyword: Pain & Touch
Link ID: 17909 - Posted: 03.18.2013
By GRETCHEN REYNOLDS For most people, exercise elevates mood. Repeated studies with humans and animals have shown that regular workouts can increase stress resistance, decrease anxiety, lessen symptoms of depression and generally leave people cheerful. But what if someone sincerely dislikes exercise and works out only under a kind of emotional duress, deeming that he or she must do so, perhaps because a doctor or worried spouse has ordered it? In that case, which is hardly uncommon, does the stress of being, in effect, forced to exercise reduce or cancel out the otherwise sturdy emotional benefits of physical activity? That issue has been of considerable interest to exercise scientists for some time, particularly those who work with animals, since in some experiments, animals are required to exercise at intensities or for durations that they don’t control. Such intense exercise greatly increases their stress, as measured by certain behaviors and by physiological markers like increased levels of the stress hormone cortisol. But no study had directly compared the emotional effects of forced and voluntary exercise on anxiety and emotional resilience. So scientists at the Center for Neuroscience at the University of Colorado at Boulder recently decided to conduct one. They began by gathering a group of healthy adult male rats of a type that generally enjoys running. Then they gave some of the animals access to unlocked running wheels and let them exercise whenever and for as long as they liked. The exercise was fully under the animals’ control. Copyright 2013 The New York Times Company
Link ID: 17899 - Posted: 03.13.2013
By JAN HOFFMAN Physically active children generally report happier moods and fewer symptoms of depression than children who are less active. Now researchers may have found a reason: by one measure, exercise seems to help children cope with stress. Finnish researchers had 258 children wear accelerometers on their wrists for at least four days that registered the quality and quantity of their physical activity. Their parents used cotton swabs to take saliva samples at various times throughout a single day, which the researchers used to assess levels of cortisol, a hormone typically induced by physical or mental stress. There was no difference in the cortisol levels at home between children who were active and those who were less active. But when the researchers gave the children a standard psychosocial stress test at a clinic involving arithmetic and storytelling challenges, they found that those who had not engaged in physical activity had raised cortisol levels. The children who had moderate or vigorous physical activity showed relatively no rise in cortisol levels. Those results indicate a more positive physiological response to stress by children who were more active, the researchers said in a study that was published this week in The Journal of Clinical Endocrinology and Metabolism. The children who were least active had the highest levels. “This study shows that children who are more active throughout their day have a better hormonal response to an acute stressful situation,” said Disa Hatfield, an assistant professor of kinesiology at the University of Rhode Island, who was not involved in the study. Copyright 2013 The New York Times Company
Link ID: 17882 - Posted: 03.09.2013
By Deborah Kotz, Globe Staff No doubt, the biggest appeal of exercise is to build biceps, heart muscle, and perhaps some definition in those abdominal muscles, but how about using exercise to build your brain? It’s been known for some time that exercise can lift your mood, ward off depression, and help the brain age more gracefully -- free of memory loss and dementia. But now researchers have found that even just one bout of exercise can -- even better than a cup of coffee -- improve your mental focus and cognitive performance for any challenging task you face that day. A new analysis of 19 studies involving 586 kids, teens, and young adults that was published Wednesday in the British Medical Journal found that short 10 to 40 minutes bursts of exercise led to an immediate boost in concentration and mental focus, likely by improving blood flow to the brain. “These results provide further evidence that doing about 20 minutes of exercise just before taking a test or giving a speech can improve performance,” said Harvard psychiatrist Dr. John Ratey, who wrote the best-selling book Spark: The Revolutionary New Science of Exercise and the Brain. Another piece of proof can be seen in the brain scan above -- from a 2009 University of Illinois study also included in the new analysis -- which compares the brain activity of 9-year-olds who took a brisk walk and those who didn’t take a walk. The walkers had far more activity in brain regions involved with focused attention and filtering out noisy distractions while they were taking a challenging test compared to the non-walkers. © 2013 NY Times Co.
Keyword: Learning & Memory
Link ID: 17881 - Posted: 03.09.2013
By Scicurious I heard the rumblings on Twitter, and then on the blogs. It was telepathy. No, it wasn’t telepathy, but it was close. It was like the Borg. No it wasn’t. It was a mind meld! Ok, maybe. So what was it? It was one rat learning to do something, while electrodes recorded his every move. In the meantime, on another continent, another rat received the signals into his own brain…and changed his behavior. Telepathy? No. A good solid proof of concept? I’m not sure. An interesting idea? Absolutely. So I wanted to look at this paper in depth. We know already that some other experts weren’t really thrilled with the results. But I’m going to look at WHY, and what a more convincing experiment might look like. So what actually happened here? Each experiment involved two sets of rats. First, you have your “encoder rats”. These rats were water-deprived (not terribly, just thirsty), and trained to press a lever for a water reward (water deprivation is one training technique for lever pressing, and is one of the fastest. But you can also food-deprive and train for food or just train the animal to something tasty, like Crisco or sweetened milk). The rats were trained until they were 95% accurate at the task. They were then implanted with electrodes in the motor cortex, that recorded the firing of the neurons as the rats pressed the left or right lever. © 2013 Scientific American,
Link ID: 17874 - Posted: 03.07.2013
But critics are sceptical about predicted organic computer. Ed Yong The brains of two rats on different continents have been made to act in tandem. When the first, in Brazil, uses its whiskers to choose between two stimuli, an implant records its brain activity and signals to a similar device in the brain of a rat in the United States. The US rat then usually makes the same choice on the same task. Miguel Nicolelis, a neuroscientist at Duke University in Durham, North Carolina, says that this system allows one rat to use the senses of another, incorporating information from its far-away partner into its own representation of the world. “It’s not telepathy. It’s not the Borg,” he says. “But we created a new central nervous system made of two brains.” Nicolelis says that the work, published today in Scientific Reports1, is the first step towards constructing an organic computer that uses networks of linked animal brains to solve tasks. But other scientists who work on neural implants are sceptical. Lee Miller, a physiologist at Northwestern University in Evanston, Illinois, says that Nicolelis’s team has made many important contributions to neural interfaces, but the current paper could be mistaken for a “poor Hollywood science-fiction script”. He adds, “It is not clear to what end the effort is really being made.” In earlier work2, Nicolelis’s team developed implants that can send and receive signals from the brain, allowing monkeys to control robotic or virtual arms and get a sense of touch in return. This time, Nicolelis wanted to see whether he could use these implants to couple the brains of two separate animals. © 2013 Nature Publishing Group
Link ID: 17862 - Posted: 03.02.2013
By Maria Konnikova Georg Tobias Ludwig Sachs was born on April 22, 1786, in the mountain village of St. Ruprecht, Kärnthen, or Carinthia – the south of present-day Austria. From the first, he was notably different from his parents and siblings: he was an albino. (His youngest sister, eleven years his junior, would be one as well.) We don’t know if this physical distinction had any negative impact on the young Georg—but it certainly piqued his curiosity. He proceeded to embark on the scientific study of albinism at the universities in Tübingen, Altdorf, and Erlangen, and at the last of these, produced his 1812 doctoral dissertation. It was about albinism: “A Natural History of Two Albinos, the Author and His Sister.” Today, though, Sachs is remembered not for his thoughts on the nature of the albino, but rather those on another curious condition that was far less noticeable—but received a chapter of its very own in his thesis all the same: synesthesia. Georg Sachs just so happens to be the first known synesthete in the medical or psychological literature. Synesthesia means, literally, a cross-mingling of the senses, when two or more senses talk to each other in a way that is not usually associated with either sense on its own. For instance, you see color when you listen to a song on the radio. Taste shapes as you take a bite of your spaghetti. Frown at the 3 on that piece of paper because it’s giving you attitude—it seems irritable. Smile at the woman you just met because her name comes with a beautiful orange glow. The variations are many, but in every scenario, there is a sensory cross-talk that reaches to a neural level. As in, if I were to put you in a scanner while you took that bite or listened to that musical composition, the relevant areas of the brain would light up: your brain would actually be experiencing color, shape, or whatever you say you’re experiencing as if you were exposed to that very stimulus. It’s a condition that affects, by the most recent estimates, roughly 4% of the population. © 2013 Scientific American
Link ID: 17854 - Posted: 02.27.2013
by Julia Sklar IT IS a nightmare situation. A person diagnosed as being in a vegetative state has an operation without anaesthetic because they cannot feel pain. Except, maybe they can. Alexandra Markl at the Schön clinic in Bad Aibling, Germany, and colleagues studied people with unresponsive wakefulness syndrome (UWS) – also known as vegetative state – and identified activity in brain areas involved in the emotional aspects of pain. People with UWS can make reflex movements but can't show subjective awareness. There are two distinct neural networks that work together to create the sensation of pain. The more basic of the two – the sensory-discriminative network – identifies the presence of an unpleasant stimulus. It is the affective network that attaches emotions and subjective feelings to the experience. Crucially, without the activity of the emotional network, your brain detects pain but won't interpret it as unpleasant. Using PET scans, previous studies have detected activation in the sensory-discriminative network in people with UWS but their findings were consistent with a lack of subjective awareness, the hallmark of the condition. Now Markl and her colleagues have found evidence of activation in the affective or emotional network too (Brain and Behavior, doi.org/kfs). © Copyright Reed Business Information Ltd.
By Susan Milius Slight electric fields that form around flowers may lure pollinators much as floral colors and fragrances do. In lab setups, bumblebees learned to distinguish fake flowers by their electrical fields, says sensory biologist Daniel Robert at the University of Bristol in England. Combining an electrical charge with a color helped the bees learn faster, Robert and his colleagues report online February 21 in Science. Plants, a bit like lightning rods, tend to conduct electrical charges to the ground, Robert says. And bees pick up a positive charge from the atmosphere’s invisible rain of charged particles. “Anything flying through the air, whether it’s a baseball, 767 jumbo jet, or a bee, acquires a strong positive electrostatic charge due to interaction with air molecules,” says Stephen Buchmann of the University of Arizona in Tucson. Robert and his colleagues checked whether bees could choose flowers based solely on the electric fields the plants produce. Purple metal disks (encased in plastic so as not to shock bees) stood in for flowers. Half of them, wired for 30 volts, held sips of sugar water. The unwired ones offered a bitter quinine solution that bees don’t like. Bombus terrestris bumblebees learned to choose sweet, wired disks more than 80 percent of the time. When researchers unplugged the wired disks, the bees bumbled, scoring sugar only by chance. © Society for Science & the Public 2000 - 2013
Link ID: 17832 - Posted: 02.23.2013
By Sandra G. Boodman, Ian Liu’s back was killing him — and no matter what he tried, it wasn’t getting better. The 39-year-old Coast Guard officer assumed he had wrenched his back caring for his infant son, not surprising given his long history of lower back problems. But this time, the pain was much more intense and persistent, and neither physical therapy nor painkillers seemed to help. For more than a month, Liu shuttled between two Washington area military hospitals, searching for an explanation and, especially, relief. “It was the worst pain I’d ever had,” Liu recalled. A series of tests failed to explain his deteriorating condition, which stumped the medical personnel who treated him. It was only after Liu’s wife confided that he sometimes seemed disoriented that a doctor looked beyond the obvious problem and discovered the source of Liu’s pain. The cause turned out to be unrelated to his orthopedic history — and far more serious than a bad back. Liu first noticed the pain on a Friday night, Dec. 3, 2004, after he finished bathing the youngest of his three sons. “I assumed it was just from bending over the tub,” recalled Liu, who figured it would improve with time, as such problems had in the past. But the next day, his pain was worse, and as he wheeled his shopping cart around a Northern Virginia commissary, Liu was glad he had something to lean on. © 1996-2013 The Washington Post
Keyword: Pain & Touch
Link ID: 17823 - Posted: 02.19.2013
By Alan Boyle, Science Editor, NBC News BOSTON — Neuroscientists are following through on the promise of artificially enhanced bodies by creating the ability to "feel" flashes of light in invisible wavelengths, or building an entire virtual body that can be controlled via brain waves. "Things that we used to think were hoaxes or science fiction are fast becoming reality," said Todd Coleman, a bioengineering professor at the University of California at San Diego. Coleman and other researchers surveyed the rapidly developing field of neuroprosthetics in Boston this weekend at the annual meeting of the American Association for the Advancement of Science. One advance came to light just in the past week, when researchers reported that they successfully wired up rats to sense infrared light and move toward the signals to get a reward. "This was the first attempt … not to restore a function but to augment the range of sensory experience," said Duke University neurobiologist Miguel Nicolelis, the research team's leader. The project, detailed in the journal Nature Communications, involved training rats to recognize a visible light source and poke at the source with its nose to get a sip of water. Then electrodes were implanted in a region of the rats' brains that is associated with whisker-touching. The electrodes were connected to an infrared sensor on the rats' heads, which stimulated the target neurons when the rat was facing the source of an infrared beam. Then the visible lights in the test cage were replaced by infrared lights. © 2013 NBCNews.com
by Hal Hodson CAN YOU imagine feeling Earth's magnetic field on the tip of your tongue? Strangely, this is now possible, using a device that converts the tongue into a "display" for output from environmental sensors. Gershon Dublon of the Massachusetts Institute of Technology devised a small pad containing electrodes in a 5 × 5 grid. Users put the pad, which Gershon calls Tongueduino, on their tongue. When hooked up to an electronic sensor, the pad converts signals from the sensor into small pulses of electric current across the grid, which the tongue "reads" as a pattern of tingles. Dublon says the brain quickly adapts to new stimuli on the tongue and integrates them into our senses. For example, if Tongueduino is attached to a sensor that detects Earth's magnetic field, users can learn to use their tongue as a compass. "You might not have to train much," he says. "You could just put this on and start to perceive." Dublon has been testing Tongueduino on himself for the past year using a range of environmental sensors. He will now try the device out on 12 volunteers. Blair MacIntyre at the Georgia Institute of Technology in Atlanta says a wireless version of Tongueduino could prove useful in augmented reality applications that deliver information to users inconspicuously, without interfering with their vision or hearing. "There's a need for forms of awareness that aren't socially intrusive," he says. Even Google's much-publicised Project Glass will involve wearing a headset, he points out. © Copyright Reed Business Information Ltd.
The latest bionic superhero is a rat: its brain hooked up to an infrared detector, it's become the first animal to be given a sixth sense. Developed by Miguel Nicolelis and colleagues at Duke University in Durham, North Carolina, the system connects a head-mounted sensor to a brain region that normally processes touch sensations from whiskers. As shown in this video, the rat's brain is tricked when infrared light is detected, giving it a new sense organ. "Instead of seeing, the rats learned how to touch the light," says Nicolelis. Even though the touch-processing brain area acquires a new role, the team found that it continues to process touch sensations from whiskers, somehow dividing its time between both types of signal. "The adult brain is a lot more plastic than we thought," says Nicolelis. The finding could lead to new brain prostheses that restore sight in humans with a damaged visual cortex. By bypassing the damaged part of the brain altogether, it might be possible to wire up a video camera to a part of the brain that processes touch, letting people "touch" what the camera sees. According to Nicolelis, it could also lead to superhero powers for humans. "It could be X-rays, radio waves, anything," he says. "Superman probably had a prosthetic device that nobody knew of." © Copyright Reed Business Information Ltd.
By Laura Sanders Before you can run, you have to walk, and before you can walk well, you have to walk like a brand-new baby. A new study uncovers the logistics of newborns’ herky-jerky, Frankensteinian stepping action and how this early reflex morphs into refined adult locomotion. In the study, electrodes on infants’ chubby legs picked up signals from neurons that tell muscles to fire, revealing that three-day old babies tense up many of their leg muscles all at once. Toddlers, preschoolers and adults, by contrast, showed a progressively more sophisticated, selective pattern of neuron activity. From birth to adulthood, motor neurons in the spine get an overhaul as neurons in different locations along the spine become specialized for various aspects of walking, such as foot position, balance and direction, Yuri Ivanenko of the Santa Lucia Foundation in Rome and colleagues conclude in the Feb. 13 Journal of Neuroscience. © Society for Science & the Public 2000 - 2013
Keyword: Development of the Brain
Link ID: 17802 - Posted: 02.14.2013
By NICHOLAS BAKALAR Being physically fit in midlife is associated with a lower risk of dementia in old age, a new study reports. Between 1971 and 2009, 19,458 healthy adults younger than age 65 took a treadmill fitness test as part of a broader health examination. Researchers followed the subjects through their Medicare records for an average of 24 years. After adjusting for age, smoking, diabetes, cholesterol and other health factors, the researchers found that compared with those in the lowest 20 percent for fitness in midlife, those in the highest 20 percent had a 36 percent reduced risk of dementia. The reason for the association is unclear, but it was independent of cardiovascular and cerebrovascular risk factors for dementia, suggesting that both vascular and nonvascular mechanisms may be involved. “Dementia is a disease with no cure and no good therapies,” said the lead author, Dr. Laura F. DeFina, the interim chief scientific officer at the Cooper Institute in Dallas. Physical activity may be “a preventive way to address dementia instead of addressing the costs of a disabled elder.” The study population was largely white and highly educated, and the researchers acknowledge that their findings, published last week in The Annals of Internal Medicine, cannot be generalized to other populations. They emphasize that the study is observational and does not prove causation. Copyright 2013 The New York Times Company
Link ID: 17790 - Posted: 02.12.2013