Chapter 16. None

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Have you ever wrongly suspected that other people are out to harm you? Have you been convinced that you’re far more talented and special than you really are? Do you sometimes hear things that aren’t actually there? These experiences – paranoia, grandiosity and hallucinations in the technical jargon – are more common among the general population than is usually assumed. But are people who are susceptible simply “made that way”? Are they genetically predisposed, in other words, or have their life experiences made them more vulnerable to these things? It’s an old debate: which is more important, nature or nurture? Scientists nowadays tend to agree that human psychology is a product of a complex interaction between genes and experience – which is all very well, but where does the balance lie? Scientists (including one of the authors of this blog) recently conducted the first ever study among the general population of the relative contributions of genes and environment to the experience of paranoia, grandiosity and hallucinations. How did we go about the research? First, it is important to be clear about the kinds of experience we measured. By paranoia, we mean the unfounded or excessive fear that other people are out to harm us. Grandiosity denotes an unrealistic conviction of one’s abilities and talents. Hallucinations are sensory experiences (hearing voices, for instance) that aren’t caused by external events. Led by Dr Angelica Ronald at Birkbeck, University of London, the team analysed data on almost 5,000 pairs of 16-year-old twins. This is the classical twin design, a standard method for gauging the relative influence of genes and environment. Looking simply at family traits isn’t sufficient: although family members share many genes, they also tend to share many of the same experiences. This is why studies involving twins are so useful. © 2014 Guardian News and Media Limited

Keyword: Schizophrenia
Link ID: 20147 - Posted: 10.02.2014

by Jason M. Breslow As the NFL nears an end to its long-running legal battle over concussions, new data from the nation’s largest brain bank focused on traumatic brain injury has found evidence of a degenerative brain disease in 76 of the 79 former players it’s examined. The findings represent a more than twofold increase in the number of cases of chronic traumatic encephalopathy, or CTE, that have been reported by the Department of Veterans Affairs’ brain repository in Bedford, Mass. Researchers there have now examined the brain tissue of 128 football players who, before their deaths, played the game professionally, semi-professionally, in college or in high school. Of that sample, 101 players, or just under 80 percent, tested positive for CTE. To be sure, players represented in the data represent a skewed population. CTE can only be definitively identified posthumously, and many of the players who have donated their brains for research suspected that they may have had the disease while still alive. For example, former Chicago Bears star Dave Duerson committed suicide in 2011 by shooting himself in the chest, reportedly to preserve his brain for examination. Nonetheless, Dr. Ann McKee, the director of the brain bank, believes the findings suggest a clear link between football and traumatic brain injury. “Obviously this high percentage of living individuals is not suffering from CTE,” said McKee, a neuropathologist who directs the brain bank as part of a collaboration between the VA and Boston University’s CTE Center. But “playing football, and the higher the level you play football and the longer you play football, the higher your risk.” ©1995-2014 WGBH Educational Foundation

Keyword: Brain Injury/Concussion
Link ID: 20146 - Posted: 10.01.2014

By Sarah C. P. Williams A wind turbine, a roaring crowd at a football game, a jet engine running full throttle: Each of these things produces sound waves that are well below the frequencies humans can hear. But just because you can’t hear the low-frequency components of these sounds doesn’t mean they have no effect on your ears. Listening to just 90 seconds of low-frequency sound can change the way your inner ear works for minutes after the noise ends, a new study shows. “Low-frequency sound exposure has long been thought to be innocuous, and this study suggests that it’s not,” says audiology researcher Jeffery Lichtenhan of the Washington University School of Medicine in in St. Louis, who was not involved in the new work. Humans can generally sense sounds at frequencies between 20 and 20,000 cycles per second, or hertz (Hz)—although this range shrinks as a person ages. Prolonged exposure to loud noises within the audible range have long been known to cause hearing loss over time. But establishing the effect of sounds with frequencies under about 250 Hz has been harder. Even though they’re above the lower limit of 20 Hz, these low-frequency sounds tend to be either inaudible or barely audible, and people don’t always know when they’re exposed to them. For the new study, neurobiologist Markus Drexl and colleagues at the Ludwig Maximilian University in Munich, Germany, asked 21 volunteers with normal hearing to sit inside soundproof booths and then played a 30-Hz sound for 90 seconds. The deep, vibrating noise, Drexl says, is about what you might hear “if you open your car windows while you’re driving fast down a highway.” Then, they used probes to record the natural activity of the ear after the noise ended, taking advantage of a phenomenon dubbed spontaneous otoacoustic emissions (SOAEs) in which the healthy human ear itself emits faint whistling sounds. © 2014 American Association for the Advancement of Science

Keyword: Hearing
Link ID: 20144 - Posted: 10.01.2014

It's not just humans who want the latest gadget. Wild chimpanzees that see a friend making and using a nifty new kind of tool are likely to make one for themselves, scientists report. "Our study adds new evidence supporting the hypothesis that some of the behavioural diversity seen in wild chimpanzees is the result of social transmission and can therefore be interpreted as cultural," an international research team writes today in the journal PLOS ONE. The findings suggest that the ability of individuals to learn from one another originated long ago in a common ancestor of chimpanzees and humans, the researchers add. "This study tells us that chimpanzee culture changes over time, little by little, by building on previous knowledge found within the community," said Thibaud Gruber, a co-author of the study, in a statement. "This is probably how our early ancestors' cultures also changed over time." Scientists already knew that chimpanzees in different groups have certain behaviours unique to their group, such as using a particular kind of tool. They suspected that wild chimpanzees learn those behaviours from other chimpanzees within their group, as scientists have observed in captive chimps. But they could never be sure. The new study documents the spread of two new behaviours among chimpanzees living in Uganda's Budongo Forest. It shows that chimps learned one of them — the making and use of a new tool called a moss sponge — by observing other chimps who had already adopted the behaviour. Chimps dip the tool in water and then put it in their mouth to drink. © CBC 2014

Keyword: Evolution
Link ID: 20141 - Posted: 10.01.2014

|By Tanya Lewis and LiveScience Dolphins can now add magnetic sense to their already impressive resume of abilities, new research suggests. When researchers presented the brainy cetaceans with magnetized or unmagnetized objects, the dolphins swam more quickly toward the magnets, the new study found. The animals may use their magnetic sense to navigate based on the Earth's magnetic field, the researchers said. A number of different animals are thought to possess this magnetic sense, called "magnetoreception," including turtles, pigeons, rodents, insects, bats and even deer (which are related to dolphins), said Dorothee Kremers, an animal behavior expert at the University of Rennes, in France, and co-author of the study published today (Sept. 29) in the journal Naturwissenschaften. "Inside the ocean, the magnetic field would be a very good cue to navigate," Kremers told Live Science. "It seems quite plausible for dolphins to have a magnetic sense." Some evidence suggests both dolphin and whale migration routes and offshore live strandings may be related to the Earth's magnetic field, but very little research has investigated whether these animals have a magnetic sense. Kremers and her colleagues found just one study that looked at how dolphins reacted to magnetic fields in a pool; that study found dolphins didn't show any response to the magnetic field. But the animals in that study weren't free to move around, and were trained to give certain responses. © 2014 Scientific American

Keyword: Animal Migration
Link ID: 20140 - Posted: 10.01.2014

By Jia You Fish larvae emit sound—much to the surprise of biologists. A common coral reef fish in Florida, the gray snapper—Lutjanus griseus (pictured above)—hatches in the open ocean and spends its juvenile years in food-rich seagrass beds hiding from predators before settling in the reefs as an adult. To study how larval snappers orient themselves in the dark, marine biologists deployed transparent acrylic chambers equipped with light and sound sensors under the water to capture the swimming schools as they travel to the seagrass beds on new-moon nights. The larval snappers make a short “knock” sound that adults also make, as well as a long “growl” sound, the team reports online today in Biology Letters. The researchers suspect that the larvae use the acoustic signals to communicate with one another and stay together in schools. If so, human noise pollution could be interrupting their communications—even adult fish have been found to “yell” to be heard above boat noises. © 2014 American Association for the Advancement of Science.

Keyword: Animal Communication; Aggression
Link ID: 20139 - Posted: 10.01.2014

Wild marmosets in the Brazilian forest can learn quite successfully from video demonstrations featuring other marmosets, Austrian scientists have reported, showing not only that marmosets are even better learners than previously known, but that video can be used successfully in experiments in the wild. Tina Gunhold, a cognitive biologist at the University of Vienna, had worked with a population of marmoset monkeys in a bit of Brazilian forest before this particular experiment. The forest is not wilderness. It lies near some apartment complexes, and the marmosets are somewhat used to human beings. But the monkeys are wild, and each extended family group has its own foraging territory. Dr. Gunhold and her colleagues reported in the journal Biology Letters this month that they had tested 12 family groups, setting up a series of video monitors, each with a kind of complicated box that they called an “artificial fruit.” All the boxes contained food. Six of the monitors showed just an unchanging image of a marmoset near a similar box. Three of them showed a marmoset opening the box by pulling a drawer, and three others a marmoset lifting a lid to get at the food. Marmosets are very territorial and would not tolerate a strange individual on their turf, but the image of a strange marmoset on video didn’t seem to bother them. Individual marmosets “differed in their reactions to the video,” Dr. Gunhold said. “Some were more shy, some more bold. The younger ones were more attracted to the video, perhaps because of greater curiosity.” © 2014 The New York Times Company

Keyword: Learning & Memory; Aggression
Link ID: 20138 - Posted: 09.30.2014

By David Z. Hambrick, Fernanda Ferreira, and John M. Henderson A decade ago, Magnus Carlsen, who at the time was only 13 years old, created a sensation in the chess world when he defeated former world champion Anatoly Karpov at a chess tournament in Reykjavik, Iceland, and the next day played then-top-rated Garry Kasparov—who is widely regarded as the best chess player of all time—to a draw. Carlsen’s subsequent rise to chess stardom was meteoric: grandmaster status later in 2004; a share of first place in the Norwegian Chess Championship in 2006; youngest player ever to reach World No. 1 in 2010; and highest-rated player in history in 2012. What explains this sort of spectacular success? What makes someone rise to the top in music, games, sports, business, or science? This question is the subject of one of psychology’s oldest debates. In the late 1800s, Francis Galton—founder of the scientific study of intelligence and a cousin of Charles Darwin—analyzed the genealogical records of hundreds of scholars, artists, musicians, and other professionals and found that greatness tends to run in families. For example, he counted more than 20 eminent musicians in the Bach family. (Johann Sebastian was just the most famous.) Galton concluded that experts are “born.” Nearly half a century later, the behaviorist John Watson countered that experts are “made” when he famously guaranteed that he could take any infant at random and “train him to become any type of specialist [he] might select—doctor, lawyer, artist, merchant-chief and, yes, even beggar-man and thief, regardless of his talents.” One player needed 22 times more deliberate practice than another player to become a master. © 2014 The Slate Group LLC.

Keyword: Learning & Memory
Link ID: 20136 - Posted: 09.30.2014

By Gary Stix If it’s good for the heart, it could also be good for the neurons, astrocytes and oligodendrocytes, cells that make up the main items on the brain’s parts list. The heart-brain adage comes from epidemiological studies that show that people with cardiovascular risk factors such as high-blood pressure and elevated cholesterol levels, may be more at risk for Alzheimer’s and other dementias. This connection between heart and brain has also led to some disappointments: clinical trials of lipid-lowering statins have not helped patients diagnosed with Alzheimer’s, although epidemiological studies suggest that long-term use of the drugs may help prevent Alzheimer’s and other dementias. The link between head and heart is still being pursued because new Alzheimer’s drugs have failed time and again. One approach that is now drawing some interest looks at the set of proteins that carry around fats in the brain. These lipoproteins could potentially act as molecular sponges that mop up the amyloid-beta peptide that clogs up connections among brain cells in Alzheimer’s. One of these proteins—Apolipoprotein J, also known as clusterin—intrigues researchers because of the way it interacts with amyloid-beta and the status of its gene as a risk factor for Alzheimer’s. A researcher from the University of Minnesota, Ling Li, recently presented preliminary work at the Alzheimer’s Disease Drug Discovery Foundation annual meeting that showed that, at least in a lab dish, a molecule made up of a group of amino acids from APOJ is capable of protecting against the toxicity of the amyloid-beta peptide. It also quelled inflammation and promoted the health of synapses—the junctions where one brain cell encounters another. Earlier work by another group showed that the peptide prevented the development of lesions in the blood vessels of animals.

Keyword: Alzheimers
Link ID: 20135 - Posted: 09.30.2014

by Sarah Zielinski Small, silver fish called Mexican tetra (Astyanax mexicanus) live in some Texas and Mexican rivers. Some members of the species — eyeless and blind — can be found in nearby freshwater caves. Sometimes the sighted fish wash into a cave, but they don’t do nearly as well as their blind brethren. Any surface dweller unlucky enough to end up in the dark would have some disadvantages: It would have to adapt to the loss of light and forage for unfamiliar foods, which may be not as abundant as those found in their home waters. But the fish’s biggest disadvantage may be its metabolism. Blind cavefish have lost their circadian rhythms and have developed more efficient metabolisms than the fish that live in the light, researchers report September 24 in PLOS ONE. To measure tetras’ metabolism, Damian Moran and colleagues at Lund University in Sweden placed fish in a contraption that let the fish swim in place while the researchers tracked their oxygen consumption, a measure of their metabolism. Surface and cave fish were placed in the tank under constant darkness or 12-hour light-and-dark cycles for 7 or 8 days. Then the researchers compared how the fish did under the different light regimes. All the fish took a few days to acclimate to the laboratory conditions. In the light-and-dark conditions, surface fish showed a clear circadian pattern to their oxygen consumption. These fish ramped up their metabolism by about 20 percent during the day. That increase in metabolism would let them have more energy for their hunts and feeding, which take place in the light. © Society for Science & the Public 2000 - 2014

Keyword: Biological Rhythms
Link ID: 20134 - Posted: 09.30.2014

Christie Nicholson reports. Shakespeare called sleep the chief nourisher in life’s feast. But today we know it’s so much more. Insufficient sleep contributes to the risk of cardiovascular disease, diabetes and obesity. And now a study finds that too little or too much sleep are both associated with a significant increase in sick days away from work. Almost 4,000 men and women between 30 and 64 years old (in Finland) participated in the study, which followed them for seven years. The research revealed that the absence from work due to illness increased dramatically for those who said they slept less than 6 hours or more than 9 hours per night. The sleep time that was associated with the lowest number of sick days was 7 hours 38 minutes for women and 7 hours 46 minutes for men. The study is in the journal Sleep. [Tea Lallukka, Sleep and Sickness Absence: A Nationally Representative Register-Based Follow-Up Study] Of course these findings are associative and not necessarily causal. Other factors may be responsible for the under- or oversleeping to begin with. But sleep patterns are still a warning sign for increased illness and health complications. Shakespeare put it best: Sleep…that knits up the ravell’d sleave of care. © 2014 Scientific American

Keyword: Sleep
Link ID: 20133 - Posted: 09.30.2014

By Linda Carroll The debate over whether violent movies contribute to real-world mayhem may have just developed a wrinkle: New research suggests they might enhance aggression only in those already prone to it. Using PET scanners to peer into the brains of volunteers watching especially bloody movie scenes, researchers determined that the way a viewer’s brain circuitry responds to violent video depends upon whether the individual is aggressive by nature. The study was published Wednesday in PLOS One. “Just as beauty is in the eye of the beholder, environmental stimuli are in the brain of the beholder,” said Nelly Alia-Klein, the study’s lead author and an associate professor at the Friedman Brain Institute and the Icahn School of Medicine at Mount Sinai Hospital in New York City. To test the importance of personality, Alia-Klein and her colleagues rounded up 54 healthy men, some of whom had a history of getting into physical fights, while the others had no history of aggression. The researchers scanned the volunteers three times: doing nothing, watching emotionally charged video and viewing a violent movie. “It wasn’t the whole [violent] movie,” Alia-Klein said, “just the violent scenes, one after another after another.” Along with the brain scans, the researchers monitored blood pressure and asked about the viewers’ moods every 15 minutes.

Keyword: Aggression
Link ID: 20132 - Posted: 09.30.2014

By Dr Michael Mosley BBC Do you have a "male" or "female" brain? Are there really significant brain differences between the sexes and if so, do these differences matter? BBC Horizon investigates. When it comes to the tricky and explosive question of how much, if at all, male and female behaviour is driven by brain differences, Professor Alice Roberts and I sit on different sides of the fence. I believe that our brains, like our bodies, are shaped by exposure to hormones in the womb and this may help explain why males tend to do better at some tasks (3D rotation), while women tend to do better at others (empathy skills), although there is, of course, an awful lot of overlap and social pressure involved. Alice, on the other hand, thinks these differences are largely spurious, the result of how the tests are carried out. She worries that such claims may discourage girls from going into science. "We live in a country where fewer than three out of ten physics A levels are taken by girls, where just 7% of engineers are women" she points out, before adding "and where men still earn on average nearly 20% more than their female colleagues." So the BBC's Horizon programme asked us to go and explore the science, put forward research that would support our different views, but also look for common ground. BBC © 2014

Keyword: Sexual Behavior
Link ID: 20129 - Posted: 09.29.2014

Posted by James Owen in Weird & Wild Bigger males may get a lot of attention, but sometimes being smaller—and sneakier—is more successful when it comes to mating. In the East African cichlid fish, Lamprologus callipterus, males come in two sizes: giants or dwarves that are 40 times smaller than their beefier rivals. (Watch a video of male cichlid fish fighting.) It’s an example of male polymorphism, a phenomenon in which males of the same species take different forms. Though people vary in height, men don’t come in two different sizes like the cichlids. Several research studies suggest that tall men—those over 5’7″—are more successful in dating and in their careers—but they get divorced at higher rates. But the variation in L. callipterus, which are found only in Lake Tanganyika (map), is “the most extreme there is,” said Michael Taborsky, co-director of the Institute of Ecology and Evolution at the University of Bern, Switzerland. “It’s an enormous size difference.” In a new study, published September 17 in the Proceedings of the Royal Society B, Taborsky and his team linked this gulf in size to the female’s unusual habit of laying eggs in empty snail shells. To attract females, the giant males collect hundreds of these shells, using their mouths to create nesting sites. But while their hefty build is ideal for lugging about the heavy shells and chasing off rivals, the giants can’t access the chambers of their female harem, instead releasing their sperm outside the shell, Taborsky explained. (Also see “Small Squid Have Bigger Sperm—And Their Own Sex Position.”) © 1996-2013 National Geographic Societ

Keyword: Sexual Behavior
Link ID: 20127 - Posted: 09.29.2014

By Bec Crew Mike meet everyone, everyone meet Mike. No, no, don’t wave. He can’t see, you’re just making this awkward. Also known as Miracle Mike, Mike the Headless Chicken was a plump, five-year-old cockerel when he was unceremoniously beheaded on 10 September 1945. Farmer Lloyd Olsen of Fruita in Colorado did the deed because his wife Clara was having her mother over for dinner that night, and Olsen knew she’d always enjoyed a bit of roast chicken neck. With that in mind, Olsen tried to save most of Mike’s neck as he lopped his head off, but in doing so, he accidentally made his axe miss Mike’s jugular vein, plus one ear and most of his brain stem, and to his surprise, Mike didn’t die. In fact, Mike stuck around for a good 18 months without his head. Immediately after it happened, Mike reeled around like any headless chicken would, but soon settled down. He even started pecking at the ground for food with his newly minted stump, and made preening motions. His crows had become throaty gurglings. Olsen, bewildered, left him to it. The next morning, when Olsen found Mike asleep in the barn, having attempted to tuck his head under his wing as he always had, the farmer took it upon himself to figure out how to feed this unwitting monstrosity. Mike had earned that much. All Olsen had to do was deposit food and water into Mike’s exposed oesophagus via a little eyedropper. He even got small grains of corn sometimes as a treat. © 2014 Scientific American

Keyword: Miscellaneous
Link ID: 20126 - Posted: 09.29.2014

by Bethany Brookshire Isaac Newton famously showed that in physics, every action has an equal and opposite reaction. A similar push-and-pull of positive and negative inputs also exists in our brains. Brain cells can send out excitatory chemical signals, and they can also receive inhibitory chemical signals, putting the brakes on further signaling. This delicate balance of excitation and inhibition allows our brains to function normally and to react to the world around us. A new study shows that the same neurons contribute excitatory and inhibitory chemical signals in a brain area linked with how we process disappointment, and that antidepressants might be able to change this delicate molecular dance and stop some of the negative thought cycles associated with depression. But while the work finds an association, it’s not yet proof that the balance of these chemicals holds the key to relieving depressive symptoms. The study, published September 19 in Science, focuses on the lateral habenula. This tiny area makes up the “stalk” connecting the pineal gland to the rest of the brain. It receives inputs from areas of the brain important in reward and emotional processing, including the basal ganglia. Some areas of the brain appear to specialize in predicting rewards, showing increases in activity in response to enjoyable things such as food, sex or drugs. Activity in these areas lets us know when things are about to get good. But for every high there is a low. The lateral habenula is thought to play a role in how we process negative events: Getting a lemon on the slot machine again or the empty inbox on your dating site. Studies in monkeys and other animals have shown that increased activity in the habenula is linked to depressive behaviors, and treatment with antidepressants decreases this activity. In addition, a study in rats and a 2009 case study in a human patient showed that deep-brain stimulation in the lateral habenula could relieve symptoms of depression. © Society for Science & the Public 2000 - 2014.

Keyword: Depression
Link ID: 20125 - Posted: 09.27.2014

By ROBERT KOLKER Reggie Shaw is the man responsible for the most moving portion of “From One Second to the Next,” the director Werner Herzog’s excruciating (even by Werner Herzog standards) 35-minute public service announcement, released last year as part of AT&T’s “It Can Wait” campaign against texting and driving. In the film, Shaw, now in his 20s, recounts the rainy morning in September 2006 that he crossed the line of a Utah highway, knocking into a car containing two scientists, James Furfaro and Keith O’Dell, who were heading to work nearby. Both men were killed. Shaw says he was ­texting a girlfriend at the time, adding in unmistakable anguish that he can’t even ­remember what he was texting about. He is next seen taking part in something almost inconceivable: He enters the scene where one of the dead men’s daughters is being interviewed, and receives from that woman a warm, earnest, tearful, cathartic hug. Reggie Shaw’s redemptive journey — from thoughtless, inadvertent killer to denier of his own culpability to one of the nation’s most powerful spokesmen on the dangers of texting while behind the wheel — was first brought to national attention by Matt Richtel, a reporter for The New York Times, whose series of articles about distracted driving won a Pulitzer Prize in 2010. Now, five years later, in “A Deadly Wandering,” Richtel gives Shaw’s story the thorough, emotional treatment it is due, interweaving a detailed chronicle of the science behind distracted driving. As an instructive social parable, Richtel’s densely reported, at times forced yet compassionate and persuasive book deserves a spot next to “Fast Food Nation” and “To Kill a Mockingbird” in America’s high school curriculums. To say it may save lives is self-evident. What makes the deaths in this book so affecting is how ordinary they are. Two men get up in the morning. They get behind the wheel. A stranger loses track of his car. They crash. The two men die. The temptation is to make the tragedy bigger than it is, to invest it with meaning. Which may explain why Richtel wonders early on if Reggie Shaw lied about texting and driving at first because he was in denial, or because technology “can hijack the brain,” polluting his memory. © 2014 The New York Times Company

Keyword: Attention
Link ID: 20124 - Posted: 09.27.2014

By Rachel Feltman With the help of electrical stimulation, a paralyzed rat is "walking" again. It's actually being controlled by a computer that monitors its gait and adjusts it to keep the rat balanced. When a spinal cord is severed, the electrical pulses sent out by the brain to control limb movement are interrupted. With this method of treatment, the rat's leg movements are driven by electrical pulses shot directly into the spinal cord (which has unfortunately been severed in the name of science). Scientists have been working on this method in humans for awhile, but have only had moderate success — some subjects have regained sensation and movement in their legs, but haven't walked on their own. In the experiment described in the video above, published Wednesday in Science Translational Medicine, researchers tweaked this use of electrical stimulation: They primed the rats with a drug to boost their ability to respond to the electrical signal. Then, while the rats were placed in treadmill harnesses to support their weight, the researchers trained a camera on their subjects. The camera tracked the rats as they took electrically stimulated steps, and corrected their movement in real time. This instant feedback made the system precise enough to get the rats up tiny sets of stairs. MIT Technology Review reports that the team hopes to use a human volunteer within the next year. If the system works on humans, doctors can prescribe its use in rehabilitation therapy. You can watch the actual experiment in the video below:

Keyword: Regeneration; Aggression
Link ID: 20122 - Posted: 09.27.2014

by Helen Thomson My, what big eyes you have – you must be trying really hard. A study of how pupils dilate with physical effort could allow us to make strenuous tasks seem easier by zapping specific areas of the brain. We know pupils dilate with mental effort, when we think about a difficult maths problem, for example. To see if this was also true of physical exertion, Alexandre Zenon at the Catholic University of Louvain in Belgium, measured the pupils of 18 volunteers as they squeezed a device which reads grip strength. Sure enough, the more force they exerted, the larger their pupils. To see whether pupil size was related to actual or perceived effort, the volunteers were asked to squeeze the device with four different grip strengths. Various tests enabled the researchers to tell how much effort participants felt they used, from none at all to the most effort possible. Comparing the results from both sets of experiments suggested that pupil dilation correlated more closely with perceived effort than actual effort. The fact that both mental effort and perceived physical effort are reflected in pupil size suggests there is a common representation of effort in the brain, says Zenon. To see where in the brain this might be, the team looked at which areas were active while similar grip tasks were being performed. Zenon says they were able to identify areas within the supplementary motor cortex – which plays a role in movement – associated with how effortful a task is perceived to be. © Copyright Reed Business Information Ltd.

Keyword: Attention
Link ID: 20121 - Posted: 09.27.2014

By Roni Caryn Rabin When I was in college, my father David started walking with an odd, barely perceptible limp. He was in his mid-40s, a gregarious physician, teacher and researcher who was always upbeat. He told his four kids that he had a “back problem” — a deliberately vague cover story that I, for one, was willing to believe. I had never heard of the real culprit — amyotrophic lateral sclerosis, or A.L.S. In fact, no one had. A.L.S. was a disease in the shadows. During my father’s life, it didn’t even have its own advocacy organization. This was the early ’80s, long before support groups and the Internet and a colored ribbon for every cause. And it was way before ice bucket challenges. My parents continued to use their code — “back problem” — to talk about the disease. They used it to protect my younger sisters, who were about to start high school, but I think they were also protecting themselves. My mother was also a physician, and they both knew exactly what lay ahead. Saying “A.L.S.” out loud was too threatening. But soon there was no getting around it. My father’s legs were getting weaker, his muscles were wasting, and he started relying on a cane to get around. I was 19, and my mother and I were out running errands one afternoon when she pulled the car over to the curb and stopped. She told me the truth. This was no slipped disc. She laid it all out for me in black and white: A.L.S. is a progressive, degenerative neurological disease that causes paralysis in the entire body. It’s fatal. There is no cure. It sounded like something from a horror movie. Over the next five years, as my father’s health deteriorated, he remained remarkably determined. He ate a high-protein diet and swam laps every day in an attempt to maintain his muscle and fend off the atrophy caused by the disease. He kept on swimming laps in our next-door neighbor’s pool, even when he had to use a walker — and later a wheelchair — to get there. © 2014 The New York Times Company

Keyword: ALS-Lou Gehrig's Disease
Link ID: 20120 - Posted: 09.27.2014