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Carl Zimmer Certain people, researchers have discovered, can’t summon up mental images — it’s as if their mind’s eye is blind. This month in the journal Cortex, the condition received a name: aphantasia, based on the Greek word phantasia, which Aristotle used to describe the power that presents visual imagery to our minds. I find research like this irresistible. It coaxes me to think about ways to experience life that are radically different from my own, and it offer clues to how the mind works. And in this instance, I played a small part in the discovery. In 2005, a 65-year-old retired building inspector paid a visit to the neurologist Adam Zeman at the University of Exeter Medical School. After a minor surgical procedure, the man — whom Dr. Zeman and his colleagues refer to as MX — suddenly realized he could no longer conjure images in his mind. Dr. Zeman couldn’t find any description of such a condition in medical literature. But he found MX’s case intriguing. For decades, scientists had debated how the mind’s eye works, and how much we rely on it to store memories and to make plans for the future. MX agreed to a series of examinations. He proved to have a good memory for a man of his age, and he performed well on problem-solving tests. His only unusual mental feature was an inability to see mental images. Dr. Zeman and his colleagues then scanned MX’s brain as he performed certain tasks. First, MX looked at faces of famous people and named them. The scientists found that certain regions of his brain became active, the same ones that become active in other people who look at faces. © 2015 The New York Times Company

Keyword: Consciousness
Link ID: 21085 - Posted: 06.23.2015

Skinny jeans can seriously damage muscles and nerves, doctors have said. A 35-year-old woman had to be cut out of a pair after her calves ballooned in size, the medics said in the Journal of Neurology, Neurosurgery and Psychiatry. She had spent hours squatting to empty cupboards for a house move in Australia. By evening, her feet were numb and she found it hard to walk. Doctors believe the woman developed a condition called compartment syndrome, made worse by her skinny jeans. Compartment syndrome is a painful and potentially serious condition caused by bleeding or swelling within an enclosed bundle of muscles - in this case, the calves. The condition caused the woman to trip and fall and, unable to get up, she then spent several hours lying on the ground. On examination at the Royal Adelaide Hospital, her lower legs were severely swollen. Although her feet were warm and had enough blood supplying them, her muscles were weak and she had lost some feeling. As the pressure had built in her lower legs, her muscles and nerves became damaged. She was put on an intravenous drip and after four days was able to walk unaided. Other medics have reported a number of cases where patients have developed tingly, numb thighs from wearing the figure-hugging low-cut denim trousers - although the chance of it happening is still slim for most people. Priya Dasoju, professional adviser at the Chartered Society of Physiotherapy, said: "As with many of these warnings, the very unfortunate case highlighted is an extreme one. © 2015 BBC

Keyword: Movement Disorders
Link ID: 21084 - Posted: 06.23.2015

By Amanda Montañez As someone who works at the intersection of art and science, I have always found it easy to make the case that all artists are scientists. From the moment we pick up a crayon and make our first mark, we are experimenting. The perceived successes and failures of our craft are indelibly tied to the many variables—physical, chemical and psychological—inherent in the experiences of creating and consuming works of art. Yet, it seems a longer stretch, somehow, to argue that all scientists are artists. At the very least, in my experience, scientists seem less willing to claim this alternate title. In fact, almost anyone who does not see her or himself as artistically inclined tends to be a little too quick to proclaim, “Oh, I’m not an artist. I can’t even draw a straight line!” With a sigh, I’ll avoid the temptation to digress into the utter irrelevance of straight lines and one’s ability to draw them. Instead, I’d like to posit the idea that, while we may not all identify as artists, scientists, of all people, really should be artists. Throughout history, much of scientific discovery and advancement has hinged not just on our ability to see certain things, but also on our capacity to reproduce what we see in faithful, critical and/or meaningful ways. The drawings of the famous Spanish neuroscientist Santiago Ramón y Cajal provide an ideal example of this phenomenon. In the late 1800s, using a novel histological staining technique developed by Italian physician Camillo Golgi, Ramón y Cajal spent countless hours examining brain tissues under the microscope and recording what he saw in pen and ink.

Keyword: Brain imaging
Link ID: 21083 - Posted: 06.23.2015

By Nicholas Bakalar Exposure to air pollution may hasten brain aging, a new study has found. Researchers studied 1,403 women without dementia who were initially enrolled in a large health study from 1996 to 1998. They measured their brain volume with M.R.I. scans in 2005 and 2006, when the women were 71 to 89 years old. Using residential histories and air pollution data, they estimated their exposure to air pollution from 1999 to 2006. They used data recorded at monitoring sites on exposure to PM 2.5 — tiny particulate matter that easily penetrates the lungs. Each increase of 3.49 micrograms per cubic centimeter cumulative exposure to pollutants was associated with a 6.23 cubic centimeter decrease in white matter, the equivalent of one to two years of brain aging. The association remained after adjusting for many variables, including age, smoking, physical activity, blood pressure, body mass index, education and income. Previous studies have shown that air pollution can cause inflammation and damage to the vascular system, but this study, in The Annals of Neurology, showed damage to the brain itself. “This tells us that the damage air pollution can impart goes beyond the circulatory system,” said the lead author, Dr. Jiu-Chiuan Chen, an associate professor of preventive medicine at the Keck School of Medicine at the University of Southern California. “Particles in the ambient air are an environmental neurotoxin to the aging brain.” © 2015 The New York Times Company

Keyword: Neurotoxins; Development of the Brain
Link ID: 21082 - Posted: 06.23.2015

By THE ASSOCIATED PRESS NEW HAVEN, Connecticut — To the untrained eye, it looked like a seismograph recording of a violent earthquake or the gyrations of a very volatile day on Wall Street — jagged peaks and valleys in red, blue and green, displayed on a wall. But the story it told was not about geology or economics. It was a glimpse into the brains of Shaul Yahil and Shaw Bronner, two researchers at a Yale lab, as they had a little chat. "This is a fork," Yahil observed, describing the image on his computer. "A fork is something you use to stab food while you're eating it. Common piece of cutlery in the West." "It doesn't look like a real fancy sterling silver fork, but very useful," Bronner responded. And then she described her own screen: "This looks like a baby chimpanzee ..." The jagged, multicolored images depicted what was going on in the two researchers' heads — two brains in conversation, carrying out an intricate dance of internal activity. This is no parlor trick. The brain-tracking technology at work is just a small part of the quest to answer abiding questions about the workings of a three-pound chunk of fatty tissue with the consistency of cold porridge. How does this collection of nearly 100 billion densely packed nerve cells, acting through circuits with maybe 100 trillion connections, let us think, feel, act and perceive our world? How does this complex machine go wrong and make people depressed, or delusional, or demented? What can be done about that? These are the kinds of questions that spurred President Barack Obama to launch the BRAIN initiative in 2013. Its aim: to spur development of new tools to investigate the brain. Europe and Japan are also pursuing major efforts in brain research. © 2015 The New York Times Company

Keyword: Brain imaging
Link ID: 21081 - Posted: 06.22.2015

Patricia Neighmond We all know that listening to music can soothe emotional pain, but Taylor Swift, Jay-Z and Alicia Keys can also ease physical pain, according to a study of children and teenagers who had major surgery. The analgesic effects of music are well known, but most of the studies have been done with adults and most of the music has been classical. Now a recent study finds that children who choose their own music or audiobook to listen to after major surgery experience less pain. The catalyst for the research was a very personal experience. Sunitha Suresh was a college student when her grandmother had major surgery and was put in intensive care with three other patients. This meant her family couldn't always be with her. So they decided to put her favorite south Indian classical Carnatic music on an iPod, so she could listen around the clock. It was very calming, Sunitha says. "She knew that someone who loved her had left that music for her and she was in a familiar place." This may be the most efficient way to get in shape, but it may also be the least fun. Suresh could see the music relaxed her grandmother and made her feel less anxious, but she wondered if she also felt less pain. That would make sense, because anxiety can make people more vulnerable to pain. At the time Suresh was majoring in biomedical engineering with a minor in music cognition at Northwestern University where her father, Santhanam Suresh, is a professor of anesthesiology and pediatrics. © 2015 NPR

Keyword: Pain & Touch
Link ID: 21080 - Posted: 06.22.2015

Children who have a good memory are better at telling lies, say child psychology researchers. They tested six and seven-year-olds who were given an opportunity to cheat in a trivia game and then lie about their actions. Children who were good liars performed better in tests of verbal memory - the number of words they could remember. This means they are good at juggling lots of information, even if they do tell the odd fib. Writing in the Journal of Experimental Child Psychology, researchers from the Universities of North Florida, Sheffield and Stirling, recruited 114 children from four British schools for their experiment. Using hidden cameras during a question-and-answer game, they were able to identify the children who peeked at the answer to a fictitious question, even though they were told not to. A potentially surprising finding (for parents) is that only a quarter of the children cheated by looking at the answer. Further questioning allowed the researchers to work out who was a good liar or a bad liar. They were particularly interested in children's ability to maintain a good cover story for their lie. In separate memory tests, the good liars showed they had a better working memory for words - but they didn't show any evidence of being better at remembering pictures (visuo-spatial memory). The researchers said this was because lying involves keeping track of lots of verbal information, whereas keeping track of images is less important. © 2015 BBC

Keyword: Learning & Memory; Development of the Brain
Link ID: 21079 - Posted: 06.22.2015

by Kate Solomon Jean-Dominique Bauby famously wrote The Diving Bell and The Butterfly by blinking as an assistant read out the alphabet, but locked-in patients could soon have a much easier way to communicate. For the first time, scientists have successfully transcribed brainwaves as text, which could mean that those unable to speak could use the system to "talk" via a computer. Carried out by a group of informatics, neuroscience and medical researchers at Albany Medical Centre, the team managed to identify the brainwaves relating to speech by using electrocorticographic (ECoG) technology to monitor the frontal and temporal lobes of seven epileptic volunteers. This involves using needles to record signals directly from a person's neurons; it's an invasive procedure requiring an incision through the skull. The participants then read aloud from a sample text while machine learning algorithms pulled out the most likely word sequence from the signals recorded by the EcOG. Existing speech-to-text tools then transcribed the continuously spoken speech directly from the brain activity. Error rates were as low as 25 percent during the study, which means the potential for the system is pretty vast. The findings could offer locked-in and mute patients a valuable communication method but it also means humans could one day communicate directly with a computer without needing any intermediary equipment.

Keyword: Brain imaging; Language
Link ID: 21078 - Posted: 06.20.2015

By Mitch Leslie After years of fasting, the Buddha’s “legs were like bamboo sticks, his backbone was like a rope, his chest was like an incomplete roof of a house, his eyes sank right inside, like stones in a deep well,” according to one account. The Buddha didn’t get what he wanted from this extreme fasting—enlightenment—but a new study suggests that a diet that replicates some effects of milder deprivation may not only lower your weight but also confer other benefits. Researchers report that following the diet for just 5 days a month improves several measures of health, including reducing the risk of developing cardiovascular disease. Eating shortens life, and not just because overindulgence can lead to diseases such as diabetes. A diet that cuts food intake by up to 40%, known as calorie restriction, increases longevity in a variety of organisms and forestalls cancer, heart disease, and other late-life illnesses. Although some short-term studies suggest that calorie restriction provides metabolic benefits to people, nobody has confirmed that it also increases human life span. The closest researchers have come are two large, long-term studies of monkeys, and they conflict about whether meager rations increase longevity. Even if calorie restriction could add years to our lives, almost no one can muster the willpower to eat so little day after day, year after year. An alternative that might be more, er, palatable is fasting, the temporary abstinence from food. Gerontological researcher Valter Longo of the University of Southern California in Los Angeles and colleagues have shown that fasting eases side effects of chemotherapy such as fatigue and weakness, and animal studies suggest that it produces health advantages similar to calorie restriction. © 2015 American Association for the Advancement of Science.

Keyword: Obesity
Link ID: 21077 - Posted: 06.20.2015

By Tina Rosenberg Elle is a mess. She’s actually talented, attractive and good at her job, but she feels like a fraud — convinced that today’s the day she’ll flunk a test, lose a job, mess up a relationship. Her colleague Moody also sabotages himself. He’s a hardworking, nice person, but loses friends because he’s grumpy, oversensitive and gets angry for no reason. If you suffer from depression or anxiety as Elle and Moody do, spending time with them could help. They are characters in a free online program of cognitive behavioral therapy called MoodGYM, which leads users through quizzes and exercises — therapy without the therapist. Cognitive behavioral therapy is a commonly used treatment for depression, anxiety and other conditions. With it, the therapist doesn’t ask you about your mother — or look at the past at all. Instead, a cognitive behavioral therapist aims to give patients the skills to manage their moods by helping them identify unhelpful thoughts like “I’m worthless,” “I’ll always fail” or “people will always let me down.” Patients learn to analyze them and replace them with constructive thoughts that are more accurate or precise. For example, a patient could replace “I fail at everything” with “I succeed at things when I’m motivated and I try hard.” That new thought in turn changes feelings and behaviors. The success of cognitive behavioral therapy is well known; many people consider it the most effective therapy for depression. What is not widely known, at least in the United States, is that you don’t need a therapist to do it. Scores of studies have found that online C.B.T. works as well as conventional face-to-face cognitive behavioral therapy – as long a there is occasional human support or coaching. “For common mental disorders like anxiety and depression, there is no evidence Internet-based treatment is less effective than face-to-face therapy,” said Pim Cuijpers, professor of clinical psychology at the Vrije Universiteit Amsterdam and a leading researcher on computer C.B.T. © 2015 The New York Times Company

Keyword: Depression
Link ID: 21076 - Posted: 06.20.2015

by Sarah Zielinski Last year in Australia, I visited Featherdale Wildlife Park where, in a couple of areas, kangaroos and wallabies hop amongst the tourists. For a dollar, you can buy an ice cream cone full of grass for the marsupials to eat. But if you’re not careful, an animal will quickly grab the cone out of your hand and feed itself. Now I’m wishing that I had paid more attention to that grabbing motion. Kangaroos are lefties, scientists report June 18 in Current Biology. And the preference for one hand over the other may be linked to the ability to walk on two legs. Humans show a definite preference for one hand over the other, usually the right. This handedness had been considered a distinctly human trait. But scientists have found more and more evidence that other species have such preferences as well. Female domestic cats, for instance, tend to use their right paws and males their left. Andrey Giljov of Saint Petersburg State University in Russia and colleagues were curious about the evolution of handedness and looked to marsupials, since these animals are an early offshoot of the mammal lineage. They observed four species in the wild — red kangaroos, eastern gray kangaroos, red-necked wallabies and Goodfellow’s tree kangaroos — performing tasks such as grooming and feeding. © Society for Science & the Public 2000 - 2015.

Keyword: Laterality
Link ID: 21075 - Posted: 06.20.2015

by Bob Holmes Lions might be one of the biggest threats to hyenas, but that doesn't stop the smaller animals teaming up to steal from the big cats. Nora Lewin from Michigan State University in East Lansing and her colleagues observed the mobbing behaviour at the Masai Mara National Reserve in Kenya. Hyenas were also spotted banding together to keep lions away from their dens. The mobbing involves a surprising degree of cooperation and communication. Male lions, which actively pursue and kill hyenas, are much more of a danger than females, who usually just make threats. This could be why the hyenas in the video above are confronting females. The team suggests the hyenas can identify their opponent's age and sex before deciding as a group whether or not to mob it. Levin and her colleagues are now investigating how the hyenas communicate to make a group decision. The findings were reported on 13 June at the annual meeting of the Animal Behavior Society in Anchorage, Alaska. © Copyright Reed Business Information Ltd.

Keyword: Attention; Evolution
Link ID: 21074 - Posted: 06.20.2015

Helen Shen Boosting activity in neurons that have stored happy memories might help to treat depression — at least according to results in mice. In a study published today (17 June) in Nature, neuroscientist Susumu Tonegawa and his colleagues at the Massachusetts Institute of Technology in Cambridge report how they reversed a depression-like state in rodents by using light to stimulate clusters of brain cells believed to have stored memories of a positive experience1. The findings are preliminary, but they hint that areas of the brain involved in storing memories could one day be a target to treat mental disorders in humans, says Tonegawa. “I want to be very careful not to give false expectations to patients. We are doing very basic science,” he adds. “This is exactly the type of work that psychiatry needs right now,” says Robert Malenka, a behavioural scientist at Stanford University in California. “This is an elegant paper.” The work has grown out of studies by Tonegawa’s lab and others that aimed to locate the memory ‘engram’ — the physical trace of a memory, thought to be encoded in an ensemble of neurons2–6. In 2012, Tonegawa and his team provided one of the clearest demonstrations of an engram. They engineered mice with light-sensitive proteins that were expressed when neurons fired. As a result, they could track any neurons that activated while the mice were given a fearful memory by being trained with repeated electric shocks to be scared of a cage3. The researchers later used blue flashes of light to make the same neurons fire again — a technique known as optogenetics — and found that they could make the animals freeze up, presumably because the fearful memory had been reawoken. © 2015 Nature Publishing Group

Keyword: Learning & Memory; Depression
Link ID: 21073 - Posted: 06.18.2015

Bill Chappell In what researchers say is a first, they've discovered the neuron in worms that detects Earth's magnetic field. Animals have been known to sense the magnetic field; a new study identifies the microscopic, antenna-shaped sensor that helps worms orient themselves underground. The sensory neuron that the worm C. elegans uses to migrate up or down through the soil could be similar to what many other animals use, according to the team of scientists and engineers at The University of Texas at Austin. The team's work was published Wednesday by eLife. In contrast to previous breakthroughs — such as a 2012 study on how pigeons' brains use information about magnetic fields, and another from the same year on olfactory cells in trout — the new work identifies the sensory neuron that detects magnetic fields. "We also found the first hint at a novel sensory mechanism for detecting the magnetic field," says Jon Pierce-Shimomura, an assistant professor of neuroscience who worked on the study. "Now researchers can check to see if this is used in other animals too." The list of animals that could be studied for their use of magnetic fields is long — and it seems to grow each year. In early 2014, for instance, a study found that dogs who need to relieve themselves of waste prefer to align themselves on a north-south axis when the magnetic conditions are right. Pierce-Shimomura says his team was surprised to make a new breakthrough in magnetism by looking at worms, which aren't known for their sophisticated migrations. © 2015 NPR

Keyword: Pain & Touch
Link ID: 21072 - Posted: 06.18.2015

by Curtis Abraham A step forward for equal LGBT rights in Africa. Last week, the influential Academy of Science of South Africa (ASSAf) published a study on the science of human sexual diversity. A comprehensive review of recent scientific papers on the subject, it concluded that sexual behaviour is naturally varied, and discrimination unjustified. It stated that there is no evidence that orientation can be altered by therapy or that being gay is contagious. The report also sets straight the idea that homosexuality is a Western malaise: "There is no basis for the view that homosexuality is 'un-African' either in the sense of it being a 'colonial import', or on the basis that prevalence of people with same-sex or bisexual orientations is any different in African countries compared to countries on any other continent." Going further, the report asserted not only that tolerance of sexual diversity benefits communities but it positively affects public health, civil society and long-term economic growth. Zero tolerance Launched at the Seventh South African AIDS Conference in Durban, the study comes a year after the Ugandan government passed a law imposing a life sentence on anyone who has sexual relations with someone of the same sex. Other countries, including Burundi, Cameroon and Nigeria, then passed similar anti-gay laws. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior
Link ID: 21071 - Posted: 06.18.2015

Maanvi Singh Teenagers aren't exactly known for their responsible decision making. But some young people are especially prone to making rash, risky decisions about sex, drugs and alcohol. Individual differences in the brain's working memory — which allows people to draw on and use information to make decisions — could help explain why some adolescents are especially impulsive when it comes to sex, according to a study published Wednesday in Child Development. "Working memory is the ability to keep different things in mind when you're making decisions or problem solving," explains Atika Khurana, an assistant professor of counseling psychology at the University of Oregon who led the study. Khurana and her colleagues rounded up 360 adolescents, ages 12 to 15, and assessed their working memory using a series of tests. For example, the researchers told the participants a string of random numbers and asked them to repeat what they heard in reverse order. "We basically tested their ability to keep information in mind while making decisions," Khurana says. The researchers then tracked all the participants for two years, and asked about the teens' sexual activity. And through another series of tests and surveys, the researcher tried to gauge how likely each teen was to act without thinking, to make rash decisions and take risks. There was a correlation between weaker working memory and the likelihood that a teen would have sex — including unprotected sex — at a younger age. And they were more likely to act without much deliberation. That trend held true even after the researchers accounted for the teenagers' age, socioeconomic status and gender. © 2015 NPR

Keyword: Development of the Brain; Learning & Memory
Link ID: 21070 - Posted: 06.18.2015

By Nicholas Bakalar A new study has found a simple way to significantly reduce teenage smoking: raise the tobacco sales age to 21. In 2005, Needham, Mass., did just that, while surrounding communities kept their age limit at 18. Researchers surveyed 16,000 high school students in Needham and 16 surrounding communities four times between 2006 and 2012, gathering data on their smoking habits. The study is in Tobacco Control. Over the seven years, the number of children under 18 buying cigarettes in Needham decreased to 11.6 percent from 18.4 percent, while in the surrounding communities it hardly changed — down to 19 percent from 19.4. In 2006, 12.9 percent of students in Needham and 14.8 percent of students in surrounding communities reported having smoked in the past 30 days. By 2010, 6.7 percent of Needham students reported smoking, compared with 12 percent in other towns. At the end of the study in 2012, smoking had declined to 5.5 percent in Needham and 8.5 percent outside. “More than 80 percent of smokers begin before 18,” said the lead author, Shari Kessel Schneider, project director at the Education Development Center in Waltham, Mass. “Our findings provide strong support for initiatives going on all across the country to increase the sales age as a means for decreasing youth access to cigarettes, initiation of smoking, and ultimately addiction.” © 2015 The New York Times Company

Keyword: Drug Abuse; Development of the Brain
Link ID: 21069 - Posted: 06.18.2015

By Greg Toppo On the morning of August 12, 2013, nearly eight months after 20-year-old Adam Lanza shot his way into Sandy Hook Elementary School in Newtown, Conn., and killed 26 people, Michael Mudry, an investigator with the Connecticut State Police, drove to nearby Danbury to try to solve a little mystery. Police had found a Garmin GPS unit in Lanza's house, and its records showed that the gunman had driven to the same spot nine times in April, May and June 2012, arriving around midnight each time and staying for hours. The GPS readout took Mudry to the vast parking lot of a suburban shopping center, about 14 miles west of Lanza's home. Workers at a movie theater there immediately recognized Lanza from a photograph. He was at the theater constantly, they told Mudry, but never to see movies. He came to the lobby to play an arcade game, the same one, over and over again, sometimes for eight to 10 hours a night. Witnesses said he would whip himself into a frenzy, and on occasion the theater manager had to unplug the game to get him to leave. Police had been scouring Lanza's home since the shootings, and on his computer hard drive they found information on weapons magazine capacities, images of Columbine killers Eric Harris and Dylan Klebold, copies of the violent movies Bloody Wednesday and Rampage, and a list of ingredients for TNT. And like many teenaged boys, Lanza owned the typical first-person shooter, fighting and action games: Call of Duty, Dead or Alive, Grand Theft Auto. © 2015 Scientific American,

Keyword: Aggression
Link ID: 21068 - Posted: 06.18.2015

Tom Bawden The mystery behind the nightingale’s beautiful song has been revealed, with scientists finding that male birds sing complex notes to prove to females that they would be a good father to their children. Nightingales use their songs to advertise their family values, according to new research which discovers that the better the singer, the more support they are likely to offer their young family by feeding and defending them from predators. But while the beauty comes from the complexity of the song, the effect it has on the females is based on something far more mundane – the amount of effort the singer has put into his performance. Researchers at the Freie Universitat Berlin found that complicated choral arrangements are much harder to sing, especially when they include frequent appearances of long buzzing sounds and require the bird to be in good physical condition. “We don’t think the female is concerned with the beauty of the song but rather the information encoded in the song that tells her about the singer’s characteristics – his age, where he was raised, the strength of his immune system and how motivated he is to contribute to bringing up the young,” Professor Silke Kipper, one of the report’s authors, told The Independent. “The songs can also be a good indication of the bird’s ability to learn, which is another important characteristic of a good parent.” © independent.co.uk

Keyword: Sexual Behavior; Hearing
Link ID: 21067 - Posted: 06.18.2015

By Andrea Alfano There are many types of touch. A cold splash of water, the tug of a strong breeze or the heat and heft of your coffee mug will each play on your skin in a different way. Within your skin is an array of touch sensors, each associated with nerve fibers that connect to the central nervous system. These sensors comprise specialized nerve endings and skin cells. Along with the fibers, they translate our physical interactions with the world into electrical signals that our brain can process. They help to bridge the gap between the physical act of touching and the cognitive awareness of tactile sensation. Even a simple stroke across the forearm engages several distinct nerve fibers. Three types—A-beta, A-delta and C fibers—have subtypes that are specialized for sensing particular types of touch; other subtypes carry information related to pain. The integration of information from these fibers is what allows us to gain such rich sensory experiences through our skin, but it has also made it more challenging for researchers to understand the fibers’ individual roles. Although these fibers do not act in isolation, the examples that follow highlight the primary nerve fibers engaged by different types of touch. © 2015 Scientific American

Keyword: Pain & Touch
Link ID: 21066 - Posted: 06.18.2015