Chapter 5. The Sensorimotor System
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By NICHOLAS BAKALAR Black and Hispanic children who go to an emergency room with stomach pain are less likely than white children to receive pain medication, a new study reports, and more likely to spend long hours in the emergency room. The analysis, published in the October issue of Pediatrics, examined the records of 2,298 emergency room visits by people under 21, a nationally representative sample from a large survey conducted by the Centers for Disease Control and Prevention. About 53 percent were white, 24 percent non-Hispanic black, 21 percent Hispanic, and the rest from other ethnic or racial groups. Over all, 27.1 percent of white children with severe pain received analgesics, but only 15.8 percent of blacks, 18.9 percent of Hispanics and 7.1 percent of children of other races did. Black children were about 68 percent more likely than white children to spend longer than six hours in the emergency room, although there were no statistically significant differences among races in results for any diagnostic test. “This data set will not answer the question of why,” said the lead author, Dr. Tiffani J. Johnson, an instructor at the University of Pennsylvania School of Medicine. “It could be that white parents are more likely to ask for pain meds, or that minority patients are likely to get care in E.R.’s that have longer wait times. And it could be racial bias.” Copyright 2013 The New York Times Company
Erika Check Hayden The power of thought alone is not enough to move inanimate objects — unless the object is a robotic leg wired to your brain, that is. A 32-year-old man whose knee and lower leg were amputated in 2009 after a motorcycle accident is apparently the first person with a missing lower limb to control a robotic leg with his mind. A team led by biomedical engineer Levi Hargrove at the Rehabilitation Institute of Chicago in Illinois reported the breakthrough last week in the New England Journal of Medicine1, including a video that shows the man using the bionic leg to walk up stairs and down a ramp, and to kick a football. The major advance is that the man does not have to use a remote-control switch or exaggerated muscle movements to tell the robotic leg to switch between types of movements, and he does not have to reposition the leg with his hands when seated, Hargrove says. “To our knowledge, this is the first time that neural signals have been used to control both a motorized knee and ankle prosthesis,” he says. Scientists had previously shown that paralysed people could move robotic arms using their thoughts and that able-bodied people can walk using robotic legs controlled by their brains (see, for example, go.nature.com/dgtykw). The latest work goes a step further by using muscle signals to amplify messages sent by the brain when the person intends to move. © 2013 Nature Publishing Group
Link ID: 18725 - Posted: 10.01.2013
The Conservative government is launching a $1.3-billion free market in medical marijuana on Tuesday, eventually providing an expected 450,000 Canadians with quality weed. Health Canada is phasing out an older system on Monday that mostly relied on small-scale, homegrown medical marijuana of varying quality, often diverted illegally to the black market. In its place, large indoor marijuana farms certified by the RCMP and health inspectors will produce, package and distribute a range of standardized weed, all of it sold for whatever price the market will bear. The first sales are expected in the next few weeks, delivered directly by secure courier. "We're fairly confident that we'll have a healthy commercial industry in time," Sophie Galarneau, a senior official with the department, said in an interview. "It's a whole other ball game." The sanctioned birth of large-scale, free-market marijuana production comes as the Conservatives pillory Liberal Leader Justin Trudeau's campaign to legalize recreational marijuana. Health Canada is placing no limits on the number of these new capital-intensive facilities, which will have mandatory vaults and security systems. Private-dwelling production will be banned. Imports from places such as the Netherlands will be allowed. Already 156 firms have applied for lucrative producer and distributor status since June, with the first two receiving licences just last week. © CBC 2013
Ballet dancers develop differences in their brain structures to allow them to perform pirouettes without feeling dizzy, a study has found. A team from Imperial College London said dancers appear to suppress signals from the inner ear to the brain. Dancers traditionally use a technique called "spotting", which minimises head movement. The researchers say their findings may help patients who experience chronic dizziness. Dizziness is the feeling of movement when, in reality, you are still. For most it is an occasional, temporary sensation. But around one person in four experiences chronic dizziness at some point in their life. When someone turns or spins around rapidly, fluid in the vestibular organs of the inner ear can be felt moving through tiny hairs. Once they stop, the fluid continues to move, which can make a person feel like they are still spinning. Ballet dancers train hard to be able to spin, or pirouette, rapidly and repeatedly. They use a technique called spotting, focusing on a spot on the floor - as they spin, their head should be the last bit to move and the first to come back. In the study, published in the journal Cerebral Cortex, the team recruited 29 female ballet dancers and 20 female rowers of similar age and fitness levels. BBC © 2013
Link ID: 18709 - Posted: 09.28.2013
By Todd Sherer Parkinson’s disease is coming to prime time. Tomorrow night Michael J. Fox returns to television as the star of his own sitcom nearly 15 years after retiring from Spin City to focus on finding a cure for his disease. Michael has been careful to emphasize that the show isn’t really about Parkinson’s. Based loosely on his real life, The Michael J. Fox Show mines laughs from the everyday trials and tribulations of family man Mike Henry as he resumes his TV news job following a Parkinson’s diagnosis. Yet simply by featuring a main character living with the disease, the show puts Parkinson’s into the national conversation. This is a good moment to consider how much work remains to be done in the realm of neurodegeneration research. The question we’ve heard most often at The Michael J. Fox Foundation is: After more than 20 years with Parkinson’s, how is Michael doing well enough to go back to work? There’s no simple answer. He acknowledges the good fortune he has in a loving, supportive family and financial independence, which have provided advantages in dealing with his disease. He says, “Everybody gets their own version of Parkinson’s. Different meds work for different people, and you’re always trying to find the perfect combination. I think I found what works for me right now. And I’m so lucky.” But the reality is that for the estimated five million Parkinson’s patients worldwide, the status quo is still not good enough. They are living with Parkinson’s movement difficulties and nonmotor symptoms such as mood and sleep disorders as well as cognitive impairment. Medication and therapies alleviate some symptoms, but create their own problems and fail to address all the effects of Parkinson’s. We have some disease-modifying treatments in clinical trials, but nothing on the market yet. The grim truth is that those diagnosed with Parkinson’s will get worse. And for every patient, a community is affected, as the impact of the disease ripples to loved ones and caregivers. This is a global problem, but one that we can solve. © 2013 Scientific American
Link ID: 18708 - Posted: 09.26.2013
by Colin Barras A man missing his lower leg has gained precise control over a prosthetic limb, just by thinking about moving it – all because his unused nerves were preserved during the amputation and rerouted to his thigh where they can be used to communicate with a robotic leg. The man can now seamlessly switch from walking on level ground to climbing stairs and can even kick a football around. During a traditional limb amputation, the main sensory nerves are severed and lose their function. In 2006, Todd Kuiken and his colleagues at the Rehabilitation Institute of Chicago in Illinois realised they could preserve some of that functionality by carefully rerouting sensory nerves during an amputation and attaching them to another part of the body. They could then use the rerouted nerve signals to control a robotic limb, allowing a person to control their prosthesis with the same nerves they originally used to control their real limb. Kuiken's team first attempted the procedure – which is called targeted muscle reinnervation (TMR) – on people who were having their arm amputated. Now, Kuiken's team has performed TMR for the first time on a man with a leg amputation. First, the team rerouted the two main branches of the man's sciatic nerve to muscles in the thigh above the amputation. One branch controls the calf and some foot muscles, the other controls the muscle running down the outside leg and some more foot muscles. © Copyright Reed Business Information Ltd
Link ID: 18707 - Posted: 09.26.2013
by Michael Slezak How do you convince someone that a finger they can't see or feel – one they don't even know is there – is actually part of their body? Turns out it's all in the wrist. The technique is a spin on the rubber hand illusion, developed almost 15 years ago. To perform the original trick, sit someone at a table and somehow hide one of their hands from their view. Then put a corresponding rubber hand on the table in front of them and stroke it while also stroking the real hand unseen. Bizarrely, they will often feel that the rubber hand is their own. Besides being a cool party trick, this illusion revealed a novel insight into how the brain develops its sense of "owning" body parts. It quickly led to treatments for conditions in which that sense is disrupted, such as phantom limb syndrome. Since then, the illusion has been tested thoroughly to find exactly what is needed for it to occur. We now know that the trick works using a rubber hand with a different colour skin to the participant and even without a rubber hand at all. You can do it just by making a person think you're going to stroke their hand. It's even been done in virtual reality. The theory emerging from these experiments is that if two different senses – like sight and touch – both suggest a rubber hand is yours, then your brain is convinced. © Copyright Reed Business Information Ltd.
Keyword: Pain & Touch
Link ID: 18700 - Posted: 09.25.2013
By Ingrid Wickelgren An attractive blonde in a bright red blouse sits in a wheelchair before the assembled scientists, doctors, writers and members of the community. We are in a conference room at the Aspen Meadows Resort, the site of the 2013 Aspen Brain Forum. Amanda Boxtel recalls what life was like for her at 24. She had been a skier, a runner and a ballet dancer, she tells us. She liked to hike in the wilderness. Pictures of a beautiful young woman appear on a screen. In the photos, she’s standing. Then one day on a slope, the tips of Boxtel’s skis crossed. She did a somersault and shattered four vertebrae. “I also shattered illusions of my immortality. I was paralyzed from here”—she hold her hands at her hips—“down. No movement and no sensation.” That life changed radically for her right then is difficult to dispute. But Boxtel eventually embraced a road to recovery. “It took time to turn wounds into wisdom. It took guts. This is a cruel injury. It is so much more than not being able to walk,” she tells us. With the aid of adaptive technology, she got back on her skis. She took up waterskiing, rock climbing, kayaking and hang gliding. But still, she couldn’t bear weight on her legs or walk. Walking seems easy to most of us, because the action is built-in; it is automatic. In reality, however, walking is a highly complex motion involving many different muscles that must contract in a precisely timed sequence. Once the spinal cord can no longer orchestrate this motion, it is exceedingly hard to replicate. Walking, for Boxtel, was arguably a pipe dream. And so she sat for 21 years. © 2013 Scientific American
Link ID: 18699 - Posted: 09.25.2013
By NICHOLAS BAKALAR Many people use copper bracelets and magnetic wrist straps to alleviate the pain of arthritis, but a new randomized, double-blinded, placebo-controlled study concludes they do not work. British researchers randomized 65 patients with rheumatoid arthritis to receive one of four treatments: wearing a powerful magnetic wrist strap, a weak magnetic strap, a non-magnetic strap and a copper bracelet. Each patient wore each device for five weeks and completed pain surveys. The study appears in the September issue of PLoS One. The patients reported pain levels using a visual scale, ranging from “no pain” to “worst pain ever,” and recorded how often their joints felt tender and swollen. Researchers used questionnaires to assess physical limitations, and tested for inflammation by measuring blood levels of C-reactive protein and plasma viscosity. There was no statistically significant difference in any of these measures regardless of which type of device patients were wearing. Stewart J. Richmond, a researcher at the University of York who led the study, acknowledged that the devices may have some benefits as a placebo. “People swear by these things,” he said. “Is it ethically correct to allow patients to live in blissful ignorance? Or is it better to provide them with the facts? We can’t deceive patients. We have to be honest with them.” Copyright 2013 The New York Times Company
Keyword: Pain & Touch
Link ID: 18695 - Posted: 09.24.2013
By JOHN SCHWARTZ Candace Pert, a neuroscientist who helped discover a fundamental element of brain chemistry as a graduate student and went on to become a major proponent of alternative medicine, died on Sept. 12 at her home in Potomac, Md. She was 67. The cause was cardiac arrest, said her sister, Deane Beebe. Dr. Pert was working at the Johns Hopkins University School of Medicine in the 1970s when a team she was on found one of the most sought-after objects in brain research: the receptor in the brain that opiates like morphine fit into, like a key in a lock, allowing the drug’s effects to work. The discovery of the opioid receptor would, in 1978, earn the coveted Albert Lasker Award, often a precursor to the Nobel Prize. The award went to Solomon H. Snyder, who headed the lab. Neither Dr. Pert nor any of the other lab assistants was cited. Such omissions are common in the world of science; the graduate student in the lab rarely gets credit beyond being the first name on the papers describing the research. But Dr. Pert did something unusual: she protested, sending a letter to the head of the foundation that awards the prize, saying she had “played a key role in initiating the research and following it up” and was “angry and upset to be excluded.” Her letter caused a sensation in the field. Some saw her exclusion as an example of the burdens and barriers women face in science careers. In a 1979 article about Dr. Pert in the The Washington Post, Dr. Snyder, who had lauded Dr. Pert’s contributions in his Lasker acceptance speech, argued that “that’s the way the game is played,” adding that today’s graduate students will be tomorrow’s lab chiefs, and that “when they have students, it will be the same.” © 2013 The New York Times Company
Keyword: Pain & Touch
Link ID: 18685 - Posted: 09.21.2013
By William Saletan In much of this country, over the last three years, pro-lifers have banned abortions 20 weeks after fertilization. They’ve justified these bans by asserting—contrary to the most authoritative studies—that fetuses at this stage of development can feel pain. Their assertions, in turn, are based on research by several doctors. But the doctors don’t buy the pro-lifers’ conclusions. They say their research doesn’t support the bans. The 12 state bans (several of which have been blocked or limited by courts) begin with legislative “findings.” The findings parrot a 33-page report posted by the National Right to Life Committee and other pro-life organizations. The report cites the work of a number of researchers. Pam Belluck, an enterprising New York Times correspondent, contacted the researchers and asked them about the abortion bans. It turns out there’s a big gap between the science and the legislation. The pro-life report cites Dr. Nicholas Fisk, a former president of the International Fetal Medicine and Surgery Society, 27 times. According to the report, Fisk’s work shows fetal “stress responses” that imply sensitivity to pain. But Fisk tells Belluck that he doesn’t buy the inference from stress hormones and cerebral blood flow to pain. Neural studies, he says, have persuaded him that until 24 weeks gestation—the current abortion limit in many states—fetal pain “is not possible at all.” The report also cites Dr. Mark Rosen, a fetal anesthesia pioneer, 16 times. Rosen’s work, the report suggests, shows that painkillers and anesthesia are common during fetal surgery because unborn children can feel pain. But Rosen tells Belluck that the real purpose of such drugs during fetal surgery is to minimize dangerous movement and harmful stress hormones, thereby facilitating recovery. The drugs don’t signify medical belief in fetal pain. Dr. Scott Adzick, another fetal surgery expert cited in the pro-life report, makes the same point. © 2013 The Slate Group, LLC
By William Skaggs At the level of personal experience, there is nothing that seems easier to understand than pain. When I jam my finger in a doorway, I have no difficulty at all recognizing the sensation that results. But this superficial simplicity covers up a world of complexity at the level of brain mechanisms, and the complexities are even greater when we try to identify pain in other people or other species of animals. Some of the complexities are purely scientific, but others are caused by moral or philosophical issues getting mixed up with scientific issues. My provocation for writing this post was a blog post called Do Octopuses Feel Pain?, by Katherine Harmon, who writes the blog Octopus Chronicles, It’s basically a nice article—there’s nothing objectionable about it—but it pressed one of my buttons. She made a number of important points, and altogether what she wrote is well worth reading, but nevertheless the result left me with a feeling of dissatisfaction, as do most scientific discussions about pain in animals. I’d like to try to explain where that discomfort comes from. In her blog post, Harmon listed three elements that are involved in feeling pain: (1) nociception, that is, having mechanisms in the body that are capable of detecting damage and transmuting it into neural signals; (2) the experience of pain; (3) the ability to communicate pain information from sensation to perception. I’m not sure I understand the third aspect, but I take it to mean the ability to transform nociception into experience. In any case, the essence of pain as most people understand it is aspect 2. Most people think of pain as a particular type of experience—as something that happens inside our minds and can only be observed by ourselves. © 2013 Scientific American
Keyword: Pain & Touch
Link ID: 18679 - Posted: 09.21.2013
By Melissa Hogenboom Science reporter, BBC News Moving in time to a steady beat is closely linked to better language skills, a study suggests. People who performed better on rhythmic tests also showed enhanced neural responses to speech sounds. The researchers suggest that practising music could improve other skills, particularly speech. In the Journal of Neuroscience, the authors argue that rhythm is an integral part of language. "We know that moving to a steady beat is a fundamental skill not only for music performance but one that has been linked to language skills," said Nina Kraus, of the Auditory Neuroscience Laboratory at Northwestern University in Illinois. More than 100 teenagers were asked to tap their fingers along to a beat. Their accuracy was measured by how closely their responses matched the timing of a metronome. Next, in order to understand the biological basis of rhythmic ability, the team also measured the brainwaves of their participants with electrodes, a technique called electroencephalography. This was to observe the electrical activity in the brain in response to sound. Using this biological approach, the researchers found that those who had better musical training also had enhanced neural responses to speech sounds. In poorer readers this response was diminished. BBC © 2013
The structure of the brain may predict whether a person will suffer chronic low back pain, according to researchers who used brain scans. The results, published in the journal Pain, support the growing idea that the brain plays a critical role in chronic pain, a concept that may lead to changes in the way doctors treat patients. The research was supported by the National Institute of Neurological Disorders and Stroke (NINDS), part of the National Institutes of Health. “We may have found an anatomical marker for chronic pain in the brain,” said Vania Apkarian, Ph.D., a senior author of the study and professor of physiology at Northwestern University Feinberg School of Medicine in Chicago. Chronic pain affects nearly 100 million Americans and costs the United States up to $635 billion per year to treat. According to the Institute of Medicine, an independent research organization, chronic pain affects a growing number of people. “Pain is becoming an enormous burden on the public. The U.S. government recently outlined steps to reduce the future burden of pain through broad-ranging efforts, including enhanced research,” said Linda Porter, Ph.D, the pain policy advisor at NINDS and a leader of NIH’s Pain Consortium. “This study is a good example of the kind of innovative research we hope will reduce chronic pain which affects a huge portion of the population.” Low back pain represents about 28 percent of all causes of pain in the United States; about 23 percent of these patients suffer chronic, or long-term, low back pain.
Keyword: Pain & Touch
Link ID: 18663 - Posted: 09.18.2013
By PAM BELLUCK It is a new frontier of the anti-abortion movement: laws banning abortion at 20 weeks after conception, contending that fetuses can feel pain then. Since 2010, a dozen states have enacted them, most recently Texas. Nationally, a bill passed the Republican-dominated House of Representatives in June. The science of fetal pain is highly complex. Most scientists who have expressed views on the issue have said they believe that if fetuses can feel pain, the neurological wiring is not in place until later, after the time when nearly all abortions occur. Several scientists have done research that abortion opponents say shows that fetuses can feel pain at 20 weeks after conception. One of those scientists said he believed fetuses could likely feel pain then, but he added that he believed the few abortions performed then could be done in ways to avoid pain. He and two other scientists said they did not think their work or current evidence provided scientific support for fetal-pain laws. Some scientists’ views have evolved as more research has been done. Dr. Nicholas Fisk, a senior maternal-fetal medicine specialist at Royal Brisbane and Women’s Hospital in Australia, said he once considered early fetal pain “a major possibility” after finding that fetuses receiving blood transfusions produced increased stress hormones and blood flow to the brain, and that painkillers lowered those levels. But Dr. Fisk, a former president of the International Fetal Medicine and Surgery Society, said neurological research has convinced him that pain “is not possible at all” before 24 weeks. © 2013 The New York Times Company
By Associated Press, Former Grateful Dead drummer Mickey Hart has a new piece of equipment accompanying him on his latest tour: a cap fitted with electrodes that capture his brain activity and direct the movements of a light show while he’s jamming on stage. The sensor-studded headgear is an outgrowth of collaboration between Hart, 70, and Adam Gazzaley, a University of California at San Francisco neuroscientist who studies cognitive decline. The subject has been an interest of the musician’s since the late 1980s, as he watched his grandmother deal with Alzheimer’s disease. When he played the drums for her, he says, she became more responsive. Since then, Hart has invested time and money exploring the therapeutic potential of rhythm. Thirteen years ago, he founded Rhythm for Life, a nonprofit promoting drum circles for the elderly. Hart first publicly wore his electroencephalogram cap last year at an AARP convention where he and Gazzaley discussed their joint pursuit of research on the link between brain waves and memory. He wore it again while making his new album, “Superorganism,” translating the rhythms of his brain waves into music. Hart’s bandmates, with input from other researchers in Gazzaley’s lab, paired different waves with specific musical sequences that were then inserted into songs. © 1996-2013 The Washington Post
by Andy Coghlan A girl who does not feel physical pain has helped researchers identify a gene mutation that disrupts pain perception. The discovery may spur the development of new painkillers that will block pain signals in the same way. People with congenital analgesia cannot feel physical pain and often injure themselves as a result – they might badly scald their skin, for example, through being unaware that they are touching something hot. By comparing the gene sequence of a girl with the disorder against those of her parents, who do not, Ingo Kurth at Jena University Hospital in Germany and his colleagues identified a mutation in a gene called SCN11A. This gene controls the development of channels on pain-sensing neurons. Sodium ions travel through these channels, creating electrical nerve impulses that are sent to the brain, which registers pain. Overactivity in the mutated version of SCN11A prevents the build-up of the charge that the neurons need to transmit an electrical impulse, numbing the body to pain. "The outcome is blocked transmission of pain signals," says Kurth. To confirm their findings, the team inserted a mutated version of SCN11A into mice and tested their ability to perceive pain. They found that 11 per cent of the mice with the modified gene developed injuries similar to those seen in people with congenital analgesia, such as bone fractures and skin wounds. They also tested a control group of mice with the normal SCN11A gene, none of which developed such injuries. © Copyright Reed Business Information Ltd.
Insect leg cogs a first in animal kingdom Philip Ball If you are a young plant hopper, leaping one metre in a single bound, you need to push off with both hind legs in perfect unison or you might end up in a spin. Researchers have discovered that this synchrony is made possible by toothed gears that connect the two legs when the insects jump. Zoologists Malcolm Burrows and Gregory Sutton at the University of Cambridge, UK, say that this seems to be the first example in nature of rotary motion with toothed gears. They describe their findings today in Science1. When the insect jumps, the cog teeth join so that the two legs lock together, ensuring that they thrust at exactly the same time (see video above and image at left). “The gears add an extra level of synchronization beyond that which can be achieved by the nervous system,” says Burrows. Infant plant hoppers, known as nymphs, can take off in just 2 milliseconds, reaching take-off speeds of almost 4 metres a second (see video below). For motions this rapid, some mechanical device is needed to keep the legs synchronized and to avoid lopsided jumps that might lead to the insects spinning out of control. The problem does not, however, arise in all jumping insects: whereas the attachments of plant hoppers' hind legs are adjacent to each other, the legs of grasshoppers and fleas attach to opposite the sides of the body and move in parallel planes. This helps to stabilize the insects and even enables them to jump one-legged. © 2013 Nature Publishing Group
Link ID: 18644 - Posted: 09.14.2013
Amanda Fiegl What's the difference between a spicy meal and being tickled? Not much, from your lips' perspective. A new study reports that Szechuan pepper activates the same nerves that respond to a light physical touch. Researchers at the University College London Institute of Cognitive Neuroscience found that people experienced the same sensation when either Szechuan pepper—a spice used in many types of Asian cuisine—or a machine vibrating at a particular frequency was placed on their lips. "The pepper is sending the same information to the brain as having a buzzer on your lips," the study's lead author, Nobuhiro Hagura, said in an email. The study, published today in Proceedings of the Royal Society B with the wry headline "Food Vibrations," delves into the little-known field of psychophysics, which "describes the relation between physical reality and what we actually perceive," Hagura said. "Our research shows just one interesting example of a case where we perceive something quite different than what is actually there," he said. "In many cases, the difference between perception and reality can be explained by understanding how the nervous system transmits information about the outside world to the brain." Previous studies have shown that other spicy ingredients, such as chili peppers and mustard oils, activate the nerve fibers associated with pain and physical heat. And studies in animals indicated that the spicy chemical in Szechuan pepper—sanshool—acts on the nervous system's "light touch" fibers. So Hagura and his colleagues wanted to find out whether sanshool produces a conscious sensation of touch in humans. © 1996-2013 National Geographic Society.
By Michele Solis Like truth and beauty, pain is subjective and hard to pin down. What hurts one moment might not register the next, and our moods and thoughts color the experience of pain. According to a report in April in the New England Journal of Medicine, however, researchers may one day be able to measure the experience of pain by scanning the brain—a much needed improvement over the subjective ratings of between one and 10 that patients are currently asked to give. Led by neuroscientist Tor Wager of the University of Colorado at Boulder, researchers used functional MRI on healthy participants who were given heated touches to their arm, some pleasantly warm, others painfully hot. During the painful touches, a scattered group of brain regions consistently turned on. Although these regions have been previously associated with pain, the new study detected a striking and consistent jump in their activity when people reported pain, with much greater accuracy than previous studies had attained. This neural signature appeared in 93 percent of subjects reporting to feel painful heat, ramping up as pain intensity increased and receding after participants took a painkiller. The researchers determined that the brain activity specifically marked physical pain rather than a generally unpleasant experience, because it did not emerge in people shown a picture of a lover who had recently dumped them. Although physical pain and emotional pain involve some of the same regions, the study showed that fine-grained differences in activation separate the two conditions. © 2013 Scientific American