Chapter 8. General Principles of Sensory Processing, Touch, and Pain
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.By JOANNA KLEIN A honey bee gathering pollen on a white flower. Dagmar Sporck/EyeEm, via Getty Images Set your meetings, phone calls and emails aside, at least for the next several minutes. That’s because today you’re a bee. It's time to leave your hive, or your underground burrow, and forage for pollen. Pollen is the stuff that flowers use to reproduce. But it’s also essential grub for you, other bees in your hive and your larvae. Once you’ve gathered pollen to take home, you or another bee will mix it with water and flower nectar that other bees have gathered and stored in the hive. But how do you decide which flowers to approach? What draws you in? In a review published last week in the journal Functional Ecology, researchers asked: What is a flower like from a bee’s perspective, and what does the pollinator experience as it gathers pollen? And that's why we're talking to you in the second person: to help you understand how bees like you, while hunting for pollen, use all of your senses — taste, touch, smell and more — to decide what to pick up and bring home. Maybe you're ready to go find some pollen. But do you even know where to look? © 2016 The New York Times Company
By Melissa Dahl Considering its origin story, it’s not so surprising that hypnosis and serious medical science have often seemed at odds. The man typically credited with creating hypnosis, albeit in a rather primitive form, is Franz Mesmer, a doctor in 18th-century Vienna. (Mesmer, mesmerize. Get it?) Mesmer developed a general theory of disease he called “animal magnetism,” which held that every living thing carries within it an internal magnetic force, in liquid form. Illness arises when this fluid becomes blocked, and can be cured if it can be coaxed to flow again, or so Mesmer’s thinking went. To get that fluid flowing, as science journalist Jo Marchant describes in her recent book, Cure, Mesmer “simply waved his hands to direct it through his patients’ bodies” — the origin of those melodramatic hand motions that stage hypnotists use today.” After developing a substantial following — “mesmerism” became “the height of fashion” in late 1780s Paris, writes Marchant — Mesmer became the subject of what was essentially the world’s first clinical trial. King Louis XVI pulled together a team of the world’s top scientists, including Benjamin Franklin, who tested mesmerism and found its capacity to “cure” was, essentially, a placebo effect. “Not a shred of evidence exists for any fluid,” Franklin wrote. “The practice … is the art of increasing the imagination by degrees.” Maybe so. But that doesn’t mean it doesn’t work. © 2016, New York Media LLC.
Tom Goldman Voters in seven more states said "yes" to marijuana this month. Pot now is legal for recreational or medicinal use in more than half the country. It's still against federal law and classified as a Schedule 1 drug, meaning U.S. officials consider marijuana to have a high risk of abuse or harm, and no accepted medical use in treatment. Also, it's still banned in professional sports. Many athletes hope that will change as momentum grows nationwide for legalization. That's especially true in the National Football League, where pain is a constant companion. Advocates say marijuana could offer a safer and better way to manage the pain. Football hurts. As a fan watching from home, that's not always obvious — players collide, fall down, pop back up. They rarely wince or show weakness. That's just not how it's done in football. Kyle Turley hurt plenty during his eight NFL seasons in the 1990s and 2000s. As an offensive lineman, he was involved in jarring collisions nearly every play when his team had the ball. He hurt after his career -– Turley sometimes walks with a cane. And in a recent video, he displayed one by one the bottles of powerful painkillers he used. "Vicodin, Flexeril, Percocets, Vioxx, morphine," Turley recited as he plopped the bottles down on a kitchen counter. © 2016 npr
By Alice Klein Alzheimer’s disease can be prevented by stopping a crucial brain protein from turning rogue, a study in mice suggests. Tau protein has long been suspected to play a role in causing the condition. In healthy brains, tau is essential for normal cell functioning. But during Alzheimer’s disease, the protein goes haywire, clumping together to form twisted tangles and, it is thought, releasing toxic chemicals that harm the brain. Now Lars Ittner at the University of New South Wales, Australia, and his colleagues have pinpointed a crucial enzyme that controls how tau proteins behave in the brain. The enzyme, called p38γ kinase, helps keep tau in a healthy, tangle-free state, preventing the onset of memory loss and other symptoms in mice that have been bred to develop Alzheimer’s disease. The enzyme seems to block Alzheimer’s by interfering with the action of another problem protein, called beta-amyloid. Like tau, clumps of this protein accumulate in the brains of people with Alzheimer’s, making it another suspected cause of the disease. When beta-amyloid forms these sticky plaques, it can also modify the structure of tau proteins, causing them to form tangles and release toxic chemicals. But Ittner’s team found that p38γ kinase makes a different kind of structural change to tau. If this change is made first, it prevents beta-amyloid from being able to turn tau bad, and mice do not develop the disease. © Copyright Reed Business Information Ltd.
Link ID: 22883 - Posted: 11.18.2016
By CHRIS BUCKLEY BEIJING — When Flappy McFlapperson and Skybomb Bolt sprang into the sky for their annual migration from wetlands near Beijing, nobody was sure where the two cuckoos were going. They and three other cuckoos had been tagged with sensors to follow them from northern China. But to where? “These birds are not known to be great fliers,” said Terry Townshend, a British amateur bird watcher living in the Chinese capital who helped organize the Beijing Cuckoo Project to track the birds. “Migration is incredibly perilous for birds, and many perish on these journeys.” The answer to the mystery — unfolding in passages recorded by satellite for more than five months — has been a humbling revelation even to many experts. The birds’ journeys have so far covered thousands of miles, across a total of a dozen countries and an ocean. The “common cuckoo,” as the species is called, turns out to be capable of exhilarating odysseys. “It’s impossible not to feel an emotional response,” said Chris Hewson, an ecologist with the British Trust for Ornithology in Thetford, England, who has helped run the tracking project. “There’s something special about feeling connected to one small bird flying across the ocean or desert.” But to follow a cuckoo, you must first seduce it. The common cuckoo is by reputation a cynical freeloader. Mothers outsource parenting by laying their eggs in the nests of smaller birds, and the birds live on grubs, caterpillars and similar soft morsels. British and Chinese bird groups decided to study two cuckoo subspecies found near Beijing, because their winter getaways were a puzzle. In an online poll for the project, nearly half the respondents guessed they went somewhere in Southeast Asia. © 2016 The New York Times Company
By Diana Kwon In people who suffer from pain disorders, painful feelings can severely worsen and spread to other regions of the body. Patients who develop chronic pain after surgery, for example, will often feel it coming from the area surrounding the initial injury and even in some parts of the body far from where it originates. New evidence suggests glia, non-neuronal cells in the brain, may be the culprits behind this effect. Glia were once thought to simply be passive, supporting cells for neurons. But scientists now know they are involved in everything from metabolism to neurodegeneration. A growing body of evidence points to their key role in pain. In a study published today in Science, researchers at the Medical University of Vienna report that glia are involved in long-term potentiation (LTP), or the strengthening of synapses, in pain pathways in the spinal cord. Neuroscientists Timothy Bliss and Terje Lømo first described LTP in the hippocampus, a brain area involved in memory, in the 1970s. Since then scientists have been meticulously studying the role this type of synaptic plasticity—the ability of synapses to change in strength—plays in learning and memory. More recently, researchers discovered that LTP could also amplify pain in areas where injuries or inflammation occur. “We sometimes call this a ‘memory trace of pain’ because the painful insult may lead to subsequent hypersensitivity to painful stimuli, and it was clear that synaptic plasticity can play a role here,” says study co-author Jürgen Sandkühler, a neuroscientist also at the Medical University of Vienna. But current models of how LTP works could not explain why discomfort sometimes becomes widespread or experienced in areas a person has never felt it before, he adds. © 2016 Scientific American
Nancy Shute Erik Vance didn't go to a doctor until he was 18; he grew up in California in a family that practiced Christian Science. "For the first half of my life, I never questioned the power of God to heal me," Vance writes in his new book, Suggestible You: Placebos, False Memories, Hypnosis, and the Power of Your Astonishing Brain. As a young man, Vance left the faith behind, but as he became a science journalist he didn't stop thinking about how people's beliefs and expectations affect their health, whether it's with placebo pills, mystical practices or treatments like acupuncture. The answer, he found, is in our brains. Erik and I chatted about the book while attending a recent meeting of the National Association of Science Writers. Here are highlights of our conversation, edited for length and clarity. You point out that even though most of us didn't grow up Christian Scientist, we often use belief to manage our health. I've learned from writing this book that there are a lot of people around the world who really rely on expectation and placebos. And I grew up in the most extreme possible group, but it's not that different from seeing a homeopath. You're using faith to manage your body; what a psychologist would call expectation. Having had that experience really prepared me to ask some of these questions. How would your mom take care of you when you were sick? As a kid we might have 7UP with orange juice; we might go that far because it made you feel better. But the treatment was to call a practitioner, to call a healer. © 2016 npr
Keyword: Pain & Touch
Link ID: 22847 - Posted: 11.09.2016
By Simon Oxenham Isy Suttie has felt “head squeezing” since she was young. The comedian, best known for playing Dobbie in the BBC sitcom Peep Show, is one of many people who experience autonomous sensory meridian response (ASMR) – a tingly feeling often elicited by certain videos or particular mundane interactions. Growing up, Suttie says she had always assumed everyone felt it too. Not everyone feels it, but Suttie is by no means alone. On Reddit, a community of more than 100,000 members share videos designed to elicit the pleasurable sensation. The videos, often described as “whisper porn”, typically consist of people role-playing routine tasks, whispering softly into a microphone or making noises by crinkling objects such as crisp packets. The most popular ASMR YouTuber, “Gentle Whispering”, has over 250 million views. To most of us, the videos might seem strange or boring, but the clips frequently garner hundreds of thousands of views. These videos often mimic real-life situations that provoke ASMR in susceptible people. Suttie says her strongest real-world triggers occur during innocuous interactions with strangers, like talking about the weather – “it’s almost as if the more superficial the subject the better,” Suttie says. She feels the sensation particularly strongly when someone brushes past her. For Suttie, the feelings are so powerful that she often feels floored by them, and they even overcome pain and emotional distress. During a trip to the dentist, she still experiences the pleasurable tingles when the assistant brushes past her, she says. © Copyright Reed Business Information Ltd.
By LISA SANDERS, M.D. Yesterday we challenged Well readers to take on the case of a 63-year-old artist who, over the course of several months, developed excruciating headaches, along with changes in his personality, his thinking, even in the way he painted. We provided you with some of the doctor’s notes and medical imaging results that led the doctor who finally made the diagnosis in the right direction. After an extensive evaluation, that doctor asked a single question that led him to make the diagnosis. We asked Well readers to figure out the question the doctor asked and the diagnosis it suggested. It must have been a tough case — or else you were all too worried about the coming election to rise to the challenge — because we got just over 200 responses, fewer than usual. Of those, only six of you figured out the right diagnosis, and only three of you got the question right as well. Despite that, I was very impressed by the thinking of even those who didn’t come up with the right diagnosis. Many of you thought about environmental factors like his recent retirement and his exposure to possible toxins from his painting, and that kind of thinking was, in my opinion, the very essence of thinking like a doctor. Strong work, all of you. The question the doctor asked that led him to the correct diagnosis was: Can you hear your heartbeat in your ears? The patient could. And that suggested the diagnosis: A dural-arteriovenous fistula, or DAVF © 2016 The New York Times Company
Keyword: Pain & Touch
Link ID: 22839 - Posted: 11.07.2016
By Kelly Servick Mark Hutchinson could read the anguish on the participants’ faces in seconds. As a graduate student at the University of Adelaide in Australia in the late 1990s, he helped with studies in which people taking methadone to treat opioid addiction tested their pain tolerance by dunking a forearm in ice water. Healthy controls typically managed to stand the cold for roughly a minute. Hutchinson himself, “the young, cocky, Aussie bloke chucking my arm in the water,” lasted more than 2 minutes. But the methadone patients averaged only about 15 seconds. “These aren’t wimps. These people are injecting all sorts of crazy crap into their arms. … But they were finding this excruciating,” Hutchinson says. “It just fascinated me.” The participants were taking enormous doses of narcotics. How could they experience such exaggerated pain? The experiment was Hutchinson’s first encounter with a perplexing phenomenon called opioid-induced hyperalgesia (OIH). At high doses, opioid painkillers actually seem to amplify pain by changing signaling in the central nervous system, making the body generally more sensitive to painful stimuli. “Just imagine if all the diabetic medications, instead of decreasing blood sugar, increased blood sugar,” says Jianren Mao, a physician and pain researcher at Massachusetts General Hospital in Boston who has studied hyperalgesia in rodents and people for more than 20 years. © 2016 American Association for the Advancement of Science
Keyword: Pain & Touch
Link ID: 22829 - Posted: 11.04.2016
A snake with the largest venom glands in the world could hold the answer to pain relief, scientists have found. Dubbed the "killer of killers", the long-glanded blue coral snake is known to prey on the likes of king cobras. The venom of the two-metre-long snake native to South East Asia acts "almost immediately" and causes prey to spasm. New research published in the journal Toxin found it targets receptors which are critical to pain in humans and could be used as a method of treatment. "Most snakes have a slow-acting venom that works like a powerful sedative. You get sleepy, slow, before you die," said Dr Bryan Fry of the University of Queensland who is one of a team of researchers working on a study into the effect of the snake's venom. "This snake's venom however, works almost immediately because it usually preys on very dangerous animals that need to be quickly killed before they can retaliate. It's the killer of killers." Turning into medicine? Cone snails and scorpions are some of a handful of invertebrates whose venom has been studied for its medical use. However, as a vertebrate, the snake is evolutionarily closer to humans, and so a medicine developed from its venom could potentially be more effective, says Dr Fry. "The venom targets our sodium channels, which are central to our transmission of pain. We could potentially turn this into something that could help relieve pain, and which might work better on us." The snake's venom glands extend to up to one-quarter of its body length. "It's got freaky venom glands, the longest of any in the world, but it's so beautiful. It's easily my favourite species of snake," said Dr Fry. © 2016 BBC.
By CATHERINE SAINT LOUIS Neither of the two drugs used most frequently to prevent migraines in children is more effective than a sugar pill, according to a study published on Thursday in The New England Journal of Medicine. Researchers stopped the large trial early, saying the evidence was clear even though the drugs — the antidepressant amitriptyline and the epilepsy drug topiramate — had been shown to prevent migraines in adults. “The medication didn’t perform as well as we thought it would, and the placebo performed better than you would think,” said Scott Powers, the lead author of the study and a director of the Headache Center at Cincinnati Children’s Hospital Medical Center. A migraine is a neurological illness characterized by pulsating headache pain, sometimes accompanied by nausea, vomiting and sensitivity to light and noise. It’s a common childhood condition. Up to 11 percent of 7- to 11-year-olds and 23 percent of 15-year-olds have migraines. At 31 sites nationwide, 328 migraine sufferers aged 8 to 17 were randomly assigned to take amitriptyline, topiramate or a placebo pill for 24 weeks. Patients with episodic migraines (fewer than 15 headache days a month) and chronic migraines (15 or more headache days a month) were included. The aim was to figure out which drug was more effective at reducing the number of headache days, and to gauge which one helped children to stop missing school or social activities. © 2016 The New York Times Company
Keyword: Pain & Touch
Link ID: 22801 - Posted: 10.28.2016
Katherine Hobson Placebos can't cure diseases, but research suggests that they seem to bring some people relief from subjective symptoms, such as pain, nausea, anxiety and fatigue. But there's a reason your doctor isn't giving you a sugar pill and telling you it's a new wonder drug. The thinking has been that you need to actually believe that you're taking a real drug in order to see any benefits. And a doctor intentionally deceiving a patient is an ethical no-no. So placebos have pretty much been tossed in the "garbage pail" of clinical practice, says Ted Kaptchuk, director of the Program for Placebo Studies and the Therapeutic Encounter at Beth Israel Deaconess Medical Center. In an attempt to make them more useful, he has been studying whether people might see a benefit from a placebo even if they knew it was a placebo, with no active ingredients. An earlier study found that so-called "open-label" or "honest" placebos improved symptoms among people with irritable bowel syndrome. And Kaptchuk and his colleagues found the same effect among people with garden-variety lower back pain, the most common kind of pain reported by American adults. The study included 83 people in Portugal, all of whom had back pain that wasn't caused by cancer, fractures, infections or other serious conditions. All the participants were told that the placebo was an inactive substance containing no medication. They were told that the body can automatically respond to placebos, that a positive attitude can help but isn't necessary and that it was important to take the pills twice a day for the full three weeks. © 2016 npr
Keyword: Pain & Touch
Link ID: 22800 - Posted: 10.28.2016
Ian Sample Science editor Experiments with a fake body part have revealed how the brain becomes confused during a party trick known as the rubber hand illusion. Researchers in Italy performed the trick on a group of volunteers to explore how the mind combines information from the senses to create a feeling of body ownership. Under the illusion, people feel that a rubber hand placed on the table before them is their own, a bizarre but convincing shift in perception that is accompanied by a sense of disowning their real hand. The scientists launched the study after noticing that some stroke patients in their care experienced similar sensations, at times becoming certain that a paralysed limb was not their own, and even claiming ownership over other people’s appendages. “It is a very strong belief,” said Francesca Garbarini at the University of Turin. “We know that the feeling of body ownership can be dramatically altered after brain damage.” For the study, healthy volunteers sat with their forearms resting on a table and their right hand hidden inside a box. A lifelike rubber hand was then placed in front of them and lined up with their right shoulder. A cloth covered the stump of the hand, but the fingers remained visible. To induce the illusion, one of the researchers stroked the middle finger of the participant’s real hand while simultaneously stroking the same finger on the rubber hand. © 2016 Guardian News and Media Limited
Keyword: Pain & Touch
Link ID: 22780 - Posted: 10.24.2016
Laura Sanders Pain is contagious, at least for mice. After encountering bedding where mice in pain had slept, other mice became more sensitive to pain themselves. The experiment, described online October 19 in Science Advances, shows that pain can move from one animal to another — no injury or illness required. The results “add to a growing body of research showing that animals communicate distress and are affected by the distress of others,” says neuroscientist Inbal Ben-Ami Bartal of the University of California, Berkeley. Neuroscientist Andrey Ryabinin and colleagues didn’t set out to study pain transfer. But the researchers noticed something curious during their experiments on mice who were undergoing alcohol withdrawal. Mice in the throes of withdrawal have a higher sensitivity to pokes on the foot. And surprisingly, so did these mice’s perfectly healthy cagemates. “We realized that there was some transfer of information about pain” from injured mouse to bystander, says Ryabinin, of Oregon Health & Sciences University in Portland. When mice suffered from alcohol withdrawal, morphine withdrawal or an inflaming injection, they become more sensitive to a poke in the paw with a thin fiber — a touchy reaction that signals a decreased pain tolerance. Mice that had been housed in the same cage with the mice in pain also grew more sensitive to the poke, Ryabinin and colleagues found. These bystander mice showed other signs of heightened pain sensitivity, such as quickly pulling their tails out of hot water and licking a paw after an irritating shot. |© Society for Science & the Public 2000 - 20
Hannah Devlin Science correspondent Migraine sufferers have a different mix of gut bacteria that could make them more sensitive to certain foods, scientists have found. The study offers a potential explanation for why some people are more susceptible to debilitating headaches and why some foods appear to act as triggers for migraines. The research showed that migraine sufferers had higher levels of bacteria that are known to be involved in processing nitrates, which are typically found in processed meats, leafy vegetables and some wines. The latest findings raise the possibility that migraines could be triggered when nitrates in food are broken down more efficiently, causing vessels in the brain and scalp to dilate. Antonio Gonzalez, a programmer analyst at the University of California San Diego and the study’s first author, said: “There is this idea out there that certain foods trigger migraines - chocolate, wine and especially foods containing nitrates. We thought that perhaps there are connections between what people are eating, their microbiomes and their experiences with migraines.” When nitrates in food are broken down by bacteria in the mouth and gut they are eventually converted into nitric oxide in the blood stream, a chemical that dilates blood vessels and can aid cardiovascular health by boosting circulation. © 2016 Guardian News and Media Limited
Linda Geddes For the first time, a paralysed man has gained a limited sense of touch, thanks to an electric implant that stimulates his brain and allows him to feel pressure-like sensations in the fingers of a robotic arm. The advance raises the possibility of restoring limited sensation to various areas of the body, as well as giving people with spinal-cord injuries better control over prosthetic limbs. But restoring human-like feeling, such as sensations of heat or pain, will prove more challenging, the researchers say. Nathan Copeland had not been able to feel or move his legs and lower arms since a car accident snapped his neck and injured his spinal cord when he was 18. Now, some 12 years later, he can feel when a robotic arm has its fingers touched, because sensors on the fingers are linked to an implant in his brain. Brain implant restores paralysed man's sense of touch Rob Gaunt, a biomedical engineer at the University of Pittsburgh, performs a sensory test on a blindfolded Nathan Copeland. Nathan, who is paralysed, demonstrates his ability to feel by correctly identifying different fingers through a mind-controlled robotic arm. Video credit: UPMC/Pitt Health Sciences. “He says the sensations feel like they’re coming from his own hand,” says Robert Gaunt, a biomedical engineer at the University of Pittsburgh who led the study. © 2016 Macmillan Publishers Limited
By Elizabeth Pennisi Although it has a face—and body—that only a mother could love, the naked mole rat has a lot to offer biomedical science. It lives 10 times longer than a mouse, almost never gets cancer, and doesn’t feel pain from injury and inflammation. Now, researchers say they’ve figured out how the rodents keep this pain away. “It’s an amazing result,” says Harold Zakon, an evolutionary neurobiologist at the University of Texas, Austin, who was not involved with the work. “This study points us to important areas … that might be targeted to reduce this type of pain.” Naked mole rats are just plain weird. They live almost totally underground in colonies structured like honey bee hives, with hundreds of workers servicing a single queen and her few consorts. To survive, they dig kilometers of tunnels in search of large underground tubers for food. It’s such a tough life that—to conserve energy—this member of the rodent family gave up regulating its temperature, and they are able to thrive in a low-oxygen, high–carbon dioxide environment that would suffocate or be very painful to humans. “They might as well be from another planet,” says Thomas Park, a neuroscientist at the University of Illinois, Chicago. Gary Lewin, a neuroscientist at the Max Delbrück Center for Molecular Medicine in the Helmholtz Association in Berlin, began working with naked mole rats because a friend in Chicago was finding that the rodent's pain fibers were not the same as other mammals'. In 2008, the studies led to the finding that naked mole rats didn’t feel pain when they came into contact with acid and didn’t get more sensitive to heat or touch when injured, like we and other mammals do. Lewin was hooked and has been raising the rodents in his lab ever since. They are a little more challenging than rats or mice, he notes, because with just one female per colony producing young, he never really has quite enough individuals for his studies. © 2016 American Association for the Advancement of Science
Emma Yasinski Two often-overlooked medications might help millions of Americans who abuse alcohol to quit drinking or cut back. Public health officials, building on a push to treat people who abuse opioids with medications, want physicians to consider using medications to treat alcohol addiction. The drugs can be used in addition to or sometimes in place of peer-support programs, they say. "We want people to understand we think AA is wonderful, but there are other options," says George Koob, director of the National Institute of Alcohol Abuse and Alcoholism, a part of the federal National Institutes of Health. It is still rare for a person struggling with alcohol to hear that medication therapy exists. This partly reflects the tradition of treating addiction through 12-step programs. It's also a byproduct of limited promotion by the drugs' manufacturers and confusion among doctors about how to use them. A key study funded by the federal government reported last year that only 20 percent people who abuse alcohol will ever receive any form of treatment, which ranges from seeing a counselor or doctor to entering a specialized treatment program. The same is true for opioid addiction — about 80 percent of people dependent on opioids will never receive treatment. © 2016 npr
Keyword: Drug Abuse
Link ID: 22698 - Posted: 09.27.2016
James Gorman When the leader of a flock goes the wrong way, what will the flock do? With human beings, nobody can be sure. But with homing pigeons, the answer is that they find their way home anyway. Either the lead pigeon recognizes that it has no clue and falls back into the flock, letting birds that know where they are going take over, or the flock collectively decides that the direction that it is taking just doesn’t feel right, and it doesn’t follow. Several European scientists report these findings in a stirring report in Biology Letters titled, “Misinformed Leaders Lose Influence Over Pigeon Flocks.” Isobel Watts, a doctoral student in zoology at Oxford, conducted the study with her advisers, Theresa Burt de Perera and Dora Biro, and with the participation of Mate Nagy, a statistical physicist from Hungary, who is affiliated with several institutions, including Oxford and the Hungarian Academy of Sciences. Dr. Biro, who studies social behavior in primates as well as pigeons, said that the common questions that ran through her work were “about group living and what types of challenges and opportunities it brings.” She and her colleagues at Oxford have pioneered a method of studying flock behavior that uses very-fine-resolution GPS units, which the birds wear in pigeon-size backpacks. The devices record a detailed position for each bird a number of times a second. Researchers in Budapest and Oxford developed software to analyze small movements and responses of every bird in a flock. With this method, the scientists can identify which pigeons are leading the way. They can build a picture of how each bird responds to changes in the flight of other birds. © 2016 The New York Times Company