Duke - Ashley Yeager https://alumni.duke.edu/magazine/author/ashley-yeager en The Hunt for the Higgs https://alumni.duke.edu/magazine/articles/hunt-higgs <div class="field field-name-body field-type-text-with-summary field-label-hidden view-mode-rss"><div class="field-items"><div class="field-item even" property="content:encoded"><p>In March 2013, capping a nearly fifty-year search, physicists, including Mark Kruse and others from Duke, reported that they had—without a doubt—found the Higgs boson, a particle that helps explain how everything we see around us got about 1 percent of its mass. One percent may not seem like much, especially in the scale of the universe. But without it, matter and life as we know it wouldn’t exist, Kruse says.</p> <p>In a way, the announcement provides validation that physicists’ current picture, or mathematical model, of how nature works is correct. The discovery also helps scientists explain what happened in the very early universe—100 trillionth of a second after it exploded into existence—why it evolved the way it did, and even why it evolved at all.</p> <p>It didn’t just take time to make the discovery; it also involved one of mankind’s most expensive and complex experimental facilities and at least $13 billion in testing.</p> <p>Yet, while it is a great triumph, the discovery doesn’t solve all the scientific and philosophical challenges physicists run into as they grapple with the consequences of the origins of the universe and its relative infinity. The Higgs particle doesn’t fully complete their model of the way nature works. There are still major holes. And possibly more concerning is that—in this time of financial uncertainty for science—physicists are not quite sure where to look to fill those holes. They wonder how they will compete with genomics, brain science, and other large-scale research projects now captivating the public imagination.</p> <p>Can the public get excited about the universe when there’s so much going on in the world?</p> <p>It's not as if physicists haven't been trying to sell the Higgs discovery as an important thing, says Andrew Janiak, a philosopher of science at Duke. "They have. I am just not sure if they have gotten traction, if they have truly captured the public's imagination with it." Getting people interested in such a seemingly esoteric discovery can be hard to do, especially since finding the Higgs “won’t change daily lives, how health is dealt with, how people get around, how we use energy,” Janiak says. “It won’t, at least immediately, so people have a hard time focusing on the research. It is harder to communicate it to a wider public.”</p> <div class="caption caption-center"> <div class="caption-width-container" style="width: 320px;"> <div class="caption-inner"><img alt="" class="media-image" src="/sites/default/files/users/196305/higgs-3.jpg" style="height:242px; width:320px" /> <p><span style="color:#272626; font-family:gothamcondensed; font-size:7pt">© James Brittain/Corbis</span></p> </div> </div> </div> <p>Explaining the Higgs particle and what it means now falls largely to Kruse and his colleagues. It’s a role to which he brings a lot of passion. The idea of existence, of life and death and infinity, used to keep Kruse awake at night. “You can’t wrap your mind around what it all really means, especially as a kid thinking about it for the first time,” he says in a slight Kiwi accent that betrays his New Zealand upbringing. What bothered him most was the disparity between such a short human life and the seemingly infinite span of the universe. He also struggled to understand why anything existed at all.</p> <p>“Everyone does,” he says. “We live in denial. We put this wall of denial up and don’t think about what it really means that when we are not here, it’s forever. It’s sad. It’s depressing, but it is a fact.”</p> <blockquote> <p>“At a very philosophical level, part of our human nature is to query why we exist. We ask questions about nature. We ask questions about the universe.”</p> </blockquote> <p>Kruse now grapples with that fact by exploring nature in search of answers. His tool of choice, as with10,000 other scientists, is the world’s biggest scientific machine, a particle smasher called the Large Hadron Collider, or LHC. The machine’s main mission is to create and study the Higgs boson, a particle thought to explain the existence of all other particles, and therefore matter and life, as we know it.</p> <p>The LHC is built around a circular tunnel up to 500 feet underground that measures 17 miles across, straddling the Franco-Swiss border near Geneva. Around the machine’s ring sit several apartment-sized instruments, which capture the aftermath of collisions of packets of protons traveling close to the speed of light. From these particle smashes, physicists teased out traces of the Higgs particle, which verified that the Higgs field exists. Kruse is the U.S. outreach and education coordinator for ATLAS, one of the apartment-sized instruments at LHC that snatches signatures of the elusive particle.</p> <p>The Higgs particle became important to physicists in 1964, when theorists developed it as a way to solve a problem with scientists’ Standard Model of particle physics. The Standard Model is scientists’ simplest explanation of the forces that drive particles to interact deep within the nucleus of an atom. Experiment after experiment has validated aspects of the model.</p> <div class="caption caption-center"> <div class="caption-width-container" style="width: 320px;"> <div class="caption-inner"><img alt="" class="media-image" src="/sites/default/files/users/196305/higgs-2_0.jpg" style="height:285px; width:320px" /> <p><strong>Big machine, small target: </strong><span style="color:#272626; font-family:gothamcondensed; font-size:9pt">The Large Hadron Collider.&nbsp;</span><span style="color:#272626; font-family:gothamcondensed; font-size:7pt">James Brittain/Corbis</span></p> </div> </div> </div> <p>But there was a problem: For the model to be correct, without alteration, some fundamental particles such as electrons should not have any mass. Experiments already had shown that electrons do have mass. So theorist Peter Higgs and six others calculated a fix. This eventually came to be called the Higgs mechanism, which included the Higgs field and the Higgs particle, and it attempted to explain how fundamental particles could gain mass.</p> <p>“Scientists sometimes have these highfalutin theories, and they believe they are correct all along,” says Duke physicist Ronen Plesser, who is not a Higgs hunter but works on other theories related to fixing the Standard Model. “In this case, the theory turned out to be right, which is a great validation of the way we understand nature. It suggests that our description of it is correct.”</p> <p>Higgs particles and the LHC also help scientists understand all the physics that’s happened in the 14 billion years since that singular moment 100 trillionth of a second after the Big Bang. “What’s even more astounding is that humans have been here for just a tiny fraction of the time scale of the universe and yet have built a huge machine to understand most of its history,” Kruse says. “At a very philosophical level, part of our human nature is to query why we exist. We ask questions about nature. We ask questions about the universe.” Physicists, he adds, depend on society’s support to build the machines that might answer these questions. “We really owe it to the rest of society to explain what we are doing and what we found, because our work is answering innate questions about why we are here. These are the questions that make us human and make us unique.”</p> <p>The Higgs particle he and other scientists have found confirms the existence of the Higgs field, which explains where and how electrons and quarks—fundamental constituents of matter—acquire mass. “This field is truly what generates mass for quarks, which are the building blocks of protons and neutrons, the building blocks of molecules, proteins, cells, plants, animals, planets, stars, galaxies, and all the stuff we see in the universe,” Kruse says.</p> <p>But the mass of quarks coming from the Higgs mechanism accounts for only 1 percent of the total mass of a proton or neutron.</p> <div class="caption caption-center"> <div class="caption-width-container" style="width: 320px;"> <div class="caption-inner"><img alt="" class="media-image" src="/sites/default/files/users/196305/higgs-3_0.jpg" style="height:213px; width:320px" /> <p><strong>Big machine, small target: </strong><span style="color:#272626; font-family:gothamcondensed; font-size:9pt">a summer tour through CERN organized by the Duke Alumni Association and featuring Duke president Richard H. Brodhead.&nbsp;</span><span style="color:#272626; font-family:gothamcondensed; font-size:7pt">Chris Hildreth.</span></p> </div> </div> </div> <p>The other 99 percent of the mass of those particles, and therefore the rest of the observable universe, comes in the form of energy, specifically the forces that bind the quarks that make up protons and neutrons. In other words, the Higgs field explains only 1 percent of the observable mass of everything we see.</p> <p>Without this 1 percent, “all the atomic structure we are familiar with wouldn’t exist. We wouldn’t exist. There may still be matter, but it wouldn’t be the same. There certainly wouldn’t be life as we know it,” Kruse says.</p> <blockquote> <p>The world's biggest scientific machine is designed to create and study a particle thought to explain the existence of all other particles.</p> </blockquote> <p>Plesser adds that, putting life aside, there are two important aspects of finding a Higgs particle. “First is the decades-long experimental search after a deep theoretical prediction and the ultimate discovery. In terms of human drama, that is really cool,” he says. And second, he adds, scientists can say, “Wow, we are awash in the Higgs field, and now we can understand it with theoretical calculations and validate it with experiments.”</p> <p>Physicists worked nearly fifty years&nbsp;to validate their theories of a Higgs&nbsp;boson. And they finally did. The discovery excites Duke physicist Ashutosh Kotwal, but disappoints him just a bit as well. “It’s good to predict correctly and know a theory is right,” he says, “but we’re always more eager to break theories rather than confirm them.”</p> <p>Now that scientists have confirmed the Higgs theory, they’re lining another one up in their cross hairs. It’s nicknamed SUSY, short for supersymmetry. And it, too, is an idea that overcomes issues with scientists’ Standard Model of particle physics. The biggest issue is that quantum mechanics—scientists’ description of how particles interact at the atomic scale—can’t quite explain gravity. With SUSY, every particle has a superpartner, a more massive “shadow” particle that carries force. The electron, for example, is matched with the selectron; the photon, with something called the photino. By adding these extra particles, scientists can start to understand how gravity can work on extremely tiny scales.</p> <p>SUSY, Kotwal says, would also solve the dark-matter problem.</p> <p>This, too, is a calculated, but so far undetected, particle that would account for the way scientists see stars and galaxies moving. The matter we know about simply doesn't account for what we're seeing. Dark matter would complete that riddle, if we could find what it is.</p> <p>"Personally, I think SUSY has so much potential to explain a whole bunch of new mysteries about nature," Kotwal says. "If I were a gambler, I'd bet on it. But I am not writing the check. I am convincing other people to do it.”</p> <p>Kotwal’s role is to crunch the numbers, to look at all the possible ways that scientists could test SUSY with old experiments such as LHC and new ones such as the International Linear Collider, or ILC. This next-generation, multi-billion-dollar machine would be made of two linear accelerators facing each other. They would shoot 10 billion electrons and their antiparticles, positrons, toward each other at nearly the speed of light, collide, and possibly make superparticles that would confirm SUSY and make more Higgs particles. Two other proposals for major particle accelerators are in the works as well.</p> <p>In negotiating the next generation of particle experiments, Kotwal essentially finds himself wearing two hats—a sombrero and a ball cap. The sombrero represents the broader picture of where high-energy physicists should go next. The ball cap represents the select decisions that need to be made about upgrading ATLAS at LHC and determining what role it can play in high-energy physics fifteen years from now. This puts physicists back at the drawing board, where they are now rigorously calculating which old and new experiments to invest in and what science each one can do to complement the others.</p> <p>Physicists are doing all of this jockeying between upgrading old experiments and building new ones in large part because they</p> <p>haven’t yet seen any SUSY particles. Unlike finding the Higgs, where there was a clear target, physicists aren’t exactly sure where the superpartners of electrons and other fundamental particles will turn up. And as a result, they aren’t quite sure what equipment they need to search for them.</p> <p>Despite the uncertainty, planning for the next big machines starts now. That’s the only way physicists can even think of having a new accelerator experiment come online in 2026, at the earliest. Up until then, a lot of what happens depends on funding and, as a direct consequence, public and policymakers’ reception to building a new particle-colliding machine, Kotwal says. And that’s where captivating the public’s imagination becomes critical, philosopher Janiak adds.</p> <p>Physicists have been trying to engage the public by linking their discoveries to understanding the origins of the universe. Hyping the Higgs, however, is a big risk. This past June, theorist Peter Higgs, for whom the Higgs boson is named, criticized physicists and the media team at CERN (the European Organization for Nuclear Research), where the LHC is housed, for overselling their results. “The way it’s been plugged by organizations like CERN has worried me. It worried me that once it was discovered they would be caught out, and the perception would be that there was no need for the machine anymore,” he said at the Times Cheltenham Science Festival, according to <em>The Times </em>of London.</p> <p>Other scientists not in the particle-physics field have said that the media buzz surrounding the discovery of the Higgs particle is a public relations effort to gain traction for rather esoteric research and support the funding of next-generation high-energy physics experiments. But thinking about the discovery in terms of the history of science, Janiak disagrees. He argues that, at the moment, it’s not clear high-energy physicists have such great public relations. “High-energy physics doesn’t appear regularly on the front pages of newspapers and magazines. It’s not as pervasive as research related to medicine and climate change.”</p> <p>“Knowing about the history of science is really important to understanding what’s going on right now. The Higgs boson and</p> <p>more generally what’s going on in physics right now poses a major problem,” Janiak adds, explaining that the discoveries in this discipline have become so mathematically technical that it’s difficult for the public to grasp what they mean. People can understand the basic idea of DNA, genetic mutations, and even evolution and quantum mechanics. But Higgs fields and bosons are a little harder to explain concretely, he says.</p> <p>Kruse says certainly the details are very technical, but that doesn’t mean he and other physicists can’t put the Higgs into a language that is understandable to a lay audience. “Whether we have done that satisfactorily and consistently is another question. I think it can be done and has been done to some extent,” he says. “There are some good explanations out there. Alas, there are also a lot of misleading and poor explanations, which may have created a fog of confusion.”</p> <p>He adds that physicists don’t think much about their science being eclipsed by other research. “It’s orthogonal to what we do. One field is looking more inward and trying to understand our physical makeup; the other looks outward and tries to understand the universe in which we exist. Both are needed for a full comprehension of why we are here and able to contemplate such questions of our existence.”&nbsp;</p> <p>&nbsp;</p> <p><em>Yeager, a former science writer for Duke’s Office of News and Communications, is web producer for </em>Science News<em>.</em></p> </div></div></div> <h3 class="field-label"> Published </h3> <span class="date-display-single" property="dc:date" datatype="xsd:dateTime" content="2013-09-12T00:00:00-04:00">Thursday, September 12, 2013</span><section class="field field-name-field-main-image field-type-image field-label-above view-mode-rss"><h2 class="field-label">Main image:&nbsp;</h2><div class="field-items"><figure class="clearfix field-item even"><img typeof="foaf:Image" class="image-style-none" src="https://alumni.duke.edu/sites/default/files/dm-main-images/higgs-main.jpg" width="1200" height="700" alt="" /></figure></div></section><section class="field field-name-field-author field-type-taxonomy-term-reference field-label-above view-mode-rss"><h2 class="field-label">Writer:&nbsp;</h2><ul class="field-items"><li class="field-item even"><a href="/magazine/author/ashley-yeager" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Ashley Yeager</a></li></ul></section><section class="field field-name-field-issue field-type-taxonomy-term-reference field-label-above view-mode-rss"><h2 class="field-label">Issue:&nbsp;</h2><ul class="field-items"><li class="field-item even"><a href="/magazine/issues/fall-2013" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Fall 2013</a></li></ul></section> <h3 class="field-label"> Featured article </h3> Yes <h3 class="field-label"> Background color </h3> blue<section class="field field-name-field-sub-header field-type-text-long field-label-above view-mode-rss"><h2 class="field-label">Sub-header:&nbsp;</h2><div class="field-items"><div class="field-item even">Can the public get excited about the universe when there&#039;s so much going on here on Earth?</div></div></section> <h3 class="field-label"> Cover Story </h3> <h3 class="field-label"> Homepage </h3> Thu, 12 Sep 2013 08:00:00 +0000 Joseph Sorensen, JOSEPH E. 18498658 at https://alumni.duke.edu https://alumni.duke.edu/magazine/articles/hunt-higgs#comments Bird Brained https://alumni.duke.edu/magazine/articles/bird-brained <div class="field field-name-body field-type-text-with-summary field-label-hidden view-mode-rss"><div class="field-items"><div class="field-item even" property="content:encoded"><div class="caption caption-center"> <div class="caption-width-container" style="width: auto;"> <div class="caption-inner">© Glenn Bartley/All Canada Photos/Corbis</div> </div> </div> <p>From a low branch of a towering oak in Duke Forest, a cardinal belts out his signature cheer, cheer, cheer, tweeee. There’s a twetwe-cha, cha-cha-cha, twee-chaaa from a well-camouflaged song sparrow and the tu-a-wee-wuwe of a brown-breasted bluebird. The forest is alive with springtime conversation, and although it’s early morning, it feels a bit like a Saturday night at a bar. All the guys are puffing out their chests and rolling out their best pick-up lines.</p> <p>For all its cacophony of chirps and trills, the dawn performance is really like one big chorus of “Hey, baby, come check me out,” according to Susan Peters, a behavioral biologist at Duke who studies animal communication. After studying songbirds for thirty years, Peters can hear the birds’ biographies in their melodies. A clear, consistent song is a male songbird’s way of saying he was fed well as a nestling and is now a strong, intelligent adult with superior genetic traits—in other words, a perfect mate.</p> <p>But there will soon be another bird with a story Peters finds even more interesting. As spring turns to summer in the woods and more male songbirds are born, somewhere in those branches a fledgling sparrow or finch will sit perfectly still in his nest. His black eyes blinking, he’ll silently wait. And then, with his beak virtually closed, he’ll whisper a note or two that he’s heard from the birds around him. At first, the sounds will not be quite in tune with the rest of the chorus and instead come out as raspy chirrups and cheeps. But with practice, the juvenile bird will catch on.</p> <p>“It’s very sweet to watch a young male bird making its first attempts at song,” Peters says. A musician herself who plays the piano and other instruments, she can relate to the trial-and-error frustration of learning how to perform a new melody. But as a scientist, she sees the bird’s song—and the weeks-long process the birds must go through to master it—as a tool for understanding how complex behaviors like singing evolve.</p> <p>And it’s not just birds she’s interested in. Peters is one of a growing number of scientists, including several at Duke, who think studying birds can help them understand how the human brain directs complicated tasks such as speech or movement, which may not be nearly as different from a finch learning to warble as once believed. As scientists have learned more about the regions of a bird’s brain involved in singing, they have made surprising connections to the mechanisms humans use to speak and move. There is now promise that birds might offer a model for figuring out human neurological diseases like Huntington’s and Parkinson’s.</p> <p>The idea that there are parallels between birdsong and human speech began to emerge in the 1960s. Among the first scientists to make the connection was Peter Marler, a behavioral biologist who studied birdsongs first at the University of California at Berkeley and then at Rockefeller University in New York. By observing and recording sparrows as they learned to sing, Marler showed that songbirds picked up the unique melodies of their species at a critical stage early in life and that, like humans, they depended on hearing themselves sing to get better. Those features of bird communication, Marler wrote in a 1970 article for American Scientist, “may in turn serve to remind us that human language is a biological phenomenon with an evolutionary history.”</p> <p>In the mid-1970s, Marler hired Susan Peters to his lab at Rockefeller’s Field Research Center in Millbrook, New York. Together, they began to explore how baby sparrows learned the chirps and trills that characterize their species’ song. Through careful experiments, they eventually traced, note by note, the birds’ musical progression from those early weak warbles, called subsong, to their first clear imitations of melodies, and finally to mastery and repetition of their species’ song. As Marler had anticipated, the birds’ pattern of development was much like the progression a human infant follows from babble to individual words to sentences.</p> <p>Marler and Peters pursued the birds’ song progression for nearly a decade, by which time a new biologist named Steve Nowicki had joined the lab. Peters and Nowicki began collaborating on birdsong studies and then married in 1986. The couple moved to Duke in 1989, and Nowicki is now a professor of biology, psychology, and neuroscience, as well as dean of undergraduate education. They also brought with them a collection of swamp and song sparrows they had captured in New York.</p> <p>Today, Peters houses dozens of new sparrows in the Biological Sciences Building. The room where the birds live is painted white, with a long row of wire cages along one wall. Each cage holds a single sparrow, along with a perch, a bath, and a trough of seeds. The room is sealed so Peters can control light and temperature, precisely simulating the seasonal changes in daylight and climate. On a day this past winter, the space is strangely silent, except for a few chirps and squawks and the hum of a heater. There are no songs.</p> <p>Songbirds typically don’t sing in the winter, Peters explains as she reaches into a cage and tries to trap a swamp sparrow, an adult male, in her hand. The bird dances just out of reach. She focuses on the bird for a moment and then gingerly corners it, closing her palm around his brown-feathered body. The bird cocks his head from side to side, surveying his situation. His black eyes blink quickly, but he remains calm. Like all males, his chest is plain gray, and he has a cap of streaked head feathers that turn brownish red in spring—or, in this case, when Peters lengthens the days and warms the air in the room to simulate the season. The longer days, she says, initiate changes in the birds’ brains, which spur them to sing.</p> <p>During her career Peters has logged thousands of hours listening to sparrows and other songbirds compose their melodies. These days most of the analysis is done with the aid of software programs that translate recorded birdsongs into sound spectrographs, which create a visual readout of the birds’ songs. Individual notes appear as tiny lines on a horizontal scale, with the length and height of the lines representing the duration and pitch of the note. It’s clear from looking at a few of these graphic representations that there’s a lot going on in a bird’s song that human ears often don’t appreciate. Even the shortest bit of sparrow song reveals multiple notes and precisely timed pauses.</p> <p>But to a bird, those subtleties make all the difference. Swamp sparrows, for example, sing two-second trills comprising identical syllables, each with between two and five notes. In 1989, Peter Marler and colleagues showed that male sparrows perceive even slight alterations in the length and arrangement of the notes. When the birds hear songs that sound different than what they have learned, they get defensive, as if an intruder has invaded their space. To look tough, the sparrows puff out their chest feathers and flap their wings (see story, page 36).</p> <p><img alt="" class="media-image" src="/sites/default/files/public/magazine/030412_birds4.jpeg" style="height:425px; width:229px" /></p> <div class="caption caption-center"> <div class="caption-width-container" style="width: auto;"> <div class="caption-inner"><strong>Deep thinkers:</strong> Researchers now believe birds have a much greater capacity for complex thought. <p><em>Zina Deretsky, National Science Foundation</em></p> </div> </div> </div> <p>In the first few weeks of life, young birds are listening and making a “mental image” of the sounds they hear, Peters says. At the same time, they are developing seven regions in their brains that they use to sing. Connections in and among those regions will allow a bird to master coordinating his beak movements and vocal tracts to make specific sounds. But this takes practice and maturation. On her computer, Peters pulls up two spectrographs from the same sparrow, one when he was nine months old and one from a month later. The improvement is obvious, with the notes and tune becoming more coherent and consistent as the bird matures.</p> <p>The similarity to a human infant’s language development—from listening to babble to words and phrases—isn’t completely unexpected. Because the basic organization of the vertebrate brain has been well-conserved by evolution, the brains of birds and humans are in some ways quite similar. What is surprising is how far the similarities run. Scientists have found that some birds can solve problems by insight and learn by example, just as human children do. Birds can learn to use tools and even do basic math. Such recent discoveries have guided neurobiologists to probe deeper, exploring the pathways birds and humans use to process information.</p> <p>One such scientist is Erich Jarvis, an associate professor of neurobiology at Duke. Jarvis is another product of the Peter Marler family tree, having studied under Marler’s former graduate student Fernando Nottebohm, who was among the first to identify regions of a songbird brain associated with learning and producing songs. Jarvis and his collaborators made a significant connection between human speech and birdsong in 2004 when they identified a gene called FOXP2—one of the key genes in human speech—in songbirds, parrots, and hummingbirds. In humans, mutations to the FOXP2 gene result in severe impairments in the ability to learn to speak, and Jarvis expected it would play a similar role in a songbird’s ability to sing. And it does—in zebra finches, the gene turns on during the critical period for song learning, and when it is blocked, birds cannot accurately imitate their tutors.</p> <p>Jarvis also has studied a gene called egr1, which too is active in all seven regions of the brain associated with singing. But he was surprised to discover that the gene is turned on also in seven areas adjacent to the song-producing regions, where it had a role in making body movements, such as when a bird hops or flaps its wings. The fact that the gene handles both duties suggests that the areas of a songbird’s brain involved in singing evolved from areas controlling movement.<br /> For Jarvis, a professionally trained dancer, the connection of song and motion offers exciting possibilities. He imagines that the same pattern may exist in humans, which could be why, for example, we naturally move and gesture with our hands when we talk.</p> <p>Carlos Botero, a former postdoctoral fellow at Duke and birdsong expert at the National Evolutionary Synthesis Center, believes Jarvis’ connection of movement, song, and speech is revolutionary, describing the theory as “kick-ass.” But not everyone is sold. Other neurobiologists call Jarvis’ model speculative and say it lacks enough evidence to be widely accepted.</p> <p>The criticisms, Jarvis argues, stem from scientists’ preconceived ideas. “The notion with song learning and spoken language is that the two are something ephemeral. They’re believed to be special and therefore different from anything else. So the minute you call them a motor behavior like learning to walk, or fly, that’s sacrilege.”</p> <p>Jarvis recently has identified other genes that have mutated over thousands of years to allow song-learning birds to control vocalization. He suggests that those same genes may contribute to our own ability to coordinate our mouth, larynx, and lung muscles to speak. “My prediction has been that if the behaviors are similar and the brain pathways are similar, then the underlying genes may be similar, and we are beginning to find that this is the case,” he says.</p> <p>Based on the commonalities of these genes, Jarvis believes he can take them from the brains of a learning species, such as zebra finches, and insert them into the brains of animals like pigeons or mice that do not have the ability to make intricate songs. In the lab, he will try to get those genes working so that they stimulate new connections in the non-song-producing animal’s brain. Essentially, he will try to develop a song-producing system in a species that doesn’t have one. And even if the experiment produces only a feeble note, it will provide compelling evidence for a link between song and muscle movement.</p> <p>A striking example of why that connection could be important comes from a lab just down the hall from Jarvis’ office in the Bryan Research Building. There, neuroscientist Richard Mooney is exploring whether understanding birdsongs—and the brain circuitry behind them—can give scientists new insights about human neurological disorders like Huntington’s and Parkinson’s diseases.</p> <p><img alt="" class="media-image" src="/sites/default/files/public/magazine/030412_birds10.jpeg" style="height:433px; width:350px" /></p> <div class="caption caption-center"> <div class="caption-width-container" style="width: auto;"> <div class="caption-inner"><strong>Song on the brain:</strong> Using a protein to make nerve cells glow bright green under a laser-powered microscope, scientists are able to observe how the structure of nerve cells in a living songbird’s brain change as the bird learns to sing. <p><em>Courtesy Richard Mooney</em></p> </div> </div> </div> <p>Mooney, the George Barth Geller Professor of neurobiology, has studied the brains of songbirds for almost thirty years to try to understand the neurological roots of learning. In 2009, he helped Susan Peters and Steve Nowicki establish how swamp sparrows tell the difference between correct and altered versions of their songs by placing electrodes into a songproducing region of the birds’ brains known as the high vocal center, or HVC. The team then recorded the birds’ brain activity and behavior as the sparrows listened to altered versions of their trills. The research showed that certain cells in the HVC were highly attuned to slight differences in the length of song notes, firing only when the notes fell within a narrow range of familiarity. This same pattern of recognition, called categorical perception, helps humans recognize subtle sounds in language, such as the difference between “ba” and “pa.” The Duke research was the first to explain the brain activity that underlies that categorical perception in birds.</p> <p>Now, Mooney is focusing on another song-producing region, located in a part of the brain known as the basal ganglia. In both birds and humans, the basal ganglia sit behind the eyes, deep within the tissues of the head. Neuroscientists think the brain cells in this area control voluntary movement of limbs and eyes, cognitive thinking, and possibly emotions. Yet, even subtle damage to cells there can severely impair movement, as in the case of Parkinson’s and Huntington’s diseases.</p> <p>Scientists are trying to gain a better understanding of how these diseases cause their effects, but researchers are limited by their ability to replicate the disorders in the lab. There are mouse models, in which the animals exhibit the same physical symptoms as patients with Parkinson’s or Huntington’s, including lack of coordination and unsteady balance while moving around. “You can tell that the behavior is abnormal, just like you can tell a person with a given neurological disorder is behaving abnormally,” says Mooney. “But it’s harder to know what’s wrong with the brain, and even more difficult to identify how damage to specific brain circuits produces certain motor abnormalities.”</p> <p>Mooney thinks songbirds might offer a better model. In his next research project, he plans to insert a gene thought to cause Huntington’s disease in the brains of zebra finches, activating it in a part of the basal ganglia known to be important in song learning. His research group will then observe how the gene affects the juvenile birds’ ability to learn a new song or repeat ones they have already learned. Because the team already knows the specific brain cells involved with learning songs, they should be able to trace learning problems to changes in specific brain cells. That, in turn, could suggest how the gene, when activated in our own basal ganglia, affects humans with the neurological disease.</p> <p>Mooney cautions that what happens in a bird’s brain is not exactly parallel to what happens in the brain of a human. But he is confident that the rich understanding scientists have gained in recent years about birds and their songs will ultimately benefit the understanding of our own minds, a revelation that adds a sweet harmony to all those tweets, chirps, and pick-up lines we hear each day at dawn.</p> <p><br /> <em>- Yeager is a science writer for the Duke Office of News and Communications. This is her first story for Duke Magazine.</em></p> </div></div></div> <h3 class="field-label"> Published </h3> <span class="date-display-single" property="dc:date" datatype="xsd:dateTime" content="2012-05-17T00:00:00-04:00">Thursday, May 17, 2012</span><section class="field field-name-field-main-image field-type-image field-label-above view-mode-rss"><h2 class="field-label">Main image:&nbsp;</h2><div class="field-items"><figure class="clearfix field-item even"><img typeof="foaf:Image" class="image-style-none" src="https://alumni.duke.edu/sites/default/files/dm-main-images/030412_birds1.jpeg" width="690" height="541" alt="" /></figure></div></section><section class="field field-name-field-topics field-type-taxonomy-term-reference field-label-above view-mode-rss"><h2 class="field-label">Tags:&nbsp;</h2><ul class="field-items"><li class="field-item even"><a href="/tags/natural-sciences" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Natural Sciences</a></li><li class="field-item odd"><a href="/tags/biological-sciences" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Biological Sciences</a></li><li class="field-item even"><a href="/tags/faculty" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Faculty</a></li></ul></section><section class="field field-name-field-author field-type-taxonomy-term-reference field-label-above view-mode-rss"><h2 class="field-label">Writer:&nbsp;</h2><ul class="field-items"><li class="field-item even"><a href="/magazine/author/ashley-yeager" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Ashley Yeager</a></li></ul></section><section class="field field-name-field-issue field-type-taxonomy-term-reference field-label-above view-mode-rss"><h2 class="field-label">Issue:&nbsp;</h2><ul class="field-items"><li class="field-item even"><a href="/magazine/issue/mar-apr-2012" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Mar - Apr 2012</a></li></ul></section> <h3 class="field-label"> Featured article </h3> Yes <h3 class="field-label"> Background color </h3> blue<section class="field field-name-field-sub-header field-type-text-long field-label-above view-mode-rss"><h2 class="field-label">Sub-header:&nbsp;</h2><div class="field-items"><div class="field-item even">A sparrow’s song may seem a simple melody, but it’s actually the product of some pretty sophisticated brainwork. In fact, studying how birds sing may give us new insights about our own ability to speak, move, and think.</div></div></section> <h3 class="field-label"> Cover Story </h3> <h3 class="field-label"> Homepage </h3> Thu, 17 May 2012 08:00:00 +0000 Joseph Sorensen, JOSEPH E. 18502440 at https://alumni.duke.edu https://alumni.duke.edu/magazine/articles/bird-brained#comments