Friday, December 21, 2012

Birdsong study pecks theory that music is uniquely human

Sometimes he sounds like music to her ears. Other times, not so much.

By Carol Clark

A bird listening to birdsong may experience some of the same emotions as a human listening to music, suggests a new study on white-throated sparrows, published in Frontiers of Evolutionary Neuroscience.

“We found that the same neural reward system is activated in female birds in the breeding state that are listening to male birdsong, and in people listening to music that they like,” says Sarah Earp, who led the research as an undergraduate at Emory University.

For male birds listening to another male’s song, it was a different story: They had an amygdala response that looks similar to that of people when they hear discordant, unpleasant music.

The study, co-authored by Emory neuroscientist Donna Maney, is the first to compare neural responses of listeners in the long-standing debate over whether birdsong is music.

“Scientists since the time of Darwin have wondered whether birdsong and music may serve similar purposes, or have the same evolutionary precursors,” Earp notes. “But most attempts to compare the two have focused on the qualities of the sound themselves, such as melody and rhythm.”

Earp’s curiosity was sparked while an honors student at Emory, majoring in both neuroscience and music. She took “The Musical Brain” course developed by Paul Lennard, director of Emory’s Neuroscience and Behavioral Biology program.

“During one class, the guest speaker was a composer and he said that he thought that birdsong is like music, but Dr. Lennard thought it was not,” Earp recalls. “It turned into this huge debate, and each of them seemed to define music differently. I thought it was interesting that you could take one question and have two conflicting answers that are both right, in a way, depending on your perspective and how you approach the question.”

Perhaps your brain would enjoy some music while reading this. Here's a sample of Earp's favorite: "Firebird."
 

As a senior last year, Earp received a grant from the Scholars Program for Interdisciplinary Neuroscience Research (SPINR), and a position in the lab of Maney, who uses songbirds as a model to study the neural basis of complex learned behavior.

When Earp proposed using the lab’s data to investigate the birdsong-music debate, Maney thought it was a great idea. “Birdsong is a signal,” Maney says. “And the definition of a signal is that it elicits a response in the receiver. Previous studies hadn’t approached the question from that angle, and it’s an important one.”

Earp reviewed studies that mapped human neural responses to music through brain imaging.

She also analyzed data from the Maney lab on white-throated sparrows. The lab maps brain responses in the birds by measuring Egr-1, part of a major biochemical pathway activated in cells that are responding to a stimulus.

The study used Egr-1 as a marker to map and quantify neural responses in the mesolimbic reward system in male and female white-throated sparrows listening to a male bird’s song. Some of the listening birds had been treated with hormones, to push them into the breeding state, while the control group had low levels of estradiol and testosterone.

During the non-breeding season, both sexes of sparrows use song to establish and maintain dominance in relationships. During the breeding season, however, a male singing to a female is almost certainly courting her, while a male singing to another male is challenging an interloper.


Justin Bieber, watch your back: A male white-throated sparrow belts out a tune.

For the females in the breeding state every region of the mesolimbic reward pathway that has been reported to respond to music in humans, and that has a clear avian counterpart, responded to the male birdsong. Females in the non-breeding state, however, did not show a heightened response.

And the testosterone-treated males listening to another male sing showed an amygdala response, which may correlate to the amygdala response typical of humans listening to the kind of music used in the scary scenes of horror movies.

“The neural response to birdsong appears to depend on social context, which can be the case with humans as well,” Earp says. “Both birdsong and music elicit responses not only in brain regions associated directly with reward, but also in interconnected regions that are thought to regulate emotion. That suggests that they both may activate evolutionarily ancient mechanisms that are necessary for reproduction and survival.”

A major limitation of the study, Earp adds, is that many of the regions that respond to music in humans are cortical, and they do not have clear counterparts in birds. “Perhaps techniques will someday be developed to image neural responses in baleen whales, whose songs are both musical and learned, and whose brain anatomy is more easily compared with humans,” she says.

Earp, who played the viola in the Emory orchestra and graduated last May, is now a medical student at the Cleveland Clinic.

So what music makes her brain light up? “Stravinsky’s ‘Firebird’ suite,” Earp says.

Related:
Doing the math for how songbirds learn to sing
Notes on the musical brain
A clinical look at the Bieber Fever pandemic
Teen brain data predicts pop song success

Photos by iStockphoto.com.

Wednesday, December 19, 2012

Anthropologist inspires students to embrace the world

“It kind of blows you away,” Peter Brown says of the many success stories of his students, who have gone on to careers in academia and health care.

By Carol Clark

Someone once videotaped Emory anthropologist Peter Brown teaching a class. One of his sons, who was around 4-years-old at the time, was shocked when he saw the video.

“He asked me, ‘Daddy, why are you yelling at all those people?’” Brown recalls, laughing. “Sometimes I can get really worked up while giving lectures.”

That passion netted Brown two major career awards in 2012: The American Anthropological Association (AAA)/Oxford University Press Award for Excellence in Undergraduate Teaching in Anthropology and the Society for Medical Anthropology Graduate Student Mentoring Award. Both awards – the first recognition by his peers, and the second by his students – were presented at the recent AAA annual meeting in San Francisco.

“I’ve been an anthropologist for half-a-century,” says George Armelagos, one of Brown’s colleagues at Emory, “and I’ve never seen anyone receive two teaching awards at one meeting. Peter has taught more than 3,000 students at Emory, but nationwide, he’s reached more than 180,000 through his books.”

When one of those former Emory students told Brown that she was headed to Malawi to apply her new skills as a medical doctor, Brown felt immensely proud, and asked her what useful knowledge she had retained from his anthropology courses.

She wrote back: “What I really remember is the story of how the town doctor (in Sardinia) came to your door after some fishermen saw you hanging out the laundry. They were worried because the only reason a man would do the laundry was if his wife was terribly sick! Your wife Betsy was fine, but you said that you learned an important lesson in appropriate sex-role behavior. It was a funny story for sure.”

The housewives of Sardinia. While researching the effects of malaria eradication in 1976, Peter Brown, at left, learned that Italian men rarely do laundry.

In nominating Brown for the awards, several of his students described how he cultivated their interest in medical anthropology by combining facts and personal stories.

“I try to draw on my experiences to help students better understand their own lives, and their own world,” Brown says.

Emory graduate student Kathryn Bouskill recalls how Brown commemorated World AIDS Day last year with a moving talk that wove in stories about his brother and brother-in-law, to whom he was very close, and who both lost their lives to AIDS. “Many students in the lecture hall had tears in their eyes, and many expressed to me afterwards that they had never heard a personal account of HIV/AIDS,” Bouskill wrote to the AAA awards committee. “They said it gave them a compassionate view of real-world issues that they will hold with them long after graduation.”

Brown grew up in Los Angeles where his early passions were ecology and the Boy Scouts. “They say anthropologists are sociologists who like to camp,” Brown says, adding that he knew fairly early that he wanted to be a teacher.

He attended Notre Dame, and then graduate school at the State University of New York at Stony Brook, where he honed his interest in medical anthropology and disease ecology. Brown was finishing up his PhD when Emory offered him a job in 1978.

"I think it's important to teach with optimism and identify heroes," says Brown. He cites a Bangladesh campaign for simple, life-saving oral rehydration as a global health success story.

“I told my wife that I would go anywhere with a football team,” Brown recalls. “That was a joke, because pretty much every college had football.”

Emory, of course, did not. The small, private college had not been on Brown’s radar, but he accepted the offer to become one of the three founding faculty members of Emory’s new anthropology department. The next year, Emory received what was then the largest single gift to higher education in U.S. history: The $105 million Woodruff Fund.

“Who gets chances like that? I felt unbelievably lucky, to be part of a growing department at a growing university,” Brown recalls.

Brown was among the key faculty who helped Emory anthropology develop a strongly collaborative, bio-cultural niche, and gain a reputation as one of the leading graduate programs for anthropologists in the country. The students can draw on resources from throughout the University, including the Rollins School of Public Health (where Brown also teaches), and the adjacent Centers for Disease Control and Prevention.

For undergraduates, Brown created a Global Health Minor. “No matter what their major, I want students to become international citizens and understand that the living conditions in most of the world are not nearly as luxurious as here,” Brown says. “In many places, what’s needed to improve health is not CAT scanners and other technology, but sewage systems and better nutrition.”

Brown has developed and taught some two-dozen different courses while at Emory, in addition to conducting research and writing books. During the course of his career, “international health” evolved into what is now called “global health,” encompassing scores of non-governmental agencies that brought more money and actors to the table.

“Incredible progress has been made,” Brown says, “things have been done that I wouldn’t have thought possible.”

After the cause of HIV/AIDS was found, he notes, anti-retroviral drugs were developed relatively fast, the price of the drugs soon came down, and wealthier nations began funding their widespread use in the developing world.

Brown shares a dinner with former students Sarah Willen, center, and Svea Closser, right, and Closser's 4-year-old son, Kaif.

Brown also cites the success of the Bangladesh Rural Advancement Committee, or BRAC, which he calls “the largest NGO you’ve never heard of.” BRAC helped spur a child-survival revolution by targeting the deadly effects of diarrheal disease. “They teach people how to use a Gatorade-like solution for oral rehydration,” Brown says. “They scaled up a liter of water, a handful of sugar and a pinch of salt into a major health-care intervention.”

Brown believes in focusing on the hopeful examples amid the complex problems facing global health. “I think it’s important to teach with optimism and identify heroes,” he says. “If you’re a pessimist, you’re not helping students at all.”

That affirming spirit made a big difference in the life of Aun Lor, who attended Emory after surviving the “killing fields” genocide of Cambodia, where he lost his father, his three older brothers and his sister. “These experiences could have set me on the wrong path to self-destruction, but among a few people who have helped me channel my frustration and energy into something positive was Peter Brown,” Lor wrote to the AAA awards committee. “I learned from Peter that among my best teaching and advocacy tools are my life experiences. These experiences give me a real voice.”

Lor, who was mentored by Brown both as an undergraduate at Emory and a graduate student at Rollins School of Public Health, now works at the CDC.

“It kind of blows you away,” Brown says of the many accomplishments of his students who have gone on to successful careers in academia and health care.

His mentoring often evolves into friendships that extend far beyond Emory.

Svea Closser, now an assistant professor at Middlebury College, wrote that one of her favorite memories of Brown occurred after she received her PhD and attended a conference in Mexico. “Peter rented a minivan to drive me and many other current and former grad students across Mexico, all the while tirelessly playing ‘Guess What Animal I Am’ with my four-year-old,” Closser wrote. “And, of course, he made time at the conference to give thoughtful, much-appreciated advice to an undergraduate student of mine.”

Related:
Great teacher thrives in unique habitat
Doctorate's ORDER: Teach your research
Uganda closing in on river blindness

Credits: Top photo by Carol Clark; Bangladesh photo by iStockphoto.com; other photos courtesy of Peter Brown. 

Monday, December 17, 2012

Doing the math for how songbirds learn to sing

A baby house finch and its father. Just like humans, baby birds learn to vocalize by listening to adults.

By Carol Clark

Scientists studying how songbirds stay on key have developed a statistical explanation for why some things are harder for the brain to learn than others.

“We’ve built the first mathematical model that uses a bird’s previous sensorimotor experience to predict its ability to learn,” says Emory biologist Samuel Sober. “We hope it will help us understand the math of learning in other species, including humans.”

Sober conducted the research with physiologist Michael Brainard of the University of California, San Francisco.

Their results, showing that adult birds correct small errors in their songs more rapidly and robustly than large errors, were published in the Proceedings of the National Academy of Sciences (PNAS).

Sober’s lab uses Bengalese finches as a model for researching the mechanisms of how the brain learns to correct vocal mistakes.

Just like humans, baby birds learn to vocalize by listening to adults. Days after hatching, Bengalese finches start imitating the sounds of adults. “At first, their song is extremely variable and disorganized,” Sober says. “It’s baby talk, basically.”

The young finches keep practicing, listening to their own sounds and fixing any mistakes that occur, until eventually they can sing like their elders.

A Bengalese finch outfitted with headphones. Research on how the birds learn to sing may lead to better human therapies for vocal rehabilitation.

Young birds, and young humans, make a lot of big mistakes as they learn to vocalize. As birds and humans get older, the variability of mistakes shrinks. One theory contends that adult brains tend to screen out big mistakes and pay more attention to smaller ones.

“To correct any mistake, the brain has to rely on the senses,” Sober explains. “The problem is, the senses are unreliable. If there is noise in the environment, for example, the brain may think it misheard and ignore the sensory experience.”

The link between variability and learning may explain why youngsters tend to learn faster and why adults are more resistant to change.

“Whether you are an opera singer or a bird, there is always variability in your sounds,” Sober says. “When the brain receives an error in pitch, it seems to use this very simple and elegant strategy of evaluating the probability of whether the error was just extraneous ‘noise,’ a problem reading the signal, or an actual mistake in the vocalization.”

Click to watch video of how the headphones are made.
The researchers wanted to quantify the relationship between the size of a vocal error, and the probability of the brain making a sensorimotor correction. The experiments were conducted on adult Bengalese finches outfitted with light-weight, miniature headphones.

As a bird sang into a microphone, the researchers used sound-processing equipment to trick the bird into thinking it was making vocal mistakes, by changing the bird’s pitch and altering the way the bird heard itself, in real-time.

“When we made small pitch shifts, the birds learned really well and corrected their errors rapidly,” Sober says. “As we made the pitch shifts bigger, the birds learned less well, until at a certain pitch, they stopped learning.”

The researchers used the data to develop a statistical model for the size of a vocal error and whether a bird learns, including the cut-off point for learning from sensorimotor mistakes. They are now developing additional experiments to test and refine the model.

“We hope that our mathematical framework for how songbirds learn to sing could help in the development of human behavioral therapies for vocal rehabilitation, as well as increase our general understanding of how the brain learns,” Sober says.

The research was supported by grants from the National Institute of Deafness and Communications Disorders, the National Institute of Neurological Diseases and Stroke and the National Institute of Mental Health.

Related:
Bird song study pecks theory that music is uniquely human
How we learn language
Notes on the musical brain
How young mice phone home

Credits: Top image by iStockphoto.com. Other images courtesy of Sam Sober.

Thursday, December 13, 2012

Primatologist meets 'minimalist human'

“Evolutionary Origins of Human Mind” was the theme of the recent International Institute for Advanced Studies conference in Kyoto, Japan. The attendees, including Emory primatologist Frans de Waal, discussed everything from chimpanzee culture to androids. In the video above, de Waal bonds with the Telenoid, a “minimalist human” who enjoys chatting.

Studying the evolution of the human mind is not only helping us understand ourselves, it is also advancing robotics. Click here to listen to a podcast with de Waal and other researchers from the Kyoto conference, recorded by the Center for International Collaboration and Advanced Studies in Primatology.

Related:
Why robots should care about their looks

Tuesday, December 11, 2012

Math formula gives new glimpse into the magical mind of Ramanujan

Ramanujan said he saw math through the eyes of a Hindu goddess.

By Carol Clark

December 22 is the 125th anniversary of the birth of Srinivasa Ramanujan, an Indian mathematician renowned for somehow intuiting extraordinary numerical patterns and connections without the use of proofs or modern mathematical tools. A devout Hindu, Ramanujan said that his findings were divine, revealed to him in dreams by the goddess Namagiri.

“I wanted to do something special, in the spirit of Ramanujan, to mark the anniversary,” says Emory mathematician Ken Ono. “It’s fascinating to me to explore his writings and imagine how his brain may have worked. It’s like being a mathematical anthropologist.”

Ono, a number theorist whose work has previously uncovered hidden meanings in the notebooks of Ramanujan, set to work on the 125th-anniversary project with two colleagues and former students: Amanda Folsom, from Yale, and Rob Rhoades, from Stanford.

Srinivasa Ramanujan
The result is a formula for mock modular forms that may prove useful to physicists who study black holes. The work, which Ono recently presented at the Ramanujan 125 conference at the University of Florida, also solves one of the greatest puzzles left behind by the enigmatic Indian genius.

While on his death-bed in 1920, Ramanujan wrote a letter to his mentor, English mathematician G. H. Hardy. The letter described several new functions that behaved differently from known theta functions, or modular forms, and yet closely mimicked them. Ramanujan conjectured that his mock modular forms corresponded to the ordinary modular forms earlier identified by Carl Jacobi, and that both would wind up with similar outputs for roots of 1.

No one at the time understood what Ramanujan was talking about. “It wasn’t until 2002, through the work of Sander Zwegers, that we had a description of the functions that Ramanujan was writing about in 1920,” Ono says.

Building on that description, Ono and his colleagues went a step further. They drew on modern mathematical tools that had not been developed before Ramanujan’s death to prove that a mock modular form could be computed just as Ramanujan predicted. They found that while the outputs of a mock modular form shoot off into enormous numbers, the corresponding ordinary modular form expands at close to the same rate. So when you add up the two outputs or, in some cases, subtract them from one another, the result is a relatively small number, such as four, in the simplest case.

“We proved that Ramanujan was right,” Ono says. “We found the formula explaining one of the visions that he believed came from his goddess.”

“No one was talking about black holes back in the 1920s when Ramanujan first came up with mock modular forms, and yet, his work may unlock secrets about them,” Ono says.

Ono uses a “magic coin” analogy to illustrate the complexity of Ramanujan’s vision. Imagine that Jacobi, who discovered the original modular forms, and Ramanujan are contemporaries and go shopping together. They each spend a coin in the same shop. Each of their coins goes on a different journey, traveling through different hands, shops and cities.

“For months, the paths of the two coins look chaotic, like they aren’t doing anything in unison,” Ono says. “But eventually Ramanujan’s coin starts mocking, or trailing, Jacobi’s coin. After a year, the two coins end up very near one another: In the same town, in the same shop, in the same cash register, about four inches apart.”

Ramanujan experienced such extraordinary insights in an innocent way, simply appreciating the beauty of the math, without seeking practical applications for them.

“No one was talking about black holes back in the 1920s when Ramanujan first came up with mock modular forms, and yet, his work may unlock secrets about them,” Ono says.

Expansion of modular forms is one of the fundamental tools for computing the entropy of a modular black hole. Some black holes, however, are not modular, but the new formula based on Ramanujan’s vision may allow physicists to compute their entropy as though they were.

Watch the trailer to a forthcoming film about the life of Ramanujan:

After coming up with the formula for computing a mock modular form, Ono wanted to put some icing on the cake for the 125th-anniversary celebration. He and Emory graduate students Michael Griffin and Larry Rolen revisited the paragraph in Ramanujan’s last letter that gave a vague description for how he arrived at the functions. That one paragraph has inspired hundreds of papers by mathematicians, who have pondered its hidden meaning for eight decades.

“So much of what Ramanujan offers comes from mysterious words and strange formulas that seem to defy mathematical sense,” Ono says. “Although we had a definition from 2002 for Ramanujan’s functions, it was still unclear how it related to Ramanujan’s awkward and imprecise definition.”

Ono and his students finally saw the meaning behind the puzzling paragraph, and a way to link it to the modern definition. “We developed a theorem that shows that the bizarre methodology he used to construct his examples is correct,” Ono says. “For the first time, we can prove that the exotic functions that Ramanujan conjured in his death-bed letter behave exactly as he said they would, in every case.”

A highlight of working on a film about Ramanujan's life was getting to browse through some of the Indian master's original notebooks, says Ono, above right.

Although Ramanujan received little formal training in math, and died at the age of 32, he made major contributions to number theory and many other areas of math.

In the fall, Ono traveled to Ramanujan’s home in Madras, and to other significant sites in the Indian mathematician’s life, to participate in a docu-drama. Ono acted as a math consultant, and also has a speaking part in the film about Ramanujan, directed by Nandan Kudhyadi and set to premiere next year.

“I got to hold some of Ramanujan’s original notebooks, and it felt like I was talking to him,” Ono says. “The pages were yellow and falling apart, but they are filled with formulas and class invariants, amazing visions that are hard to describe, and no indication of how he came up with them.”

Ono will spend much of December in India, taking overnight trains to Mysore, Bangalore, Chennai and New Dehli, as part of a group of distinguished mathematicians giving talks about Ramanujan in the lead-up to the anniversary date.

“Ramanujan is a hero in India so it’s kind of like a math rock tour,” Ono says, adding, “I’m his biggest fan. My professional life is inescapably intertwined with Ramanujan. Many of the mathematical objects that I think about so profoundly were anticipated by him. I’m so glad that he existed.”

Related:
New theories reveal the nature of numbers
A surprise dimension to adding and counting
How a hike in the woods led to a math 'Eurkea!'

Image credits: Hindu temple by iStockphoto.com; Ramanujan photo via Oberwolfach Photo Collection/Konrad Jacobs; black hole simulation by NASA, M. Weiss (Chandra X-Ray Center); bottom photo courtesy of Ken Ono.

Monday, December 10, 2012

Aladdin to Lincoln: How stories shape a life


The tales that we read, and the tales that we spin about ourselves, play a role in helping us realize our full potential, says Jordan Greenwald, who gave a TEDxEmory talk last spring (see above video) as an Emory senior, majoring in psychology.

Greenwald counts stories of both the fictional Aladdin, and the real-life Abraham Lincoln as strong influences in shaping his own life.

“Stories give us an emotional education, “ Greenwald says. “If we don’t address this inner world of dreams, desires, anxieties, we risk meandering, which really means forfeiting who we could become.” 

Related:
Prometheus: Seeding wonder and science
Stories your parents should have told you

Tuesday, December 4, 2012

Uganda closing in on river blindness


In 2007, Uganda announced a bold plan to eliminate river blindness by 2020. The Carter Center’s Moses Katabarwa, a graduate of Emory’s Rollins School of Public Health, has been in the battle from the beginning— and he believes they’re going to win. Photos by Kay Hinton.

By Paige Parvin, Emory Magazine

The River Nile is the longest in the world, moving mightily over more than four thousand miles and through ten African countries before emptying itself into the Mediterranean Sea. For millions it is the source of life and legend, death and mystery, symbol and song—not to mention water, food, transportation, and money. It is at once mythic and utterly real, visible from space and from bridges, banks, and boats.

As the matriarch of Uganda’s many rivers and streams, the Nile holds innumerable secrets, including a tiny black fly that breeds only in swift-moving waters and carries inside it the makings of a particular sort of human misery: onchocerciasis, or river blindness.

Black fly larvae cling to underwater vegetation, developing until they eventually take wing and break the surface as adult flies. 

It’s this fly that Moses Katabarwa, a Uganda native and senior epidemiologist for The Carter Center’s River Blindness Program, has been chasing for more than 20 years. The black fly Simulium—about the size of a Georgia gnat—is unusual in its preference for moving water, since so many of its brethren pests like to breed in warm, stagnant puddles and ponds. Two different types of the fly carry the river blindness parasite, Onchocerca volvulus—one, S. damnosum, dives into flowing waters to lay its eggs, shooting them from its tiny body bundled in a superglue-like substance that sticks them firmly to underwater rocks or vegetation. The other, S. neavei, can lay eggs only in small river crabs and has a shorter flight range than its wily cousin.

When people are bitten by female flies (the males don’t bite), they can become infected with onchocerciasis microfilaria, pre-larval-stage parasitic worms that wriggle their way around under the skin. Like the Guinea worm parasite—another of The Carter Center’s targeted diseases—these worms can breed inside the body; they multiply and sometimes form writhing nodules that can be felt and even seen.

Ojok Charles lost his sight completely after he became severely infected at age 12 with the river blindness parasite. He says he could feel the worms moving in his eyes as the disease progressed.

And they love to migrate up to the eye, where they cause irritation and nerve damage, and eventually, as they die, leave debris that can build up to the point of diminished vision and permanent blindness. Affecting some eighteen million people in Africa and the Americas, the disease is the second-leading cause of preventable blindness in the world.

River blindness infection triggers an immune response similar to that of an allergic reaction, which is why it causes intense itching, swelling, rashes, lesions, and skin discoloration—a pattern commonly referred to as “leopard skin.” Ironically, a strong immune system can produce a more severe reaction.

“If you have an efficient immune system, you will suffer much more,” says Katabarwa. “The more you scratch, the more you want to.”

It takes many fly bites to produce a bad infection—what health workers offhandedly call a high “worm load”—but in rural villages that are situated near swift-moving rivers and streams, it’s not hard to become bait.

Read more in Emory Magazine.

Related:
On the trail of black flies

Tuesday, November 27, 2012

Psychedelics, the brain and shamanism



“Call upon me, for I am the black jaguar. It is me you must evoke if you wish to scare the illness away.” These words of a Brazilian shaman describe the ancient practice of creating a charismatic intermediary with the divine.

In the above video, Emory art historian Rebecca Stone gives a brief overview of an ongoing exhibit at the Carlos Museum, “For I Am the Black Jaguar,” that explores shamanism through art, zoology, botany, religion and anthropology.

The trances that transformed shamans into totems like jaguars and whale sharks were brought about in part by the ingestion of etheogenic substances. Psychiatrists Katherine MacLean and Charles Raison will discuss what happens in the brain during these trances in a special lecture at the museum, on Thursday, November 29 at 7:30 pm.

Related:
Tapping traditional remedies to fight modern super bugs

Saturday, November 24, 2012

Chemists fine-tune ideas on how life evolved


By Carol Clark

An iPod can store a music library in a wafer-thin device that fits in your palm, providing a vast amount of data at your fingertips. But a human cell, only a few microns across, contains all of the information that made you. And even more remarkable, the first complex cells are thought to have somehow self-assembled from the fundamental building blocks of life.

The Accounts of Chemical Research (ACR) devoted its entire December issue to ideas about this self-assembly process, and how it could have enabled life to emerge from the chemical soup of early Earth and grow increasingly complex. By understanding this process, chemists hope to boost our ability to bioengineer living systems in ways that benefit us, just as computer engineers do with digital devices like iPods.

“Chemists have spent a long time breaking down cells and looking at their individual components,” says Emory chemist Anil Mehta. “Now we have a fantastic understanding of these parts. So how do we put them together? How can we, as chemists, get new complex networks to emerge from these components that communicate with each other? We are right on the verge of achieving this.”

The special ACS issue was edited by three Emory chemists – Mehta, Jay Goodwin and David Lynn, who are all also part of the NSF/NASA Center for Chemical Evolution – and a University of Utah chemist, Cynthia Burrows.

“We’re trying to figure out how to get from inanimate matter to living matter,” Goodwin says. “It’s one of science’s greatest challenges, and a problem the scientific community has been working on for centuries.”

The quest has heated up during the last decade, largely driven by genetic sequencing technology and our growing understanding of the minimum amount of information needed for evolution.

Fossils from Western Australia indicate that the earliest life may have been primitive bacteria going back about 3.4 billion years. “But it wasn’t until the ribosome appeared, around 3 billion years ago, that life exploded,” Mehta says. “Everything seems to have radiated from the ribosome.”

Ribosomes are essentially little machines that churn out proteins from nucleic acids. And proteins and nucleic acids are two biological macromolecules that learned to collaborate in encoding, transmitting and expressing genetic information.

In a paper included in the ACR issue, the Emory chemists use a digital-to-analog converter model to explain how the polymer cooperation of ribosomes may have helped the first dynamic functional networks reach the critical threshold for the emergence of cellular life.

Presumably, the polymers of proteins and nucleic acids evolved separately, and then found a way to join forces. “They both have strengths and weaknesses,” Goodwin says. “And together they make a system that takes advantage of the strengths of both, generating greater diversity and evolutionary potential.”

The nucleic acids are the digital part of the system, providing the ability to store vast amounts of information, like songs on an iPod, with crucial and exacting accuracy. Proteins are analog, delivering responsiveness and a continually variable range of functionality, such as the ability to communicate with internal and external networks, or play the songs. The ribosome functions like a digital-analog convertor that joins these two components into a single, dynamic system.

“We recognize that the march of molecular history likely had many pathways,” Lynn says. The aim of the special ACR issue is to bring together different areas of research on the problem, he adds. “Just as it takes a diversity in chemical composition for the evolution of life, it takes a diversity of ideas to fully comprehend the origins of that evolution.”

Related:
Chemists go in search of little green molecules
Peptides may hold 'missing link' to life

Top image: iStockphoto.com.

Tuesday, November 20, 2012

Paleontologist goes wild for Thanksgiving


Emory paleontologist Anthony Martin has prepared a special Thanksgiving treat -- a post about wild turkeys on his blog, "Life Traces of the Georgia Coast." Here's an excerpt:

"Unfortunately, because I live in the metropolitan Atlanta area, I never see turkeys other than the dead packaged ones in grocery stores. Nonetheless, one of the ways I experience turkeys as wild, living animals is to visit the Georgia barrier islands, and the best way for me to learn about wild turkey behavior is to track them. This is also great fun for me as a paleontologist, as their tracks remind me of those made by small theropod dinosaurs from the Mesozoic Era. And of course, as most schoolchildren can tell you, birds are dinosaurs, which they will state much more confidently than anything they might know about Benjamin Franklin."

Click here to read more.

Related:
Polar dinosaur tracks open new trail to past

Image: Wikipedia Commons.

Friday, November 16, 2012

A clinical look at the Bieber Fever pandemic



Why does the pop superstar Justin Bieber cause most adults to roll their eyes and many adolescent girls to scream and swoon? In the above video, Emory psychologist Jared DeFife explains how cases of Bieber Fever may be tied to both mental, biological and chemical processes of human development.

Related:
Batman and the psychology of trauma

Tuesday, November 13, 2012

Positive mental health boosts lifespan, study finds


People who are flourishing – both feeling happy and functioning well in their lives – are 60 percent less likely to die prematurely, finds a major study that followed more than 3,000 U.S. adults over 10 years.

The results, published in the American Journal of Public Health, applied to both men and women of varying ages, races, weights and socio-economic status.

“We’ve shown that, even when you factor in many other variables, if you are flourishing you have a dramatically lower risk of premature mortality, no matter what the cause of death,” says lead author Corey Keyes, a sociologist at Emory University and a pioneer of positive psychology.

The data for the analysis drew from the Midlife in the United States Study, which measured baseline positive mental health of the participants in 1995, and followed up in 2005. The ages of the participants spanned 25 to 74 at the beginning of the study, and 35 to 84 at the conclusion.

In the baseline survey, the participants were asked if they had suffered within the past year from depression, panic disorder or generalized anxiety, conditions that have been associated with a higher risk of premature mortality. They were also assessed for emotional happiness, or simply feeling good, and for whether they were functioning well in life, or flourishing. The term flourishing encompasses factors such as managing stress, achieving intimacy with others, working productively and making a contribution to society.

Nearly 50 percent of the study participants, who were representative of the general population, met the criteria for sufficiently high emotional well-being. Only 18 percent, however, were flourishing, meaning they met the full criteria of sufficiently high emotional well-being, combined with sufficiently high social well-being.

“You need both of these qualities for complete happiness,” Keyes says.

A total of 6.3 percent of the participants died during the study period. The odds ratio for mortality was 1.62 for adults who were not flourishing, relative to participants with flourishing mental health.

“What was most amazing to me was that the results held for all ages,” Keyes says. “Even late in life, if you are flourishing you are significantly less likely to die prematurely.”

Tobacco use and physical inactivity, behaviors associated in previous studies with people who have lower levels of emotional well-being, may partially explain how positive mental health affects mortality, Keyes says.

“We focus so much of our national health resources on treating mental illness, when it’s actually the absence of well-being that is getting to us,” Keyes says. “It may be common sense, but it’s uncommon public policy to invest more in promoting well-being.”

Related:
Compassion meditation may boost empathy
The pursuit of happiness

Image: iStockphoto.com.

Wednesday, November 7, 2012

Optical experiment eyes Parthenon mystery

The Parthenon ruins in Athens. "For complex visual and psychological reasons, it's an extremely powerful building," Bonna Wescoat says.

By Carol Clark

The Parthenon, one of the most important buildings in world history, has been studied for centuries, but many questions remain about the 2,500-year-old centerpiece to the Acropolis. Among them is the mystery of why an ornate frieze was located in a seemingly obscure position, high on the outside wall of the Parthenon’s central chamber, and partially blocked by the surrounding colonnade.

An optical experiment, to be led by students of Emory University art historian Bonna Wescoat, will take a fresh look at the puzzle. Volunteer observers have been recruited to participate in the event, to take place on Saturday, November 10, at the Nashville Parthenon, a full-scale replica of the original building.

“We’re recreating the experience of how the ancient Athenians may have viewed the frieze as they approached the Parthenon,” Wescoat says. “This experiment could become a paradigm-shifting intervention in the studies of the frieze. We’re bringing the science of seeing into the discussion, an important and overlooked area.”

The original Parthenon, in Athens, Greece, was built to honor the goddess Athena, the patron of the city. “For complex visual and psychological reasons, it’s an extremely powerful building,” says Wescoat, whose research focuses on ancient Greece. “There’s not a straight line in the Parthenon, every single stone in it is curved and tapered slightly. And the proportions are not the usual one-to-two, which is stable, but four-to-nine. These subtle refinements produce an energy and tension that engages the eye.”

One section of the Parthenon's frieze was still in place when William Stillman took this photograph in the 1860s. (Michael C. Carlos Museum.)

The building was elaborately painted, and outfitted with beautiful statuary and adornments, including the celebrated frieze. Wrapping around the four sides of the building, the carved marble panels depict a ceremonial procession. Now dispersed between museums in London, Paris and Athens, the frieze is considered an icon of Western art.

It has long been debated why such a refined work of art was placed in what seems like an obscure, cramped location. Scholars have surmised that viewers would have to crane their necks to glimpse the frieze, and much of its detail would be lost in the shadowy, ambient light. Some have even suggested that the frieze was not part of the original plan for the Parthenon, and may have been added as an afterthought.

Wescoat is among the doubters of that theory. Her perspective has been shaped both by her work on major archeology projects in Greece and frequent visits to the Nashville Parthenon, about a four-hour drive from Atlanta.

The Nashville Parthenon, originally built for Tennessee’s 1897 Centennial Exposition, is made of concrete, not marble, and it does not include all of the original structure’s ornamentations, such as the frieze. But the replica offers a vision of the Parthenon not as a ruin, but as a complete building.


Bonna Wescoat and graduate student An Jiang compare images of the original frieze to a canvas simulation. Photo by Ann Borden.

“Each time I’ve taken students to the Nashville Parthenon, I’ve thought that the area where the frieze would be located is not as bad as it is made out to be,” Wescoat says. “It’s an intimate area. Tracking the panels with your eye, catching shifting views of them between columns, requires an effort that draws you in. You have to keep moving, just as in the procession portrayed by the frieze. The scene is both timeless and timely, an enduring visual expression of the citizens’ relationship to their divine patron, Athena.”

After officials at the Nashville Parthenon gave their blessing, Wescoat and the 11 students in her seminar called Ancient Greek Architectural Decoration set about designing an experiment to test the visibility of the frieze. They decided to create facsimiles of some of the panels and install them in situ.

Their work began with a reconnaissance trip to Nashville in September, where the students decided to concentrate on panels that would have adorned the northwest corner of the building.



The students returned to Atlanta and set up a workshop in the Michael C. Carlos Museum for their Parthenon Project. They made full-scale line drawings for each of the original marble panels. They researched what colors the ancient Greek artists might have used, and how color might have factored in with the visibility. The end result is five painted canvas panels, and a sixth panel made of insulation foam to imitate the 2-inch relief of the original frieze.

“It gives you a much better appreciation for the artists who carved this out of marble,” says Rebecca Levitan, a senior art history major, as she dabs a finishing touch of paint on a horse’s hoof.

The ancient Greek figures take on a new vibrancy with paint. “They start to come alive as we add color and shading,” says Katie Cupello, a graduate student in art history.

Click on the photo above, to enlarge the image and get a better view of the completed panels. Photo by Katie Cupello.

This weekend, the students will return to the Nashville Parthenon with the completed panels, where they will be installed in their correct positions on the building. They will recreate the processional routes of the Athenian Acropolis, using contractor’s spray to stake out the paths. On Saturday, the volunteer observers will move along the passages, starting about 35 feet away from the building, and describe how well, and how much of the frieze they can see, using a detailed questionnaire form. As they move along, the volunteers will also use green contractors’ flags to mark particularly good viewing spots.

The result will be the first experimental data on the frieze gathered from conditions similar to the ones in which it was originally viewed. The volunteer observers will be asked to take their time, and pay attention to detail, in ways that our modern eyes rarely do, Wescoat says.

“The Athenians must have felt great pride when they approached the Parthenon,” she says. “The frieze was meant to communicate something meaningful, there is no question about that. It wasn’t a message that you needed to get with absolute clarity in 30 seconds, like driving by a billboard today. It was meant to be appreciated over a lifetime, and down through generations.”

Related:
Emory University Parthenon Project
Digging into the mystery of a Greek Island
How the Greek gods measure up

Friday, November 2, 2012

Predictive Health: A call to reinvent medicine



"Predictive Health: How We Can Reinvent Medicine to Extend Our Best Years," a new book Emory physicians Kenneth Brigham and Michael M.E. Johns, proposes focusing on health first instead of disease.

Brigham and Johns want to harness the formidable power of medicine and technology — including genome-sequencing, protein-cataloging, massive data-sorting — as tools for health assessment, diagnosis, and intervention. The ultimate goal is to guide people to the improvement and maintenance of their health.

Physicians who practice predictive health would assemble a health portrait by running sophisticated tests on an infant at birth. Potential risk factors for diseases, such as type II diabetes or a genetic propensity for obesity, would become evident long before they are problematic, and physicians could initiate personalized strategies for treatment.

"Our approach involves more than curing disease or making an early diagnosis," Brigham says. "We see it as important to develop a mindset in which to see health as defined positively. We look at disease risk but more importantly at what a person can do to live a healthy, fulfilling life. We look at body fat and what is in a person's blood, yes, but we also look at how you live, where you live, who you live with, and how you react to stress, to determine a healthy lifestyle for an individual."

Read more.

Related:
New health course switches to peer-led, personalized approach

Monday, October 29, 2012

Ethicists to wrestle with zombies on Halloween

Among the questions the "Walking with the Dead" conference will tackle is why many people have embraced the zombie fad, such as these enthusiasts in Marietta Square on Saturday. 

By Carol Clark

Karen Rommelfanger’s husband got her hooked on “The Walking Dead.” She had resisted, but finally succumbed to the AMC TV series when her husband was watching an episode on zombie neurobiology set at the Centers for Disease Control and Prevention.

“He called out to me, ‘You’ve got to see this,’” says Rommelfanger, a neuroscientist and director of the Neuroethics Program at the Emory Center for Ethics.

The fictionalized researchers were gathered around a glorified brain scanner, discussing the “you” part of a brain, where thoughts reside, and whether the “you” part was gone.

“This is exactly the kinds of questions we talk about in neuroethics,” Rommelfanger says. “Is the brain the seat of personhood? What does ‘brain dead’ really mean?”

It wasn’t long before the Emory Center for Ethics coined the term “zombethics” and created a public forum to discuss them. “Walking with the Dead: An Ethics Symposium for the Living” is the brainchild of Rommelfanger and Cory Labrecque, a scholar of bioethics and religious thought at the Center for Ethics. All the reserved seats for the event on Wednesday, October 31, are filled, but people can still participate in the campus Zombie Walk, starting at the center at 11:30 am and proceeding up to Asbury Circle.

Zombies are becoming as emblematic of Atlanta as the Varsity drive-in. 

“The Walking Dead,” filmed in and around Atlanta, has resurrected zombies and turned them into visceral symbols of all sorts of modern-day fears.

“The show is full of ethics questions dressed up in zombie suits,” says Labrecque, who wrote his dissertation on radical life extension and teaches courses on personhood theory and religion and medicine.

A close friend recommended the series to him. “I was initially reluctant about wasting my time on a series about zombies, but was hooked after the first episode,” Labrecque says. “I watched the whole first season in one sitting.”

His fiancĂ©e was too afraid to watch the show. But after he described it to her, Labrecque says she wanted to know: “Would you shoot me if I was bitten by a zombie?”

(Apparently, he gave a satisfying response because the wedding went as planned on October 13.)

Since “The Walking Dead” is set in Atlanta, it seemed especially fitting to launch a zombethics conference here, Rommelfanger says.

Harvard psychiatrist Steve Schlozman will be among the panelists at the Emory conference. In the video below, he describes a zombie brain autopsy:

Zombies touch on fears beyond death, such as slowly disappearing to Alzheimer’s, or wasting away in a coma. “We are not equating real-life patients with zombies, we’re using zombies as an entry point to start a conversation about really difficult subjects,” Labrecque says.

The conference panelists include psychiatrists, philosophers, religious scholars, physicians, CDC officials, historians, ethicists and neuroscientists. They will grapple with questions like: When is a human being no longer a person? What is free will? What does end-of-life care look like for those for whom biological death is not the end? How should healthcare resources be allocated when pandemics hit? 

And, finally, what’s behind the public obsession with a gory series like “The Walking Dead?”

“Some scholars have suggested that it’s massive group therapy,” Rommelfanger says. “Zombies are a way to experience fears of death, degeneration and other scary things in ways that you can manage.”

Related:
The science and ethics of X-Men
Why robots should care about their looks

Photos by Carol Clark

Friday, October 26, 2012

When chemistry becomes a piece of cake


It's National Chemistry Week, when chemists show just how clever they really are by cooking up things like periodic tables made of cupcakes. Non-chemists are also invited to join in the festivities at Emory, which will hold its annual Mole Day party this evening at 5:30 pm in the courtyard between the Emerson and Atwood buildings. Bring your own beaker.

Related:
Sparking a love of chemistry

Wednesday, October 24, 2012

Higher-math skills entwined with lower-order magnitude sense

While many animals understand the concept of less and more, only humans can learn formal math.

By Carol Clark

The ability to learn complex, symbolic math is a uniquely human trait, but it is intricately connected to a primitive sense of magnitude that is shared by many animals, finds a study to be published by the Proceedings of the National Academy of Sciences (PNAS).

“Our results clearly show that uniquely human branches of mathematics interface with an evolutionarily primitive general magnitude system,” says lead author Stella Lourenco, a psychologist at Emory University. “We were able to show how variations in both advanced arithmetic and geometry skills specifically correlated with variations in our intuitive sense of magnitude.”

Babies as young as six months can roughly distinguish between less and more, whether it’s for a number of objects, the size of objects, or the length of time they see the objects. This intuitive, non-verbal sense of magnitude, which may be innate, has also been demonstrated in non-human animals. When given a choice between a group of five bananas or two bananas, for example, monkeys will tend to take the bigger bunch.

“It’s obviously of adaptive value for all animals to be able to discriminate between less and more,” Lourenco says. “The ability is widespread across the animal kingdom – fish, rodents and even insects show sensitivity to magnitude, such as the number of items in a set of objects.”

Only humans, however, can learn formal math, including symbolic notations of number, quantitative concepts and computational operations. While the general magnitude system has been linked primarily to the brain’s intraparietal sulcus (IPS), higher math requires the use of more widely distributed areas of the brain.

For the PNAS study, the researchers wanted to build on work by others indicating that a lower-order sense of number is not just a separate function, but plays a role in the mental capacity for more complex math.

The dot test shows variation in people's ability to intuit number and area.

The researchers recruited 65 undergraduate college students to participate in an experiment. To test their knack for estimating magnitude of numbers, participants were shown images of dots in two different colors, flashed for only 200 milliseconds on a computer screen. They then had to choose which color had the greater number of dots. Most people can quickly distinguish that a group of 10 dots is greater than a group of five, but some people have a finer-grained number sense that allows them to discriminate between 10 and nine dots.

The participants were also shown dots of varying sizes and colors to test their ability to gauge magnitude of area.

They then completed a battery of standardized math tests.

The results showed that the more precise the participants’ abilities were at estimating the magnitude of a number, the better they scored in advanced arithmetic. The same correlation was found between precision at gauging magnitude of area and the geometry portion of the standardized math test.

“By better understanding the psychological mechanisms underlying math abilities such as arithmetic and geometry, we hope to eventually inform how we come to learn symbolic math, and why some people are better at it than others,” says study co-author Justin Bonny, an Emory graduate student of psychology. “It may then be possible to develop early interventions for those who struggle with specific types of math.”

U.S. teens lag in math skills compared to other industrialized countries. China ranked number one in math in 2010, the first year that the country participated in the Program for International Student Assessment, while the United States ranked number 31.

“Falling behind in math is a huge problem,” Lourenco says, “given that we live in an increasingly technological society and a globally competitive world.”

Related:
How babies use numbers, space and time

Top image: iStockphoto.com.

'No offense to anyone,' except women scientists

Karen Rommelfanger, program director of the Neuroethics Program at the Emory Center for Ethics, wrote an opinion piece for the Chronicle of Higher Education. An excerpt:


"What does it mean when a highly successful neuroscientist … states that he is disappointed there aren’t more “super model types” at a major conference? Here’s what he wrote:

My impression of the Conference of the Society for Neuroscience in New Orleans. There are thousands of people at the conference and an unusually high concentration of unattractive women. The super model types are completely absent. What is going on? Are unattractive women particularly attracted to neuroscience? Are beautiful women particularly uninterested in the brain? No offense to anyone. 

"There are some who will say that it is no surprise, given the large number of attendees (30,000 plus), that an ugly statement appeared on an individual’s Facebook page. Some might say it’s inevitable, and perhaps inconsequential, given how large the membership is, that you will find a bad seed. But dismissing [his] comments would be a mistake and represents part of the problem for women."

Click here to read the full article.

Related:
Academia's female brain drain 

Tuesday, October 23, 2012

Election markets take stock of presidential race

If buying shares in an election market sounds like online gambling, that's because it is, says economist Monica Capra. (Emory photo/video.)

By Kimber Williams, Emory Report

Ever wonder how a presidential candidate's stock is trading?

As voters weigh the odds of their candidates prevailing in a close race, an Emory economist suggests that beyond pundits and pollsters, the curious may also consult a lesser-known crystal ball: election markets.

Through election markets, also called prediction markets, voters put their money where their mouths are by buying "shares" that reflect a candidate's chances of winning — essentially betting in an online futures market about the nation's election outcome.

Though rarely referenced by news programs or political analysts, election markets are actually a viable tool that can be used in conjunction with polls and statistical models to help predict election outcomes, says Monica Capra, an associate professor of economics at Emory with research interests in behavioral and experimental economics.

"Basically, the prediction markets are futures markets, exchanges in which people trade asset shares — candidates, in this case — based upon what they believe will happen in the future," says Capra, who teaches about the topic in her experimental economics classes. "The idea that presidential markets can predict election outcomes comes from the fact that markets are aggregators of individual beliefs," she adds. "It's a perfect application for elections — we know when the election will take place and who the candidates are. Trades are made on the belief of who will win."

Election trading typically takes place through online websites, such as Intrade.com, based in Ireland, Betfair.com in England, and the University of Iowa Electronic Markets, where spectators follow the fortunes of their candidates — or other real-world events — by tracking how they're "trading" in the eyes of the public, or bettors.

This week, for example, activity at Intrade.com showed the odds of President Barack Obama winning re-election improving throughout Tuesday night's debate, rising from 61.7 percent before the debate to 64.1 percent shortly afterward — a trend noted on the other sites, as well.

If it sounds like online gambling, that's because it is, acknowledges Capra, who doesn't play the market herself, nor require her students to play it. But as an economist, she does consult it: beneath the profit motive lies a fascinating glimpse into the mind of the American voter. And there can be value in listening to the betting public.

"The fact that there is money on the table gives people more inspiration to gather information and do some homework," Capra says. 

"Markets are information aggregators," she explains. "People arrive with different sets of information and beliefs that are revealed through their trading behavior and captured by the market. That idea is what makes predictive markets work. Basically, it's an economist's crystal ball."

The system works like this: Let's say you want to bet on the likelihood that Mitt Romney will win the 2012 presidential race. You buy "shares" — this week, they're running around $3.66 on Intrade. If he wins, all shares jump to $10 each and you make money. If he loses, all shares immediately plunge to $0 and you lose.

Predictive market sites also post a probability for each candidate winning. This week, for instance, Obama's shares were running about $6.32, which puts him at a 63.1 percent chance of winning. In contrast, Romney's shares were selling at $3.67 each, with a 36.9 percent chance of victory. That can change in an instant.

With websites updating trading around the clock, "it's a market that never closes," Capra observes. However, she offers an important caveat: predictive markets traders don't necessarily represent the average voter. While a political pollster may seek a representative sample of the population, predictive market traders in the Iowa Electronic Market, for instance, tend to be predominantly male, younger, wealthier and more educated than the average voter.

"But as long as you have people informed and motivated to trade in order to make money, that's all you need for the market to work well," she adds, suggesting that traders are more likely to make choices based on solid data rather than emotional impulse when money is at stake.

Capra says she consults predictive markets every day. "Right now, Gallup polls give the edge to Romney," she notes. "But InTrade says Obama will win — his predicted percentage rose both during and after this week's debate. The fact that he did much better in this debate was reflected by people immediately buying shares. The second debate also appeared to stop the upward movement of Romney shares."

So how accurate are online election markets? Though researchers are divided on the topic, Capra says she considers them a valid predictive tool: "As an economist, you have three main sources for predicting election outcomes: forecasting models, daily polls and prediction markets. If I had to choose one, I would choose prediction markets."

Monday, October 22, 2012

'Still crazy' for Paul Simon's pop psychology



Emory psychologist Marshall Duke, who is 70, came of age listening to the music of Paul Simon, who just turned 71. As a scientist who studies the importance of stories and rituals to the human experience, Duke is fascinated by what he calls Simon’s “theory of mind,” or his uncanny capacity to understand what it is to be someone else and to tell the stories of people across generations.

“The songs he writes are not necessarily contemporaneous with his own age,” Duke says. He cites “Old Friends,” written by Simon during his 20s, as just one example:

Old friends sat on their park bench like bookends / Winter companions / The old men lost in their overcoats / Waiting for the sunset / The sounds of the city sifting through trees settle like dust on the shoulders of the old friends / Can you imagine us, years from today, sharing a park bench quietly? / How terribly strange to be 70

“As I turned 70 a few weeks ago,” Duke says. “I realized how profound the words were, even though they were written by a young man.”

Duke describes Simon’s song “Slip Slidin’ Away” as “a verbal equivalent of the skull that is placed at the bottom of the crucifix paintings in the Renaissance, which says, ‘Be aware, life is temporary, life is fragile.’” A few of the lyrics:

We work our jobs / Collect our pay / Believe we’re gliding down the highway / When in fact we’re slip slidin’ away.

“Paul Simon understands that we’re all still crazy after all these years,” Duke says. “He understands that we don’t ever lose the childishness that belongs to us as a gift when we’re little. It’s something that allows us, even when we’re astounded that we’re 70, to hold onto some of the behaviors and fun of being seven.”

Paul Simon will deliver the 2013 Richard Ellmann Lectures in Modern Literature at Emory, February 10-12. The series of free public talks will include Simon's reflections on his early music. Click here for more information.

Related:
Margaret Atwood on aliens and angels
Stories your parents should have told you
The dawn of collective human unconsciousness

Tuesday, October 16, 2012

Sharing ideas about the concept of fairness

You've got just two pieces of Halloween candy left in the bowl. Who are you going to give them to?

By Carol Clark

Ask a three-year-old to divide pieces of a favorite candy between himself and two other children and he will likely question why he should share any at all. “At that age, children basically self-maximize. They have a guiltless selfishness,” says Emory psychologist Philippe Rochat, who studies the emergence of a moral sense in children.

By the age of five, children tend to be more principled in the way that they regard others. A five-year-old, for example, may go so far as to split the candies in half to ensure everyone gets an equal share.

“Something else interesting happens around the age of seven,” Rochat says. “The earlier tendency to self-maximize regains power as children start aligning themselves with groups. They generate inequity by favoring their own group when it comes to sharing.” 

Emory is inviting the public to an October 18-19 event, the "Fairness Conference: An Interdisciplinary Reflection on the Meanings of Fairness." An international group of scholars, from psychology, law, anthropology, ethics, philosophy, economics and politics will offer their views on the concept of fairness. Click here to see the full schedule and to register for the free event, to be held at the Silverbell Pavilion of the Emory Conference Center.

Fairness is the foundation of what makes us sociable and able to live together, but it can be hard to define.

“It is something that we often take for granted, as ingrained into our being,” Rochat says. “But ideas about what’s fair change through child development, across cultures and amid different political and economic circumstances. The conference aims to bring light and clarity to the subject from multiple scientific perspectives.”

Jerome Bruner, an educational psychologist from New York University, will give the keynote entitled “The Ambiguities of Fairness.” His presentation will cover how the violation of fairness was handled by the ancient Greeks, a group of islanders in remote Melanesia and in contemporary Sicily – the source of the proverb “Vengeance is a dish that must be served cold.”

In addition to Emory researchers, the speakers include scholars from the University of Pennsylvania, Harvard, Yale, Lebanese American University, and the Universidad Autonoma de Entre Rios, Argentina.

President Jimmy Carter will give a presentation at the conference entitled “Fairness and Equity in Politics and Human Affairs.”

The issue of fairness will grow increasingly important as the human population increases, Rochat says. Climate change, pollution, diminishing resources, global commerce and immigration are just a few of the issues that will put more pressure on the question of fairness.

“We want to give a scientific rooting to a problem that affects every part of society,” Rochat says. “Much of the tension in the current U.S. presidential election, for example, boils down to different views of what is fair. How much tax should the rich pay? How much support should the poor get?”

Related:
First blush: When babies get embarrassed

Images: iStockphoto.com.

Monday, October 15, 2012

Physicists crack another piece of the glass puzzle

The experiment showed how particles on the verge of becoming a glass move like cars trying to get out of a grid-locked parking lot.

By Carol Clark

When it comes to physics, glass lacks transparency. No one has been able to see what’s happening at the molecular level as a super-cooled liquid approaches the glass state – until now. Emory University physicists have made a movie of particle motion during this mysterious transition.

Their findings, showing how the rotation of the particles becomes decoupled from their movement through space, are being published in the Proceedings of the National Academy of the Sciences.

“Cooling a glass from a liquid into a highly viscous state fundamentally changes the nature of particle diffusion,” says Emory physicist Eric Weeks, whose lab conducted the research. “We have provided the first direct observation of how the particles move and tumble through space during this transition, a key piece to a major puzzle in condensed matter physics.”

Weeks specializes in “soft condensed materials,” substances that cannot be pinned down on the molecular level as a solid or liquid, including everyday substances such as toothpaste, peanut butter, shaving cream, plastic and glass.

Scientists fully understand the process of water turning to ice. As the temperature cools, the movement of the water molecules slows. At 32 F, the molecules lock into crystal lattices, solidifying into ice. In contrast, the molecules of glasses do not crystallize.The movement of the glass molecules slows as the temperature cools, but they never lock into crystal patterns. Instead, they jumble up and gradually become glassier, or more viscous. No one understands exactly why.

The phenomenon leaves physicists to ponder the molecular question of whether glass is a solid, or merely an extremely slow-moving liquid.

This purely technical physics question has stoked a popular misconception: That the glass in the windowpanes of some centuries-old buildings is thicker at the bottom because the glass flowed downward over time.

“The real reason the bottom is thicker is because they hadn’t yet learned how to make perfectly flat panes of glass,” Weeks says. “For practical purposes, glass is a solid and it will not flow, even over centuries. But there is a kernel of truth in this urban legend: Glasses are different than other solid materials."


Shattering myths: For all practical purposes, glass is a solid. But physicists are still struggling to explain how, and when, a liquid transitions into a glassy material.

To explore what makes glasses different, the Weeks lab uses mixtures of water and tiny plastic balls, each about the size of the nucleus of a cell. This model system acts like a glass when the particle concentration is increased.

A major drawback to this model system is that actual glass molecules are not spherical, but irregularly shaped.

“When the hot molten liquid that forms a glass cools down, it’s not just that the viscosity becomes enormous, growing by a factor of a billion, there is something different about how the molecules are moving,” Weeks says. “We wanted to set up an experiment that would allow us to see that movement, but spheres move differently than irregular shapes.”

In 2011, however, the physics lab of David Pine, at New York University, developed a way to join clusters of these tiny plastic balls together to form tetrahedrons.

Kazem Edmond, while a graduate student at Emory, added these tetrahedral particles to the glass model system and led the experiments. Using a confocal microscope, he digitally scanned the samples as the viscosity increased, creating up to 100 images per second.

The result was three-dimensional movies that showed the movement and the behavior of the tetrahedrons as the system reached a glassy state.



The movie and data from the experiment provide the first clear picture of the particle dynamics for glass formation. As the liquid grows slightly more viscous, both rotational and directional particle motion slows. The amount of rotation and the directional movements of the particles remain correlated.

“Normally, these two types of motion are highly coupled,” Weeks says. “This remains true until the system reaches a viscosity on the verge of being glass. Then the rotation and directional movements become decoupled: The rotation starts slowing down more.”

He uses a gridlocked parking lot as an analogy for how the particles are behaving. “You can’t turn your car around, because it’s not a sphere shape and you would bump into your neighbors. You have to wait until a car in front of you moves, and then you can drive a bit in that direction. This is directional movement, and if you can make a bunch of these, you may eventually be able to turn your car. But turning in a crowded parking lot is still much harder than moving in a straight line.”

Previous research has inferred this decoupling of movement by experimenting with actual molecular glasses. The Weeks lab used a simple model system to scale up glassy material so that you can actually watch the decoupling process happening.

“Glass is important in everyday life,” Weeks says. “The more we understand its fundamental nature, the more we may be able to improve it and use it in different ways. One reason that smart phones are getting smaller and better, for example, is that stronger and thinner glass is being developed.”

Related:
Crystal-liquid interface made visible for the first time
A microcosm of awesome

Images: iStockphoto.com.