Epigenetics zeroes in on nature vs. nuture

Epigenetics is a relatively new field that looks at changes in gene expression that are not caused by changes in the underlying DNA sequence. DNA, in other words, is not necessarily destiny. One of the best-known examples of epigenetic change is seen in baby rats. Research has shown that rat pups that are licked and groomed more by their mothers are healthier and grow at a faster rate than those that don’t receive this maternal stimulation. And the pups that receive better nurturing also develop epigenetic differences that enable them to respond better to stress later in life.

While DNA cannot be changed, its packaging can be, and the process appears remarkably flexible. Emory biologist Victor Corces is among the researchers trying to piece together the mechanics of the processes behind epigenetics. One of the questions that his lab is currently focused on is how the organization of chromatin fibers in a cell nucleus affects gene expression. Watch the video of Corces’ recent presentation for the National Institute of Health’s afternoon lecture series, below, to learn more.



Photo at top by iStockphoto.com.

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The price of your soul: How your brain decides whether to 'sell out'

By Carol Clark

A neuro-imaging study shows that personal values that people refuse to disavow, even when offered cash to do so, are processed differently in the brain than those values that are willingly sold.

“Our experiment found that the realm of the sacred – whether it’s a strong religious belief, a national identity or a code of ethics – is a distinct cognitive process,” says Gregory Berns, director of the Center for Neuropolicy at Emory University and lead author of the study. The results were published in Philosophical Transactions of the Royal Society.

Sacred values prompt greater activation of an area of the brain associated with rules-based, right-or-wrong thought processes, the study showed, as opposed to the regions linked to processing of costs-versus-benefits.

Berns headed a team that included Emory economist Monica Capra; Michael Prietula, a professor of information systems and operations management at Emory's Goizueta Business School; a psychologist from the New School for Social Research and anthropologists from the Institute Jean Nicod in Paris, France. (Click here to see the full list of names.) The research was funded by the U.S. Office of Naval Research, the Air Force Office of Scientific Research and the National Science Foundation.

“We’ve come up with a method to start answering scientific questions about how people make decisions involving sacred values, and that has major implications if you want to better understand what influences human behavior across countries and cultures,” Berns says. “We are seeing how fundamental cultural values are represented in the brain.”


The researchers used functional magnetic resonance imaging (fMRI) to record the brain responses of 32 U.S. adults during key phases of an experiment. In the first phase, participants were shown statements ranging from the mundane, such as “You are a tea drinker,” to hot-button issues such “You support gay marriage” and “You are Pro-Life.” Each of the 62 statements had a contradictory pair, such as “You are Pro-Choice,” and the participants had to choose one of each pair.

Click here to download the full list of questions, and the responses by the subjects.

At the end of the experiment, participants were given the option of auctioning their personal statements: Disavowing their previous choices for actual money. The participants could earn as much as $100 per statement by simply agreeing to sign a document stating the opposite of what they believed. They could choose to opt out of the auction for statements they valued highly.

“We used the auction as a measure of integrity for specific statements,” Berns explains. “If a person refused to take money to change a statement, then we considered that value to be personally sacred to them. But if they took money, then we considered that they had low integrity for that statement and that it wasn’t sacred.”

The brain imaging data showed a strong correlation between sacred values and activation of the neural systems associated with evaluating rights and wrongs (the left temporoparietal junction) and semantic rule retrieval (the left ventrolateral prefrontal cortex), but not with systems associated with reward.


“Most public policy is based on offering people incentives and disincentives,” Berns says. “Our findings indicate that it’s unreasonable to think that a policy based on costs-and-benefits analysis will influence people’s behavior when it comes to their sacred personal values, because they are processed in an entirely different brain system than incentives.”

Research participants who reported more active affiliations with organizations, such as churches, sports teams, musical groups and environmental clubs, had stronger brain activity in the same brain regions that correlated to sacred values. “Organized groups may instill values more strongly through the use of rules and social norms,” Berns says.

The experiment also found activation in the amygdala, a brain region associated with emotional reactions, but only in cases where participants refused to take cash to state the opposite of what they believe. “Those statements represent the most repugnant items to the individual,” Berns says, “and would be expected to provoke the most arousal, which is consistent with the idea that when sacred values are violated, that induces moral outrage.”

The study is part of a special issue of the Philosophical Transactions of the Royal Society, titled “The Biology of Cultural Conflict.” Berns edited the special issue, which brings together a dozen articles on the culture of neuroscience, including differences in the neural processing of people on the opposing sides of conflict, from U.S. Democrats and Republicans to Arabs and Israelis.

“As culture changes, it affects our brains, and as our brains change, that affects our culture. You can’t separate the two,” Berns says. “We now have the means to start understanding this relationship, and that’s putting the relatively new field of cultural neuroscience onto the global stage.”

Future conflicts over politics and religion will likely play out biologically, Berns says. Some cultures will choose to change their biology, and in the process, change their culture, he notes. He cites the battles over women’s reproductive rights and gay marriage as ongoing examples.

Images, top and bottom: iStockphoto.com.

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Shedding light on a pre-electric sleep culture

A sleeping Buddha in Southeast Asia. "The window of opportunity to understand sleep without electricity is closing, because the traditional cultures of sleep are vanishing," says anthropologist Carol Worthman.

By Carol Clark

About 20 percent of the world population lives without electricity. You may wonder how these people make it through their waking hours, but Carol Worthman wants to know how they sleep.

Worthman, an anthropologist at Emory University, is leading the first quantitative study of sleeping habits in a pre-electric environment. The sleep study is just one part of a larger, five-year project to begin soon in rural Vietnam, involving 14 villages that have not been electrified or exposed to television. Half of the villages will eventually be introduced to generator-powered televisions for the experiment, while the other half will not.

The National Institute of Health and the Vietnamese government are supporting the project, headed by Penn State, which aims to answer questions about how watching television affects human health and behavior.

Worthman, a leading expert on the ecology of sleep, is most excited about garnering the baseline data for pre-electric sleep. “The window of opportunity to understand sleep without electricity is closing, because the traditional cultures of sleep are vanishing,” she says. One of the development goals of WHO, she notes, is to see every populated part of the world electrified by 2020.

“We will be filling a gap in scientific knowledge by getting the first empirical data for how people sleep with no electricity, just the sun, when their whole world revolves around subsistence and nature,” Worthman says. “Many people have this idea that in the good old days we got more sleep, but did we? Are we romanticizing our history?”

A Vietnamese woman relaxes with her baby. One development goal of WHO is to see every part of the world electrified by 2020.

The 14 villages involved in the study are in a remote, mountainous location of Vietnam, near the Laotian border. Most of the people in the area belong to the Tai ethnic group and are subsistence farmers. Whole families generally sleep in one or two rooms, due to the small size of the homes.

Participants in the experiment will continuously wear a sleep actigraph, a wristwatch-like device that records movement. An actigraph is sensitive enough to detect whether its wearer is sleeping or just resting, has entered a deep sleep state, known as REM, and how often the wearer stirs or wakes up from a deep sleep.

“The data will suggest the architecture of their sleep,” Worthman says. “We will get a sense of how much sleep they are getting, whether it is interrupted frequently, and whether their sleep is mostly consolidated, or more scattered across 24 hours through naps.”

The experiment is expected to begin this Spring. After the baseline data are collected, seven of the villages will serve as controls for the experiment, while televisions powered by generators will be introduced to the other half. Every 20th household will get a communal TV set, with three channels of programming that run from 4 pm to 10 pm. At several points over the course of five years after the introduction of TV, the sleep patterns of the subjects will again be monitored to see if they have changed.

A satellite dish pokes up between two thatched huts in an isolated area of Vietnam. Anthropologists want to know how TV changes people's sleep patterns, and their outlook on life.

“This experiment is not going to answer all the questions about human sleep, but it could provide us with some fresh ideas and questions,” Worthman says.

Are some of the sleep disorders common to modernized society tied to electricity and TV viewing? One theory holds that people who watch TV lose major chunks of time, forcing them to stay up later to complete other tasks like cleaning or doing homework. Some people watch TV to relax in the evening, but how does all that light beamed into their eyes just before bed affect their ability to get to sleep? Does the content of the programs affect sleep?

Adolescents typically experience a change in their biological clocks, causing them to want to stay up later and get up later. “TV and other forms of media can feed that propensity,” Worthman says, “but then they get slammed the next day because they have to get up for school.”

The overarching study will look at larger effects of TV viewing on health and well-being, beyond sleep. Worthman will also collect both baseline and follow-up data for this segment of the study, with a focus on adolescents.

Her team will look at how the activities, social lives and relationships of teenagers, along with their values, goals and attitudes, change after the introduction of TV.

“One thing we’re interested in is how learning about life outside of their village through TV may affect them,” Worthman says. “Will they will find TV programming inspirational or frustrating? What’s the role of a globalized world in fostering anxiety? If you are plugged into media, are you less, or more, depressed and anxious?”

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Some eye-opening thoughts on sleep

In the U.S., it's perfectly normal to sleep with your dog or cat, but huge cultural battles are being fought over whether it's odd, or even detrimental, to sleep with your baby. In much of the developing world, people think just the opposite, says anthropologist Carol Worthman.

By Carol Clark

Emory anthropologist Carol Worthman first began thinking about the cultures of sleep while traveling across Kenya in 1979 as a postdoctoral fellow. She was headed to the coast in an old, classic train with wooden slats that rolled down over the windows. The cheap ticket section was so packed for the overnight journey that mothers and children shared bunks in the women’s section.

“Children were crying. It was really noisy and I couldn’t get comfortable. I didn’t sleep much at all,” Worthman says.

The locals, however, took it in stride. “In the morning, everyone around me got up looking bright and beaming,” Worthman says. “I thought, ‘They don’t sleep like Westerners do.’”

Nearly two decades later, Worthman was asked by a pediatrician to sum up what anthropologists know about sleep. She thought about it and had to respond, “Not much.” While most waking moments of human activity were well-documented, their sleeping ones were largely ignored by anthropologists.

“When people go to sleep is when we can finally write up our notes,” Worthman jokes.

But the realization that her field had overlooked one-third of human life spurred her to work on the first analytic framework for comparative studies of human sleep behavior in 1998.

She pored over the literature, and interviewed field researchers about their observations of the ecology of sleep from across continents, cultures and climates in the developing world. From foragers to farmers, islanders to mountain dwellers, patterns of sleep behavior began to emerge.

“I was startled,” Worthman says. “You learn just how weird our sleeping habits are in the United States.”

For instance, many Americans consider it odd, and perhaps detrimental, to sleep with a newborn baby. And yet it’s perfectly normal to sleep with a dog or cat.

“In much of the developing world, people think just the opposite,” Worthman says. “It’s pretty much universal that babies don’t sleep alone. They either lie right next to their mothers, or nearby on a mat, or in a cradle or a sling.”

Putting a baby in a separate room to sleep would be viewed as tantamount to child abuse in many cultures, Worthman says.

For much of human history, humans have slept in family groups, with one ear cocked for danger. They were comforted by the sounds of their livestock shuffling, their babies breathing and the crackle of a smoky fire to ward off bugs and larger predators. “Sleeping like a log” is not so desirable if you could roll into the fire, or miss the sound of an approaching predator.

Worthman’s work has shown that rural, and even some urban, communities of the developing world have markedly different sleeping patterns than the typical American. “You can actually quantitatively show that culture drives human sleep behavior,” she says.

Building on her decades of research, Worthman is about to launch the first quantitative study of a pre-electric sleep culture, a major experiment set to begin soon in rural Vietnam. Click here to read more about the study.

It’s only relatively recently that electricity, larger homes, box springs, non-allergenic mattresses and climate-controlled interiors have altered our sleep environments. This rapid shift leads Worthman to wonder if modern sleep practices have set us up for chronic problems such as insomnia, sleep apnea and parental anxiety over a newborn’s sleep patterns.
Photo by Klaus Roesch

For instance, in many cultures, people tend to take more naps and have less rigid expectations for sleeping straight through the night. Some evidence indicates that in pre-gaslight Europe, it was not uncommon for people to have an early evening sleep, then wake up later in the night for a while, before returning to a deeper sleep state.

Modern-day insomniacs may actually be the more normal ones, Worthman notes. “In our culture, we have this very fixed idea that you should lie down and go out like a light,” she says. “One of the problems with insomnia is that people become very anxious about it. If they relaxed, went with the flow, and perhaps took a nap during the day, maybe it would help.”

All images, iStockphoto.com, unless otherwise noted.

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Exploring the cognitive basis of religion and science

Neuroscience promises "startling new insights about science, about religion, and about their comparison," says Robert McCauley. Photo by Kay Hinton.

The conflict between the scientific mindset and the religious mindset is an old one. What’s new are tools of cognitive science that allow us to probe why we choose to follow paths of religion and/or science, says Robert McCauley, a philosopher of science at Emory.

McCauley’s written a new book, “Why Religion is Natural and Science is Not,” in which he explains why the modern-day version of science is more in danger of extinction than religion.

Here’s an excerpt from a Boston Globe interview with McCauley:

BOSTON GLOBE: Why do you say religion is “natural” but not science?

MCCAULEY: Religion overwhelmingly depends upon what I’m calling natural cognition, thinking that is automatic, that is not conscious for the most part. Once our attention is drawn to it, we find it fairly difficult to articulate. For example, when we talk, our talking arises pretty spontaneously and yet it’s incredibly complex. We’re conforming to all sorts of rules about our natural language, which we’re usually incapable of articulating.

Science, probably more than any other human intellectual endeavor, supersedes natural cognition. It’s conscious, usually in the form of language. It’s usually slow, it’s deliberative. Science is extremely unnatural. That’s why scientists have to take courses in all these things--and then it’s still hard. The products of scientific reflection are inevitably radically counterintuitive. They challenge common sense.

Read the whole Boston Globe interview here.

And here’s a recent column by McCauley in Psychology Today.

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Tobacco stats can take your breath away

Globally, tobacco kills 5 million people each year, about 8.8 percent of all deaths.
Image: iStockphoto.com

On January 11, 1964, U.S. Surgeon General Luther Terry issued an official warning that smoking cigarettes can kill you. The report “hit the nation like a bombshell,” Terry later recalled. “It was front page news and a lead story on every radio and television station in the United States and many abroad."

Nearly 50 years later, however, more than 45 million American adults still smoke, more than 8 million are living with a serious illness caused by smoking, and about 438,000 Americans die prematurely each year as a result of tobacco use, according to the CDC.

The anti-tobacco movement is just getting under way in much of the developing world. Globally, tobacco kills more than 5 million people each year, accounting for about 8.8 percent of all deaths, according to the Tobacco Atlas. If current trends continue, tobacco will kill 7 million people annually by 2020 and more than 8 million people by 2030, most of them in low- and middle-income countries. (The Tobacco Atlas is produced by the World Lung Foundation and the American Cancer Society.)



“Nicotine use is a complex addiction,” said Gregory Connolly, director of Harvard’s Center for Global Tobacco Control, during a recent health conference held at Emory. If you inject someone with nicotine, you can’t make them dependent on it the way you can with heroin or cocaine, he explains. Nicotine dependency is driven by a range of factors including ease of use, chemo-sensory cues, activation of the dopamine-reward pathway and learned behavior.

Treating individuals is helpful in the short-term, but policy measures that remove smoking from the social norm are better in the long-term, Connolly said.

“Kids do what adults do,” he said. “You really have to de-normalize the behavior and take away the social benefits.”



On January 1, Emory became a tobacco-free campus. Smoking and all other forms of tobacco use are now prohibited on all Emory University and Emory Healthcare properties. More than 580 U.S. colleges and more than 2,800 hospitals and health-care organizations have adopted similar policies.

At least on U.S. college campuses, smoking is become a harder habit to continue.

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Does science need a universal symbol?

Paul Root Wolpe, director of the Emory Center for Ethics, sparked a debate with his proposal in New Scientist to develop a unifying symbol for science: A sort of bumper sticker for passionate nerds, and those who support their mission. Wolpe writes:

"A single, unified symbol would have many uses. It could be displayed to represent a position: opposition to the politicizing of science in government, support for increased research spending, or concern about global warming and species loss. It could be displayed by an astronomer or geologist or sociologist or teacher as a symbol of their allegiance to science. It could be used on car bumpers and web pages, and in public venues. ...

"Perhaps it could even accommodate a cross or star of David or some other symbol to state: 'I am a Christian (or Jew or Muslim) and support science as an enterprise.'"

You can read the full New Scientist article here.

Do you agree with Wolpe? You can send your ideas for a symbol to sciencesymbol@emory.edu, or join the discussion via a special science symbol Facebook page Wolpe set up.

Graphic: iStockphoto.com.

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