Scenes from our wild campus

Foxes, deer, otters and ... beavers? Keep your eyes peeled. You never know what you'll see strolling about Emory's woodsy campus. But please don't pet the wildlife.

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Tracking clues to life

A brainy time traveler

By Carol Clark

Anthropologist James Rilling, founder of Emory's Laboratory for Darwinian Neuroscience, is mapping the evolution of our minds.

"It's like the space program," he explains. "We believe that we should be trying to understand the universe around us. I feel the same way about exploring the brain to learn who we are and how we got here."

The Milwaukee native came to Emory as a graduate student, drawn by the anthropology department's emphasis on human biology. "It's a definite strength," says Rilling, citing the department's access to the Yerkes National Primate Research Center and the quality of the faculty.

For his dissertation, Rilling used fMRI to compare the neuroanatomy of humans and 10 other primate species at Yerkes. The 1998 study was the first in-depth look at whether the human brain is merely a scaled-up version of the brains of other primates.

“We found that human temporal lobes are larger than you would expect for a primate of our brain size,” Rilling says. “We’ve done subsequent work that shows this larger size is likely due to the evolution of language pathways in humans.”

The Laboratory for Darwinian Neuroscience is a leader in the use of non-invasive imaging technology to compare the neuroanatomy of living primates.

Much previous work has focused on the gray matter of brains. Rilling's group is the only one in the world using diffusion tensor imaging (DTI) to compare the white matter connections of monkeys, humans and our closest relative, chimpanzees. White matter contains the fiber tracts that connect and "wire" the brain.

“We’ve discovered a difference in both the size and the trajectory of the fiber tract that runs between Wernicke’s area in the left temporal lobe and Broca’s area in the left inferior frontal cortex,” Rilling says. Broca’s area is involved in speech production and Wernicke’s in understanding language. In humans, the pathway that connects the two areas is much more massive, and projects beyond Wernicke’s area down to the ventral part of the temporal lobe.

“There’s something special going on in the human brain with that pathway,” Rilling says. “It’s organized differently than in other primates.”

The lab is also exploring the neural basis of human cognition and behavior. One of its studies showed that reciprocation in humans is tied to activation of a reward pathway in the brain. “The magnitude of that reaction correlated to how likely the person was to cooperate in the future,” Rilling says.

Why are some people more cooperative than others? How does the brain change with age? What promotes social bonding and attachment? These are just a few of the many research questions the lab is tackling.

"We want to start to understand individual human differences in social behavior, at both the genetic and neurological levels," Rilling says.

He's particularly interested in understanding why some men are more nurturing as fathers than others. “It’s important to have someone besides the mother involved in a child’s care. I think one way that we could improve childhood development is to have more committed dads,” says Rilling, who is married to a psychiatrist and hopes to one day become a father.

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The science of love

Economists do it with models

Heard any good economist jokes lately? The recent Economics Convention in Atlanta was full of them, as the so-called "dismal science" celebrated the fact that sex and humor sell, even during a recession.

PBS NewsHour covered the event, including a presentation by Emory's Hugo Mialon on the economics of faking ecstasy in lovemaking.

"This paper was suggested to me by my lovely wife and colleague, Sue Mialon," he says.

Listen to the full report by PBS. Believe it or not, there is even a knock-knock joke.

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Who's more likely to fake it?

Grounded cognition gives your mind a hand

Before you read this, pour yourself a cup of hot tea.

Now, sit up straight. Smile. Hold that warm cup in your hand. Research is showing that these kinds of actions can positively influence what you think about a piece of writing.

"All the states of your body affect how you think. So does the environment," says Lawrence Barsalou, an Emory psychologist and a leading researcher of grounded cognition -- the idea that thought is shaped by bodily states. And vice-versa.

For instance, you may feel anxious about an upcoming presentation. Just thinking about forgetting your speech can produce the same physical stress reactions that occur when you actually are standing in front of a group of people and draw a blank.

"We're just barely beginning to understand the mechanisms, at a detailed and specific level, that operate to produce these experiences," Barsalou says.

We are entering a new era in psychology research, says Barsalou, who is especially interested in how meditation might be used to alleviate stress reactions.

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Putting teeth into Barker hypothesis

Teeth from a site near Cuzco, Peru, show grooves of enamel damage. Source: Valerie Andrushko.

By Carol Clark

Ancient human teeth are telling secrets that may relate to modern-day health: Some stressful events that occurred early in development are linked to shorter life spans.

"Prehistoric remains are providing strong, physical evidence that people who acquired tooth enamel defects while in the womb or early childhood tended to die earlier, even if they survived to adulthood," says Emory anthropologist George Armelagos.

Armelagos led a systematic review of defects in teeth enamel and early mortality recently published in Evolutionary Anthropology. The paper is the first summary of prehistoric evidence for the Barker hypothesis – the idea that many adult diseases originate during fetal development and early childhood.

"Teeth are like a snapshot into the past," Armelagos says. "Since the chronology of enamel development is well known, it's possible to determine the age at which a physiological disruption occurred. The evidence is there, and it's indisputable." 

The Barker hypothesis is named after epidemiologist David Barker, who during the 1980s began studying links between early infant health and later adult health. The theory, also known as the Developmental Origins of Health and Disease Hypothesis (DOHaD), has expanded into wide acceptance.

As one of the founders of the field of bioarcheology, Armelagos studies skeletal remains to understand how diet and disease affected populations. Tooth enamel can give a particularly telling portrait of physiological events, since the enamel is secreted in a regular, ring-like fashion, starting from the second trimester of fetal development. Disruptions in the formation of the enamel, which can be caused by disease, poor diet or psychological stress, show up as grooves on the tooth surface.

Armelagos and other bioarcheologists have noted the connection between dental enamel and early mortality for years. For the Evolutionary Biology paper, Armelagos led a review of the evidence from eight published studies, applying the lens of the Barker hypothesis to remains dating back as far as 1 million years.

One study of a group of Australopithecines from the South African Pleistocence showed a nearly 12-year decrease in mean life expectancy associated with early enamel defects. In another striking example, remains from Dickson Mounds, Illinois, showed that individuals with teeth marked by early life stress lived 15.4 years less than those without the defects.

"During prehistory, the stresses of infectious disease, poor nutrition and psychological trauma were likely extreme. The teeth show the impact," Armelagos says.

Until now, teeth have not been analyzed using the Barker hypothesis, which has mainly been supported by a correlation between birth weight in modern-day, high-income populations and ailments like diabetes and heart disease.

"The prehistoric data suggests that this type of dental evidence could be applied in modern populations, to give new insights into the scope of the Barker hypothesis," Armelagos says. "Bioarcheology is yielding lessons that are still relevant today in the many parts of the world in which infectious diseases and under-nutrition are major killers."

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