Gender gap in spatial reasoning starts in elementary school, meta-analysis finds

"We're interested in the origins of gender differences in spatial skills because of their potential role in the gender gap we see in math and science fields," says Jillian Lauer, who is set to graduate from Emory in May with a PhD in psychology. (Getty Images)

By Carol Clark

It is well-established that, on average, men outperform women on a spatial reasoning task known as mental rotation — imagining multi-dimensional objects from different points of view. Men are not, however, born with this advantage, suggests a major meta-analysis by psychologists at Emory University. Instead, males gain a slight advantage in mental-rotation performance during the first years of formal schooling, and this advantage slowly grows with age, tripling in size by the end of adolescence.

The Psychological Bulletin, a journal of the American Psychological Association, is publishing the findings.

“Some researchers have argued that there is an intrinsic gender difference in spatial reasoning — that boys are naturally better at it than girls,” says lead author Jillian Lauer, who is set to graduate from Emory in May with a PhD in psychology. “While our results don’t exclude any possibility that biological influences contribute to the gender gap, they suggest that other factors may be more important in driving the gender difference in spatial skills during childhood.”

Co-authors of the paper include Stella Lourenco, associate professor of psychology at Emory, whose lab specializes in the development of spatial and numerical cognition. Co-author Eukyung Yhang worked on the paper as an Emory undergraduate, funded by the university’s Institute for Quantitative Theory and Methods. Yhang graduated in 2018 and is now at Yale University School of Medicine.

The meta-analysis included 128 studies of gender differences in spatial reasoning, combining statistics on more than 30,000 children and adolescents aged three to 18 years. The authors found no gender difference in mental-rotation skills among preschoolers, but a small male advantage emerged in children between the ages of six and eight.

While differences in verbal and mathematical abilities between men and women tend to be small or non-existent, twice as many men as women are top performers in mental rotation, making it one of the largest gender differences in cognition.

Mental rotation is considered one of the hallmarks of spatial reasoning. “If you’re packing your suitcase and trying to figure out how each item can fit within that space, or you’re building furniture based on a diagram, you’re likely engaged in mental rotation, imagining how different objects can rotate to fit together,” Lauer explains.

It takes most of childhood and adolescence for the gender gap in spatial skills to reach the size of the difference seen in adulthood.

Prior research has also shown that superior spatial skills predict success in male-dominated science, technology engineering and math (STEM) fields, and that the gender difference in spatial reasoning may contribute to the gender disparity in these STEM fields.

“We’re interested in the origins of gender differences in spatial skills because of their potential role in the gender gap we see in math and science fields,” Lauer says. “By determining when the gender difference can first be detected in childhood and how it changes with age, we may be able to develop ways to make educational systems more equitable.”

It takes most of childhood and adolescence for the gender gap in spatial skills to reach the size of the difference seen in adulthood, Lauer says. She adds that the meta-analysis did not address causes for why the gender gap for mental rotation emerges and grows.

Lauer notes that previous research has shown that parents use more spatial language when they talk to preschool sons than daughters. Studies have also found that girls report more anxiety about having to perform spatial tasks than do boys by first grade, and that children are aware of gender stereotypes about spatial intelligence during elementary school.

“Now that we’ve characterized how gender differences in spatial reasoning skills develop in children over time we can start to hone in on the reasons for those differences,” Lauer says.

Meanwhile, she adds, parents may want to be aware to encourage both their daughters and sons to play with blocks and other construction items that might help in the development of spatial reasoning skills, since evidence shows that these skills can be improved with training.

“Giving both girls and boys more opportunities to develop their spatial skills is something that parents and educators have the power to do,” Lauer says.

Lauer has accepted a post-doctoral fellowship position at New York University. Her PhD advisor is Patricia Bauer, a professor of psychology at Emory focused on cognition and child development.

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Machine learning used to understand and predict dynamics of worm behavior

The roundworm C. elegans is a well-established laboratory model system. While the worm is a fairly simple living system, it is complicated enough to serve as "a kind of sandbox" for testing out methods of automated inference, says Emory biophysicist Ilya Nemenman. (Getty Images)

By Carol Clark

Biophysicists have used an automated method to model a living system — the dynamics of a worm perceiving and escaping pain. The Proceedings of the National Academy of Sciences (PNAS) published the results, which worked with data from experiments on the C. elegans roundworm.

“Our method is one of the first to use machine-learning tools on experimental data to derive simple, interpretable equations of motion for a living system,” says Ilya Nemenman, senior author of the paper and a professor of physics and biology at Emory University. “We now have proof of principle that it can be done. The next step is to see if we can apply our method to a more complicated system.”

The model makes accurate predictions about the dynamics of the worm behavior, and these predictions are biologically interpretable and have been experimentally verified.

Collaborators on the paper include first author Bryan Daniels, a theorist from Arizona State University, and co-author William Ryu, an experimentalist from the University of Toronto.

The researchers used an algorithm, developed in 2015 by Daniels and Nemenman, that teaches a computer how to efficiently search for the laws that underlie natural dynamical systems, including complex biological ones. They dubbed the algorithm “Sir Isaac,” after one of the most famous scientists of all time — Sir Isaac Newton. Their long-term goal is to develop the algorithm into a “robot scientist,” to automate and speed up the scientific method of forming quantitative hypotheses, then testing them by looking at data and experiments.

While Newton’s Three Laws of Motion can be used to predict dynamics for mechanical systems, the biophysicists want to develop similar predictive dynamical approaches that can be applied to living systems.

For the PNAS paper, they focused on the decision-making involved when C. elegans responds to a sensory stimulus. The data on C. elegans had been previously gathered by the Ryu lab, which develops methods to measure and analyze behavioral responses of the roundworm at the holistic level, from basic motor gestures to long-term behavioral programs.

C. elegans is a well-established laboratory animal model system. Most C. elegans have only 302 neurons, few muscles and a limited repertoire of motion. A sequence of experiments involved interrupting the forward movement of individual C. elegans with a laser strike to the head. When the laser strikes a worm, it withdraws, briefly accelerating backwards and eventually returning to forward motion, usually in a different direction. Individual worms respond differently. Some, for instance, immediately reverse direction upon laser stimulus, while others pause briefly before responding. Another variable in the experiments is the intensity of the laser: Worms respond faster to hotter and more rapidly rising temperatures.

For the PNAS paper, the researchers fed the Sir Isaac platform the motion data from the first few seconds of the experiments — before and shortly after the laser strikes a worm and it initially reacts. From this limited data, the algorithm was able to capture the average responses that matched the experimental results and also to predict the motion of the worm well beyond these initial few seconds, generalizing from the limited knowledge. The prediction left only 10 percent of the variability in the worm motion that can be attributed to the laser stimulus unexplained. This was twice as good as the best prior models, which were not aided by automated inference.

“Predicting a worm’s decision about when and how to move in response to a stimulus is a lot more complicated than just calculating how a ball will move when you kick it,” Nemenman says. “Our algorithm had to account for the complexities of sensory processing in the worms, the neural activity in response to the stimuli, followed by the activation of muscles and the forces that the activated muscles generate. It summed all this up into a simple and elegant mathematical description.”

The model derived by Sir Isaac was well-matched to the biology of C. elegans, providing interpretable results for both the sensory processing and the motor response, hinting at the potential of artificial intelligence to aid in discovery of accurate and interpretable models of more complex systems.

“It’s a big step from making predictions about the behavior of a worm to that of a human,” Nemenman says, “but we hope that the worm can serve as a kind of sandbox for testing out methods of automated inference, such that Sir Isaac might one day directly benefit human health. Much of science is about guessing the laws that govern natural systems and then verifying those guesses through experiments. If we can figure out how to use modern machine learning tools to help with the guessing, that could greatly speed up research breakthroughs.”

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A nod to World Sleep Day

World Sleep Day is March 15 this year. The annual event is a celebration of sleep and a call to action on issues related to sleep, including medicine, education and social aspects.

In Emory anthropologist Carol Worthman's research around the world, "sleep has emerged as both more flexible and more social than one would think from the perspective of the West," writes Todd Pitock in Aeon Magazine.

"When Worthman started exploring the anthropology of sleep more than a decade ago," the article continues, "the topic was way below the radar of colleagues who believed that culture was something you did while awake. But she found otherwise."

Read the whole article here.

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The importance of puberty: A call for better research models

“Due to the global slowdown in fertility, this is probably the biggest cohort of young people we will ever see,” says anthropologist Carol Worthman. “If we are ever going to get serious about helping adolescents reach their full potential, now is the time.”

By Carol Clark

Puberty is much more than just a time of biological overdrive, propelled by sexual maturation. Progress in developmental science has greatly broadened the perspective of this critical maturational milestone.

“We’ve moved beyond thinking of puberty as simply raging hormones,” says Carol Worthman, professor of anthropology at Emory University. “Major advances in understanding of brain development clearly show that the sociological and psychological impacts during puberty are just as important as the hormones.”

What’s needed now, Worthman argues as lead author on a new paper, is to integrate this understanding into more comprehensive research models. The Journal of Research on Adolescence published the paper, which reviews key theories and methods that are relevant to studies of puberty.

“Puberty was once thought of as the biological process of teen development and adolescence was considered the cultural process,” Worthman says. “We want to raise awareness that bracketing research in this way is no longer a useful approach.”

For decades, researchers have focused on improving the health of infants and children, resulting in substantial declines in child mortality worldwide.

While babies and children are labeled as cute and positive, full of possibility, adolescents are more often seen as problems. They have generally been less studied, Worthman says, even though the second decade of life is a critical time when risks spike for the development of mental illness, substance abuse and the escalation of injuries. And what happens in puberty, she adds, impacts health and well-being across the lifespan.

The global population is now bulging with young people aged 10 to 19, who today number more than 1.2 billion, or 17 percent of humanity. These young people must deal with finding their way into adulthood amid massive, rapid social transformations.

“Due to the global slowdown in fertility, this is probably the biggest cohort of young people we will ever see,” Worthman says. “If we are ever going to get serious about helping adolescents reach their full potential, now is the time.”

In her own research, Worthman uses a biocultural approach to conduct comparative interdisciplinary studies of human development. Samatha Dockray, a co-author of the paper from University College Cork, studies psychobiological mechanisms to understand their effects on adolescent health and behavior. The third co-author, Kristine Marceau from Purdue University, integrates genetics, prenatal risk, neuroendocrine development and the family environment into her developmental research.

The paper outlines minimally invasive methods to study different aspects of puberty. For instance, hair and fingernail clippings can be used to track stress levels and hormones over time. Changes in the microbiome, immune function and brain are other critical aspects of puberty that can be measured, along with cognition, behavior and ecological contexts.

“By taking advantage of new methods, and working in interdisciplinary teams, developmental scientists can explore more questions about adolescent development and welfare in more integrated ways,” Worthman says.

The review paper is part of a special section on puberty published by the Journal of Research on Adolescence. Topics covered include emerging genetic-environmental complexities of puberty, the role of puberty in the developing brain, how puberty impacts health and well-being across the lifespan and the need to explore puberty in understudied populations.

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Changes in rat size reveal habitat of 'Hobbit' hominin

At the Liang Bua cave site, paleoanthropologist Matthew Tocheri, left, measures a modern giant rat with the assistance of Bonefasius Sagut. At right is a reconstruction of Homo floresiensis carrying a giant rat, by paleo artist Peter Schouten.

By Carol Clark

A study of rat body sizes shifting over time gives a glimpse into the habitat of the mysterious hominin Homo floresiensis — nicknamed the “Hobbit” due to its diminutive stature.

The Journal of Human Evolution is publishing the study, based on an analysis of thousands of rodent bones, mainly fore- and hind-limbs, from an Indonesian cave where H. floresiensis was discovered in 2003. The results indicate that the local habitat was mostly open grasslands more than 100,000 years ago, but began shifting rapidly to a more closed environment 60,000 years ago.

“Our paper is the first that we know of to use the leg bones of rats in this way to interpret ecological change through time, and it provides new evidence for the local environment during the time of Homo Floresiensis,” says Elizabeth Grace Veatch, a PhD candidate at Emory University and a first author of the study.

Veatch with an H. floresiensis skull.

H. floresiensis stood only about 3 feet 6 inches tall and was known to have lived about 190,000 to 50,000 years ago on the oceanic island of Flores in eastern Indonesia. The tiny hominin shared the island with animals that could have come from the pages of a Tolkien novel, including giant Komodo dragons, six-foot-tall storks, vultures with a six-foot wingspan, and pygmy Stegodons — herbivores that looked like small elephants with swooping, oversized tusks.

It was the rats, however, that most interested Veatch.

Murids, as the rat family is known, are more taxonomically diverse than any other mammal group and are found in nearly every part of the world. “They exhibit an incredible range of behaviors occupying many different ecological niches,” Veatch says. “And because small mammals are typically sensitive to ecological shifts, they can tell you a lot about what’s going on in an environment.”

The study was based on remains recovered from the limestone cave known as Liang Bua, where partial skeletons of H. floresiensis have been found, along with stone tools and the remains of animals — most of them rats. In fact, out of the 275,000 animal bones identified in the cave so far, 80 percent of them are from rodents.

Veatch came to Emory to work with paleoanthropologist Jessica Thompson, a leading expert in using taphonomy — the study of what happens to bones after an organism dies — to learn more about the evolution of the human diet. Although Thompson has now moved to Yale University, she continues to mentor Veatch in her graduate studies at Emory.

Veatch became part of the Liang Bua project while doing an internship with the Human Origins Program of the Smithsonian Institution’s National Museum of Natural History. Her mentor there was paleoanthropologist Matthew Tocheri (now with Lakehead University in Ontario) who shares first-authorship of the current paper with Veatch.

“Matthew asked me if I wanted to analyze some rat bones and I said, ‘Sure,’” Veatch recalls. “I had no idea what I was getting into.”

A graphic of the rat species included in the study.

The study encompassed about 10,000 of the Liang Bua rat bones. The remains spanned five species with distinct sizes, from the mouse-sized Rattus hainaldi up to the housecat-sized Papagomys armandvillei — commonly known as the Flores giant rat. After categorizing the bones, the researchers could then directly link them to both species and environmental types.

While rats can adjust to new environments, the morphologies of different species tend to be adaptive to their preferred environment. For example, the habitat of the medium-sized Komodomys rintjanus, included in the study, is primarily open grasslands intermittent with patches of forest. In contrast, the tiny R. hainaldi and the giant P. armandvillei both prefer more closed or semi-closed forested habitats.

Tracking the relative abundances of the different rat species over time indicated that the local ecology was mostly open grassland 100,000 years ago, transitioning to a more-closed, forested habitat around 60,000 years ago. That is around the same time that skeletal elements belonging to Homo floresiensis, the pygmy Stegodon, giant storks, vulture and Komodo dragons disappear from Liang Bua.

“The evidence suggests that Homo floresiensis may have preferred more open habitats where they may have been a part of this scavenging guild of Stegodons, storks and vultures,” Veatch says. “We think that when the habitat changed, becoming more forested, Homo floresiensis probably left the Liang Bua area, tracking these animals to more open habitats elsewhere on the island.”

Veatch looks at piles of sediment excavated from Luang Bua as it is being wet sieved using the irrigation system of a rice paddy near the cave site.

Many more mysteries remain regarding H. floresiensis, Veatch says, and the Liang Bua rat bones may help solve some of them. One key question is whether H. floresiensis hunted small game.

“Our early ancestors adapted to consuming large amounts of big game through hunting or scavenging — or both,” Veatch says. “Big game undoubtedly became a critical food source, resulting in numerous social and physiological adaptations, including social cooperation and brain expansion. It’s much less known, however, what role small-game hunting may have played in our early evolution — if any at all.”

Liang Bua, she says, offers an ideal opportunity to study what a small-brained hominin, like H. floresiensis, might hunt if it had both sources of big game, like the Stegodon, and small game, like the giant Flores rat and other rat species.

Veatch is conducting field studies at the Liang Bua site, including running experiments to determine how difficult it would be to capture wild Flores rats. She is also doing research at the Pusat Penelitian Arkeologi Nasional (ARKENAS) Museum in the Indonesian capital of Jakarta where many of the bones from the cave site are now stored. She is analyzing a large sample of the bones to determine if any have cut marks — indicating butchering with tools — or pitted marks that would indicate they were digested by owls or other raptors that may have deposited them in the cave.

“In Indonesia, my nickname is Miss Tikus, which means ‘Miss Rat,’” Veatch says. “I’m perfectly fine with that because rats are really intelligent and extraordinary animals. We see them through the entire sequence in the archeology of Liang Bua and we will continue to use them in future studies to learn more about what went on in the cave.”

Co-authors of the current paper include Thomas Sutikna, E. Wahyu Saptomo and Jamiko, who are all from ARKENAS and the University of Wollongong in Australia; Kate McGrath from the University of Bordeaux, France; and Kristofer Helgen from the University of Adelaide in Australia.

Photo credits: All images courtesy of the Liang Bua research team. Photo of Veatch with skull was taken by Kristofer Helgen. The photo of Veatch and sediment was taken by Hanneke Meijer.

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From Stone Age chips to microchips: How tiny tools made us human

Tiny stone flakes such as the one above, from a site in South Africa called Boomplaas, may have helped some humans survive the last period of rapid climate change, 17,000 years ago, says Emory anthropologist Justin Pargeter.

Anthropologists have long made the case that tool-making is one of the key behaviors that separated our human ancestors from other primates. A new paper, however, argues that it was not tool-making that set hominins apart — it was the miniaturization of tools.

Just as tiny transistors transformed telecommunications a few decades ago, and scientists are now challenged to make them even smaller, our Stone Age ancestors felt the urge to make tiny tools. “It’s a need that we’ve been perennially faced with and driven by,” says Justin Pargeter, an anthropologist at Emory University and lead author of the paper. “Miniaturization is the thing that we do.”

The journal Evolutionary Anthropology is publishing the paper — the first comprehensive overview of prehistoric tool miniaturization. It proposes that miniaturization is a central tendency in hominin technologies going back at least 2.6 million years.

Learn more by clicking here.

Computer scientist explains 'Dangers of the Coded Gaze'

Watch a video of Joy Buolamwini discussing her work.

As a master’s student at MIT, Joy Buolamwini discovered that her own face read as male in many facial-analysis software systems — if her face was detected at all. And, no, it was not a personal slight; it turns out that many darker-skinned women of color also read as male. If you were what Buolamwini terms a “pale male,” though, most systems could categorize you with a high rate of accuracy. 

Buolamwini, a computer scientist and digital activist, went on to found the Algorithmic Justice League, raising awareness to the problem of any company refusing to acknowledge bias in its facial-recognition software. She recently spoke at Emory as part of the Provost Lecture Series, which is designed to inspire the Emory community to think about big questions and collaborate on innovative solutions.

As Deboleena Roy, chair of Emory’s Department of Women’s, Gender, and Sexuality Studies and faculty in Neuroscience and Behavioral Biology, said in introducing Buolamwini, “Rather than sit back and see the creation of new technologies that work to reinforce dominant and discriminatory gender and racial norms, she instead is using her expertise as a scientist to envision a more socially just technological future. Applying her awareness of gender and race issues, she has dedicated her research and her career to creating more inclusive code and more inclusive coding practices.”

Click here to read more about Buolamwini's Emory talk, entitled "Dangers of the Coded Gaze."

Atlanta Science Festival to launch at Emory with the power of WOW!

Wow in the World host Mindy Thomas, center, will kick off the Atlanta Science Festival with the help of musical duo The Pop Ups (Jacob Stein, left, and Jason Rabinowitz).

By Carol Clark

Watch for serious fun to spring up all around town as part of the 2019 Atlanta Science Festival, March 9 to March 23. The festival begins with a Wow in the World Pop Up Party on Saturday, March 9 from 11 am to noon on the Emory University campus. Mindy Thomas, a host of the popular NPR science-themed podcast Wow in the World, will engage curious kids and their grown-ups in games and skits with mad musical accompaniment by the Pop Ups — creators of the children’s music album Giants of Science.

A "Wow in the World" launch

“Wow in the World is an excellent program for kids and we really wanted to bring the energy of its team to Atlanta,” says Meisa Salaita, co-director of the Atlanta Science Festival. “They tie new and relevant research into interesting topics for kids, everything from ants that explode to seaweed that might boost your brain power. Kids are our future and getting them excited about science is so important.”

Kids will enjoy skits and games inspired by topics from the podcast like “Contagion Alert: The Science of Trying Not to Laugh” and “It SNOT What You Think.” Tickets are required for the launch event, set at Emory’s Glenn Memorial United Methodist Church, and it is expected to sell out.

The Atlanta Science Festival, or ASF, will feature more than 100 events throughout the metro area hosted by school districts, universities, museums, businesses and civic and community groups. Delta Air Lines is the presenting sponsor for 2019.

This year, Emory scientists will lead a walk with Mesozoic dinosaurs, discuss how neuro-engineering is blurring the lines between mind and machine and describe the physics of how babies learn to talk. Click here to see a full list of events connected to Emory.

Hundreds of visitors are expected on the Emory campus on Friday, March 22 for the perennial festival favorites, "Chemistry Carnival" and "Physics Live!"

“Science on Stage: The Forgotten Organ,” stars the bacteria, fungi and viruses within the human microbiome that shapes every one of us from birth. The Emory Center for the Study of Human Health teamed up with Theater at Emory to have playwrights quickly produce short plays about the microbiome. The playwrights drew their inspiration from a New York Times bestselling book by science writer Ed Yong, “I Contain Multitudes: The Microbes Within Us and a Grander View of Life.”

Yong will join the playwrights for readings of their works and a panel discussion of this unique collaboration between art and science. This event is set for Wednesday, March 20, at 6:30 pm at the Carter Presidential Library and Museum.

The Emory event “Become an Archaeologist” returns on Thursday, March 21 from 6 to 8 pm. This year the faculty and students involved are taking their bones off campus, to Brownwood Park in East Atlanta Village. The Emory experts will teach community members how to extract DNA and put pieces of ancient objects back together like a puzzle. “It’s a great example of the festival taking events that we know are popular and setting them in other parts of the city so that we can continue to reach new audiences and connect in different ways,” Salaita says. “Our goal is to keep broadening access to our programming.”

Two perennial festival favorites — Chemistry Carnival and Physics Live! — return this year to the Emory campus on Friday, March 22 from 3:30 to 7 pm. Emory science faculty and students will explain their research, give lab tours, and entertain with games like Peptide Jenga, a chance to play with giant soap bubbles and tastings of liquid nitrogen ice cream. Hundreds of visitors are expected to turn out for the events, held in the Mathematics and Science Center and Atwood Chemistry Center.

Oxford hosts "Ada and the Engine"

A highlight on Emory’s Oxford campus will be performances of the play “Ada and the Engine,” portraying the groundbreaking career of Ada Lovelace — a mathematician, poet and the first computer programmer. The play was written by Lauren Gunderson, an acclaimed playwright who graduated from Emory in 2004. During the festival, the play will be performed Friday and Saturday, March 21 and 22, at 7:30 pm. Performances will be followed by talks on the themes of women working in a field dominated by men, and a chance to walk through a special interactive exhibition, "Reviving Ada," curated by Oxford students to celebrate women's contributions to STEM fields from throughout history.

The festival culminates on Saturday, March 23 with the Exploration Expo at Piedmont Park — a day-long, free carnival of science with hundreds of hands-on activities. More than a dozen booths will feature Emory faculty and students, who will engage crowds in activities with names like “Air Pollution Particle Toss,” “Opening a Can of Worms: Exploring Biomaterials and Nanotechnology with Alginate Gummy Worms,” “Smell the World,” and “Can You Guess What Your Brain is Thinking?”

Founded in 2014 by Emory University, Georgia Tech and the Metro Atlanta Chamber, the ASF celebration of local science, technology, engineering and math has brought programming to more than 200,000 people in the metro region, reaching a diverse audience of a wide variety of ages. 

Special funding from sponsors such as Delta, the Arthur M. Blank Family Foundation and others is helping ASF soar to new heights and extend some of its programming and events year-round. A chief science officer program charges student representatives from middle schools and high school to foster science communities at their schools.

“These chief science officers, who are elected by their student bodies, receive leadership training, meet with state legislators and learn about the role of science and policy,” Salaita says. “We launched the program this year with 22 students and we plan to grow exponentially over the next three years to 200 students.”

Another program piloted this past year by the ASF is a science communication training fellowship for graduate students and post-doctoral fellows. “We’ve started with eight students who met monthly to learn about narrative in science communication, data visualization and other communication techniques,” Salaita says. “They will use their new skills to create events for the science festival and give informal talks to the general public.”

Another new component of the ASF is a year-round calendar of STEM-themed activities. “We want people to stay connected to science,” Salaita explains. “Our new events calendar is a guide for family friendly activities in the metro Atlanta area when the festival’s not happening.”

A new spin on computing: Chemist leads $3.9 million DOE quest for quantum software

"Quantum computers are not just exponentially faster, they work in a radically different way from classical computers," says chemist Francesco Evangelista, who is leading a project to develop quantum software.

By Carol Clark

When most people think of a chemistry lab, they picture scientists in white coats mixing chemicals in beakers. But the lab of theoretical chemist Francesco Evangelista looks more like the office of a tech start-up. Graduate students in jeans and t-shirts sit around a large, round table chatting as they work on laptops.

“A ‘classical’ chemist is focused on getting a chemical reaction and creating new molecules,” explains Evangelista, assistant professor at Emory University. “As theoretical chemists, we want to understand how chemistry really works — how all the atoms involved interact with one another during a reaction.”

Working at the intersection of math, physics, chemistry and computer science, the theorists develop algorithms to serve as simulation models for the molecular behaviors of atomic nuclei and electrons. They also develop software that enables them to feed these algorithms into “super” computers — nearly a million times faster than a laptop — to study chemical processes.

The problem is, even super computers are taxed by the mind-boggling combinatorial complexity underlying reactions. That limits the pace of the research.

“Computers have hit a barrier in terms of speed,” Evangelista says. “One way to make them more powerful is to make transistors smaller, but you can’t make them smaller than the width of a couple of atoms — the limit imposed by quantum mechanics. That’s why there is a race right now to make breakthroughs in quantum computing.”

Evangelista and his graduate students have now joined that race.

The Department of Energy (DOE) awarded Evangelista $3.9 million to lead research into the development of software to run the first generation of quantum computers. He is the principal investigator for the project, encompassing scientists at seven universities, to develop new methods and algorithms for calculating problems in quantum chemistry. The tools the team develops will be open access, made available to other researchers for free.

Watch a video about Francesco Evangelista's work, 
produced by the Camille & Henry Dreyfus Foundation:


While big-data leaders — such as IBM, Google, Intel and Rigetti — have developed prototypes of quantum computers, the field remains in its infancy. Many technological challenges remain before quantum computers can fulfill their promise of speeding up calculations to crack major mysteries of the natural world.

The federal government will play a strong supporting role in achieving this goal. President Trump recently signed a $1.2 billion law, the National Quantum Initiative Act, to fund advances in quantum technologies over the next five years.

“Right now, it’s a bit of a wild west, but eventually people working on this giant endeavor are going to work out some of the current technological problems,” Evangelista says. “When that happens, we need to have quantum software ready and a community trained to use it for theoretical chemistry. Our project is working on programming codes that will someday get quantum computers to do the calculations we want them to do.”

The project will pave the way for quantum computers to simulate chemical systems critical to the mission of the DOE, such as transition metal catalysts, high-temperature superconductors and novel materials that are beyond the realm of simulation on “classical” computers. The insights gained could speed up research into how to improve everything from solar power to nuclear energy.

Unlike objects in the “classical” world, that we can touch, see and experience around us, nature behaves much differently in the ultra-small quantum world of atoms and subatomic particles.

“One of the weird things about quantum mechanics is that you can’t say whether an electron is actually only here or there,” Evangelista says.

He takes a coin from his pocket. “In the classical world, we know that an object like this quarter is either in my pocket or in your pocket,” Evangelista says. “But if this was an electron, it could be in both our pockets. I cannot tell you exactly where it is, but I can use a wave function to describe the likelihood of whether it is here or there.”

To make things even more complicated, the behavior of electrons can be correlated, or entangled. When objects in our day-to-day lives, like strands of hair, become entangled they can be teased apart and separated again. That rule doesn’t apply at the quantum scale where entangled objects are somehow intimately connected even if they are apart in space.

“Three electrons moving in three separate orbitals can actually be interacting with one another,” Evangelista says. “Somehow they are talking together and their motion is correlated like ballerinas dancing and moving in a concerted way.”

Graduate students in Evangelista's lab are developing algorithms to simulate quantum software so they can run tests and adapt the design based on the results.

Much of Evangelista’s work involves trying to predict the collective behavior of strongly correlated electrons. In order to understand how a drug interacts with a protein, for example, he needs to consider how it affects the hundreds of thousands of atoms in that protein, along with the millions of electrons within those atoms.

“The problem quickly explodes in complexity,” Evangelista says. “Computationally, it’s difficult to account for all the possible combinations of ways the electrons could be interacting. The computer soon runs out of memory.”

A classical computer stores memory in a line of “bits,” which are represented by either a “0” or a “1.” It operates on chunks of 64 bits of memory at a time, and each bit is either distinctly a 0 or a 1. If you add another bit to the line, you get just one more bit of memory.

A quantum computer stores memory in quantum bits, or qubits. A single qubit can be either a 0 or a 1 — or mostly a 0 and part of a 1 — or any other combination of the two. When you add a qubit to a quantum computer, it increases the memory by a factor of two. The fastest quantum computers now available contain around 70 qubits.

“Quantum computers are not just exponentially faster, they work in a radically different way from classical computers,” Evangelista says.

For instance, a classical computer can determine all the consequences of a chess move by working one at a time through the chain of possible next moves. A quantum computer, however, could potentially determine all these possible moves in one go, without having to work through each step.

While quantum computers are powerful, they are also somewhat delicate.

“They’re extremely sensitive,” Evangelista says. “They have to be kept at low temperatures to maintain their coherence. In a typical setup, you also need a second computer kept at very low temperatures to drive the quantum computer, otherwise the heat from the wires coming out will destroy entanglement.”

The potential error rate is one of the challenges of the DOE project to develop quantum software. The researchers need to determine the range of errors that can still yield a practical solution to a calculation. They will also develop standard benchmarks for testing the accuracy and computing power of new quantum hardware and they will validate prototypes of quantum computers in collaborations with industry partners Google and Rigetti.

Just as they develop algorithms to simulate chemical processes, Evangelista and his graduate students are now developing algorithms to simulate quantum software so they can run tests and adapt the design based on the results.

Evangelista pulled together researchers from other universities with a range of expertise for the project, including some who are new to quantum computing and others who are already experts in the field. The team includes scientists from Rice University, Northwestern, the University of Michigan, CalTech, the University of Toronto and Dartmouth.

The long-range goal is to spur the development of more efficient energy sources, including solar power, by providing detailed data on phenomena such as the ways electrons in a molecule are affected when that molecule absorbs light.

“Ultimately, such theoretical insights could provide a rational path to efforts like making solar cells more efficient, saving the time and money needed to conduct trial-and-error experiments in a lab,” Evangelista says.

Evangelista also has ongoing collaborations with Emory chemistry professor Tim Lian, studying ways to harvest and convert solar energy into chemical fuels. In 2017, Evangelista won the Dirac Medal, one of the world’s most prestigious awards for theoretical and computational chemists under 40.

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Take a 60-minute tour of space, time and spacetime

“I’ll begin with Saint Augustine,” says Emory physicist Erin Bonning, referring to the 4th-century philosopher and theologian who wrote some of the earliest known reflections on time and how humans perceive it. He summed time up: “I know well enough what it is, provided that nobody asks me; but if I am asked what it is, and try to explain, I am baffled.”

Bonning, director of the Emory Planetarium and a lecturer in the Department of Physics, collapses centuries of ideas and discovery about the universe into a mind-bending, 60-minute talk, “Space, Time and Spacetime,” that you can watch in the video above.

Bonning explains the ongoing quest for our understanding of time and how it relates to space: From recognition of the regular appearances of the sun, to the sense of time flowing through an hour glass, to the ticking of the first mechanical clocks, and on through the insights of Newton, Copernicus, Galileo, Michelson, Einstein and more. She even gives the perspective of aliens whizzing by Earth in a spaceship.

She winds up her talk, a recently delivered Emory Williams Lecture in the Liberal Arts, by discussing explorations of gravitational waves, dark matter and the drive to manipulate spacetime deliberately.

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Growing knowledge and healthy food

Oxford student Gratia Sullivan unearths a bunch of radishes destined for the campus kitchens and community consumers. Photo by Kay Hinton.

From Emory Magazine

As an undergraduate biology major at Clemson University, Daniel Parson recognized the disconnect between environmental sustainability and traditional agriculture. He went on to get a masters degree in plant and environmental science from Clemson and spent more than a dozen years working in organic farming in Georgia and South Carolina.

"We look at nature as wilderness, but we also need things from nature and we need to learn how to get them without destroying it," says Parson.

He joined Emory's Oxford campus in 2014 to run the Oxford Organic Farm, an 11-acre piece of land that provides produce for the university's dining halls and farmers markets and unique learning opportunities for students.

"We try to match the seasons with when students are on campus so our work-student students who are here every day have the best experience possible and so we can work with faculty to connect course curriculum to the farm," says Parson, whose official title is farmer-educator. "For economics classes I might talk about how we set prices and interact with markets, but for other classes I may just be talking about the experiences I've had and how that connects with what they are discussing in class."

Click here to read more.

Chemical catalyst turns 'trash' to 'treasure'

Emory graduate student J.T. Fu, first author of the Nature paper, holds vials of the catalyst and the reagent used in the reaction.

By Carol Clark

For decades, chemists have aspired to do carefully controlled chemistry on carbon-hydrogen bonds. The challenge is staggering. It requires the power of a miniature wrecking ball to break these extremely strong bonds, combined with the finesse of microscopic tweezers to single out specific C-H bonds among the many crowded onto a molecule.

The journal Nature published a method that combines both these factors to make an inert C-H bond reactive — effectively turning chemical “trash” to “treasure.”

“We can change a cheap and abundant hydrocarbon with limited usefulness into a valuable scaffold for developing new compounds — such as pharmaceuticals and other fine chemicals,” says J.T. Fu, a graduate student at Emory University and first author of the paper.

The Nature paper is the latest in a series from Emory University demonstrating the ability to use a dirhodium catalyst to selectively functionalize C-H bonds in a streamlined manner, while also maintaining virtually full control of the three-dimensional shape of the molecules produced.

“This latest catalyst is so selective that it goes cleanly for just one C-H bond — even though there are several C-H bonds very similar to it within the molecule,” says Huw Davies, Emory professor of organic chemistry and senior author of the paper. “That was a huge surprise, even to us.”

Click here to read more about the discovery.

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Your past is calling: Can you ID stone toolmaking 'ring' tones?

Emory anthropologist Dietrich Stout invites you to participate in an online experiment, Sounds of the Past, investigating the human ability to discriminate and interpret the sounds produced by stone toolmaking. (Photo by Ann Watson, Emory Photo/Video)

By Carol Clark

Long before everyone started carrying a smart phone everywhere they went — attuned to the sounds of a text, call or email — our ancestors carried a hand axe.

“Stone tools were the key human technology for two million years,” says Dietrich Stout, director of the Paleolithic Technology Laboratory at Emory University. In fact, he adds, the process of making them may have played an important role in our ability to communicate.

If you can spare just 10 minutes for science, you can use your smart phone and a pair of headphones to log onto a web site to help Stout test whether ancient tool-making promoted special acoustic abilities — perhaps even honing the development of spoken language.

Stout is an experimental archeologist who recreates prehistoric stone toolmaking, known as knapping, to study the evolution of the human brain and mind. In many of his experiments, subjects actually bang out the tools as activity in their brains is recorded via functional magnetic resonance imaging (fMRI). He’s already found evidence that the visual-spatial skills used in knapping activate areas of the brain that are involved in language processing.

But what about the sounds of knapping?

“An experienced knapper once told me that he would rather be blindfolded than wear ear plugs while making a stone tool, because he got so much valuable information out of the sound when he struck the stone,” Stout says. “That got me wondering: Do knappers just think that the sounds are giving them meaningful information? Could we give them a test to find out if that’s true?”

Stout teamed up with Robert Rein, from the German Sport University Cologne, to develop just such a test. The result is the online experiment Sounds of the Past, open to everyone — from expert knappers to those who have never knapped at all.

During stone tool production a stone flake is produced by hitting a stone core with another stone, used like a hammer. Factors like the geometry of the core stone and the location and the strength of the strike determine the size of the flake that falls off.

The researchers recorded the sounds of flakes breaking off during stone tool production. Participants in the online experiment are presented with a series of these sounds, with no accompanying visuals, and asked to estimate the length of the flakes produced, within a range of parameters.

Participants are also asked whether they have prior experience knapping. The aim is to get as many experienced knappers as possible to participate, and at least an equal number of those without experience, then compare the results.

“No one is going to guess all the flake sizes, to the millimeter,” Stout says. “But if we plot out the results, we should see if there is a correlation between the level of accuracy and whether someone is an experienced or novice knapper.”

The study is self-funded and does not provide compensation for participants. Individual test results are also not available. “It’s really something that we hope participants will just have fun doing, along with the satisfaction that they are providing data to help us understand the evolution of the human brain,” Stout says.

The length of time the experiment will be available is open ended, he adds, although the researchers hope to have enough results in hand for analysis sometime next year.

Click here to participate in the experiment.

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Learn ethnobotany while making holiday gifts

What does an ethnobotanist give for presents during the holidays? If you’re Cassandra Quave, you enlist your kids to help you make herbal-infused, bees-wax chapstick from scratch. Marigold, cinnamon, nutmeg and black pepper are just a few of the ingredients.

Quave is an assistant professor in Emory’s Center for the Study of Human Health and in the School of Medicine’s Department of Dermatology. Her specialty of ethnobotany takes her around the world, studying how traditional healers use plants. She’s particularly interested in plants for treating skin infections and wounds. She collects the plants, extracts their chemical compounds, and tests them for efficacy in combating antibiotic-resistant infections.

Watch Quave’s latest video on her Teach Ethnobotany YouTube channel to learn how to make your own botanical chapstick. And check out some of her other videos. She’ll take you to a traditional market in Kuwait to learn about dates, and to the Atlanta Botanical Garden for the backstory of “the vine of the soul.”

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'Potato gene' reveals how ancient Andeans adapted to starchy diet

A woman sells potatoes at a market in the Andes. DNA analyses show that ancient populations of the Peruvian highlands adapted to the introduction of agriculture in ways distinct from other global populations. 

By Carol Clark

Potatoes, native to South America, became an agricultural crop thousands of years ago in the Andean highlands of Peru. And just as the ancient Andean people turned wild tubers into the domesticated potato, the potato may have altered the genomes of the Andeans who made it a staple of their diet.

Science Advances published the findings. DNA analyses show that ancient populations of the Peruvian highlands adapted to the introduction of agriculture and an extreme, high-altitude environment in ways distinct from other global populations.

“We see a different configuration of a gene associated with starch digestion in the small intestine — MGAM — in the agricultural ancient Andean genome samples, but not in hunter-gatherers down the coast,” says Emory University geneticist John Lindo, first author of the paper. “It suggests a sort of co-evolution between an agricultural crop and human beings.”

In contrast, European populations that began consuming more grains with the rise of agriculture show different genomic changes. Research has shown that their genomes have an increased number of copies of the gene coding for amylase — an enzyme in saliva that breaks down starch.

Lindo, an assistant professor of anthropology at Emory, integrates the approaches of ancient whole genomes, statistical modeling and functional methods into ancient DNA research. The international team of 17 researchers also included Anna Di Rienzo of the University of Chicago (who specializes in physiology and genetics) and high-altitude archeologists Mark Aldenderfer, from the University of California, Merced, and Randall Haas, from the University of California, Davis.

The study looked at seven ancient whole genomes from the Lake Titicaca region of the Andean highlands of Peru, dating back from 1,800 to 7,000 years. The researchers also compared the ancient whole genomes with 64 modern-day genomes from both highland Andean populations and lowland populations in Chile, to identify genetic adaptions that took place before the arrival of Europeans in the 1500s.

The hardy potato helped people adapt to the harsh environment of the Andean highlands.

The Andean highlands make an ideal natural laboratory for ancient DNA studies, due to the strong selective pressure needed for ancient populations to adapt to altitudes greater than 2,500 meters. “Frigid temperatures, low oxygen levels and intense ultraviolet radiation make the highlands one of the most extreme environments that human beings have occupied,” Lindo says. “It provides a glimpse of our potential for adaptability.”

Both the ancient and modern high-altitude populations showed strong positive selection on variants in the MGAM gene, which is evident by at least 1,800 years ago. That fits with archeological evidence indicating that the domesticated potato — a crop resistant to cold that grows mainly underground — became a staple of the Peruvian highlands as far back as 3,400 years ago.

The researchers also discovered that the Andean highland population’s genomes do not share the same genetic changes previously seen in Tibetan genomes in response to hypoxia, or low levels of oxygen. That suggests that the Andean genomes adapted to high altitude in different ways.

One possibility uncovered in the study is differentiation in the DST gene, which has been linked to proper cardiac muscle in mice. DST histone modifications in the Andean genomes associated with blood and the right ventricle of the heart may correlate to the tendency of Andean highlanders to have enlarged right ventricles. That finding fits with a previous study suggesting that Andeans may have adapted to high altitude hypoxia via cardiovascular modifications.

A gene flow analysis found that the low- and high-elevation populations split between 8,200 to 9,200 years ago.

The arrival of the Spanish in South America — who brought new diseases, along with social disruption and war — coincided with an estimated reduction of 90 percent of the total Andean population. The current analysis, however, showed that the effective breeding population in the highlands went down by only 27 percent.

“We found a very strong selection in the highlands population on an immune gene that has been correlated with smallpox, which may have had a protective effect,” Lindo says. The harsh environment of the highlands, he adds, may have also buffered them from the devastation seen in the lowlands.

“Understanding the diet, environment and historical events of various ancestries, and how those ancestries adapted to these factors, may be one way to understand some health disparities among different populations,” Lindo says.

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Photos: Getty Images

Schadenfreude sheds light on the darker side of humanity

“We all experience schadenfreude but we don’t like to think about it too much because it shows how ambivalent we can be to our fellow humans,” says Emory psychologist Philippe Rochat.

By Carol Clark

Schadenfreude, the sense of pleasure people derive from the misfortune of others, is a familiar feeling to many — perhaps especially during these times of pervasive social media.

This common, yet poorly understood, emotion may provide a valuable window into the darker side of humanity, finds a review article by psychologists at Emory University. New Ideas in Psychology published the review, which drew upon evidence from three decades of social, developmental, personality and clinical research to devise a novel framework to systematically explain schadenfreude.

The authors propose that schadenfreude comprises three separable but interrelated subforms — aggression, rivalry and justice — which have distinct developmental origins and personality correlates.

They also singled out a commonality underlying these subforms.

“Dehumanization appears to be at the core of schadenfreude,” says Shensheng Wang, a PhD candidate in psychology at Emory and first author of the paper. “The scenarios that elicit schadenfreude, such as intergroup conflicts, tend to also promote dehumanization.”

Co-authors of the study are Emory psychology professors Philippe Rochat, who studies infant and child development, and Scott Lilienfeld, whose research focuses on personality and personality disorders.

Dehumanization is the process of perceiving a person or social group as lacking the attributes that define what it means to be human. It can range from subtle forms, such as assuming that someone from another ethnic group does not feel the full range of emotions as one’s in-group members do, all the way to blatant forms — such as equating sex offenders to animals. Individuals who regularly dehumanize others may have a disposition towards it. Dehumanization can also be situational, such as soldiers dehumanizing the enemy during a battle.

“Our literature review strongly suggests that the propensity to experience schadenfreude isn’t entirely unique, but that it overlaps substantially with several other ‘dark’ personality traits, such as sadism, narcissism and psychopathy,” Lilienfeld says. “Moreover, different subforms of schadenfreude may relate somewhat differently to these often malevolent traits.”

One problem with studying the phenomenon is the lack of an agreed definition of schadenfreude, which literally means “harm joy” in German. Since ancient times, some scholars have condemned schadenfreude as malicious, while others have perceived it as morally neutral or even virtuous.

“Schadenfreude is an uncanny emotion that is difficult to assimilate,” Rochat says. “It’s kind of a warm-cold experience that is associated with a sense of guilt. It can make you feel odd to experience pleasure when hearing about bad things happening to someone else.”

Psychologists view schadenfreude through the lens of three theories. Envy theory focuses on a concern for self-evaluation, and a lessening of painful feelings when someone perceived as enviable gets knocked down a peg. Deservingness theory links schadenfreude to a concern for social justice and the feeling that someone dealt a misfortune received what was coming to them. Intergroup-conflict theory concerns social identity and the schadenfreude experienced after the defeat of members of a rival group, such as during sporting or political competitions.

The authors of the current article wanted to explore how all these different facets of schadenfreude are interrelated, how they differ, and how they can arise in response to these concerns.

Their review delved into the primordial role of these concerns demonstrated in developmental studies. Research suggests that infants as young as eight months demonstrate a sophisticated sense of social justice. In experiments, they showed a preference for puppets who assisted a helpful puppet, and who punished puppets that had exhibited antisocial behavior. Research on infants also points to the early roots of intergroup aggression, showing that, by nine months, infants preferred puppets who punish others who are unlike themselves.

“When you think of normal child development, you think of children becoming good natured and sociable,” Rochat says. “But there’s a dark side to becoming socialized. You create friends and other in-groups to the exclusion of others.”

Spiteful rivalry appears by at least age five or six, when research has shown that children will sometimes opt to maximize their gain over another child, even if they have to sacrifice a resource to do so.

By the time they reach adulthood, many people have learned to hide any tendencies for making a sacrifice just for spite, but they may be more open about making sacrifices that are considered pro-social.

The review article posits a unifying, motivational theory: Concerns of self-evaluation, social identity and justice are the three motivators that drive people toward schadenfreude. What pulls people away from schadenfreude is the ability to feel empathy for others and to perceive them as fully human and to show empathy for them.

Ordinary people may temporarily lose empathy for others. But those with certain personality disorders and associated traits — such as psychopathy, narcissism or sadism — are either less able or less motivated to put themselves in the shoes of others.

“By broadening the perspective of schadenfreude, and connecting all of the related phenomena underlying it, we hope we’ve provided a framework to gain deeper insights into this complex, multi-faceted emotion,” Wang says.

“We all experience schadenfreude but we don’t like to think about it too much because it shows how ambivalent we can be to our fellow humans,” Rochat says. “But schadenfreude points to our ingrained concerns and it’s important to study it in a systematic way if we want to understand human nature.”

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Study gives new insight into how the brain perceives places

Example of an image from the fMRI study. Participants were asked to imagine they were standing in the room and indicate through a button press whether it was a bedroom, a kitchen or a living room. On separate trials, they were asked to imagine that they were walking on the continuous path through the room and indicate which door they could leave through. (Image by Andrew Persichetti)

By Carol Clark

Nearly 30 years ago, scientists demonstrated that visually recognizing an object, such as a cup, and performing a visually guided action, such as picking the cup up, involved distinct neural processes, located in different areas of the brain. A new study shows that the same is true for how the brain perceives our environment — it has two distinct systems, one for recognizing a place and another for navigating through it.

The Journal of Neuroscience published the finding by researchers at Emory University, based on experiments using functional magnetic resonance imaging (fMRI). The results showed that the brain’s parahippocampal place area responded more strongly to a scene recognition task while the occipital place area responded more to a navigation task.

The work could have important implications for helping people to recover from brain injuries and for the design of computer vision systems, such as self-driving cars.

“It’s thrilling to learn what different regions of the brain are doing,” says Daniel Dilks, senior author of the study and an assistant professor of psychology at Emory. “Learning how the mind makes sense of all the information that we’re bombarded with every day is one of the greatest of intellectual quests. It’s about understanding what makes us human.”

Entering a place and recognizing where you are — whether it’s a kitchen, a bedroom or a garden — occurs instantaneously and you can almost simultaneously make your way around it.

“People assumed that these two brain functions were jumbled up together — that recognizing a place was always navigationally relevant,” says first author Andrew Persichetti, who worked on the study as an Emory graduate student. “We showed that’s not true, that our brain has dedicated and dissociable systems for each of these tasks. It’s remarkable that the closer we look at the brain the more specialized systems we find — our brains have evolved to be super efficient.”

Persichetti, who has since received his PhD from Emory and now works at the National Institute of Mental Health, explains that an interest in philosophy led him to neuroscience. “Immanuel Kant made it clear that if we can’t understand the structure of our mind, the structure of knowledge, we’re not going to fully understand ourselves, or even a lot about the outside world, because that gets filtered through our perceptual and cognitive processes,” he says.

The Dilks lab focuses on mapping how the visual cortex is functionally organized. “We are visual creatures and the majority of the brain is related to processing visual information, one way or another,” Dilks says.

Researchers have wondered since the late 1800s why people suffering from brain damage sometimes experience strange visual consequences. For example, someone might have normal visual function in all ways except for the ability to recognize faces.

It was not until 1992, however, that David Milner and Melvyn Goodale came out with an influential paper delineating two distinct visual systems in the brain. The ventral stream, or the temporal lobe, is involved in object recognition and the dorsal stream, or the parietal lobe, guides an action related to the object.

In 1997, MIT’s Nancy Kanwisher and colleagues demonstrated that a region of the brain is specialized in face perception — the fusiform face area, or FFA. Just a year later, Kanwisher’s lab delineated a neural region specialized in processing places, the parahippocampal place area (PPA), located in the ventral stream.

While working as a post-doctoral fellow in the Kanwisher lab, Dilks led the finding of a second region of the brain specialized in processing places, the occipital place area, or OPA, located in the parietal lobe.

Dilks set up his own lab at Emory the same year that discovery was published, in 2013. Among the first questions he wanted to tackle was why the brain had two regions dedicated to processing places.

Persichetti designed an experiment to test the hypothesis that place processing was divided in the brain in a manner similar to object processing. Using software from the SIMS life simulation game, he created three digital images of places: A bedroom, a kitchen and a living room. Each room had a path leading through it and out one of three doors. Study participants in the fMRI scanner were asked to fixate their gaze on a tiny white cross. On each trial, an image of one of the rooms then appeared, centered behind the cross. Participants were asked to imagine they were standing in the room and indicate through a button press whether it was a bedroom, a kitchen or a living room. On separate trials, the same participants were also asked to imagine that they were walking on the continuous path through the exact same room and indicate whether they could leave through the door on the left, in the center, or on the right.

The resulting data showed that the two brain regions were selectively activated depending on the task: The PPA responded more strongly to the recognition task while the OPA responded more strongly to the navigation task.

“While it’s incredible that we can show that different parts of the cortex are responsible for different functions, it’s only the tip of the iceberg,” Dilks says. “Now that we understand what these areas of the brain are doing we want to know precisely how they’re doing it and why they’re organized this way.”

Dilks plans to run causal tests on the two scene-processing areas. Repetitive transcranial magnetic stimulation, or rTMS, is a non-invasive technology that can be attached to the scalp to temporarily deactivate the OPA in healthy participants and test whether someone can navigate without it.

The same technology cannot be used to deactivate the PPA, due to its deeper location in the temporal lobe. The Dilks lab plans to recruit participants suffering brain injury to the PPA region to test for any effects on their ability to recognize scenes.

Clinical applications for the research include more precise guidance for surgeons who operate on the brain and better brain rehabilitation methods.

“My ultimate goal is to reverse-engineer the human brain’s visual processes and replicate it in a computer vision system,” Dilks says. “In addition to improving robotic systems, a computer model could help us to more fully understand the human mind and brain.”

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Scientists chase mystery of how dogs process words

Eddie, one of the dogs that participated in the study, poses in the fMRI scanner with two of the toys used in the experiments, "Monkey" and "Piggy." (Photo courtesy Gregory Berns)

By Carol Clark

When some dogs hear their owners say “squirrel,” they perk up, become agitated. They may even run to a window and look out of it. But what does the word mean to the dog? Does it mean, “Pay attention, something is happening?” Or does the dog actually picture a small, bushy-tailed rodent in its mind?

Frontiers in Neuroscience published one of the first studies using brain imaging to probe how our canine companions process words they have been taught to associate with objects, conducted by scientists at Emory University. The results suggest that dogs have at least a rudimentary neural representation of meaning for words they have been taught, differentiating words they have heard before from those they have not.

“Many dog owners think that their dogs know what some words mean, but there really isn’t much scientific evidence to support that,” says Ashley Prichard, a PhD candidate in Emory’s Department of Psychology and first author of the study. “We wanted to get data from the dogs themselves — not just owner reports.”

Study participant Stella and her toys.

“We know that dogs have the capacity to process at least some aspects of human language since they can learn to follow verbal commands,” adds Emory neuroscientist Gregory Berns, senior author of the study. “Previous research, however, suggests dogs may rely on many other cues to follow a verbal command, such as gaze, gestures and even emotional expressions from their owners.”

The Emory researchers focused on questions surrounding the brain mechanisms dogs use to differentiate between words, or even what constitutes a word to a dog.

Berns is founder of the Dog Project, which is researching evolutionary questions surrounding man’s best, and oldest friend. The project was the first to train dogs to voluntarily enter a functional magnetic resonance imaging (fMRI) scanner and remain motionless during scanning, without restraint or sedation. Studies by the Dog Project have furthered understanding of dogs’ neural response to expected reward, identified specialized areas in the dog brain for processing faces, demonstrated olfactory responses to human and dog odors, and linked prefrontal function to inhibitory control.

For the current study, 12 dogs of varying breeds were trained for months by their owners to retrieve two different objects, based on the objects’ names. Each dog’s pair of objects consisted of one with a soft texture, such as a stuffed animal, and another of a different texture, such as rubber, to facilitate discrimination. Training consisted of instructing the dogs to fetch one of the objects and then rewarding them with food or praise. Training was considered complete when a dog showed that it could discriminate between the two objects by consistently fetching the one requested by the owner when presented with both of the objects.

During one experiment, the trained dog lay in the fMRI scanner while the dog’s owner stood directly in front of the dog at the opening of the machine and said the names of the dog’s toys at set intervals, then showed the dog the corresponding toys.

Eddie, a golden retriever-Labrador mix, for instance, heard his owner say the words “Piggy” or “Monkey,” then his owner held up the matching toy. As a control, the owner then spoke gibberish words, such as “bobbu” and “bodmick,” then held up novel objects like a hat or a doll.

The results showed greater activation in auditory regions of the brain to the novel pseudowords relative to the trained words.

“We expected to see that dogs neurally discriminate between words that they know and words that they don’t,” Prichard says. “What’s surprising is that the result is opposite to that of research on humans — people typically show greater neural activation for known words than novel words.”

The researchers hypothesize that the dogs may show greater neural activation to a novel word because they sense their owners want them to understand what they are saying, and they are trying to do so. “Dogs ultimately want to please their owners, and perhaps also receive praise or food,” Berns says.

Half of the dogs in the experiment showed the increased activation for the novel words in their parietotemporal cortex, an area of the brain that the researchers believe may be analogous to the angular gyrus in humans, where lexical differences are processed.

The other half of the dogs, however, showed heightened activity to novel words in other brain regions, including the other parts of the left temporal cortex and amygdala, caudate nucleus, and the thalamus.

These differences may be related to a limitation of the study — the varying range in breeds and sizes of the dogs, as well as possible variations in their cognitive abilities. A major challenge in mapping the cognitive processes of the canine brain, the researchers acknowledge, is the variety of shapes and sizes of dogs’ brains across breeds.

“Dogs may have varying capacity and motivation for learning and understanding human words,” Berns says, “but they appear to have a neural representation for the meaning of words they have been taught, beyond just a low-level Pavlovian response.”

This conclusion does not mean that spoken words are the most effective way for an owner to communicate with a dog. In fact, other research also led by Prichard and Berns and recently published in Scientific Reports, showed that the neural reward system of dogs is more attuned to visual and to scent cues than to verbal ones.

“When people want to teach their dog a trick, they often use a verbal command because that’s what we humans prefer,” Prichard says. “From the dog’s perspective, however, a visual command might be more effective, helping the dog learn the trick faster.”

Co-authors of the Frontiers in Neuroscience study include Peter Cook (a neuroscientist at the New College of Florida), Mark Spivak (owner of Comprehensive Pet Therapy) and Raveena Chhibber (an information specialist in Emory’s Department of Psychology).

Co-authors of the Science Reports paper also include Spivak and Chhibber, along with Kate Athanassiades (from Emory’s School of Nursing).

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