Computer Science Research Profile: Virtual Embodiment

From the Summer 2013 issue of Threads

Professor Tabitha Peck in the Duke immersive Virtual Environment (DiVE)

The room is unexceptional but for a mirror on the wall that grabs your attention. You look in the mirror. Is it really you? Your skin color is different! You wave and the image waves back, tracking and mirroring your movements seamlessly. After the initial surprise wears off, you gradually start to think of the image staring back at you as you. How could this be possible? Does this experience change the way you think about yourself? Can it change the way you think about others?

Visiting faculty member Tabitha Peck studies the technology to make such experiences possible, leading to a host of fascinating, sometimes even disquieting, questions that she pursues in collaboration with social and medical scientists. Has computer science launched a new collaboration with cosmetic dermatology? No - the room is virtual and the image in the mirror is an avatar. Peck's research focuses on system design, development, and evaluation of immersive virtual reality systems -- head-tracked computer-simulated environments that emulate real and imaginary worlds. Her current research focus is on developing virtual-reality systems that evoke virtual-body-ownership illusions virtual embodiment experiences in which a person accepts a virtual body as a replacement for his or her own.

Making a Credible Virtual Environment

Of the many applications of virtual reality technology, virtual embodiment poses some distinct challenges. Peck explains that there can be a significant gap between a useful virtual reality tool and one that is fluid and realistic enough to achieve convincing virtual embodiment. There are many situations where people could tolerate a slight lag in head tracking, but looking in a virtual mirror may not be one of them. Getting it right requires carefully tuned algorithms and tightly coupled software and hardware systems, but can anything short of perfection suffice? It's well-known that people are acutely sensitive to rendering flaws in images of humans, the so-called uncanny valley, but researchers are still investigating the extent to which the illusion of virtual embodiment is hindered or enhanced by changes in the underlying virtual reality technology.

Peck is interested both in understanding what is required to do virtual embodiment well and in expanding the use of virtual embodiment by finding ways to do it more cost effectively. She has started a collaboration with Regis Kopper, director of the Duke immersive Virtual Environment (DiVE), to develop a system for inducing virtual-body ownership illusions in the DiVE. This will enable a new range of experiences for DiVE users and open the door to virtual embodiment experiments on the Duke campus.

The DiVE will be an effective platform for virtual embodiment experiments, but it's not a low-cost solution. Some of Peck's previous work involved developing an algorithm for simulating realistic eye-movement of self-avatars without the use of special eye tracking hardware. She is planning to explore additional methods for simulating body motion with simpler hardware, as well as to determine minimal system requirements for inducing effective virtual-body-ownership illusions. This work is intended to enable cost-effective, yet impressive virtual environment systems.

The Potential Impact of Virtual Embodiment

People aren't always honest about their true feelings - not even with themselves. One trick psychologists use for getting at an individual's true feelings is the Implicit Association Test (IAT). The IAT asks participants to associate positive or negative words with a concept (image or word) that is presented to the participant. A series of rapid-fire questions and answers give insight into the participant's true thinking, though not always in the most straightforward way. Participants may be predisposed to give the expected or socially acceptable answer, but their response times can belie their true feelings. Longer response times can indicate weaker associations between concepts.

The IAT for race uses images of people of different race. Existing results show that even among those who have no explicitly communicated racial biases, there may be implicit biases that are demonstrated both in their responses and response times in the test. Could a virtual embodiment experience with an avatar of different race reduce bias? During her postdoctoral experience in Spain, Peck investigated this question. She administered a race IAT to participants both before and after a virtual embodiment experience. The initial results were very encouraging: Participants whose avatar was a race different from their own showed reduced implicit bias in the second IAT.

For logistical reasons, the participants in Peck's initial study were white women, but she would like to generalize this work by determining the effect on more diverse populations. The next step will be collaborating with psychologists to determine if the measured implicit bias reduction can extend to real world changes in attitudes and behaviors. Peck said she envisions a time when virtual embodiment will be used frequently to help overcome implicit and explicit biases. According to existing racism research, education is key to getting people to think about their reactions and biases, and she's hopeful this type of experiment could be effective in reaching that goal.

"These implicit or explicit biases very much affect things," she said. "I'd really like to see this research used in hiring practices or implemented in a kind of training that could benefit everyone."

Impact on Students

In addition to her research, Peck has many teaching responsibilities and opportunities to interact with Duke students. Currently, she leads the Data Structures and Algorithms course of approximately 200 students, teaching the analysis, design, and use of abstract data types, algorithms, and programming techniques. She also co-teaches a non-majors course, Information and the Internet, focusing on the impact of computing and the Internet on science and society.

Peck advises numerous independent study students, two of whom have developed a fully-immersive educational game for teaching electromagnetics in the DiVE. These students are currently evaluating their system by running a user study. In addition she has partnered with instructor Robert Duvall for a project-based computer graphics independent study experience for 10 students. These students have designed and are building projects, such as a fully immersive and interactive drawing program for the DiVE, a baseball game using the Microsoft Kinect, and a stained-glass rendering simulation.

Essential Collaborations

Peck also has forged collaborative relationships at her alma mater, UNC Chapel Hill, and with the Duke University Medical Center. For example, she plans to partner with physical therapists to explore the use of virtual embodiment experiences for pain management. Existing results indicate that patients who visualize themselves achieving a difficult or painful task have an easier time managing the challenges of these tasks in the real world. By facilitating this visualization process, virtual embodiment could be a powerful tool to help patients manage pain and achieve their therapy goals.

Each of Peck's projects involves unique challenges, but they have many common elements. Peck explains, "Unless you have artists, psychologists, computer scientists, and healthcare professionals who can work together, you won't get good results. All this work requires expertise in many disciplines." Pulling it all together requires well-planned, solid partnerships. Peck adds, "It's a multidisciplinary challenge to develop these types of systems, so the work is fundamentally collaborative."


Reference: Tabitha C. Peck, Sofia Seinfeld, Salvatore M. Aglioti, Mel Slater, Putting yourself in the skin of a black avatar reduces implicit racial bias, Consciousness and Cognition, Volume 22, Issue 3, September 2013, Pages 779-787.