Virtual humans, programmed to feel

May 8, 2014 by Angela Herring
Professor Stacy Marsella, who develops computer programs that simulate human emotion across a variety of applications, has joint appointments in the College of Science and the College of Computer and Information Science. Credit: Mariah Tauger.

A clenched fist thumps the air to emphasize a point; a sweeping hand signals the array of possibilities; furrowed eyebrows question the veracity of the politician's remarks. These are all examples of the ways we express our emotions while we converse. They're strategies we may spend a lifetime learning, based on our particular cultures and backgrounds. But that doesn't mean they can't be programmed.

Newly appointed Northeastern professor Stacy Marsella is doing just that. His program, called Cerebella, gives the same ability to convey emotion through and as they communicate with other virtual—or even real—humans.

'Normally these virtual human architectures have some sort of perception, seeing the world, forming some understanding of it, and then deciding how to behave,' said Marsella, who holds joint appointments in the College of Computer and Information Science and the College of Science. "The trouble is some of these things are very hard to model, so sometimes you cheat."

One way to cheat, Marsella explained, is to infer connections between given utterances and appropriate responses. Once the program knows what words a virtual human will use to respond, it can form a library of associated facial expressions, gaze patterns, and gestures that make sense in conjunction with those words.

In one version of the program, Cerebella infers the deeper meaning behind the spoken words. The program is capable of interpreting the meaning and responding appropriately.

In addition to Cerebella, Marsella's work touches on a broad spectrum of applications at the intersection of emotion and technology. For instance, UrbanSim uses similar techniques to generate large-scale models of human populations. Here, virtual models of people aren't doing the same kind of "," as Marsella called it, but they're still interacting with one another and determining follow-up behaviors based on a theory of mind, a model that allows them to reason about how others in the virtual world will act.

"They're abstract social interactions, where agents are either assisting or blocking each other," Marsella explained. The result gives his program the capacity to simulate whole cities for purposes ranging from city planning to military training.

At Northeastern, Marsella is eager to apply his methods to a range of multidisciplinary collaborative projects. In particular, he's interested in working with the personal health informatics team. "The interactive health interventions are the applications that really interest me," he said.

For another project, he designed a training tool for medical students to develop their patient interaction skills, in which they must navigate difficult conversations with a virtual human embedded with the emotional personality of a real human. One task requires the students to inform the virtual human of his cancer diagnosis.

"We want these interactions to be natural," Marsella said, summing up the underlying goal of almost all his programs.

Explore further: Talk to the virtual hands

Related Stories

Talk to the virtual hands

October 12, 2011

Body language of both speaker and listener affects success in virtual reality communication game.

Comforting chatbot

February 5, 2014

Chatting with the customer service is now considered normal. But what if 'Eva', 'John' or 'Julia' were capable of not just solving technical problems but also providing us with emotional support? Janneke van der Zwaan investigated ...

New avatars capable of laughing

April 4, 2014

Today's computer-based avatars lack one of our most deeply rooted human characteristics: laughter. Computer scientists have now teamed up with psychologists to give avatars the ability to laugh.

Recommended for you

US Navy keeps electromagnetic cannon in its sights

June 25, 2016

The US Navy is quietly pushing ahead with a radical new cannon that one day could transform how wars are fought, even though some Pentagon officials have voiced concerns over its cost and viability.

Ultra-thin solar cells can bend around a pencil

June 20, 2016

Scientists in South Korea have made ultra-thin photovoltaics flexible enough to wrap around the average pencil. The bendy solar cells could power wearable electronics like fitness trackers and smart glasses. The researchers ...

Mapping coal's decline and the renewables' rise

June 23, 2016

Even as coal-fired power plants across the U.S. are shutting down in response to new environmental regulations and policy mandates, defenders of the emissions-heavy fuel still have cost on their side. Coal, after all, is ...

Electric racing car breaks world record

June 23, 2016

The Formula Student team at the Academic Motorsports Club Zurich (AMZ) accomplished its mission today: the grimsel electric racing car accelerated from 0 to 100 km/h in just 1.513 seconds and set a new world record. It reached ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.