When you combine natural language interface, emotion modeling, CG animation, and various forms of Artificial Intelligence, you get lifelike computer characters with autonomous interaction.   This new kind of digital actor is called a Virtual Human, and can be deployed across a wide spectrum of functions -- enabling authentic human interaction with machines. From psychological counseling to education to customer service to endless other applications, virtual humans will play an increasingly active role in society.   My guest today is Jonathan Gratch, Director for Virtual Human Research at the USC Institute for Creative Technologies -- among the most comprehensive research and development facilities for Virtual Humans. Jon is also a USC Research Professor of Psychology and Computer Science – the two areas most central to the development of Virtual Humans.   We talk with Jon about emotional interactive machines, what we learn about human beings by modeling human behavior in algorithms, and the potential for people developing emotional connections to digital agents.