THE EFFECT OF FACIAL EXPRESSION ASYMMETRY ON THE BELIEVABILITY, APPEAL, AND NATURALNESS OF VIRTUAL AGENTS

With the recent virtualization of our everyday lives and the development of intelligent AI technology, realistic virtual agents are becoming a useful tool for research, education, and entertainment. With virtual agents customized content can be created and individualized for specific users. However, virtual agents are only effective tools if they can form a connection with the individual. To form a connection the virtual agent must be believable.

The literature review evaluates topics of virtual agent believability, appeal, and naturalness and how they relate to asymmetry in facial expression animation. The literature suggests that asymmetries can affect the perception of virtual agents. Additionally, it suggests that emulating human behavior is beneficial to increasing perception of believability, appeal, and naturalness.

In this study we evaluated the effects of facial expression asymmetry on the believability, appeal, and naturalness of virtual agents. To do this we ran an online perception study with students at Purdue University. We found, in brief, that facial expression asymmetries do have significant effect on the believability, appeal, and naturalness of a virtual agent compared to animations that do not include facial expression asymmetries.