Emotion Recognition of Avatar Facial Expressions Generated Using Action Units Based on Plutchik's Emotion Model

With conversational artificial intelligence (AI) be- coming increasingly present in our daily lives, some people have begun to view it as a friend, rather than merely a tool. Among young people in particular, the use of conversational AIs as confidants is becoming more widespread, signaling the emergence of a new form of interaction between humans and AI. However, current conversational AIs are limited to text- based communication and lack the nonverbal cues found in human communication, such as facial expressions, intonation, and gestures. This lack of nonverbal cues raises concerns that the user might miss the nuanced richness of meaning that is intended to be conveyed. To expand the expressive capabilities of future conversational AIs, we propose an avatar that conveys facial expressions, which play an important role in conveying emotions. Based on Plutchik’s emotion model, the avatar can display eight primary facial expressions and composite expressions by combining them. We experimentally investigated how participants perceive the expressions of the proposed avatar. This experiment revealed that anger, fear, disgust, and trust are difficult to recognize. Additionally, the results suggest that, even when male and female avatars express the same emotions, they may be perceived slightly differently.