Agent's Internal State Expression Related to Desire and Suppress Based on Behavior and Physiological Expression

There are various studies on multimodal internal state expression by robots and virtual agents. Some communication robots, especially soft robots such as stuffed toy robots, are often used for intimate communication with physical contact. In this research, we focused on "internal desire" as one of the internal states of an agent, and discussed a method of expressing desire by combining voluntary behavior and heartbeat expression as an involuntary physiological phenomenon. In this experiment, first, we verified the expression of desire by behavior or heartbeat expression individually. Next, we verified how the strength of internal desire and the suppression of desire change through a combination of agent behavior and heart rate, and we analyze their relationship. The results showed that both desire behaviors, which are gazing behavior and approaching the object, and the different patterns of heart rate changes affected the intensity of desire. In addition, the combination of large heart-rate changes and low desire-level behaviors expressed the agent's suppressed desire state.