Human responses to an expressive robot
This paper reports the results of the first study comparing subjects’ responses to robotic emotional facial displays and human emotional facial displays. It describes step by step the building of believable emotional expressions in a robotic head, the problems raised by a comparative approach of robotic and human expressions, and the solutions found in order to ensure a valid comparison. Twenty adults and 15 children aged 3 were presented static (photos) and dynamic (2-D videoclips, or 3-D live) displays of emotional expressions presented by a robot or a person. The study compares two dependent variables: emotional resonance (automatic facial feed-back during an emotional display) and emotion recognition (emotion labeling) according to partners (robot or person) and to the nature of the display (static or dynamic). Results for emotional resonance were similar with young children and with adults. Both groups resonated significantly more to dynamic displays than to static displays, be they robotic expressions or human expressions. In both groups, emotion recognition was easier for human expressions than for robotic ones. Unlike children that recognized more easily emotional expressions dynamically displayed, adults scored higher with static displays thus reflecting a cognitive strategy independent from emotional resonance. Results are discussed in the perspective of the therapeutic use of this comparative approach with children with autism that are described as impaired in emotion sharing and communication.