Did You Notice? Unveiling Robot-Induced Synchronization in Human-Robot Interaction

Lixiao Zhu, Christopher Yee Wong, AJung Moon

Abstract: Decades of studies in psychology and neuroscience establish that humans naturally synchronize their movements with others. This phenomenon is not limited to Human-Human Interaction (HHI) but also observed in Human-Robot Interaction (HRI), where individuals align their motions to the rhythm of a robot without conscious effort. While such influences are often subtle, characterizing the dynamics of robot-to-human synchronization is critical for designing effective collaborative systems. This study explores whether humans synchronize differently to the movements of robots compared to other humans, and at what point individuals become conscious of the changes in the robot's movements. Our results reveal an asymmetry in synchronization between HHI and HRI. We find that participants are more likely to notice changes in a robot's speed, particularly when the robot speeds up or slows down by over 20% compared to the base speed. Participants' perception of the robot's animacy is also influenced by these speed changes. Building on our findings, we provide insights into how roboticists can design robot behaviours to minimize unwanted influence and respect human autonomy.

External IDs:dblp:conf/humanoids/ZhuWM25