Investigation of Joint Action in Go/No-Go Tasks: Development of a Human-Like Eye Robot and Verification of Action Space

Human–robot collaboration (HRC) is a natural progression of technological development and can improve job performance, address labor shortages, and reduce labor costs. However, it is still uncertain whether joint action, similar to that occurring between humans, can be replicated between humans and robots. Many robotic researchers have focused on joint action, and it has been demonstrated that gaze cueing plays a significant role in this context. Currently, previous studies on joint action use humanoids; however, robots utilized in the research on human-robot collaboration lack human-like eyes needed for verification. Therefore, this study focuses on the development of an eye robot with gaze-cueing behaviors that can be easily integrated into existing robotic systems. As another theme of this study, we proposed the use of fixation duration as a new metric, which is distinct from the commonly used response time, for the quantitative evaluation of joint action research. These are verified through a Go/No-go task under six conditions—three behavioral (i.e., joint action, joint attention-only, and alone), each with two partner conditions (robot or human partner). While developing a human-like eye robot, this study demonstrates the potential of a robot to be a better joint action partner than an uncertain human, with participants exhibiting the best reaction times when partnered with a robot. The shared action space of the participants was investigated, where a transference of the action space indicates the expression of joint action. The fixation duration indicates that the proposed robot cause participants to move their action space to include that of the robot. These results suggest that the proposed collaborative robot can initiate a joint action between a robot and a human, and can perform as a more effective partner in joint actions compared to an unfamiliar human. This study showcased the capacity of fixation duration as a quantitative assessment metric for joint action.