Designing a social humanoid robot to enhance human cognitive multitasking in a mixed human-robot team is anything but straightforward. In fact, the robot's presence and behavior can either improve or impair human performance. In this study, we examined how different vitality forms-expressed through the robot's actions, speech and facial expressions-affect cognitive multitasking. Analysis of human facial expressions and skin conductance data revealed that a robot exhibiting a gentle vitality form fostered a more positive and relaxed state than one displaying a rude vitality form. Moreover, the gentle vitality form improved human performance on tasks involving short-term memory and continuous target tracking. To our knowledge, this is the first study to explore the long-term impact of vitality forms. Overall, our findings suggest that properly designing a social humanoid robot's vitality forms can significantly enhance cognitive multitasking performance in human-robot teams.
Keywords: cognitive multitasking; facial expressions; human-robot interaction; mental workload; social robots; vitality forms.
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