Abstract
<title>Abstract</title> <p>Socially assistive robots have demonstrated their ability to aid vulnerable groups such as older adults with cognitive activities. However, maintaining long-term engagement and motivation remains challenging in human-robot interaction, particularly given older adults’ diverse and evolving needs. Using a mixed-methods approach, we conducted a month-long longitudinal user study with residents of a long-term care home. We compared two robot behavior conditions while facilitating the Simon electronic game: one condition displayed multimodal persuasive behaviors, while the other used only instructional speech. Our findings revealed that both the persuasive and instructional robot behavior conditions maintained engagement and increased motivation over sustained interactions. However, older adults responded more positively to the persuasive robot; they also spent a longer time on the game in the persuasive condition. As interactions continued, perceived emotional interdependence, a measurement of social presence, declined for the instructional robot condition. These findings suggest that the persuasive robot interaction style may be more effective at engaging and emotionally stimulating for older adults. Overall, a hybrid approach combining both persuasive and instructional robot behaviors may be effective at maintaining engagement and motivation over sustained interactions among older adults during cognitive activities. In this paper, we also discuss game design considerations when developing robot assistive behaviors at different stages of a robot-assisted cognitive game, including factors that can influence the sustained engagement and motivation of older adults.</p>