Designing and Evaluating Socially Assistive Robots: The Role of Language Choice in Dementia Care Scenarios

Language plays a central role in person-centered care, shaping communication, emotional expression, memory recall, and identity. While socially assistive robots (SAR) show promise for reminiscence-based activities in dementia care, most systems remain monolingual and overlook bilingual users. This work investigated how language choice in SAR interactions influenced engagement, emotional experience, and user perception among Turkish-German bilingual adults aged 50 and above. An embodied conversational agent based on a Q.bo One robot and a large language model was developed to enable interactions in German and Turkish. A qualitative user study was conducted in which four participants engaged in robot-led reminiscence sessions over a week, with three days per language condition. We situate our findings in the context of linguistic relativity and symbolic interactionism theories; and propose design considerations for linguistically adaptive SAR.