Factors Influencing Conversational Engagement in Robot-Delivered Individual Cognitive Stimulation Therapy (iCST) for Dementia in Home Settings

2026-07-08

AI Summary

This study investigates key factors influencing engagement with robot-delivered individualized Cognitive Stimulation Therapy (iCST) among people living with dementia in home settings, with a focus on the interplay between conversational dynamics, user characteristics, and personalized prompting. An autonomous social robot, Co-STAR, was deployed in the homes of eight participants to conduct daily 30-minute iCST sessions over one week. Longitudinal analysis leveraged natural language processing to extract multidimensional metrics—including word count, speech rate, response latency, and self-referential language. The study reveals, for the first time, that personalized prompts significantly increase response duration and self-referential utterances; cognitive fatigue emerges in later session phases, marked by reduced verbal output and autobiographical engagement; initial-session performance strongly predicts long-term willingness to engage; and living alone significantly modulates interaction patterns. These findings provide empirical grounding for designing adaptive conversational agents for dementia care.

Abstract

Social robots offer a promising means of supporting cognitive therapies for dementia care by guiding structured conversation and therapeutic activities. However, little is known about the conversational dynamics that emerge during robot-delivered cognitive stimulation therapy (CST) sessions. This study analysed the interaction patterns from robot-delivered individual CST (iCST) sessions conducted with people living with dementia in home settings. Our Co-STAR (Cognitive Stimulation Therapy by an Autonomous Robot) system was deployed in the homes of eight PwDs for one week, who completed 30-minute sessions. Conversational metrics, including words per turn, speech production rate, response duration, response latency, and self-referential language, were analysed to examine how conversational engagement is shaped by prompt personalisation, interaction phase, and participant characteristics. The findings highlight three key interactional properties of robot-delivered iCST. First, personalised prompts significantly increase response duration, self-referential language, and overall engagement compared to generic prompts. Second, conversational behaviour changes within sessions, with a reduction in the verbal output and autobiographical engagement observed during later interaction phases, which suggests cognitive fatigue. Third, first-session conversational metrics were associated with long-term participation, while living situation influenced conversational engagement patterns. These findings provide empirical insights into the factors that shape conversational engagement in robot-delivered iCST. They inform the design of adaptive conversational robots for dementia therapy.

Problem

• conversational engagement
• robot-delivered therapy
• dementia
• cognitive stimulation therapy
• social robots

Innovation

• personalised prompts
• conversational engagement
• cognitive fatigue
• adaptive social robots
• individual cognitive stimulation therapy