Digital Photo Elicited Storytelling and Alpha Band EEG Dynamics in Older Adult Caregiver Dyads

Digital technologies can support meaningful social interaction by providing personally relevant prompts for memory, communication, and shared reflection. In later life, mobile phone photography may offer an accessible medium through which older adults and caregivers construct stories, express meaning, and participate in relational engagement. However, limited psychophysiological evidence is available on how digital photo supported storytelling engages cognitive and social processes in older adult caregiver dyads. This study examined alpha band EEG dynamics during digital photo elicited storytelling in two museum settings. Thirty two older adult caregiver dyads completed cognitive and psychological screening and participated in a museum-based storytelling protocol. During the museum visit, participants used mobile-phone photography to capture personally meaningful objects, scenes, or exhibition spaces. Each participant then selected one photograph as a digital prompt for a structured but naturalistic storytelling interaction. EEG was recorded during eyes closed resting, eyes open resting, storytelling, and listening conditions. Relative alpha power was analyzed using a predefined 10 electrode sensor level set. Task related alpha modulation was examined relative to eyes open resting. Associations between Cz alpha power and MoCA scores were tested, and dyad level alpha band inter brain similarity was explored using spatial alpha power patterns with within site shuffled dyad surrogate comparisons. Alpha power was higher during eyes closed resting and lower during storytelling and listening relative to eyes-open resting, indicating task-related alpha modulation during digital photo supported narrative interaction. Associations between MoCA scores and Cz alpha power were weak, condition-specific, and did not survive false discovery rate correction. During storytelling, dyad level alpha-band inter brain similarity was modestly higher than within site shuffled dyad estimates, but this effect did not remain significant after correction across conditions. These findings suggest that digital photo elicited storytelling can provide a meaningful medium for studying cognitive and social engagement in older adult caregiver dyads. Alpha band EEG activity was sensitive to storytelling and listening, although cognition related and dyadic similarity effects were modest. The study contributes to research on technology supported human behavior by showing how digital image prompts can structure naturalistic social interaction while enabling psychophysiological measurement in real-world contexts.