Meaningful activities in dementia care can promote the co-construction of narrative identity in caregiving relationships, helping to preserve the sense of self in people with dementia.<b>Purpose</b>: Informed by symbolic interactionism and Deweyan transactionalism, the aim of this study was to develop a transactional model of how narrative identity and relationships are promoted through the use of a new technological solution, SENSE-GARDEN, that uses digital technologies and multisensory stimuli to facilitate individualized, meaningful activities.<b>Method</b>: We conducted a qualitative interview study to explore the experiences of people with moderate to advanced dementia and their caregivers in Norway and Portugal. After using SENSE-GARDEN for 12-16 weeks, 20 participants (7 persons with dementia and 13 caregivers) were interviewed. The interviews were analysed using reflexive thematic analysis.<b>Results</b>: Three themes were generated: openness, learning, and connection. Findings suggest that SENSE-GARDEN can stimulate emotional experiences, preserve narrative identity, and foster interpersonal relationships. These findings are illustrated through a transactional model.<b>Conclusion</b>: This study highlights the complex multitude of factors affecting person-environment interactions in which narrative identity and relationships are constructed. To better understand these factors, future work should adopt a holistic approach to studying new methods of creating meaningful activities in dementia care.