Olfactory Context Cues for Procedural Skill Transfer from Digital Twin-Based Mixed Reality Learning to Real-World...

Mixed Reality (MR) learning systems employ Digital Twins (DTs) to replicate real-world tasks, yet sensory discontinuity between DT-based MR environments and physical task contexts can hinder skill transfer. We investigate whether olfactory contextual cues can bridge this gap by serving as cross-environment anchors for memory encoding and retrieval. In a two-day study, 48 participants learned Rubik's Cube rotation notations in a DT-based MR environment and were tested on a physical cube (Day 1), then completed a transfer test approximately 24 hours later (Day 2). A 2 × 2 between-subjects design manipulated rosemary odor presence during learning and testing. Results showed that rosemary during DT-based MR learning increased spatial presence and motivation while producing equivalent short-term task completion time compared to the no-odor condition. For overnight transfer, when rosemary was present during learning, reinstating the same odor at testing yielded higher transfer performance and lower cognitive load, and reduced recall difficulty compared to the no-odor condition at retrieval. More broadly, matched olfactory conditions between learning and testing produced higher accuracy and reduced cognitive load relative to mismatched conditions. These findings provide the first evidence that olfactory contextual cues can support visuospatial-procedural skill transfer from DT-based MR environments to real-world execution, and suggest that when real-world tasks involve characteristic ambient odors, replicating them in virtual training may help preserve encoding-retrieval congruence.