Feasibility, Usability, and Effects of Leisure-Based Cognitive Training Using a Fully Immersive Virtual Reality System in Older Adults: Single-Arm Pretest-Posttest Pilot Study.

Background: Cognitive training is an effective approach to support cognitive function in older adults. Incorporating meaningful leisure activities, such as gardening, may enhance both engagement and training outcomes. While fully immersive virtual reality (VR) offers ecologically valid and engaging environments that can further boost motivation, limited research has explored the combination of VR-based cognitive training and leisure activities for older adults. Objective: This study aims to assess the feasibility, usability, and preliminary effectiveness of leisure-based VR cognitive training for community-dwelling older adults. Methods: A fully immersive VR cognitive training system, controlled via a head-mounted display, was developed, incorporating gardening-themed activities such as planting, fertilizing, watering, and harvesting. These tasks were designed to engage multiple cognitive domains, including memory, attention, executive function, processing speed, and visuospatial abilities. The program consisted of 16 sessions delivered over 8 weeks (twice weekly, 1 hour per session). Cognitive outcomes were assessed before and after training using the Montreal Cognitive Assessment, the digit symbol substitution test, word list immediate and delayed recall, spatial span, and the Stroop Color and Word Test. Feasibility, acceptance, and usability were evaluated using the System Usability Scale and a posttraining questionnaire. Licensed occupational therapists from both community and institutional settings assessed the training system's usability. Results: All 41 participants (mean age 69.79, SD 5.05 y) completed the training with 100% adherence and no serious adverse events. Feasibility ratings-particularly for perceived usefulness, intention to use, and subjective norms-reflected strong acceptance. Usability ratings from older adults indicated high ease of use, enjoyment, and positive experience, while professionals rated the system as moderately usable (mean System Usability Scale score 68.01, SD 8.38). Statistically significant improvements were observed in general cognition (P=.004), processing speed (P=.049), immediate and delayed memory (P<.001), and executive function (P=.002). No significant changes were found in visuospatial memory (P=.29). Conclusions: This study provides preliminary evidence supporting the feasibility and usability of a gardening-based VR cognitive training program for older adults. Feasibility was demonstrated through full adherence, absence of major adverse events, and high participant acceptance. Usability feedback was favorable from both older adults and professionals across community and long term care settings. Additionally, improvements in multiple cognitive domains, including general cognition, processing speed, memory, and executive function, suggest potential cognitive benefits. Future randomized controlled trials with more diverse samples and extended follow-up are warranted to confirm and expand upon these findings.