Digital Mahjong-Based Cognitive Engagement Intervention for Older Adults: Randomized Controlled Trial.

backgroundGamified digital training may support long-term engagement in aging populations, yet randomized evidence linking behavioral effects to convergent neuroimaging outcomes remains limited.

objectiveThis study tested whether a home-based digital mahjong-based cognitive engagement intervention enhanced cognition in community-dwelling older adults and explored brain changes using multimodal magnetic resonance imaging (MRI).

methodsWe conducted a single-blind, parallel-group randomized controlled trial in Taipei, Taiwan (July 2020-November 2021). Community-dwelling adults aged 55 years and older were randomized (1:1) to a 6-month digital mahjong-based intervention (two 30-minute sessions per week via an iPad app) with an incentivized walking component (Mi Band step tracking with in-game tokens) or no intervention. Primary MRI outcomes were gray matter volume, regional homogeneity (ReHo), fractional amplitude of low-frequency fluctuations (fALFF), and global brain connectivity. Secondary outcomes included cognition (Montreal Cognitive Assessment), physical activity (International Physical Activity Questionnaire), mental health (Brief Resilience Scale and Mandarin version of the Demoralization Scale), quality of life (EQ-5D with a visual analog scale), physical fitness and body composition, and blood biomarkers. Per-protocol analyses were performed. Voxel-wise imaging analyses used analysis of covariance in SPM12 with family-wise error (FWE) correction at the cluster level (P<.05). Sensitivity analyses controlling for MRI delay duration were conducted to assess robustness of findings.

resultsIn total, 60 participants were enrolled (n=30, 50% per group); 96.7% (29/30) in the intervention group and 90% (27/30) in the control group completed primary assessments. Compared with controls, the intervention group showed a greater improvement in Montreal Cognitive Assessment delayed recall (between-group difference=-0.79 points, 95% CI -1.538 to -0.042; P=.04). Neuroimaging revealed increased ReHo in the right insula (FWE-corrected P<.05) and decreased gray matter volume in the left frontal pole and orbitofrontal cortex, with reduced fALFF in the left frontal pole. Changes in delayed recall were positively associated with right insular ReHo and also showed significant associations with the right anterior cingulate gyrus (ReHo), left inferior frontal gyrus, and right paracingulate gyrus (fALFF; FWE-corrected P<.05 in all cases). In exploratory dose analyses, right insular ReHo correlated with total practice sessions (r=0.48; P=.009). Among physiological outcomes, the intervention group had a larger reduction in diastolic blood pressure (-3.50 mm Hg, 95% CI -6.911 to -0.091; P=.04), whereas the thyroid-stimulating hormone decreased but remained within the normal range. Sensitivity analyses confirmed that primary findings remained stable after controlling for MRI delay duration.

conclusionsThis 6-month home-based digital mahjong intervention improved delayed recall and increased right insular ReHo. Integrating culturally familiar cognitive challenges with lifestyle engagement may be a feasible strategy associated with salience network-related functional changes and memory performance. Future large-scale trials should use active control conditions and factorial designs to rigorously isolate component-specific mechanisms.

trial registrationClinicalTrials.gov NCT05808426; https://clinicaltrials.gov/study/NCT05808426.