What this trial measures

• Cognition - The Tablet-based Cognitive Assessment Tool (TabCAT)Baseline, halfway through (1.5 months), and post-intervention (3 months)

  This test battery assesses performance in various cognitive components. A composite score across subtasks will be computed. Higher scores in the composite indicates better cognition.

• Mobility - Grip StrengthBaseline, halfway through (1.5 months), and post-intervention (3 months)

  This test assesses grip strength in kg. A composite score across trials will be computed. Higher scores indicate more strength.

• Mobility - 10 Meter Gait SpeedBaseline, halfway through (1.5 months), and post-intervention (3 months)

  This test assesses speed in seconds during unassisted walking for 10 meters. A composite score across trials will be computed. Higher scores indicate lower walking speed.

• Mobility - Clinical Test of Sensory Interaction on Balance (CTSIB)Baseline, halfway through (1.5 months), and post-intervention (3 months)

  This test assesses sway area (measured in m\^2/s\^4) with eyes open and closed while standing on a hard and a foam surface. A larger sway area indicates greater postural instability and poorer balance control during specific sensory conditions

• Affect - Profile of Mood States Second Edition (POMS-2)Baseline, halfway through (1.5 months), and post-intervention (3 months)

  This questionnaire assesses transient feelings and mood on a scale from 0 = not at all to 4 = extremely). A composite score across items will be computed as primary outcome. Higher scores indicate greater intensity of the mood state.

• Affect - Ryff Scales of Psychological WellbeingBaseline, halfway through (1.5 months), and post-intervention (3 months)

  This questionnaire assesses psychological well-being via 42 statements using a 6-point scale (1 = strongly agree; 6 = strongly disagree). A composite score across items will be computed as primary outcome. Higher scores indicate greater psychological wellbeing.

• Affect - Satisfaction with Life ScaleBaseline, halfway through (1.5 months), and post-intervention (3 months)

  This questionnaire assesses satisfaction with life. A composite score across items will be computed as primary outcome. The possible range of scores is 5-35. Scores between 5-9 indicate the respondent is extremely dissatisfied with life, whereas scores between 31-35 indicate the respondent is extremely satisfied. A composite score across items will be computed as primary outcome. Higher scores indicate greater life satisfaction.

• Brain Markers - StructureBaseline, halfway through (1.5 months), and post-intervention (3 months)

  Cortical thickness (in mm) will be determined via a T1 MRI scan in dorsolateral prefrontal, sensorimotor, and insular cortices using the CAT computational anatomy toolbox. Greater values indicate greater cortical thickness.

• AD Biomarkers - AmyloidBaseline, halfway through (1.5 months), and post-intervention (3 months)

  These assays will determine amyloid (e.g., Aβ17) sensitive to Alzheimer's Disease. Higher values indicate higher amyloid levels.

• Biomarkers - P-TauBaseline, halfway through (1.5 months), and post-intervention (3 months)

  These assays will determine p-tau levels sensitive to Alzheimer's Disease. A composite score across items will be computed as primary outcome. Higher values indicate higher p-tau levels.

• Brain Markers - Network FunctionBaseline, halfway through (1.5 months), and post-intervention (3 months)

  Brain network function will be assessed via resting-state fMRI (in Blood oxygen level dependent response) to capture functional segregation of dorsolateral prefrontal, sensorimotor, and insular networks using the CONN toolbox. Greater values indicate greater functional connectivity.