The Efficacy of an IADL-based Non-immersive Virtual Reality Training Program to Enhance ADL Performance and Cognitive Function for Persons at Risk of Dementia

The goal of this clinical trial is to learn if a touchscreen-based virtual reality (VR) training program that simulates everyday life tasks works to improve daily living skills and thinking abilities in adults aged 50 and older, including those at risk of dementia (individuals with Subjective Cognitive Decline or Mild Cognitive Impairment). It will also explore what personal factors influence the training results. The main questions it aims to answer are: * Does the daily life VR training program improve participants\' ability to perform complex everyday activities and adapt flexibly to daily life challenges? * Does the training improve overall thinking skills (such as memory, attention, and problem-solving), brain activity, and mood (depression and anxiety)? Researchers will compare the daily-life VR training program (IADL-VR) to a non-situational game VR program (Game-VR) and a traditional in-person tabletop cognitive training program (Cog-Entity) to see if realistic daily-life VR simulation works better to enhance everyday functioning and brain health. Participants will: * Be randomly assigned to one of the three training groups (daily-life VR tasks, digital brain-training mini-games, or traditional tabletop board games). * Attend a 2-hour group session once a week for 12 weeks, which includes 1 hour of assigned cognitive training and 1 hour of physical fitness exercise. * Complete assessments of their daily living skills, thinking abilities, mood, and brain activity (using functional magnetic resonance imaging, or fMRI) within 2 weeks before and after the 12-week program.