Crossover Study

The goal of this clinical trial is to validate if temporal interference brain stimulation (TIBS) is safe in healthy volunteers aged 20 to 65. The main questions it aims to answer are: * Is it safe to apply TIBS intervention to the left hippocampus in healthy participants? * Is it safe to apply TIBS intervention to the left insula in healthy participants? * Is it safe to apply TIBS intervention to the left anterior cingulate cortex in healthy participants? * Is it safe to apply TIBS intervention to the right inferior frontal cortex in healthy participants? Participants will: * Be Randomly allocated to either sham-first group or treat first-group, stratified by stimulated brain region, following a crossover-controlled experimental design * Complete baseline cognitive evaluations and mental status assessments, and undergo a baseline MRI scan on the same day * Receive stimulation for 5 consecutive days, followed by a 2-days washout period, then complete the remaining 5 days of stimulation. * Complete post-intervention cognitive evaluations and mental status assessments, and undergo a post-intervention MRI scan on the same day