Study design:
This study uses a prospective, double-masked, randomized, placebo-controlled training RCT design.
The eligible participants will be randomly allocated into 3 groups:
(A) Placebo-Perceptual learning + Sham-tES; (B) Real-Perceptual learning + Sham-tES; (C) Real-Perceptual learning + Real-tES.
All participants will complete forty-three study visits:
Visit 1: Eligibility assessment (refer to the recruitment criteria); Visit 2-3: Outcome measures (Pre-intervention/ baseline); Visit 4-13: 10 sessions intervention (1st batch); Visit 14-15: Interim 1 Outcome measures; Visit 16-25: 10 sessions intervention (2nd batch); Visit 26-27: Interim 2 Outcome measures; Visit 28-37: 10 sessions intervention (3rd batch); Visit 38-39: Post-training 1 Outcome measures; Visit 40-41: Post-training 2 Outcome measures (to evaluate the retention effect after 1 month); Visit 42-43: Post-training 3 Outcome measures (to evaluate the retention effect after 2 months).
Six sessions of assessment will be conducted: (1) Baseline; (2) Interim-1 (after 10-sessions training); (3) Interim-2 (after 20-sessions training); (4) Post-1 (after 30-sessions training); (5) Post-2 (1-month post training); and (6) Post-3 (2-month post training).
