To fulfill out study purposes, a cross-sectional study (Part I) and an interventional randomized controlled trial (Part II) are designed. In Part I, people with PD and the age-matched healthy controls will be recruited and perform imagery and actual walking tasks. The questionnaire for fatigue, motor imagery ability, and brain activation during walking tasks will be recorded and compared between groups using independent t test. Pearson's correlation coefficient will be used to determine the relationship between fatigue and MI ability. In Part II, people with PD will be randomly allocated to either NFB-MI or MI group. Every participant will receive 12 sessions including three lab-visit sessions and nine home-bases training sessions. Each session consists of 10 min of MI, followed by 20 min of exercise focusing on balance and gait ability. During the lab-visit sessions, participants in experimental group will receive 10 minutes of NFB-MI. Outcome measures, including Mini Balance Evaluation Systems Test (Mini-BEST), Timed up-and-go test (TUG), gait performance, MI ability and fatigue, will be assessed at pre-, post-test, and follow-up. A two-way analysis of variance (ANOVA) with repeated measure will be used to determine the time by group interaction for all the outcomes. Post hoc test with Bonferroni correction will be applied for significant interaction. Significant level for part I and part II will be set at p < 0.05.
A cross-sectional study (part 1) aims to investigate the influence of fatigue on the MI ability in PD compared to healthy controls. A randomized controlled trial (part 2) aims to compare the effect of fNIRS-based NFB-MI on balance and gait performance versus MI only in people with PD.