People with Parkinson's disease have been known to have low motivation and motor learning impairment, which might limit the effectiveness of neurorehabilitation, exacerbate motor performance and quality of life, and increase the burden on caregivers. Therefore, enhancing motor learning ability and motivation is crucial for people with PD. According to the OPTIMAL theory, practice under self-controlled conditions has been shown to improve motivation and learning in healthy individuals. However, few studies have explored the effects of self-controlled practice on motor learning and motivation in people with PD and examined the underlying neurophysiological mechanisms. This study aims to investigate the effects of self-controlled practice on motor learning and motivation in people with PD, as well as the associated neurophysiological changes.

People with PD and age-matched healthy controls without neurological disorders will be recruited. Participants will be pair-matched based on age, gender, and disease severity, and then assigned to either the self-controlled group or the yoked group. The participants will be required to visit the lab for a total of three times in one week: on Day 1 for baseline assessments, neurophysiological evaluation using transcranial magnetic stimulation (TMS), practice of the trajectory matching task, motivation evaluation, and exercise education; on Day 2 for additional trajectory matching task practice, motivation evaluation, immediate retention test of the task, neurophysiological evaluation using TMS, and exercise education; and on Day 7 for delayed retention and transfer tests and final TMS assessment. On Days 1 and 2, all participants will practice the trajectory matching task. At the beginning of each trial, a target trajectory will be shown, and participants will be asked to replicate it using a joystick. Feedback will be provided after each trial to indicate accuracy. The self-controlled group will be allowed to choose the story contents they prefer when practicing the task, and the exercise they would like to learn after the task. In contrast, yoked participants will receive the same story and exercise education as their matched counterparts in the self-controlled group.

This study will help clarify the effects of self-controlled practice on motor learning and motivation in people with PD, offering a new perspective for clinical interventions and emphasizing the importance of patients actively participating in treatment planning.

Inclusion Criteria:

• age above 20-year-old
• able to follow instructions and the rules of the motor task
• do not have surgery or injury in their upper extremities in the past 6 months

Exclusion Criteria:

• neurological disorders other than PD
• symptoms of severe tremor in upper extremities
• symptoms of anxiety and depression
• deep brain stimulator or pacemaker implanted in the body
• history of seizure or epilepsy
• unstable medical conditions
• migraines or tinnitus uncontrolled by medication
• pregnant

Participants with PD are idiopathic PD diagnosed by a neurologist. Healthy controls are without any neurological disorders.