This is a hypothesis-driven study. We will compare the depotentiation effect in patients with focal dystonia to that in healthy volunteers. Patients will be evaluated with a clinical rating scale during the screening visit. Three interventional procedures will be tested during three study visits. Specifically, PAS25-cTBS150 tests the primary hypothesis with a depotentiation effect. PAS25 tests LTP-like effect and PAS10 tests the LTD-like effect. We will investigate the difference in outcome measures between patients and healthy volunteers after the interventional procedures. We will perform genetic tests to identify the brain-derived neurotrophic factor genotype in the patients and healthy volunteers.