Motor-cognitive Dual-task in Healthy Older Adults and Early Parkinson's Disease Patients

Inclusion Criteria: Inclusion criteria for the healthy older participants will be: * no diagnosis of cognitive or movement disorder, * score \> 7 for the Short Physical Performance Battery (SPPB), * living independently in the community, * age range between 55 and 70 years, * no color blindness. Inclusion criteria for the early-stage PD patients: * diagnosed according to the last MDS criteria (2015), * duration of the disease less than 5 years, * positive DATSCAN, * diagnosed akinetic-rigid or mixed phenotype, * score of 1 or maximally 2 on the Hoehn and Yahr scale (Hoehn \& Yahr, 1967), * MoCA score ≥ 24 points, * score \> 7 for the SPPB, * age range between 50 and 75 years, * no color blindness * living independently in the community. Exclusion Criteria: * advanced stages of PD (Hoehn and Yahr score \> 2) * any acute or chronic diseases, especially of the peripheral and central nervous system, heart failure, respiratory failure, severe osteoarthritis, and major psychiatric illness such as depression * MoCA score \< 24 points, * severe disabling tremor, * recurrent falls, * impaired vision that is not corrected with e.g., glasses, * low SPPB score