Additional Study Information: Why? By investigating individuals with SCA, we will gain valuable insights into the specific mechanisms through which the cerebellum participates in cognitive processes. Who? Healthy adults over the age of 18, who would like to participate as controls. What? Participation involves one clinic visit for 3-4 Hours, involving cognitive baseline measurements, an electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) recording during which a decision-making two-step task will be performed. Cost to me? There is no cost involved for participating in the study. You will receive $75 after completion of the study. Location: 710 W 168th St, New York, NY 10033