Interval Timing Task

This experiment includes 139 subjects: 94 individuals with Parkinsons disease, and 45 controls. Subjects completed this IntervalTiming task (along with multiple other cognitive tasks) while EEG was recorded with a 64-channel BrainVision cap. This task presented black instructional text on the center of a white screen that read "Short interval" on 3-second interval trials and "Long interval" on 7-second interval trials. The researchers never communicated the actual interval durations to the patient. The instructions were displayed for 1 second, and the appearance of an image of a solid box in the center of the computer screen indicated the start of the interval. The cue was displayed on the screen for the entire trial, which lasted 6 s for 3-s intervals and 14 s for 7-s intervals. The researchers instructed participants to press the keyboard spacebar when they judged the target interval to have elapsed. Participants were directed not to count, and a distractor vowel appeared at random intervals in the screen center.