RecruitingDevice studyStudy to Investigate Vagus Nerve Stimulation to Augment Executive Function in Healthy and Cognitively Impaired PopulationsThis study plans to learn more about how stimulating the vagus nerve through gentle electrical stimulation applied to the ear can affect decision-making, problem-solving, and other thinking abilities. This process, called transcutaneous auricular vagus nerve stimulation (taVNS), could help improve brain function in both healthy individuals and people with Parkinson's disease (PD).