Developing Brain, Impulsivity and Compulsivity

* INCLUSION CRITERIA: In order to be eligible to participate in this study, an individual must meet all of the following criteria: 1. Stated willingness to comply with all study procedures and availability for the duration of the study. 2. Must be between 6 and 80 years of age. 3. Ability of participant to understand and the willingness to sign a written informed consent document. EXCLUSION CRITERIA: An individual who meets any of the following criteria will be excluded from participation in this study: 1. Cognitively not capable of performing study procedures or lack of capacity to provide informed consent. Indications of a lack of cognitive capacity could include a known full-scale IQ under 70, or a history from the screening interview that implies global intellectual disabilities (e.g., placement in a school for children with intellectual disability etc.) 2. Very premature birth (i.e., birth before 32 weeks of gestational age). 3. Any known brain abnormalities (e.g., tumor, periventricular leukomalacia, microcephaly) or history of medical conditions known to affect cerebral anatomy (e.g., epilepsy, history of stroke, head injury with a loss of consciousness of one hour or more). 4. Psychotic disorders (including schizophrenia, psychosis not otherwise specified). 5. Dementia, or other conditions that, in the opinion of the investigators, would impede compliance or possibly hinder completion of the study. 6. Pregnant women. 7. Any other medical or psychiatric condition that in the opinion of the PI may confound study data/assessments. Additional exclusion criteria for optional MRI procedure: 1\. Individuals who are not able to receive an MRI (e.g., metal bioimplants, claustrophobia, inability to lie flat on their backs, pregnant women, and any other contraindications for MRI scanning according to the NMR Center MRI safety guidelines).