adolescents Grooved Pegboard Test were administrated separately for each hand (Lafayette-Instrument 2002). All participants underwent an informed consent process with a research associate trained in human subject research protocols. Adult participants provided written informed consent as did the parents of minor participants before engaging in the study. Minor participants provided assent before participation. The Internal Review Boards of each site approved this study, and each site followed this procedure to obtain voluntary informed consent or assent, depending on the age of the participant. The follow-up rate of Year 2 was 82% (N=185), which was not impacted by age, sex, ethnicity, and site (p<0.05; two sample t-test). Of those 185 participants, 177 of them had 3 MRI scans with 1.03 years being the average time between acquisitions.
