*2.2. Procedure*

All study procedures were approved by the Streamlined, Multisite, Accelerated Resources for Trials (SMART) IRB platform at Cincinnati Children's Hospital Medical Center (2018-0253, approved 23 April 2018), and informed consent was obtained for each subject before they participated. To be eligible for the study, participants were required to have a diagnosis of DS, have English as their primary language, and have an estimated nonverbal cognitive level of approximately three or older, per parent report, to support completion of at least a portion of the study procedures. Participants were recruited through medical clinics and DS associations at two sites. After being enrolled in the study, participants completed two visits, two weeks apart, as part of a broader longitudinal study on cognitive measurement in DS. To be included in analyses, participants were required to complete study measures at both time points.
