PROJECT SUMMARY This is a one-year administrative supplement to the parent award titled “Role of early motor experience in infants with Down syndrome (DS)”. Infants with DS show significant lower physical activity compared to their typically developing counterparts. Furthermore, almost half of infants with DS suffer from sleep problems such as decreased sleep time and increased wake bouts. Poor sleep quality in children with DS has been linked to slower and weaker attainment of cognitive function and language milestones. Our parent project will examine the effect of both GM and GM+FM intervention on motor, cognitive, and language development in infants with DS. However, assessment of physical activity and sleep pattern was not included in the parent project. Therefore, there is a significant need to add the assessment of physical activity and sleep pattern using accelerometry to the parent project. In addition, NIH recently launched the UNITE initiative to identify and address structural racism within the NIH workforce as well as the NIH-supported greater scientific community. In line with the NIH UNITE initiative, NICHD launched the STRIVE initiative to continue promoting diversity, equity, and inclusion in all aspects of its research and workforce. We therefore propose to add an additional diversity component to the parent project. The goal of this supplement project is to evaluate physical activity and sleep pattern among GM, GM+FM, and control groups, and promote diversity, equity, and inclusion in the parent and supplement projects. Aim 1: Evaluate the effect of both GM and GM+FM motor experiences on physical activity and sleep quality in infants with DS. We will use wearable accelerometers (Actigraphy) to collect the data of physical activity and sleep from the ankle and the wrist for seven consecutive days in all three groups (GM, GM+FM, and control) at time point T3 (at the conclusion of GM intervention) and T4 (five months post intervention). We hypothesize that both GM and GM+FM groups will show greater daytime physical activity and better nighttime sleep pattern than the control group at both time points T3 and T4. The supplement project will generate important knowledge of physical activity and sleep quality and enhance the comprehensive assessment of health-related outcomes in the parent project. Aim 2: Promote the equity, diversity, and inclusion (EDI) of the parent project by increasing EDI in participant recruitment and student mentoring. We will use the framework of the NIH UNITE and NICHD STRIVE initiatives to diversify the composition of our research team by mentoring two underrepresented graduate students for their research training and career development. The mentoring plan will include, but not limited to, the training on (a) human subject recruitment and community outreach, (b) data collection, coding, and analysis, (c) weekly meetings with the PIs to discuss research progress and address questions and obstacles, (d) dissem...