Executive Function Intervention for Young Children with Down Syndrome - Abstract Down syndrome (DS) is associated with executive function (EF) challenges throughout the lifespan. Although early intervention has the potential for positive downstream effects on adaptation in DS, to date, intervention approaches have not proactively aimed to strengthen EF foundations in ways that capitalize on early neuroplasticity in this population. This R61/33 proposal will refine and test the effects of EXPO (EXecutive Function Play Opportunities), a 12-week caregiver-mediated intervention designed to strengthen EF in young children with DS. EXPO is tailored to the behavioral strengths and challenges associated with DS, thus reducing cognitive and linguistic barriers to EF intervention participation. A preliminary implementation of EXPO during Spring/Summer 2023 has demonstrated promising feasibility and acceptability trends, as well as preliminary efficacy trends at the overall group level. Additionally, heterogeneity in child intervention response was also observed, which likely corresponds to varying degrees of delay in developmental skill acquisition observed in this population during childhood. In line with the growing recognition of the need for personalized and precision approaches to intervention, in this project, we will transform EXPO into an adaptive intervention to better meet the needs of children who are slower to respond to the current intervention design. During the R61 phase, we will incorporate usability and feasibility caregiver feedback and the preliminary efficacy data from the Spring/Summer 2023 trial to refine the structure, organization, and materials of EXPO. We anticipate that we will develop two adaptive EXPO pathways to be subsequently tested and compared: (1) lengthening the duration of EXPO to allow for more practice of each skill, and (2) augmenting EXPO with activities that strengthen play foundations necessary for EXPO engagement (e.g., establishing social routines). During the R33 phase, we will test the EXPO adaptive intervention conditions via a two-arm, Singly Randomized Trial. Findings from this R61/33 project will yield a novel adaptive EF intervention designed to meet a wide range of needs within the population of young children with DS, in preparation for a large Randomized Controlled Trial.
