PROJECT SUMMARY This proposal aims to improve the rigor and reproducibility of research on plasticity in human working memory (WM), and related executive functions (EFs) in adolescent youth. We address a critical gap between research and practice that is characterized by a growing commercial space marketing cognitive training approaches (with WM being one of the most common targets), which are particularly catering to typically developing children and those diagnosed with ADHD to improve mental health and scholastic performance. However, despite expansive literature, there exists limited basic research on WM and EF training in adolescents, and both methods and findings are mixed across studies. Here, we address these significant gaps that pose obstacles to understanding interventions’ reliability and validity by collecting a large-scale open dataset that compares different training approaches on a common set of outcome measures. This is addressed through 4 aims, all based upon a large- scale study involving 720 adolescents, stratified across age, sex and ADHD status randomized across interventions: Aim 1 – What ingredients of cognitive training mediate training outcomes? We compare training conditions that represent some of the most common ingredients used across cognitive training studies (gamification, multiple domain training, and coaching) in comparison to basic non-gamified n-back training, using a common set of outcomes measures. Aim 2 – How do training ingredients differentially impact youth with ADHD? With ADHD being one of the most common targets of cognitive training, we examine whether and how youth with ADHD are differentially impacted by the training conditions. Aim 3 – What individual characteristics moderate training outcomes? We examine how cognitive training outcomes may differ across individuals, and whether this variability may explain differential effects across studies. Aim 4 - Promote open science through sharing of software tools and data. We will develop and share a cross-platform training and assessment app and a research portal that will promote data sharing, replication, and access to other groups using common individual difference variables and outcome measures. As a renewal, targeting adolescents with and without ADHD is a natural next step in this research program that started in typically functioning adults. This research is significant and timely as it addresses the limited basic research of cognitive training in adolescents with and without ADHD, whom are understudied, but at the same time, are common targets of commercial products in this space. This will lead to a more robust and representative understanding of factors that moderate and mediate cognitive training that will be impactful whether or not one hypothesizes near or far transfer from cognitive training. Further, findings could inform future research to understand broader age groups (younger children and older adults) as well as to address lifespan and ...