Obsessive-Compulsive Symptoms

The goal of this clinical trial is to learn about brain function and cognition in children ages 8-12 who have subclinical obsessive-compulsive symptoms (OCS), such as unwanted thoughts or repetitive behaviors. The study will also examine whether patterns of brain activity are related to how children respond to cognitive training. The main questions this study aims to answer are: * Are there different patterns of brain activity related to cognitive control among children with OCS? * Are these patterns related to differences in OCS or cognition? * Can brain activity before training help predict changes in cognitive control or OCS severity after cognitive training? Participants will: * Complete clinical interviews, questionnaires, and tests of cognition. * Have a magnetic resonance imaging scan while completing a cognitive control task. * Complete video-game-based cognitive training on an iPad for about 25 minutes a day, 5 days a week, for 4 weeks. * Complete another set of clinical interviews and questionnaires after the training.