RecruitingClinical trialInvestigating Mediodorsal Thalamus Representations Underlying Human Cognitive FlexibilityThe goal of this basic experimental research study is to examine how the human thalamus supports flexible thinking and behavior. Specifically, the research aims to elucidate how the mediodorsal (MD) thalamus encodes and updates "context"-the mental framework that determines which rules or actions are relevant in a given situation. This work may contribute to understanding why certain psychiatric conditions, such as schizophrenia and ADHD, involve difficulties with cognitive flexibility and control. The primary research questions are: Does the MD thalamus represent the context that organizes how working memory guides task selection? Does the MD thalamus signal when context needs to be updated after a change in task demands? Do these thalamic representations support generalization to new situations or rules? Participants will complete cognitive tasks while undergoing high-resolution brain imaging using 7-Tesla MRI. The investigators will combine behavioral data, computational modeling, and advanced neuroimaging analyses to examine how the thalamus interacts with the cortex during flexible decision-making.