This basic research will identify brain networks that allow humans to be sophisticated planners and will develop novel tools for modeling those neural systems. In the real world people use multiple strategies to plan an action. They might guess what to do and through trial and error gain some success with repeated practice. Or, they might use a familiar plan drawn from memory. Between these extremes is the ability to simulate possible actions. We will use novel tasks to capture these different strategies and employ network control theory as a convenient framework to model brain data.