Adaptive reasoning and problem-solving are critical skills that allow for accurate decisions to be made based on varying levels of information. In many situations these decisions must be made and communicated under stressful, time-sensitive conditions. In such contexts, an ability to apply inductive and deductive reasoning to complex, ambiguous, and/or novel problems is critical. The objective of the INSIGHT project is to establish a comprehensive and rigorous brain training protocol to significantly improve adaptive reasoning and problem solving. We will examine a variety of interventions (cognitive training, physical fitness training, physiological stimulation, , and combinations thereof) to assess their ability to improve adaptive reasoning and problem solving abilities. Multimodal interventions are hypothesized to act synergistically to significantly enhance fluid intelligence (Gf) and underlying brain structure and function.