This research aims to gain insight into optimal wargaming decision-making mechanisms using neurophysiological measures by investigating whether brain activation and visual scan patterns predict attention, perception, and/or decision-making errors through human-in-the-loop wargaming simulation experiments. We investigate whether brain activity and visual scan patterns can explain optimal wargaming decision making and its development with a within-person design; i.e., the transition from exploring the environment to exploiting the environment. We describe ongoing research that uses neurophysiological predictors in two military decision making tasks that tap reinforcement learning and cognitive flexibility.