Decision-making is a complex process that comprises the assessment of a situation, the selection of an action, and the evaluation of an outcome. Distinct neural systems may contribute differentially during various stages within a decision-making situation. This study investigated whether neural activation during assessment or action selection is critically dependent on previous outcomes or actions. Twelve healthy, right-handed subjects (6 females) played a Rock Paper Scissors (RPS) computer game during functional magnetic resonance imaging. Bilateral insula and medial prefrontal cortex (including the anterior cingulate) were specifically engaged during the assessment and action selection stages of decision-making, whereas bilateral superior frontal gyrus and right inferior parietal lobule activated more during the outcome. Two regions of activation within the bilateral superior temporal gyrus activated only when the previous outcome was a win. Moreover, right insula and superior temporal gyrus were active more when the subject switched responses relative to staying with the same choice made on the previous trial. These findings support the hypothesis that distinct neural systems underlie different stages of the decision-making process. Furthermore, the superior temporal gyrus may play an important role in integrating previous actions and successful outcomes into one's decision-making strategy.