Our lives consist of a constant stream of decisions and choices, from the mundane ("Will I answer this email?") to the highly consequential ("Will I have a child?"). Decision neuroscience offers a novel approach to the study of both individual and interactive decision-making by combining the methods of behavioral experiments, functional neuroimaging, and formal economic models. Examining sophisticated high-level behavior at a neural level, such as deciding on how much risk to take with an investment or when to cooperate with a colleague, can provide important clues as to the fundamental mechanisms by which decision-making operates.