Avoidance behavior is a critical component of many psychiatric disorders, and as such, it isimportant to understand how avoidance behavior arises, and whether it can be modified. Inthis study, we used empirical and computational methods to assess the role of informationalfeedback and ambiguous outcome in avoidance behavior. We adapted a computer-basedprobabilistic classification learning task, which includes positive, negative and no-feedbackoutcomes; the latter outcome is ambiguous as it might signal either a successful outcome(missed punishment) or a failure (missed reward).