Shades of surprise: Assessing surprise as a function of degree of deviance and expectation constraints.

Merging recent surprise theories renders the prediction that surprise is a function of how strong an event deviates from what was expected and of how easily this event can be integrated into the constraints of an activated expectation. The present research investigates the impact of both these factors on the behavioral, affective, experiential, and cognitive surprise responses. In two experiments (total N = 1257), participants were instructed that ten stimuli of a certain type would appear on the screen. Crucially, we manipulated the degree of deviance of the last stimulus by showing a stimulus that deviated to either no, a medium, or a high degree from the previous nine stimuli. Orthogonally to this deviation, we induced an expectation with either high, moderate, or low constraints prior to the experimental task. We measured behavioral response delay and explicit ratings of liking, surprise, and expectancy. Our findings point out an overall only low association between the behavioral, affective, experiential, and cognitive surprise responses and reveal rather dichotomous response patterns that differentiate between deviance and non-deviance of an event. Challenging previous accounts, the present evidence further implies that surprise is not about the ease of integrating an event with the constraints of an explicit a-priori expectation but rather reflects the automatic outcome of implicit discrepancy detection, resulting from a continuous cognitive fine-tuning of expectations.