Modeling Forms of Surprise in an Artificial Agent

Mainly rooted in the cognitive-psychoevolutionary model of surprise proposed by the research group of the University of Bielefeld (Meyer, Reisenzein, Schützwohl, etc.), the computational model of surprise described in this paper relies on the assumption that surprise-eliciting events initiate a series of mental processes that begin with the appraisal of unexpectedness, continue with the interruption of ongoing activity and the focusing of attention on the unexpected event, and end with the analysis and evaluation of that event plus revision of beliefs. With respect to the computation of unexpectedness, the model also incorporates suggestions by Ortony and Partridge. This model of surprise is implemented in an artificial agent called S-EUNE, whose task is to explore uncertain and unknown environments. The accuracy of our surprise model was evaluated in a series of experimental tests that focused on the comparison of surprise intensity values generated by the artificial agent with ratings by humans under similar circumstances.