@masterthesis { gomes10, abstract = {The objective of this thesis was to create a model for agent memory retrieval of emotionally relevant episodes. Additionally we wished to assess if including such a system in an architecture would improve the agents' believability. We reviewed some core concepts concerning human memory, appraisal theories and believability. Then we analyzed agent architectures that support memory and emotions, realizing that none fulfilled all our requirements for memory retrieval. We proceeded by describing our retrieval model consisting of two main steps: ecphory, in which the perceived stimuli (retrieval cues) are matched with memories; and recollective experience that re-appraises memories that had a positive match. We proposed a location ecphory approximation, in which locations serve as indirect retrieval cues. We described how we implemented our model and used it to drive the behavior of characters in a game application. We implemented the location ecphory approximation, and the recollective experience consisting of a reactive appraisal module with reaction rules for events generated by the former. We recorded the application running and used the videos to create a non-interactive evaluation. The evaluation's structure was a between-groups pre-test/post-test one with two control groups, and we had 96 participants. The evaluation's results are consistent with our hypothesis that agents modeled by our architecture would be perceived as more believable than agents modeled in similar architectures without episodic retrieval.}, address = {Av. Prof. Dr. Aníbal Cavaco Silva, 2744-016 Porto Salvo - Portugal}, keywords = {Memory Retrieval, Episodic Memory, Believability, Emotions, Appraisal, Ecphory}, month = {Setembro}, school = {Universidade Técnica de Lisboa - Instituto Superior Técnico}, title = {MEEMOs: Believable Agents with Episodic Memory Retrieval}, year = {2010}, author = {Paulo F. Gomes} }