PMID- 27030803 OWN - NLM STAT- PubMed-not-MEDLINE LR - 20240325 IS - 1943-068X (Print) IS - 1943-0698 (Electronic) IS - 1943-068X (Linking) VI - 8 IP - 1 DP - 2016 Mar 12 TI - Discovering Multimodal Behavior in Ms. Pac-Man through Evolution of Modular Neural Networks. PG - 67-81 AB - Ms. Pac-Man is a challenging video game in which multiple modes of behavior are required: Ms. Pac-Man must escape ghosts when they are threats and catch them when they are edible, in addition to eating all pills in each level. Past approaches to learning behavior in Ms. Pac-Man have treated the game as a single task to be learned using monolithic policy representations. In contrast, this paper uses a framework called Modular Multi-objective NEAT (MM-NEAT) to evolve modular neural networks. Each module defines a separate behavior. The modules are used at different times according to a policy that can be human-designed (i.e. Multitask) or discovered automatically by evolution. The appropriate number of modules can be fixed or discovered using a genetic operator called Module Mutation. Several versions of Module Mutation are evaluated in this paper. Both fixed modular networks and Module Mutation networks outperform monolithic networks and Multitask networks. Interestingly, the best networks dedicate modules to critical behaviors (such as escaping when surrounded after luring ghosts near a power pill) that do not follow the customary division of the game into chasing edible and escaping threat ghosts. The results demonstrate that MM-NEAT can discover interesting and effective behavior for agents in challenging games. FAU - Schrum, Jacob AU - Schrum J AD - Department of Mathematics and Computer Science, Southwestern University, Georgetown, TX 78626 USA ( schrum2@southwestern.edu ). FAU - Miikkulainen, Risto AU - Miikkulainen R AD - Department of Computer Science, University of Texas, Austin, TX, 78712 USA ( risto@cs.utexas.edu ). LA - eng GR - R01 GM105042/GM/NIGMS NIH HHS/United States PT - Journal Article PL - United States TA - IEEE Trans Comput Intell AI Games JT - IEEE transactions on computational intelligence and AI in games JID - 101659801 PMC - PMC4809543 MID - NIHMS694381 OTO - NOTNLM OT - Modularity OT - Ms. Pac-Man OT - Multimodal Behavior OT - Multiobjective Optimization OT - Neuroevolution EDAT- 2016/04/01 06:00 MHDA- 2016/04/01 06:01 PMCR- 2016/03/28 CRDT- 2016/04/01 06:00 PHST- 2016/04/01 06:00 [entrez] PHST- 2016/04/01 06:00 [pubmed] PHST- 2016/04/01 06:01 [medline] PHST- 2016/03/28 00:00 [pmc-release] AID - 10.1109/TCIAIG.2015.2390615 [doi] PST - ppublish SO - IEEE Trans Comput Intell AI Games. 2016 Mar 12;8(1):67-81. doi: 10.1109/TCIAIG.2015.2390615.