Sung Soo Kim is interested in understanding the brain-wide, multi-sensory information processing and integration that underlie the ability to get one's bearings in a room they've never seen before. To elucidate how the brain enables navigational decisions, he uses a powerful genetic model organism, Drosophila melanogaster. He combines a wide range of techniques including two-photon calcium imaging and electrophysiology in head-fixed behaving flies, cell-type specific optogenetic perturbation, electron-microscopy (EM) based neural circuit reconstruction, quantitative behavioral analysis of freely behaving flies and computational modeling of networks, to establish causal links from the neural circuit dynamics to cognitive behavior.