Abstract: Sensory stimuli evoke rich spatiotemporal neural patterns. A central question of my work is which features of those patterns drive behavior. Using the mammalian olfactory system, we pair multi-level neural recordings with targeted perturbations. Behavioral responses to parametrically defined optogenetic activation show that early responses carry far more behaviorally relevant information than later ones. Odor experiments and optogenetic masking link these early signals to concentration-invariant coding. To probe the role of later activity, we recorded extended temporal sequences of mitral and tufted cells with fast calcium imaging and analyzed the geometry of mitral-cell receptive fields. The data suggest later signals encode relationships within odor space and support learning and cortical mapping.