The understanding of the brain mechanisms of emotion and motivation has grown steadily in the past two decades. The majority of the work in the rodent and human literatures has relied heavily on particular paradigms, such as the perception of faces with emotion content in humans, and aversive conditioning procedures in both humans and animals. The present application proposes a series of experimental paradigms that are ecologically inspired, semi- naturalistic, and dynamic. The objective of this application is to investigate the dynamics of threat processing during escape behaviors, as well as the dynamics of threat/reward processing during approach- avoid conflict paradigms. Across experiments, we seek to both characterize and test specific hypotheses centered around a set of brain regions implicated in aversive and appetitive processing. We seek to characterize their contributions individually but also as distributed circuits that collectively and dynamically support behaviors. The proposed work is organized around two aims. Aim 1 investigates the circuits supporting threat escape. Rodent studies suggest that the ventral striatum/accumbens is an important node during escape behaviors. Whereas some work in humans (e.g., avoidance conditioning) supports this notion, other work with ethologically inspired paradigms has also revealed the participation of regions such as the mid-cingulate cortex and the anterior hippocampus. Experiments will test the contributions of these and other brain regions to escape mechanisms. Aim 2 investigates the circuits involved in aversive and appetitive interactions during dynamic threat and reward processing. Experiments will employ dynamic stimuli where the proximity to threat and reward vary dynamically. Collectively, the work addresses a set of basic research questions aimed at understanding how emotion/motivation circuits outlined in the past decades supports dynamic processing. The potential results may inform the clinically-oriented human literature, which has been heavily informed and inspired by research with standard experimental paradigms.