The processing of negative information and its often deleterious impact on behavior has been extensively investigated. Importantly, how the brain processes negative information is thought to be centrally linked to the psychopathologies of depression and the anxiety disorders. The processing of positive information, say as manipulated via reward, also has been extensively studied. In this case, how the brain processes positive information is thought to be centrally linked to drug abuse and addiction. Although a lot is known about the systems involved in processing negative and positive information, we are only starting to make progress in understanding how they simultaneously act in the brain and thus influence normal and clinically relevant behaviors. Filling this gap is important because in many real-world situations both negative and positive systems simultaneously contribute to behaviors. From a clinical standpoint, for example, in depression both systems likely play important roles. The objective of the present application is to advance our understanding of the interactions between negative and positive information processing in the brain and their impact on behavior. Critical questions that will be investigated include: do negative and positive systems interact always antagonistically as often assumed following classical theories of opponent processing? Under what conditions, if any, do they interact synergistically? What is the role of context, say as determined by which information is task relevant, in shaping the interactions between negative and positive systems? Across two aims, we will test whether the interactions between negative and positive processing are antagonistic vs. cooperative. Aim 1 will investigate interactions between negative and positive processing when aversive information is punctual (e.g., an aversive image or a CS+ stimulus presented at a specific point in time). Both the impact of negative information on reward processing and the impact of reward on the processing of aversive stimuli will be investigated. Aim 2 will investigate the interactions between negative and positive processing when aversive information is state like (e.g., aversive events linked to prolonged situations in which aversive events may occur; say, tens of seconds to minutes). Collectively, we expect to shed light on the mechanisms underlying the interactions between negative and positive processing in the brain, and make important new contributions to cognitive/affective neuroscience that have the potential to be of clinical relevance.