Additive effects of monetary loss and positive emotion in the human brain.

In many real-life scenarios, our decisions could lead to multiple outcomes that conflict in value. Hence, an appropriate neural representation of the net experienced value of conflicting outcomes, which plays a crucial role in guiding future decisions, is critical for adaptive behavior. As some recent functional neuroimaging work primarily focused on the concurrent processing of monetary gains and aversive information, very little is known regarding the integration of conflicting value signals involving monetary losses and appetitive information in the human brain. To address this critical gap, we conducted a functional MRI study involving healthy human male participants to examine the nature of integrating positive emotion and monetary losses. We employed a novel experimental design where the valence (positive or neutral) of an emotional stimulus indicated the type of outcome (loss or no-loss) in a choice task. Specifically, we probed two plausible integration patterns while processing conflicting value signals involving positive emotion and monetary losses: interactive vs. additive We found overlapping main effects of positive (vs. neutral) emotion and loss (vs. no-loss) in multiple brain regions, including the ventromedial prefrontal cortex, striatum, and amygdala, notably with a lack of evidence for interaction. Thus, our findings revealed the additive integration pattern of monetary loss and positive emotion outcomes, suggesting that the experienced value of the monetary loss was not modulated by the valence of the image signaling those outcomes. These findings contribute to our limited understanding of the nature of integrating conflicting outcomes in the healthy human brain with potential clinical relevance. Significance Statement In everyday life, our decisions could lead to outcomes that involve both positive and negative values-for instance, getting well paid when working under hostile conditions. Hence, an appropriate neural representation of the net value of such conflicting outcomes plays an important role in guiding future decisions. However, our current understanding of how the human brain integrates value signals from conflicting outcomes is rudimentary. Using functional MRI, we investigated the nature of integrating positive emotion and monetary losses. We found that both positive emotion and monetary losses recruited the same brain regions, but their effects were largely independent of each other. These findings contribute to a small but growing literature on the integration of conflicting outcomes in the human brain.