Brain network connectivity underlying decisions between the "lesser of two evils"

In daily life we are often forced to choose between the “lesser of two evils,” yet there remains limited understanding of how the brain encodes choices between aversive stimuli, particularly choices involving hypothetical futures. We tested how choice framing affects brain activity and network connectivity by having participants make choices about individualized, aversive, hypothetical stimuli (i.e. illnesses, car accidents, etc.) under approach and avoidance frames (“which would you rather have/avoid”) during fMRI scanning. We tested whether limbic and frontal regions show patterns of signal intensity and network connectivity that differed by frame, and compared this to response to similar appetitive choices involving appetitive preferences (i.e. hobbies, vacation destinations). We predicted that regions such as the insula, amgydala, and striatum would respond differently to approach vs. avoidance choices during aversive hypothetical choices. We identified activations for both choice frames in areas broadly associated with decision making, including the putamen, insula, and anterior cingulate, as well as deactivations in areas shown to be sensitive to valence, including the amygdala, insula, prefrontal cortex, and hippocampus. Connectivity between brain regions differed based on choice frame, with greater connectivity among deactive regions including the amygdala, insula, and ventromedial prefrontal cortex during avoidance frames compared to approach frames. These differences suggest that approach and avoidance frames lead to different behavioral and brain network response when deciding which of two evils are the lesser.