A translational approach to measuring the neural systems underlying approach-avoidance conflict in humans

Approach-avoidance conflict (AAC) arises from decisions with embedded positive and negative outcomes, and appropriate management of these decisions is essential for adaptive functioning. However, translating key advances on AAC in non-human primates to tasks in humans has proven difficult in part due to the inherent limitations in existing human tasks in isolating relevant neural substrates of behavior. Here, we present, and validate, a novel task in humans (N= 38) of both sexes, derived from work in non-human primates utilizing primary reinforcers (shock/juice), and in doing so identify neural features specific to conflict, implementing a computational model of task behavior. We found that neural patterns of activation within the parietal, frontal, temporal and cingulate regions were associated with conflict-specific avoidance behavior. Importantly, a number of these regions were associated with trait anxiety, implicating a potential link between these neural regions and anxiety-driven avoidance behavior. This task platform may help advance both behavioral and biological research examining the neural patterning underlying approach-avoidance behavior in humans, providing an empirically oriented framework with which to translate between non-human primate and human work. Significance StatementThe current paper describes and validates a novel task for studying Approach-Avoidance Conflict behavior that capitalizes on innate reinforcers and stringent thresholding, effectively bridging animal and human work in this field. The task is then used to identify the neural correlates of AAC behavior in humans, identifying patterns of activation linked to temporal variation in avoidance behavior specific to conflict. Further, a novel model is developed and applied to the behavioral data to more sensitively quantify response patterns using reinforcement learning, and neural patterns relating to these behavioral effects were identified. Finally, as anxiety is strongly associated in the animal and human literature with avoidance responding, we identified a subgroup of neural effects associated with trait anxiety.