Introduction
CORTEX
During choice, we often face the difficult decision of when to leave a known option in favor of a potentially better, but unknown alternative. While the exploitation of a known option comes with a predictable immediate reward, exploring new options is associated with a potentially higher payoff but also the risk of a low(er) reward. At the same time, exploration provides information for improving future decisions [Neural data suggest that exploration and exploitation rely on distinct brain systems, with exploitation being associated with a mechanism in the ventromedial prefrontal cortex (vmPFC) [Noradrenaline has also been repeatedly associated with exploratory behavior. For instance, high levels of noradrenaline have been shown to increase the probability of strategy shifts, whereas low levels of noradrenaline facilitate perseverative behavior [Understanding the exact roles of dopamine and noradrenaline in the exploration-exploitation tradeoff may aid the development of new tools enabling the modulation of this tradeoff. However, to date, the distinct roles of dopamine and noradrenaline in the exploration-exploitation balance are not fully understood. Thus, the present experiment aimed to elucidate the specific roles of dopamine and noradrenaline in the exploration-exploitation tradeoff in human choice. We disentangled the involvement of dopamine and noradrenaline in specific sub processes underlying exploration and exploitation in a virtual patch-foraging task, which has been used before to dissociate exploration, operationalized as patch switching, and exploitation processes [