What confidence and the eyes can tell about interacting with a partner

Abstract

Every decision we make is accompanied by a sense of confidence. Confidence mechanisms allow evaluating the evidence that supports our decisions such as the quality of our perceptual representations. Confidence is thought to play a critical role in guiding decision-making, but only a few empirical studies have actually investigated the function of confidence. To address this, we designed a perceptual task in which participants provided a confidence judgment on the accuracy of their perceptual decision. Then, they viewed the response of a machine or human partner, and they were instructed to decide whether to keep or change their initial response. We observed that confidence predicted participants' decision to keep or change their initial responses more than task difficulty and perceptual accuracy. This suggests that confidence, as a subjective evaluation of uncertainty, enables us to weigh our decisions in order to adapt our decision-making behavior driving the interaction with a partner. Furthermore, confidence judgments could be predicted by eye pupil dynamics, suggesting that arousal changes are linked to confidence computations. This study contributes to our understanding of the function of confidence in decision-making and highlights the possibility of using pupil dynamics as a proxy of confidence.