Perceptual decisions are naturally accompanied by a sense of confidence in the accuracy of the decision. However, it remains unclear whether perceptual decision making and confidence are supported by the same or different neural circuits. To address this question, we conducted two functional MRI (fMRI) experiments in which we dissociated the periods related to perceptual decision making and confidence by either decorrelating their respective regressors or asking for confidence ratings only in the second half of the experiment. We found that perceptual decision making and confidence were supported by large and mostly overlapping brain circuits including frontal, parietal, posterior, and cingulate regions with the results being remarkably consistent across the two experiments. Further, the confidence period recruited a number of unique regions, whereas there was no evidence for the decision period recruiting unique regions not involved in the confidence period. These results suggest that the neural circuits supporting perceptual decision making and confidence have a very high degree of overlap, which suggests largely shared computational mechanisms with unique components for the confidence but not for the perceptual judgments.

Overlapping and unique neural circuits support perceptual decision making and confidence