Neural dynamics of confidence formation under uncertainty
Our perceptual decision-making can vary depending not only on changes in the surrounding environment but also on metacognitive processes. In particular, the balance between confidence and uncertainty may play a critical role in shaping behavior and the underlying neural dynamics over time, yet how this balance operates remains largely unclear, especially when uncertainty is high and confidence is low, or vice versa, during perceptual decision-making. To address this, we employed the Multi-Attribute Attention Task, along with an option to opt-out of perceptual judgments. During this task, we recorded multichannel electroencephalography (EEG) data from 26 healthy individuals. Our results showed that EEG-based functional connectivity increased in density across the whole brain, which was associated with the emergence of confidence during perceptual decision-making. Moreover, increased functional connectivity density emerged in correct trials but was not observed in incorrect trials. Notably, this density increase was specific to correct trials and became evident prior to the decision being made. Thus, correct decisions may be characterized by the early recruitment of distributed neural networks that support the integration of sensory evidence and the formation of reliable confidence. Building on these findings, we provide novel evidence that confidence formation under uncertainty relies on dynamic changes in densely interconnected networks across distributed brain regions that support highly accurate and high-confidence perceptual decision-making in humans.