||Multivoxel neurofeedback selectively modulates confidence without changing perceptual performance
A central controversy in metacognition studies concerns whether confidence directly reflects the reliability of perceptual or cognitive processes. The affirmative view enjoys popularity in the computational and animal literatures, but it has also been suggested that confidence may depend on a late-stage estimation dissociable from perceptual processes. Yet, at least in humans, experimental tools have lacked the power to resolve these issues convincingly. Here we overcome this difficulty by employing the recently developed method of decoded neurofeedback (DecNef) and systematically manipulate multivoxel correlates of confidence in a frontoparietal network. With this method, confidence was bi-directionally changed without affecting perceptual accuracy. Further psychophysical analyses ruled out accounts based on simple shifts in criterion or reporting strategy for confidence. Our results provide clear neuroscientific evidence that confidence can be dissociated from perceptual performance.