An Automatic Domain-General Error Signal Is Shared across Tasks and Predicts Confidence in Different Sensory Modalities

Understanding the ability to self-evaluate decisions is an active area of research. This research has primarily focused on the neural correlates of self-evaluation during visual tasks and whether neural correlates before or after the primary decision contribute to self-reported confidence. This focus has been useful, yet the reliance on subjective confidence reports may confound our understanding of key everyday features of metacognitive self-evaluation: that decisions must be rapidly evaluated without explicit feedback and unfold in a multisensory world. These considerations led us to hypothesize that an automatic domain-general metacognitive signal may be shared between sensory modalities, which we tested in the present study with multivariate decoding of electroencephalographic (EEG) data. Participants (<i>N</i> = 21, 12 female) first performed a visual task with no request for self-evaluations of performance, prior to an auditory task that included rating decision confidence on each trial. A multivariate classifier trained to predict errors in the speeded visual task generalized to distinguish correct and error trials in the subsequent nonspeeded auditory discrimination. This generalization did not occur for classifiers trained on the visual stimulus-locked data and further predicted subjective confidence on the subsequent auditory task. This evidence of overlapping post-response neural activity provides evidence for automatic encoding of confidence independent of any explicit request for metacognitive reports and a shared basis for metacognitive evaluations across sensory modalities.