AbstractThe Sense of Agency (SoA), our sensation of control over our actions, is a fundamentalmechanism for delineating the Self from the environment and others. SoA arises fromimplicit processing of sensorimotor signals as well as explicit higher-level judgments.Psychosis patients suffer from difficulties in the sense of control over their actions andaccurate demarcation of the Self. Moreover, it is unclear if they have metacognitiveinsight into their aberrant abilities. In this pre-registered study, we examined SoA and itsassociated confidence judgments using an embodied virtual reality paradigm inpsychosis patients and controls. Our results show that psychosis patients not only havea severely reduced ability for discriminating their actions but they also do not showproper metacognitive insight into this deficit. Furthermore, an exploratory analysisrevealed that the SoA capacities allow for high levels of accuracy in clinicalclassification of psychosis. These results indicate that SoA and its metacognition arecore aspects of the psychotic state and provide possible venues for understanding theunderlying mechanisms of psychosis, that may be leveraged for novel clinical purposes.