Impaired sense of agency and associated confidence in psychosis

Abstract

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

Fig. 1. Group mean and individual ratings of SoA, confidence and metacognitive performance.

A Self attribution in the temporal aspect (left) and in the spatial aspect (right). Shaded area represents 95% CI, large shapes represent group means. B Confidence in the temporal (left) and spatial (right) aspects following correct answers to the SoA question. C Distribution of metacognitive performance in the temporal (left) and spatial (right) aspects.

Fig. 2. Group classifier performance.

A Classification of two sample subjects (exemplar control participant and psychosis patient, linear fit in dashed red line), that are accurately classified as “control” (left) and “psychosis” (right). B Classifier performance, leaving out 20% of the participants (i.e. 6) in each iteration. Sensitivity is the percent of psychosis patients correctly classified, specificity is the percent of HC correctly classified. C Classifier accuracy across different proportions of participants left out and number of trials sampled. Trials were randomly sampled from the entire experiment (left), or from the first block (right).

Fig. 3. Trial flow.

Each trial began with a fixation cross (i), followed by the VH presentation (ii), agency question (iii) and the confidence question (iv).