ERP indices of performance monitoring and feedback processing in psychosis: A meta-analysis

Background: Although individuals with, or at risk for, psychotic disorders often show difficulties with performance monitoring and feedback processing, findings from studies using event-related potentials (ERPs) to index these processes are not consistent. This meta-analytic review focused on studies of two different indexes of performance monitoring, the early error-related negativity (ERN; n = 25) and the later error positivity (Pe; n = 17), and one index of feedback processing, the feedback negativity (FN; n = 6). Methods: We evaluated whether individuals (1) with psychotic disorders, or (2) at heightened risk for these disorders differ from healthy controls in available studies of the ERN, Pe, and FN. Results: There was a significant, large ERN reduction in those with psychosis (g = 0.96) compared to controls, and a significant, moderate ERN reduction in those at-risk (g = 0.48). In contrast, there were uniformly nonsignificant, small between-group differences for Pe and FN (g(s) <= vertical bar 0.16 vertical bar). Conclusions: The results reveal a differential pattern of impairment in psychosis. Early performance monitoring (ERN) impairments are substantial among those with psychotic disorders in general and may be a useful vulnerability indicator for these disorders. However, later performance monitoring (Pe) and basic feedback processing (FN) appear to be relatively spared in psychosis.