Response-related negativities following correct and incorrect responses: evidence from a temporospatial principal component analysis.

Two ERP components have been observed following correct and incorrect responses, the error-related negativity (ERN/Ne) and the correct-related negativity (CRN). The function of these components is still under debate. We used a visual size discrimination task at three difficulty levels and utilized a temporospatial principal component analysis (PCA) to examine whether ERN/Ne and CRN could be explained by one or more factors. While ERN/Ne decreased with higher task difficulty, amplitudes increased for correct responses at parietal electrodes. PCA revealed two temporospatial factors: a centrally distributed factor differing between correct and incorrect responses and a more frontoparietally distributed factor contributing to both ERN/Ne and CRN. These data support the notion that ERN/Ne and CRN might reflect a combination of two underlying processes: an error-sensitive and an outcome-independent aspect of response monitoring.