When two become one: Electrocortical correlates of the integration of multiple action consequences.

In a recent study we have demonstrated that the feedback-related negativity (FRN) reflects the integrated value of instantaneous and delayed decision consequences (Osinsky et al. 2017). In the present work, we extend this research by using a novel choice task in which instant and delayed consequence values of a single decision outcome can be manipulated independently of each other in a trial-wise manner. Fifty-nine healthy participants completed this task while EEG was recorded. Twenty-two of them returned one week later for a retesting, allowing for investigating temporal stability of individual FRN indices. Our results show that the FRN mainly reflects the additively integrated value of instant and delayed outcome consequences. Individual differences in the FRN sensitivity to the two consequence dimensions were specifically predictive for consequence-driven adjustments in choice behavior and moderately stable over time. Altogether, our findings are inconsistent with the idea that the FRN reflects a simple binary distinction between favorable and unfavorable action outcomes. Rather, the FRN appears to mirror a fine-grained scaling of action outcomes, which results from stable personal reward preferences and which is used for adjusting choice behavior. Given that the FRN is generated in the anterior midcingulate cortex, our study adds to recent literature according to which this structure uses multiple information to learn complex action-outcome values.