Defensive motivation increases conflict adaptation through local changes in cognitive control: Evidence from ERPs and mid-frontal theta.

Cognitive control is highly dynamic, and liable to variations in the affective state of participants. Recently, we found that defensive motivation, elicited by means of loss-related feedback contingent on task performance, actually increased conflict adaptation at the behavioral level, and hence tightened cognitive control. However, it remains unclear at which stage during stimulus processing this facilitatory effect takes place, and what his electrophysiological manifestation may be. To address this question, in the current study, we compared conflict adaptation between two conditions that differed in the amount of defensive motivation, and recorded 64-channel electroencephalography concurrently. Results showed that conflict adaptation was larger at the behavioral level when defensive motivation was elicited. Interestingly, event-related brain potentials showed that this effect was captured by a systematic amplitude modulation of the conflict-related N2 component, suggesting that defensive motivation could alter conflict processing locally and at an early stage following stimulus onset. In comparison, mid-frontal theta (MFT) power was globally augmented when defensive motivation was elicited, but did not co-vary with conflict adaptation however. Taken together, these neurophysiological results suggest that defensive motivation can exert specific facilitatory effects on cognitive control (N2), which can be dissociated from a more global alteration in information processing that likely reflects unspecific control or even motivational changes (MFT).