Conflict processing in the anterior cingulate cortex constrains response priming

A prominent function of the anterior cingulate cortex (ACC) is to process conflict between competing response options. In this study, we investigated the role of conflict processing in a response-priming task in which manual responses were either validly or invalidly cued. Examining electrophysiological measurements of oscillatory brain activity on the source level, we found response priming to be related to a beta power decrease in the premotor cortex and conflict processing to be linked to a theta power increase in the ACC. In particular, correlation of oscillatory brain activities in the ACC and the premotor cortex showed that conflict processing reduces response priming by slowing response time in valid trials and lowering response errors in invalid trials. This relationship emerged on a between subjects level as well as within subjects, on a single trial level. These findings suggest that conflict processing in the ACC constrains the automatic priming process. (C) 2010 Elsevier Inc. All rights reserved.