Functional dissociations of multiple conflict-driven cognitive control networks

Abstract

Recent functional neuroimaging studies suggest that multiple conflict-driven cognitive control mechanisms are implemented in the brain depending on the level of processing; the dorsolateral prefrontal cortex (DLPFC) and the rostro-dorsal cingulate cortex (rdACC) for response conflict, and the dorsal portion of the premotor cortex (pre-PMd) and the caudal dACC (cdACC) for perceptual conflict (Egner et al, 2007 NeuroImage 35 940-948; Kim et al, in press Human Brain Mapping). A functional dissociation of DLPFC and rdACC has been further suggested for detecting and regulating response conflict, respectively. However, the functional roles of pre-PMd and cdACC remain unclear. In this study, we employed a conflict adjustment paradigm using a modified version of the Stroop task to measure post-conflict effects on those brain regions. Behavioral results demonstrated post-conflict adjustments in both perceptual and response conflict conditions. Imaging data showed a functional dissociation of pre-PMd and cdACC analogous to that of DLPFC and rdACC; cdACC activation was increased in the occurrence of perceptual conflict, but decreased in the subsequent perceptual conflict, whereas pre-PMd was associated with both the current and preceding perceptual conflicts. These findings suggest that cdACC is involved in detecting perceptual conflict, and pre-PMd plays a critical role in regulating perceptual conflict.