Anterior cingulate cortex and response conflict: Effects of response modality and processing domain

Studies of a variety of higher cognitive functions consistently activate a region of anterior cingulate cortex (ACC), situated posterior to the genu a nd superior to the corpus callosum. However, it is not clear whether the sa me ACC region is activated for all response modalities (e.g. vocal and manu al) and/or all processing domains (e.g. verbal and spatial). To explore thi s question, we used rapid event-related functional magnetic resonance imagi ng and a spatial Stroop task with conditions tapping both verbal and spatia l processing. We also employed novel methods that allowed us to acquire the accuracy and reaction times of both manual and vocal responses. We found o ne large ACC region that demonstrated significant response conflict effects with both vocal and manual responses, and three ACC regions that demonstra ted significant response conflict effects with both spatial and verbal proc essing. We did not find any ACC regions that demonstrated activity selectiv e to either a specific response modality or processing domain. Thus, our re sults suggest that the same regions of ACC are responsive to conflict arisi ng with both manual and vocal output and with both spatial and verbal proce ssing.