Color-word matching stroop task: Separating interference and response conflict

The Stroop interference task requires a person to respond to a specific dim ension of a stimulus while suppressing a competing stimulus dimension. Prev ious PET and fMRI studies using the Color Stroop paradigm have shown increa sed activity in the "cognitive division" of the cingulate cortex In our fMR I study with nine subjects, we used a Color-Word Matching Stroop task. A fr ontoparietal network, including structures in the lateral prefrontal cortex , the frontopolar region, the intraparietal sulcus, as well as the lateral occipitotemporal gyrus, was activated when contrasting the incongruent vs t he neutral condition. However, no substantial activation in either the righ t or left hemisphere of the anterior cingulate cortex (ACC) was detected. I n accordance with a series of recent articles, we argue that the ACC is not specifically involved in interference processes. The ACC seems rather invo lved in motor preparation processes which were controlled in the present Co lor-Word Matching Stroop task. We argue that the region around the banks of the inferior frontal sulcus is required to solve interference problems, a concept which can also be seen as a component of task set management. (C) 2 001 Academic Press.