Dissociable neural correlates of spatial attention and response inhibition in spatially driven interference.

Neural mechanisms underlying response inhibition have been investigated using spatially driven interference tasks such as the arrow-word Stroop task. However, neural responses, which are observed in the arrow-word Stroop task, may reflect not only response inhibition, but spatial attention modulation as well due to the spatial properties of an arrow stimulus. The current study aimed to identify whether individual cortical regions associated with spatially driven interference contribute to either spatial attention modulation or response inhibition, or both. We therefore developed a new task that measures these two functions independently and then conducted a functional magnetic resonance imaging experiment. Our results indicate that the right inferior parietal lobule and precentral gyrus were engaged by the spatial attention modulation, while inhibition was closely associated with the bilateral inferior frontal gyri, aided by the left superior prefrontal gyrus and dorsal anterior cingulate cortex. The left inferior parietal lobule was associated with common processes engaged in allocating attentional resources. These findings provide new evidence that spatially driven interference may recruit distinct cortical regions involved in spatial attention modulation and/or response inhibition.