Visual spatial localization conflict: an fMRI study.

fMRI and ERP studies have shown that tasks comprising conflicting stimulus-response associations activate a variety of cortical regions. It remains unclear whether any of these areas are activated by all conflict tasks, or whether conflict resolution is a common property of a number of distinct anatomical regions. Several regions in frontal and parietal cortex are activated by both exogenous (position) and endogenous (arrow direction) localization cues. The present event-related fMRI study used a version of the Simon task with independent positional and directional cues. The results indicated that spatial localization conflict activated pre-motor and superior parietal regions in the right hemisphere known to be involved in spatial localization, but anterior cingulate activation did not reach threshold. This suggests that conflict within a single functional modality may be processed in the region embodying that modality, and anterior cingulate may be called on only to resolve conflict between modalities.