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Abstract:
Recent imaging studies of the Stroop task have suggested a
role for both lateral and medial frontal areas in monitoring and
resolving conflict. Our studies first examined whether there was
evidence of conflict in both linguistic and spatial conflict
paradigms. Second, we considered the circumstances under which
conflict is correlated across these two domains. Third, we asked
whether these two forms of conflict involved the same frontal
cortical areas. We compared a color-word Stroop task with a flanker
task that introduced conflict between a central and surrounding
arrows. We also used a picture matching task that introduces a
spatial conflict between location and the side of response.
Reaction times for each of the three tasks were significantly
longer in the incongruent condition, thus demonstrating conflict.
The color-word task produced the most conflict, and the picture
location task produced the least. Significant correlations between
spatial and linguistic conflict were uncovered only with a modified
version of the Stroop task that required subjects to focus
attention on the word by surrounding it with flankers. Twelve
subjects were run in an event-related fMRI study while performing
each of the three tasks. We will discuss the data from this imaging
study in terms of similarities and differences in the strength of
activation in medial and lateral frontal areas in the three
tasks.
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