THE ROLE OF PREFRONTAL REGIONS IN THE STROOP TASK

The Stroop is a classical paradigm that presumably involves the inhibi tion of automatic responses and is frequently used to assess the front al lobe functions. We investigated the effect of discrete prefrontal l esions in a Stroop task. A sample of 32 patients with frontal lesions were matched with normal controls by sex, age and years of education. Significant differences between patients and controls were found for e rrors but not for reaction time. Regression analysis showed that the r egion most related to errors was the right prefrontal lateral cortex. Left lobectomies did not impair the Stroop performance. Our results fa vour the role of the right prefrontal cortex in sustained attention, a nd disagree with the conception of the left prefrontal cortex having a role in the inhibition of verbal automatic responses.