FMRI of the prefrontal cortex during overt verbal fluency.

Verbal fluency is known to be associated with activity in the left prefrontal cortex. Recent positron emission tomography (PET) results confirmed this finding. In the present study, high resolution functional magnetic resonance imaging (fMRI) was used to further localize activity in the prefrontal cortex related to verbal fluency. Activation was observed in three behavioral tasks: (1) Repeat-subjects repeated words, (2) Opposite-subjects produced the antonym of words, and (3) Generate-subjects generated words beginning with a given letter. When comparing Generate with both Repeat and Opposite, we observed small areas of activation in the left inferior frontal gyrus and anterior cingulate, similar to the centers of mass reported using PET. We also found additional activation around the superior frontal sulcus.