Verbal and figural fluency in patients with mass lesions of the left or right frontal lobes.

Impaired verbal and figural fluency has been shown to be associated with frontal lobe dysfunction. Jones-Gotman and Milner (1977) demonstrated a double dissociation between verbal and nonverbal fluency in a small sample of patients with frontal lesions of the left or right hemisphere. The present study has examined verbal and nonverbal fluency in 25 healthy participants and 95 patients with mass lesions of the left or right frontal lobes. In comparison with healthy participants, verbal fluency was reduced in patients with frontal lesions of the left hemisphere. Patients with right-sided lesions did not differ from either the control group or from the patients with left-sided frontal mass lesions. In the figural fluency task, the performance of the groups did not differ. The finding that patients with left frontal lesions produced fewer words than healthy participants suggests an association between left frontal lobe pathology and reduced verbal fluency. The results do not support the hypothesis of a double dissociation between verbal/figural fluency and the side of lesion within the frontal lobes.