Verbal and design fluency in patients with frontal lobe lesions

• Published in: Journal of the International Neuropsychological Society 2001-07, Vol.7 (5), p.586-596
• Main Authors: BALDO, JULIANA V., SHIMAMURA, ARTHUR P., DELIS, DEAN C., KRAMER, JOEL, KAPLAN, EDITH
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Aphasia, Wernicke - diagnosis; Aphasia, Wernicke - physiopathology; Brain Damage, Chronic - diagnosis; Brain Damage, Chronic - physiopathology; Brain Diseases - diagnosis; Brain Diseases - physiopathology; Brain Mapping; Design fluency; Dominance, Cerebral - physiology; Executive function; Female; Frontal Lobe - physiopathology; Humans; Male; Memory; Mental Recall - physiology; Middle Aged; Prefrontal cortex; Problem Solving; Psychomotor Performance - physiology; Semantics; Stroke; Verbal Behavior - physiology; Verbal fluency; Wechsler Scales
• ISSN: 1355-6177; 1469-7661
• DOI: 10.1017/S1355617701755063

The ability to generate items belonging to categories in verbal fluency tasks has been attributed to frontal cortex. Nonverbal fluency (e.g., design fluency) has been assessed separately and found to rely on the right hemisphere or right frontal cortex. The current study assessed both verbal and nonverbal fluency in a single group of patients with focal, frontal lobe lesions and age- and education-matched control participants. In the verbal fluency task, participants generated items belonging to both letter cues (F, A, and S) and category cues (animals and boys' names). In the design fluency task, participants generated novel designs by connecting dot arrays with 4 straight lines. A switching condition was included in both verbal and design fluency tasks and required participants to switch back and forth between different sets (e.g., between naming fruits and furniture). As a group, patients with frontal lobe lesions were impaired, compared to control participants, on both verbal and design fluency tasks. Patients with left frontal lesions performed worse than patients with right frontal lesions on the verbal fluency task, but the 2 groups performed comparably on the design fluency task. Both patients and control participants were impacted similarly by the switching conditions. These results suggest that verbal fluency is more dependent on left frontal cortex, while nonverbal fluency tasks, such as design fluency, recruit both right and left frontal processes. (JINS, 2001, 7, 586–596.)