The contribution of the frontal lobe to creativity. Insights from epilepsy

Purpose: This study was aimed to evaluate the impact of frontal (FLE) and temporal lobe epilepsy (TLE) on graphic creativity. Methods: A hundred and six patients with FLE (n = 32) or TLE (n = 74) and 38 healthy subjects underwent a design fluency (DF) test constituted by a free and a fixed condition. For each condition, the number of correct designs, as an index of creativity, and unacceptable nonperseveration or perseveration designs were calculated. The participants also underwent a comprehensive neuropsychological battery. Results: The number of novel correct designs significantly differed between the groups: patients with FLE produced fewer designs than patients with TLE and controls, while epilepsy laterality had no effect. Patients with FLE also produced more unacceptable nonperseveration designs than controls, with no between-group differences in the perseverations. The number of novel designs was predicted by the type of epilepsy, whereas word fluency, comprehension, attention, set shifting, visual matching, and constructive praxis had no influence. This score was a sensitive marker of FLE discriminating FLE cognitive pattern from the pattern of TLE and healthy condition. Conclusions: Left or right FLE, but not TLE, can impair graphic creativity. This finding and that DF was unrelated to other cognitive abilities suggest that creativity is a specific domain, sensitive to epilepsy-related frontal lobe dysfunctions. This behavioral approach including test accuracy may have implications in defining FLE cognitive phenotype.