Abstract

Performance on the Twenty Questions task has been assumed to be deficient in those with fron-tal lobe damage, although few studies have specifically examined this. In the present study, 88 participants with frontal lobe epileptic dysfunction were assessed on this task, as were 57 partici-pants with temporal lobe epileptic disturbance and 28 participants with no evidence of any neu-rological damage. Results indicated that those with either left or bifrontal lobe damage were more impaired on several indexes of test performance. Analysis also revealed that participants with orbitofrontal damage were impaired on the measure of “first guess ” as compared to groups with damage to other regions of the prefrontal cortex (p.05). Overall, the results support the utility of the Twenty Questions task in assessing frontal lobe damage and may suggest that qual-itatively different deficits may be recorded depending on the region of frontal lobe dysfunction. © 1999 National Academy of Neuropsychology. Published by Elsevier Science Ltd The role of the frontal lobes in higher level cognitive activity has been recognised for many years (e.g., Boller & Grafman, 1994; Nauta, 1971; Stuss & Benson, 1986). In partic-ular, the importance of these regions in executive skills has been reported (Levin, Eisen-berg, & Benton, 1991; Stuss, Eskes, & Foster, 1994). Numerous studies have reported on the role of the frontal lobes in formation of strategies, rule following, flexibility, and evaluation of outcome. Deficits in any one of these have been assumed to be responsible for the characteristic impairments in “problem solving ” or “executive skills ” reported to follow frontal lobe dysfunction (Benton, 1994; Fuster, 1989; Stuss & Benson, 1986). Numerous measures have been devised to demonstrate impairment following dam-age to the frontal lobes, and hence reflecting deficits in executive skills (Anderson, 1994;