Effect of Intellectual Level on Neuropsychological Test Performance: A Response to Dodrill (1997)

Abstract

Recently, Dodrill (1997) presented data suggesting that individuals with above average intelligence do not perform any better on neuropsychological tests than those with average intelligence. The current study examines the neuropsychological performance of 157 patients referred for neuropsychological evaluation who were determined to be neurologically normal based on neurodiagnostic procedures. Patients were divided into below average, average, and above average WAIS-R FSIQ ranges, and each group's mean performance on major Halstead-Reitan Battery (HRB) measures and the Wechsler Memory Scale was calculated. Contrary to Dodrill's findings, our results show a clear pattern in which patients with above average FSIQs perform better on the majority of HRB measures and memory measures than do patients with average FSIQs, who in turn perform better than do individuals with below average FSIQs. These results suggest that intellectual status can serve as an effective estimate of expected neuropsychological performance in patients referred for evaluation, and provide support for the common practice of using premorbid intellectual estimates as general indicators of expected neuropsychological performance.