“…Examination of regional cerebral blood flow by single photon emission computed tomography and PET shows activation of the frontal cortex region during performance of theWCST Daniel et al, 1991;Marenco, Coppola, Daniel, Zigun, & Weinberger, 1993;Rezai et al, 1993;Rubin et al, 1991) and the Stroop test (Bench et al, 1993). These studies provide independent confirmation that the tasks selected for assessment of frontal lobe function in this study do depend on the function of the frontal lobes.…”