Selective Impairments in Managerial Knowledge Following Pre-Frontal Cortex Damage

Script generation was investigated in patients with lesions in the prefrontal (n=9) and posterior (n = 8) cortical regions and in normal subjects (n =16). Three different activities ranging in degree of familiarity were studied. Frontal patients did not differ from patients with posterior lesion and Normal subjects in the number of actions evoked, mean evocation time, or centrality. Impairments in script information processing were observed only in patients with prefrontal lesions, for the three types of scripts. Specifically these patients made errors in ordering actions in the correct temporal sequence, failed to close scripts and to remain within the stated boundaries, made deviant estimates of action importance. The results suggest that pre-frontal cortical lesions provoke a selective impairment in managerial knowledge (Grafman, 1989) that may contribute to difficulties in the formulation and execution of plans.