The present study explored the ability of patients with unilateral frontal or temporal lobe excisions to use advance information in a choice-reaction-time task that required the discrimination of alphanumeric characters on the basis of their form of presentation, normal or mirror-image. The response time of the subjects in all the groups depended upon the target's angular orientation, when no information regarding the orientation and the identity of the impending target was provided (No Information condition). In the Advance Information condition, reaction time did not vary greatly with changes in the target's orientation except for the subjects with left or right frontal lobe excisions. These findings provide evidence of the importance of the frontal cortex in the use of advance information.