Effects of frontal or temporal lobectomy on the use of advance information in a choice reaction time task.

The ability to make use of directional cues presented to subjects before they are asked to make a specific response was studied in 69 patients who had undergone a unilateral frontal or temporal lobe excision, and in 24 normal control subjects. Choice reaction time was measured in two conditions: (1) informative, where a centrally presented cue indicated in advance the target's location, and (2) neutral, where the cue was a symbol carrying no directional information. Patients with excisions from the left or right frontal lobe did not benefit from the available information to the same extent as patients with either left or right temporal lobe excisions or normal control subjects.