Smooth pursuit and saccadic eye movement performance in a prefrontal leukotomy patient.

The authors wished to examine the role of the prefrontal cortex in oculomotor performance. They assessed smooth pursuit and saccadic performance in a patient with schizophrenia who had undergone a bilateral prefrontal leukotomy. Her performance on neuropsychological test measures sensitive to frontal lobe functioning were also examined. Against a background of intact intellectual and neurological functioning, the patient displayed a dissociation in premotor and prefrontal functioning. Smooth pursuit performance was within normal limits, as were the patient's finger tapping scores. In contrast, the patient performed poorly on the Wisconsin Card Sorting Test, and verbal and design fluency tasks. Similarly, her performance on the antisaccade task was markedly deviant. Despite advanced age and a frontal leukotomy, this patient with schizophrenia displayed intact smooth pursuit, indicating that the frontal cortex is not necessary for normal smooth pursuit performance.