The role of the frontal eye fields in the oculomotor inhibition of reflexive saccades: evidence from lesion patients.

The current study investigated the role of the frontal eye fields (FEF) in the suppression of an unwanted eye movement ('oculomotor inhibition'). Oculomotor inhibition has generally been investigated using the antisaccade task, in which an eye movement to a task-relevant onset must be inhibited. Various lines of research have suggested that successful inhibition in the antisaccade task relies heavily on the FEF. Here, we tested whether the FEF are also involved in the oculomotor inhibition of reflexive saccades. To this end, we used the oculomotor capture task in which the to-be-inhibited element is task-irrelevant. Performance of four patients with lesions to the FEF was measured on both the antisaccade and oculomotor capture task. In both tasks, the majority of the patients made more erroneous eye movements to contralesional elements than to ipsilesional elements. One patient showed no deficits in the antisaccade task, which could be explained by the developmental origin of his lesion. While we confirm the role of the FEF in the inhibition of task-relevant elements, the current study also reveals that the FEF play a crucial role in the oculomotor inhibition of task-irrelevant elements.