Fixational eye movements are not affected by abrupt onsets that capture attention.

Recent work shows that abrupt onsets reflexively capture attention and trigger saccades that compete with voluntary saccades. To test whether oculomotor capture occurs when no saccade is being planned, we measured fixational eye movements in the absence or presence of an abrupt onset at peripheral locations. We found no effect of abrupt onset location on the average pattern of eye movements during fixation. We conclude that the capture of eye movements by an abrupt onset only happens when the oculomotor system has been preset to make a saccade. This implies that the oculomotor system is not obligatorily driven by events in the visual array.