ABSTRACT

Saccadic eye movements are among the most common and most stereotyped behavioral responses made by human subjects. The eyeball presents a constant load to the oculomotor muscles and thus control may be made by means of a preprogrammed ballistic pattern of activation. A characteristic feature of human saccadic eye movements to targets that appear in peripheral vision is that saccadic response is generally directed by “global” aspects of the visual information. Evidence for the assertion has come from examination of the amplitude of saccades generated when subjects are presented with two targets that appear simultaneously in the periphery. A notable feature of the results on the global effect was that it appeared only slightly affected by the context in which the saccadic eye movement was made. The demonstration of the global effect suggests that under normal circumstances, the visual information used by the saccadic system is coming from channels tuned to low or very low spatial frequencies.