Effect of Non-Target Stimuli upon Length of Voluntary Saccades

The length of initial voluntary saccades to a target were measured in three experiments. It was found that saccade length varied as a function of the number, locus and distance of non-target stimuli present in the visual field. Eye movements tended to be directed toward the “center of gravity” of the stimuli close to the target. These systematic changes seem to be independent of task requirements for acuity. Some implications are discussed.