The Effects of Target-Distractor Competition on the Oculomotor System

We use our eyes to investigate the world around us and decide what we want to act on. In a crowded scene, we direct our gaze to a single object of interest to gather more information about it. We do this effortlessly, but the underlying neural circuitry is complex. In this thesis, I look at temporal, spatial, and object identity factors that feed into the oculomotor system to drive eye movements in a target selection task. We varied the distance and similarity of complex objects to examine the effects of target-distractor competition on saccade trajectories and pupil size. We found that the effects of distance and similarity on saccade trajectories depended on the development of target-distractor competition. However, these factors did not modulate pupil size. Overall, these findings show that information processed in higher order visual areas is projected to the oculomotor system for saccade planning but not pupillary control.