Abstract
Attention is important for selecting targets for action. Several studies have shown that attentional selection precedes eye movements to a target, and results in an enhanced sensitivity at the saccade goal. Typically these studies have used isolated targets on unrealistic blank backgrounds. We examined how the spatial profile of sensitivity changes when the target is presented on a textured background. We also measured the sensitivity profile at different times before the saccade to determine how the influence of the surrounding context develops over time. A central cue indicated which one of two potential targets on the left or right of fixation was the saccade target. The targets appeared alone, or on one of 2 textured backgrounds: a single uniform texture, or a concentric arrangement of 2 textures with orthogonal orientations. The cue lasted 300 ms and its offset served as the saccade-go signal. A dim, brief probe was presented before the saccade occurred and observers judged whether it appeared above or below the target. Both the spatial position of the probe and its delay with respect to the cue were varied. To ensure that observers accurately planned a saccade to the target, a post-cue indicated which one of two tasks to perform: an increment detection task on the target or a report of probe location. When the target was on a blank background or a uniform textured background, spatial sensitivity peaked at the target location about 300 ms after cue onset and declined with distance from the target. However, when the background was made up of an inner and outer texture, sensitivity to the inner texture was transiently increased at latencies typically required for the segmentation of orientation-defined textures. Thus our results indicate that spatial selectivity around the target interacts with other processes that group and segment the visual scene.
Meeting abstract presented at VSS 2012