Abstract
Previous research has shown that the perceptual load involved in the processing of the target is a major determinant of selective attention. Whereas low perceptual load leads to high distractor interference, high perceptual load typically results in low distractor interference (e.g., Lavie, 1995). However, recent findings suggest that the relationship between perceptual load and the magnitude of distractor interference is more complex than was previously conceived (e.g., Chen, 2000; Wilson & MacLeod, 2000). In the present series of experiments, the size of the attentional window prior to the target display was manipulated while the perceptual load involved in the processing of the target was kept constant within an experiment. The results suggest that distractor interference is a joint function of the size of the attentional window and perceptual load. Whereas the magnitude of distractor interference is generally greater with low perceptual load compared to high perceptual load, it is also modulated by the size of the attentional window before and during target selection. When target selection requires a narrow attentional focus, distractor interference is low regardless of the size of the attentional window set previously. However, when target selection does not require a narrow attentional focus, the magnitude of distractor interference correlates positively with the size of the attentional window.