The visual search task reveals important functions and properties of the spotlight of attention

Selective attention can be employed to a restricted region in space or to specific objects. Many properties of the spotlight of attention are not well understood. In the present study, the question examined was whether the putative shape of the attentional spotlight can be determined by endogenous cueing within a visual search paradigm. Moreover, the current investigation examined the role of spatial cueing on the detrimental effect of the irrelevant background elements during a visual search task. The results confirmed that attention was confined to the cued area only. In addition, the cueing technique was successful in partially eliminating the background effect. This study shows that top-down processes, just like bottom-up processes, can be manipulated. Most importantly, this study has provided converging evidence for an attentional spotlight whose shape can be adjusted flexibly by appropriate endogenous cueing. The present experiments have shed some light into the roles that attention plays in perception.