Abstract
Attentional resolution (AR) is the precision with which one can discretely move attention among closely spaced items, and it is remarkably coarse given the precision with which people can perceive simply that there are multiple items present (He, Intriligator, & Cavanagh, 1996). One method of measuring AR is the attentional-walk task, which was developed by Intriligator and Cavanagh (2001). In this task, a start disk within an array is cued and the subject must shift attention, stepping between disks in the array, in accordance with a series of directional commands. A probe disk is then indicated and the subject's task is to report whether or not his/her attentional walk ended on that disk. As the density of the array increases, subjects' ability to attentionally walk through the array decreases, as measured by decreased accuracy on the probe task. In the present study, we sought to measure AR using an attentional-cuing paradigm in order to link AR to the existing literature on selective attention. In this task, an individual item was cued (e.g., by a brief luminance increase), and then a target stimulus was presented either at the cued location or at an uncued location. Results indicate that exogenously cuing attention to a single item even in dense arrays allowed the target to be identified more efficiently than when it appeared at uncued locations. The contrast between these results and those from the attentional-walk task suggests that the resolution of exogenously controlled attention may be finer than the resolution of endogenously controlled attention. Follow-up experiments using the attentional-cuing paradigm with endogenous cues are underway.