Abstract
Figure-ground organization can be influenced by spatial attention: cuing exogenous attention to a region of an ambiguous figure-ground display prompts that region';s designation as figure (Vecera et al., 2004). But can the width of the attentional scope also affect figure-ground organization? The spatial window of attention influences the interpretation of an entire visual scene (e.g., Navon, 1977; Pan & Eriksen, 1993), such as allowing one to focus on a global shape versus focusing on local elements of that global shape. Because cues giving rise to figural assignment vary along the shared contour, the window of spatial attention may also influence their use for figure-ground segmentation. For example, a figure with a contour shaped like the right side of a ‘;B’; contains two convexities, but also contains a single concavity on the ground side (the point at which the loops of the B intersect). If attention is constricted around this single ground convexity, then this convexity cue may demand the opposite figural assignment from what is anticipated when considering the entire contour (i.e., the B shape as figure). To examine this possibility, observers attended to a figure-ground display either globally or locally. When attention was set broadly, figural assignment aligned with the global interpretation. However, when attention was set locally, the local convexity dictated which region was seen as figure, even though this local convexity opposed the global interpretation of the display. These results suggest that the width of the attentional window can impact what image-based cues may be used to complete figure-ground assignment.
NSF grant: BCS 03-39171 awarded to S. P. Vecera