Object-based selection operates on a grouped array of locations

In two experiments, space- and object-based selection effects were investig ated, using variants of the ring-cuing paradigm of Egly and Homa (1984). Th e results revealed significant cuing modulation for nonring configurations of target locations spanning a range of retinal eccentricities, with the cu ing effects independent of eccentricity and confined to the configuration o f locations (rather than extending to locations within the space enclosed b y the cued configuration). These results are consistent with object-based s election operating on a grouped spatial a array (Vecera & Farah, 1994). Obj ect selection may be based on a supradimensional saliency map representatio n of the field, modulated by feature-specific segmentation mechanisms (e.g. , an object may be made salient on the basis of its color). Complex objects may be represented by grouped saliency signals. In this way, a two-dimensi onal spatial (saliency) representation may provide the common format for ob ject-based selection, prior to full object definition.