Abstract
When a part of an object is cued, targets presented in other locations on the same object are detected more rapidly and accurately than targets on other objects. Oftentimes in such experiments the cues and targets appear not only on the same object, but also on the same surface. In classic paradigms, the objects are often defined by a single closed surface (i.e. a rectangle). It is therefore unclear whether the ‘object’ of attentional selection is truly the object itself or simply one of its surfaces. In four psychophysical experiments, we examined whether the facilitating effects of attentional cuing extend to other non-cued surfaces on the same object or on different objects. In Experiment 1, facilitation effects were found for targets on non-cued, adjacent, bounded surfaces on the same object, even when the cued and uncued surfaces were oriented in different directions in depth. This suggests that the ‘object based’ benefits of attention are not restricted to individual surfaces. We further confirmed this finding in two control experiments. A fourth experiment examined the interaction of perceptual grouping and object-based attention. This experiment found that the benefit of cueing an object defined by one closed-contour surface can extend to another non-contiguous object if they are presented in a configuration that facilitates perceptual grouping. This suggests that the objects of attention do not necessarily map onto discrete physical objects defined by closed contours. Instead, attentional selection can be allocated to perceptual groups of surfaces and objects in the same way as it can to a location or to groups of features that define a single object.
Acknowledgement: National Science Foundation: NSF 1632738 and NSF 1632849