Abstract
The Inhibition of Return (IOR; Posner et al, 1988) effect reflects a mechanism that biases attention from re-examining previously attended regions (Posner & Cohen, 1984) or objects (Jordan & Tipper, 1998; Tipper, Jordan & Weaver, 1999). A previously attended object, if moved to a novel location, also carries with it an inhibitory ‘tag’. Object-based IOR is carried both by outlined-objects (Jordan & Tipper, 1998) or surfaces defined by a field of dots, even when superimposed upon another surface (Johnson, Fallah, & Jordan, VSS 2008). We probed the level of hierarchical organization that maintains object-based IOR as the object moves across the visual field.
A modified version of the cueing paradigm, which dissociates object- and location-based IOR effects was used (Tipper et al, 1999). In the present study, we investigated whether object-based IOR is mediated at a local (individual dots) or global (surface) stage of object processing. The display consisted of a single surface of dots in the shape of an annulus. The surface was visible through three apertures in an invisible occluder. While controlling for perceptual complexity, in one display condition the dots rotated (local), while in the other display condition the aperture rotated over the static surface (global).
The location-based IOR effect was significantly larger in the local condition (p = .003). Despite manipulating the hierarchical organization of the objects in the display, remarkably there was no difference in the object-based IOR effects observed in the two conditions (p = .557). These results are discussed in light of previous research and current models of spatial and object-based attention.