Spreading of Visual Attention to Modally Versus Amodally Completed Regions

Abstract

Regions of objects that are partially obscured in the current retinal image are often perceptually filled in by the visual system (Kantzsa, 1979) In some cases (modal completion), this causes the filled-in region to appear tinged with the color and brightness of unobscured parts of that object, but in other cases (amodal completion), it does not (Michotte & Burke, 1951) It has recently been argued that modal and amodal completion both arise in preattentive vision, and may operate equivalently at that level (Davis & Driver, 1994, He & Nakayama, 1992, Shipley & Kellman, 1992) In this article, we show that they have different effects on attentive vision, with attention tending to spread to (and from) modally completed regions and their visible inducers, but not to (or from) comparable amodally completed regions and their inducers This finding is consistent with visual attention operating on surfaces (eg, He & Nakayama, 1995) in a viewer-centered representation of the scene, after the operation of filling-in processes.