Abstract
Objects do not exist in isolation, rather they are part of environments in which objects serve to support scene interpretation. Our knowledge about objects and their perceptual properties, for example their size, modulates attentional allocation. Attention has been shown to be more efficiently oriented in small squares compared to large squares. Similar findings have been observed for attentional orienting in real-world objects, such that attention is more efficiently oriented within small objects (e.g., a domino) vs. large objects (e.g., a door) even when their retinal size is identical. While the findings clearly show that object size, both retinal and inferred, influences attentional orienting, it is unclear to what degree context contributes to size-related attentional modulation. We used the Ebbinghaus Illusion to influence object size perception with context. In a set of several experiments, we first established that perceived size manipulated by the surrounding context, as induced by the Ebbinghaus Illusion, does influence attentional allocation. We then extend this paradigm to real-world objects, manipulating perceived size of a central object by surrounding it with either small or large objects . Given the illusion induced change in perceived size of a central object, we predict that attention will be more efficient for targets within objects that are perceived to be smaller. There are two possible explanations for these results: (i) central objects will seem smaller than their real-world size when surrounded by semantically larger real-world objects, following the original illusion; and (ii) objects will scale in relation to one another, using depth as a cue, making the central object seem closer when surrounded by semantically larger objects. Our results point to an influence of context on perceived size of objects, and characterize its influence on attentional guidance.