Dissociating location-based and object-based cue validity effects in object-based attention.

Encoding predictive information and allocating visual attention according to the probability distribution is one of the marvelous achievements of our visual system. Unlike previous studies on object-based attention in which the validity of location-based cues and that of object-based cues covaried, we differentiate the two and examine whether our visual system can calculate the usefulness of the cue based on, separately and independently, the probability distribution of location on one hand and object that contains multiple locations on the other. We adopted the cueing paradigm with the double-rectangle display (Egly, Driver, & Rafal, 1994) and manipulated cue validity with respect to a particular location or the object as a whole. Results showed a spatial-cueing effect when location-based cues were informative and a same-object advantage when object-based cues were informative. We thus demonstrate here that different kinds of cue validity (location-based vs. object-based) determine different attention effects respectively (spatial-cueing effect vs. object-based advantage).