Object-Based Inhibition of Return: Evidence from Overlapping Objects

Abstract

Inhibition of return (IOR) refers to the delayed response to a location or an object that has recently been cued. Previous studies showing object-based IOR in either dynamic or static displays have used spatially separate stimuli that unavoidably involved spatial representation. It thus remains unclear whether the object-based IOR is a special case limited to the condition in which objects are separated in a 2-dimensional space. To rule out confounding with location-based IOR, we used two overlapping triangles constituting a ”Star of David” in this study to examine whether and under what conditions object-based IOR can be observed. An object cuing paradigm was used in which one of the two triangles was brightened as the cued object. The target was a luminance change in one of the three disks connected to the vertexes of the cued or the uncued triangle. The participants judged whether the target brightened or dimmed. Results show that object-based IOR can occur for spatially overlapping object under two necessary conditions: A long enough cue-to-target SOA and the existence of an attractor that is presented after the cue and before the target.