Abstract
Purpose: Uniform connectedness (UC) is an organizing principle thought to underlie the segregation of the visual field into figure/ground and ultimately into separate objects. At what point does object-based attention begin to have an influence as processing progresses from UC regions to objects? To address this question we explored a boundary condition of the object advantage utilizing a cuing paradigm with a self-splitting figure that was a single UC region. Would object-based attention treat the UC region as a single object, or separate objects, as the splitting figure was perceived? Method: The self-splitting figure was perceived as two pairs of “objects,” rectangles diagonally overlapping elongated ovals. In separate sessions, participants started a trial when the rectangles were perceived in front, and when the ovals were perceived in front. Cues and targets appeared at four equidistant positions in the regions where the rectangles and ovals overlapped. On 10% of the trials no target appeared. Cues were valid on 70% of the trials and invalid on 20%, with half the invalid trials requiring a within-object shift and half requiring a between-object shift of attention. RT to target onset was measured. Results: RTs were always faster on valid than invalid trials. Invalid within- and between-object RTs were the same. Conclusions: Although our single UC region stimulus was parsed perceptually into separate objects, object-based attention treated it as a single UC region/object indicating the representation associated with the perceptual experience may be different from that which object-based attention operates on.