Perceived distance modulates attention allocation

Recent experiments suggest that objects perceived to be near our body are processed more quickly and precisely than those that appear farther away. While it is clear this phenomenon, (appropriately termed the “close advantage effect”) occurs, the source of this improved processing remains an open question. One possibility is that attention is allocated more readily to closer objects than those that seem farther away. To examine this hypothesis, we evaluated whether attention orientation is modulated by perceived depth. As in previous experiments, depth differences were created using versions of the Ponzo illusion. In Experiment 1, we used a Posner cuing task where participants detected a target after receiving valid or invalid spatial cues to its location. Critically, on each trial the possible target locations (and cue) were confined to be either on the close or far surface of the illusion. We found greater accuracy for targets on the close surface (consistent with previous studies), and an advantage for the cued location. Notably, the positive effect of the cue was similar for close and far surfaces, suggesting that attention allocation within each surface was similar. In Experiment 2, we used the Egly-Driver task to explore whether attention operates differently when moving between close and far surfaces. In this case, cues and targets appeared on the same surface or different surfaces (valid or invalid). We found an interaction between cue validity and location of the target, such that the close advantage effect was greater for invalid trials. This suggests that observers had more difficulty disengaging attention from the apparently closer surface, even though the two regions were on the same physical plane. Taken together, our results suggest that there is privileged allocation of attention for objects perceived as closer, particularly when attention is split across distance.