| Popis: |
People are faster at detecting a visual target at a cued, compared to an uncued location. With exogenous cues only, a reversal of this cost-benefit pattern occurs with cue-target intervals exceeding 250ms (Inhibition of Return = IOR). We suggest that no IOR is found with endogenous cues, because most volitional attention shifts act upon higher processing levels, while IOR may act upon bottom-up saliency-based orienting processes only. To investigate this, participants had to orient to one out of two differently colored salient peripheral cues, indicated by a (preceding) central instruction (endogenous). With sufficient time between instruction and peripheral cues, IOR was observed, demonstrating the effect of endogenous orienting acting upon low-level saliency processes. No IOR was observed when the central cue was presented simultaneously with or after the peripheral cues. These results suggest that the use of saliency-based processes in endogenous orienting is a prerequisite for the appearance of IOR. |
