Abstract
Some studies suggest that attentional selection is determined by top-down search intentions whereas others show the impact of bottom-up saliency signals. In the additional singleton paradigm, attention is oriented to a color singleton because of its saliency and despite observers’ intention to search for a form singleton. In contrast, attentional capture in the modified spatial cueing paradigm only occurs when the color of a salient singleton in the cue display is equal to the color of a singleton in the subsequent target display. That is, salient objects only capture attention when they correspond to observers’ search intention. Recently, Müller, Geyer, Zehetleitner, and Krummenacher (2009) showed in the additional singleton paradigm that capture by a salient but irrelevant singleton depends on its probability: Capture increased when the probability of the irrelevant singleton decreased. We investigated effects of cue probability in a version of the modified spatial cueing paradigm (Folk & Remington, 1998). The target had a different color from the cue so that search intentions did not correspond to the feature of the cue singleton. Because of the mismatch, only weak attentional capture was expected. In Experiment 1, however, significant capture was observed. The capture effect was larger when the cue singleton occurred on only 25% of the trials than when it appeared on 100% of the trials. In Experiment 2, a second color singleton in the target display was added, forcing feature search. When the cue singleton occurred on 25% of the trials, no capture was observed. When it occurred on 100% of the trials, the effect was small. Importantly, there was no difference between the 25% and 100% condition in feature search mode. Our results suggest that salient objects with low-probability may override search intentions in singleton search mode, but not in feature search mode.
Meeting abstract presented at VSS 2012