Is attentional capture by irrelevant color stimuli affected by expectancies?

Abstract

<p>Previous research has indicated that the presence of a salient stimulus (singleton) affects the detection of relevant less salient stimuli in a search task (Theeuwes and Godijn 2001). A salient novel stimulus seems to capture attention. Recent evidence suggests that effects may be stronger when the salient singleton is presented randomly on only 20% of trials rather than every trial (Geyer, Muller, and Krummenacher 2008). Previous research from our lab suggests capture by a singleton is contingent on the relationship between the color of the target stimulus and the singleton distractor color (Amster 2005). However, there is debate as to whether involuntary capture by an irrelevant singleton is contingent on the relevance the singleton has to the observer's task (Wright and Ward 2008). This study examined if capture by an irrelevant singleton was contingent on the relationship between the singleton color and the less salient color target, if the singleton appears randomly on a relatively small percentage of trials. One block of trials with no singleton present was conducted as a control condition followed by a block of trials with an irrelevant singleton present on 20% of trials. Four different singleton colors were used: red, blue, green, and bright white; but the singleton was always red. A second experiment with singletons present on 100% of trials was also conducted and results were compared with 20% conditions. We expected detection of a target to be poorer when singletons were present in 20% conditions versus the 100% conditions, but this hypothesis was not supported. Data did support our general hypothesis that attentional capture is contingent on the proportion of trials the singleton is present and the color of the salient singleton.</p><p>This presentation occurred at the Wright State University Campus-Wide Celebration of Research, Scholarship and Creative Activities on April 16, 2010</p>