Abstract
Context plays a powerful role in guiding attention towards relevant objects. In the present study, we investigated whether context can similarly drive salient distractor suppression. Observers were asked to indicate the orientation of the line inside a singleton shape target (e.g., one diamond among five circles). On some trials, a salient color (red) singleton distractor was presented. Otherwise, all objects were presented in either all green or all blue (hereafter labeled display color); display color varied randomly from trial-to-trial. While salient distractors typically capture attention, capture is reduced when distractors appear frequently (e.g., Müller et al., 2009). Thus, we varied the probability that a salient distractor would be present as a function of the display color. One display color was associated with a high probability that a salient distractor would be present (80%), and the other color was associated with low singleton distractor probability (20%). Color contingencies were counterbalanced across participants, and debriefing questionnaires revealed that participants were not aware of color contingencies. On distractor present trials, response times were shorter when the display color indicated high distractor probability (1113 ms) relative to low distractor probability (1139 ms). Thus, observers were able to learn context-specific distractor probabilities and selectively implement distractor suppression mechanisms when a distractor was highly likely. Furthermore, compatibility effects – response times depending on whether the line inside the distractor matched the line inside the target - were also greater in the low probability condition (80 ms) than in the high probability condition (12 ms). This result indicates processing of the distractor line on high probability trials was minimal, again consistent with increased distractor suppression in contexts where salient distractors are likely. Together, these results indicate that distractor suppression is selectively applied in contexts where distractors are expected. Thus, contextual learning can drive salient distractor suppression.
Meeting abstract presented at VSS 2015