UC Santa Barbara

Our visual environment is complex and contains both target and distractor objects. To navigate effectively, an ability to ignore visual distractors is as important as being able to focus on target information. While there has been a lot of research studying target processing, understanding of how distractors are processed is less clear. The goal of this research was to investigate how distractors are processed. In part I, distraction was examined as a function of spatial information available in the display. The motivation for this comparison was to assess predictions made by two theories of attention: Load theory (LT) and Theory of visual attention (TVA). LT posits that attention is allocated in a two-step process with an underlying assumption that spatial information is available pre-attentively. TVA, on the other hand, suggests a one-step attention allocation process, where spatial information needs to be computed or builds up over time. To test these predictions, distraction was compared across displays in which possible target and distractor locations were marked with placeholders, to displays in which no explicit spatial information was provided. If spatial information is available pre-attentively, providing spatial information should make no difference in distraction. Results from four experiments show reduced distraction when spatial information was provided compared to when it was not. This showed that spatial information is not available pre-attentively and in the absence of any expectation or bias, all objects are processed simultaneously. In part II, the extent to which advance knowledge of distractor location impacts distractor processing was examined. This study was motivated by 1) mixed evidence of reduced distraction when a cue indicates the location of an upcoming distractor, 2) mixed evidence for whether distractor cue leads to inhibition at the cued location and 3) lack of knowledge around how a distractor cue compares to target cue in impacting behavior. Results show some benefit of cueing the location of the distractor- reduced distraction as a function of distractor cue was seen in one out of three experiments. Cueing the target showed the most clear impact on behavior. Finally, there was no evidence that any benefit observed from distractor cueing was due to inhibition at the cued location.