The impact of Degraded distractors on (Nondegraded) target identification.

In this series of experiments, based on Biederman's Recognition by Components theory, we postulate that corners (vertices) of objects are crucial in programming and execution of goal-directed action. We used a distractor interference paradigm to present line drawings of letters (M and W) with distractors (also M and W), which were either nondegraded or degraded (that is, corners or line segments missing). Degraded distractors caused less interference overall (reduced response times and errors) than Nondegraded distractors, when these were presented peripherally or at fixation (Experiments 1 and 2). When presented at fixation, however, distractors with corners missing caused greater interference than distractors with line segments missing. This pattern was not replicated with non-identical, non-mirror reversed stimuli (H and E: Experiment 3). We speculate that corners are critical in determining the extent of distractor interference. When missing from view, and given sufficient attentional resources and structural similarity, they may be reconstructed by the visuomotor system to aid performance to the target.