Effect of familiarity and feature differences on visual search

grantor: University of TorontoQ. Wang, P. Cavanagh and M. Green (1994) demonstrated a pop-out effect in searching an unfamiliar target among familiar distractors (U-F condition), and argued for the importance of familiarity difference between the target and distractors in determining the search efficiency. In Experiment 1a, we replicated this pop-out effect with targets and distractors which differed in low-level features. However, in Experiments 1b and 2, a pop-out effect was not uniformly obtained with targets and distractors which differed in line arrangement but not in their orientation. The results suggest that a U-F pop-out effect may be partially mediated by feature differences between targets and distractors. In Experiments 3 and 4, we used target-distractor pairs with feature differences controlled across F-F, U-F, F-U, and U-U conditions. We found that the familiarity of the distractors, instead of the familiarity difference between the target and distractors, contributed to efficient searches.M.A