Searching for camouflaged targets: effects of target-background similarity on visual search

Do observers search for camouflaged targets by looking through the distractors or by scrutinizing the target-similar background? In four experiments observers searched for toy targets among distractors under varying set size and target-background similarity (TBS) conditions. Manual errors and RTs increased with TBS, although search slopes did not significantly differ. Eye movement analyses revealed that the majority of fixations fell on discrete distractors rather than on the target-similar background, even under high TBS conditions. These data suggest a biased search process; salient patterns segmented from a background are preferred while more target-similar unsegmented regions of the background are relatively neglected.