Visual search selectively enhances recognition of the search target

In Experiment 1, subjects performed a probe recognition task embedded withi n a task in which they searched for a single target letter (either a T or a n L) in a field of distractor letters (Ls or Ts, respectively). Pairs of ta rgets were more often correctly recognized as identical than were pairs of distractors. Also, pairs of items consisting of a distractor and a hybrid c omposed of a T and an L were correctly recognized as different more often t han were pairs of items consisting of a target and a hybrid. This result wo uld be expected if subjects were more likely to interpret a hybrid as the t arget. In Experiment 2, subjects performed the same search task used previo usly, but now the probe task involved recognition of either a single target , a single distractor, or a single hybrid. A probe L was recognized better when it served as the target than when it served as the distractor in the c oncurrent search task. The hybrid was more likely to be incorrectly identif ied as the letter that served as the target. These results are consistent w ith models which assume that search instructions activate in a top-down man ner the central representation of the search target, even in the absence of target stimuli. This interpretation is supported by the finding that neuro ns that code objects in higher-order cortical visual areas show enhanced ac tivity when monkeys are preparing to search for the object that they code, even when it is not present.