Abstract
We evaluated whether the meaning of objects and the search strategy adopted by observers influences search efficiency. In two experiments, observers were trained to associate verbal labels with simple shapes. By training observers it was possible to vary the semantic similarity between targets and distractors in the visual search displays while eliminating the influence of target-distractor visual similarity through counterbalancing. In one condition the target and distractor shapes were associated with the same verbal label and therefore observers searched for targets embedded among semantically similar distractors. In another condition the target and distractor shapes were associated with different verbal labels and therefore observers searched for targets embedded among semantically dissimilar distractors. In addition, search strategy was varied across experiments by instructing observers to adopt either an active or a passive search strategy. The efficiency of search was assessed in terms of the slopes of the search functions. The results showed that when observers searched passively, search was more efficient in the semantically dissimilar condition than in the semantically similar condition. In contrast, when observers searched actively, there was no difference in search efficiencies between the semantically similar and semantically dissimilar conditions. These findings indicate that the meaning of objects influences search efficiency and that this influence of meaning depends on the search strategy adopted by observers.