The association of targets modulates the search efficiency in multitarget searches.

Previous studies have found that distractors can affect visual search efficiency when associated with the target in a single-target search. However, multitarget searches are frequently necessary in daily life. In the present study, we examined how the association of targets in a multitarget search affected performance when searching for two targets simultaneously (Experiment 1). In addition, we explored whether the association affected switch cost (Experiment 2) and preparation cost (Experiment 3). Participants were required to learn associations between different colors or shapes and then performed feature search and conjunction search tasks. For all experiments, the results of search efficiency showed that for conjunction search, the search efficiency under the associated condition was significantly higher than that under the neutral condition. Similarly, the response times in the associated condition were significantly faster than those in the neutral condition under the conjunction search condition in Experiments 1 and 2. However, in Experiment 3, the response times in the associated condition were longer than those in the neutral condition. These results indicate that the association between targets can improve the efficiency of multitarget searches. Furthermore, associations can reduce the time spent searching for individual targets and the switch cost; however, the preparation cost increases.