Abstract
When performing categorical visual search (e.g., find the bird), we must generate a search template based on our memory representation of that specific category. However, it is unclear the flexibility of category representations, particularly how encountered exemplars modify attentional deployment in category search. In Experiment 1, we examined how categorical representations are shaped by encountered exemplars from long-term memory. Participants first completed an exposure phase, where trials consisted of two real-world objects presented side by side. They were instructed to pay attention to one only side of the screen and to label those objects as natural or artificial. Then, in the search phase, object category labels were presented, and participants had to search for those objects in arrays and make a present/absent responses. Results showed that attended exemplars were faster to search for than ignored exemplars, suggesting that category exemplars learned in the exposure phase shaped the category attentional template used in later search. In Experiment 2, we then tested whether these categorical representations can also be altered by more recently encountered exemplars. Here we cued participants to either attend or suppress one of the two encoded objects belonging to the same category (single cue), or attend one while suppressing the other at the same time (double cue). Immediately after encoding, participants had to search for that category within an array and make a present/absent response. We found that search for suppressed exemplars was slower than attended exemplars, but only when presented with double cues. This suggests that a biased competition mechanism is required during exemplar encoding for successful suppression of category members when deploying search. Overall, our findings suggest that category representations are quite flexible, and can be modified with either immediate or long-term experience.