Learned prioritization yields attentional biases through selection history

While numerous studies have provided evidence for selection history as a robust influence on attentional allocation, it is unclear precisely which behavioral factors can result in this form of attentional bias. In the current study, we focus on “learned prioritization” as an underlying mechanism of selection history and its effects on selective attention. We conducted two experiments, each starting with a training phase to ensure that participants learned different stimulus priorities. This was accomplished via a visual search task in which a specific color was consistently more relevant when presented together with another given color. In Experiment 1, one color was always prioritized over another color and inferior to a third color, such that each color had an equal overall priority by the end of the training session. In Experiment 2, the three different colors had unequal priorities at the end of the training session. A subsequent testing phase in which participants had to search for a shape-defined target showed that only stimuli with unequal overall priorities (Experiment 2) affected attentional selection, with increased reaction times when a distractor was presented in a previously high-priority compared with a low-priority color. These results demonstrate that adopting an attentional set where certain stimuli are prioritized over others can result in a lingering attentional bias and further suggest that selection history does not equally operate on all previously selected stimuli. Finally, we propose that findings in value-driven attention studies where high-value and low-value signaling stimuli differentially capture attention may be a result of learned prioritization rather than reward.