Abstract
Much of the recent evidence suggests that reward modulates bottom-up as well as top-down attentional selection. Interestingly, this modulation persists within the same type of task even when reward contingency is no longer relevant. It remains unclear whether the effect of learned reward contingency is transferred across different modes of attention. Successful transfer would provide evidence for an integrated reward-based priority map used for both top-down and bottom-up attentional guidance. Here, we investigate whether reward-based contingency learned within a context of a bottom-up search task is transferred to a subsequent top-down search task. To elucidate how a reward-based priority map is constructed, we also examine whether the reward-based transfer influences search efficiency by enhancing target salience, or changing distractor filtering, or both. Results showed that a biased reward schedule modulated search efficiency in a pop-out search task, and that this modulation effect was transferred to a conjunction search task with an unbiased reward schedule. Compared to baseline, search for a target containing a feature previously associated with higher reward became more efficient. Additionally, a direct relationship was observed between the magnitude of reward effects in the pop-out and conjunction search tasks, giving further evidence for reward-based transfer across different types of attentional control. We also show that reward history influences search efficiency by both enhancing target salience and changing distractor filtering. Interestingly, previously rewarded distractors either enhance or interfere with search efficiency depending on what critical feature they share with the target (color or orientation). A direct relationship was observed between the magnitudes of reward-based target enhancement and distractor interference, indicating that a reward-based priority map is influenced by values associated with both target as well as distractors. These results strongly suggest that an integrated priority map, based on reward information, guides both top-down and bottom-up attention.
Meeting abstract presented at VSS 2013