Top-down motivation both decreases and increases feature interference following a saccade

Spatial attention is rarely static, but instead highly dynamic in real-life. Recent studies have revealed that shifts of attention and eye movements incur consequences for ongoing feature perception, such as systematic feature-binding (swapping and mixing) errors. Here we investigated if these consequences are sensitive to top-down control, such that they could be flexibly mitigated when participants are motivated to improve their performance, or if feature interference reflects a more automatic byproduct of attentional remapping mechanisms following a saccade. In a preregistered experiment, 40 healthy adults reported the color of an item appearing at a pre-cued spatiotopic location. Following the cue, participants made a saccade, and then an array of colored items briefly appeared at the spatiotopic target location, retinotopic nontarget location, and two control nontarget locations. Crucially, across blocks we provided two different levels of performance-contingent reward (monetary incentives for precise spatiotopic target reports) to induce differences in top-down motivation. Compared to baseline lower-reward blocks, during higher performance-contingent reward ("bonus") blocks, participants showed improved general performance and reduced subtle retinotopic mixing errors immediately after the saccade. However, we found the opposite effect on retinotopic swapping errors, with higher reward/motivation associated with increased retinotopic swapping errors early after the saccade, indicating that retinotopic swapping errors may reflect a structural limitation of the attentional remapping process. Overall, these results uncover effects of motivation on distinct attentional mechanisms underlying spatial remapping across saccades, and provide novel insights into the role of top-down control in dynamic spatial attention and visual perception more generally.