Ziyao Zhang¹ (), Jarrod Lewis-Peacock¹; ¹The University of Texas at Austin

In visually complex and dynamically changing environments, humans must often filter out salient but task-irrelevant stimuli. Prior work shows that with repeated exposure to search arrays containing color singleton distractors, individuals can learn to divert attention away from these salient items even before they capture attention. However, the neural mechanisms supporting such attentional suppression remain unclear. The present study examined the temporal trajectories of singleton distractor representations during visual search to address this gap. Using multivariate pattern analyses of EEG data (N = 40), we identified two clusters of decodable singleton distractor representations: an early cluster from 100-200 ms and a later cluster from 200-400 ms. Temporal generalization analyses showed that the later representations were transformed versions of early ones. Training classifiers on early activity yielded negative decoding evidence when tested on later activity, indicating an inversion of representational format. Importantly, stronger late, but not early representations, predicted faster search responses, suggesting that the later signals support distractor suppression rather than attentional capture. We hypothesized that this transformation facilitates suppressing singleton distractors in the spatial priority map. To test this, we trained decoders on singleton-absent trials, where target locations are enhanced, and applied these decoders to singleton-present trials. Comparing decoding evidence across locations revealed that target locations were consistently enhanced relative to non-singleton distractors, whereas singleton distractor locations were suppressed. Moreover, comparing the neural coding of locations revealed that the spatial organization in the singleton distractor neural space was inverted relative to that in the target neural space. Together, these findings reveal a rapid representational transformation underlying salient distractor suppression at the onset of visual search. This rapid inversion of singleton distractor signals was likely driven by top-down control mechanisms that transform bottom-up saliency signals, producing an inverted arrangement of target and distractor information within a shared parietal-occipital neural space.