Dynamic competition between bottom-up saliency and top-down goals in early visual cortex

Task-irrelevant yet salient stimuli can elicit automatic, bottom-up attentional capture and compete with top-down, goal-directed processes for neural representation. However, the temporal dynamics underlying this competition, and how they influence early visual processing, remain poorly understood. Here, we combined electroencephalography (EEG) with Rapid Invisible Frequency Tagging (RIFT) to non-invasively and simultaneously track early visual cortex responses to target and distractor. Both target and distractor evoked stronger initial RIFT responses than nontargets, reflecting top-down and bottom-up attentional effects on early visual processing. Importantly, the presence of a distractor attenuated the initial RIFT response to the target, reflecting competition during the initial stages of visual processing and predicting subsequent behavioral performance. RIFT responses to the distractor eventually even decreased below responses to the target and nontarget, representing active suppression of task-irrelevant but salient stimuli. We show that the dynamic interplay between top-down control and bottom-up saliency directly impacts early visual responses, thereby illuminating a complete timeline of attentional competition in visual cortex.