Broadband high-frequency activity initializes distractor suppression.

Selective attention requires fast and accurate distractor suppression. We investigated if broadband high-frequency activity (BHA; 80-150 Hz), indicative of local neuronal population dynamics in early sensory cortices, indexes rapid processing of distracting information. In a first experiment we tested whether BHA distinguishes targets from distracting information in a visual search paradigm using tilted gratings as targets and distractors. In a second experiment, we examined whether BHA distractor processing can be trained by statistical regularities. In both experiments, BHA preceded the target enhancement (NT) and distractor suppression (PD; 1-40 Hz) event-related field (ERF) components and distinguished between targets and distractors. Only the BHA but not ERF component amplitude correlated with participants' performance and was higher for lateral distractors versus lateral targets. Furthermore, BHA predicted the strength of the PD. These results indicate that BHA initiates stimulus discrimination via distractor suppression.