Broadband high frequency Activity initializes Distractor Suppression

Abstract

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 the first experiment we tested whether BHA distinguishes targets from distracting information in a visual search paradigm using tilted gratings as targets and distractors. In the second experiment, we examined whether BHA distractor processing can be trained by statistical learning. In both experiments, BHA preceded the low-frequency target enhancement (NT) and distractor suppression (PD; 1-40 Hz) components and distinguished between targets and distractors. Only the BHA but not low-frequency 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. Significance StatementSelective attention is the net result of successful target selection and distractor suppression, representing a key mechanism of humans everyday life. Here, we shed light on the neural mechanisms of distractor processing by showing that the early occipital broadband high-frequency activity (BHA) is linked to successful distractor suppression. Specifically, the BHA predicted individual performance and PD strength, a component associated with distractor suppression. We found the BHA and later the PD increased in amplitude during implicit statistical learning indicative of a trainable distractor suppression mechanism. We demonstrate that the BHA serves as an early marker for a successful initiation of distractor suppression.