Visual Awareness Sharpens and Accelerates Attentional Sampling Through Enhancing Inhibitory Neural Modulation in the Attention Network

Attentional sampling, driven by neural oscillations in the fronto-parietal attention network, sequentially focuses on stimuli in a rhythmic pattern, enhancing the efficiency of attentional selection. While this function is considered inherent and default, the role of conscious awareness in this process remains largely unexplored. In this study, we employed the Chromatic Flicker Fusion (CFF) method to render attentional cues invisible and investigated how visual awareness modulates attentional sampling. Using a high-temporal-resolution behavioral paradigm and EEG in conjunction with the time response function method, we found that both visible and invisible cues induced behavioral rhythmic attentional sampling and reset neural connectivity between the frontal and right occipito-parietal regions, indicating that attention samples rhythmically regardless of cue awareness. Intriguingly, visible cues not only elicited additional inhibition effects in behavioral performance and enhanced inhibitory alpha activity in the neural response function, but also triggered faster attentional sampling (~8 Hz vs. ~4 Hz) and higher frequency top-down connectivity between the prefrontal and right occipito-parietal regions (alpha vs. theta band). These findings provide the first evidence that the conscious representation of attentional cues influences inhibitory neural response in the fronto-parietal attention network and modulates the attentional sampling process. The emergence of consciousness enables humans to more effectively sample information and navigate the ever-changing external world.