Spontaneous eye blinks as temporal markers of internal attention

Abstract

While eye blinks interrupt the flow of visual information, their timing may reveal the temporal organisation of cognitive processing. Here, we asked whether the temporal distribution of blinks across trials provides a time-resolved signature of attentional focusing in working memory. In Experiment 1, blink-locked EEG analyses showed that blink timing was aligned with neural activity reflecting attentional focusing on a relevant memory representation. In Experiment 2, participants remembered the same visual information across conditions, but the relevant item was cued either early during storage, or later with presentation of the memory probe. Blink-frequency profiles shifted accordingly, increasing after the cue when selection was possible early and after the probe when selection was delayed. Post-cue blinks in the early-selection condition were also associated with better memory performance. Thus, our findings establish eye-blink frequency profiles as an unobtrusive chronometric signal for tracking latent cognitive processing in settings where neuroimaging is not feasible.