Vigilant attention mediates the association between resting EEG alpha oscillations and word learning ability

•The study is the first to reveal significant positive correlations between resting EEG alpha oscillations and novel word learning ability.•The study is the first to discover the mediating role of vigilant attention in linking EEG alpha oscillations to an individual's learning ability, which advances the understanding of the underlying mechanism between spontaneous alpha-band activities and multiple learning abilities.•The above findings were validated across two independent experiments with a total of 140 participants, which has not only enriched the representational meaning of alpha rhythm, but also provided potential neurocognitive markers for the early detection of the individuals with word learning difficulties. Individuals exhibit considerable variability in their capacity to learn and retain new information, including novel vocabulary. Prior research has established the importance of vigilance and electroencephalogram (EEG) alpha rhythm in the learning process. However, the interplay between vigilant attention, EEG alpha oscillations, and an individual's word learning ability (WLA) remains elusive. To address this knowledge gap, here we conducted two experiments with a total of 140 young and middle-aged adults who underwent resting EEG recordings prior to completing a paired-associate word learning task and a psychomotor vigilance test (PVT). The results of both experiments consistently revealed significant positive correlations between WLA and resting EEG alpha oscillations in the occipital and frontal regions. Furthermore, the association between resting EEG alpha oscillations and WLA was mediated by vigilant attention, as measured by the PVT. These findings provide compelling evidence supporting the crucial role of vigilant attention in linking EEG alpha oscillations to an individual's learning ability.