A Large-scale Investigation of the Resting-state Alpha-band Activity in Relation to Interindividual Differences in Visual Perception

A growing body of evidence indicates that spontaneous, moment-to-moment fluctuations of the EEG alpha power (7-15 Hz) affect perception, with a lower amplitude of alpha oscillations right before the stimulus onset facilitating its detection and visibility. However, whether a similar relationship exists also at the interindividual level has not yet been established. Therefore, the present study aimed to determine whether resting-state alpha power constitutes a robust trait-like predictor of differences in cortical excitability and perceptual abilities. To this end, we used data collected from 302 participants who took part in an EEG recording session and, on separate days, performed a battery of visual tasks and had phosphene and motor thresholds estimated with TMS (here n = 45). Resting-state EEG signals were characterized in terms of both oscillatory (periodic) and background (aperiodic) components. We found that higher overall alpha power predicted higher phosphene thresholds (but not motor thresholds). However, across several behavioral paradigms-using different types of tasks and stimuli, and analyzing both objective accuracy and subjective visibility-we did not find evidence that alpha activity correlated with perceptual abilities. Therefore, although alpha power robustly predicts perception of visual threshold stimuli at the intra-individual level, our study suggests that the relation between alpha power and perception does not extend to the interindividual level.