A large-scale investigation of the resting-state alpha-band activity in relation to inter-individual differences in visual perception

A growing body of evidence indicates that spontaneous, moment-to-moment fluctuations of the EEG alpha activity (7-15 Hz) affect perception, with a lower amplitude of alpha oscillations right before the stimulus onset facilitating its detection and visibility. The present study aimed to determine whether alpha-band activity predicts perception also at the inter-individual level, namely whether participants with overall weaker resting-state alpha activity perform better in stimuli detection and identification tasks. To this end, we used data collected from 302 participants who took part in two EEG sessions and, on separate days performed a battery of visual and auditory 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 and particularly amplitude of periodic alpha oscillations 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 correlates with perceptual abilities. Our work thus indicates that resting-state alpha activity is related to the TMS-estimated visual system excitability, but we did not find evidence for a relation between alpha-band and perception of visual threshold stimuli. Therefore, while a robust relation between alpha power and perception is present at the intra-individual level, our study suggests that it does not extend to the inter-individual level.