Alpha frequency shapes perceptual sensitivity by modulating optimal phase likelihood.

Abstract

Whether alpha frequency oscillations orchestrate the pace of sensory sampling is current matter of debate. Using EEG, we test this hypothesis by investigating whether pre-stimulus instantaneous alpha frequency accounts for perceptual sensitivity. Our results support the role of alpha frequency in shaping the accuracy of sensory acquisition. Spontaneous alpha frequency inter-trial fluctuations emerged as a predictor of perceptual decision-making sensitivity and accuracy, with higher pace accounting for higher sensory precision - an observation supported across complementary analytical approaches, including Bayesian statistics and computational modelling. Here, we provide insights into the neural candidate mechanisms through which alpha frequency relates to perceptual decisions. Specifically, alpha frequency would determine the extent of phase angles covered within the stimulus timeframe. As a result, higher alpha frequencies may provide more opportunities for the stimulus to coincide with optimal phases for perception, thereby increasing the likelihood of accurate sensory processing.