Dissociable rhythmic mechanisms enhance memory forconscious and nonconscious perceptual contents

Abstract

Understanding the neural mechanisms of conscious and unconscious experience is amajor goal of fundamental and translational neuroscience. Here, we target the earlyvisual cortex with a protocol of noninvasive, high-resolution alternating current stimu-lation while participants performed a delayed target–probe discrimination task andreveal dissociable mechanisms of mnemonic processing for conscious and unconsciousperceptual contents. Entrainingβ-rhythms in bilateral visual areas preferentiallyenhanced short-term memory for seen information, whereasα-entrainment in the sameregion preferentially enhanced short-term memory for unseen information. The short-term memory improvements were frequency-specific and long-lasting. The results add amechanistic foundation to existing theories of consciousness, call for revisions to thesetheories, and contribute to the development of nonpharmacological therapeutics forimproving visual cortical processing.