Tetanizing wakeful consolidation: ten-hertz repetitive visual stimulation enhances the offline gain of visual learning

Abstract

Consolidation of encoded information is vital for learning and memory, often explored during sleep. However, the consolidation during post-encoding offline wakefulness remains largely uncharted, especially regarding its modulation and brain mechanisms. Here, we unraveled frequency-dependent modulatory effects of repetitive visual stimulation (RVS) on wakeful consolidation of visual learning and investigated the underlying neural substrates. After training on an orientation discrimination task, exposure to 10-Hz grating-form RVS enhanced, while 1-Hz RVS deteriorated, the discrimination performance in a subsequent retest. However, 10-Hz uniform-disk RVS failed to facilitate wakeful consolidation, suggesting that alpha entrainment alone was not the facilitative mechanism. Using neuroimaging of multiple modalities, we observed augmented event-related potential and heightened neural excitation in the early visual cortex after 10-Hz grating-form RVS, implying an involvement of long-term potentiation-like (LTP-like) plasticity. Collectively, we provide a new photic method for modulating the offline processing of encoded sensory information and suggest a role of sensory tetanization in the modulation.