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