Rhythmic visual stimulation enhances visual search via occipito-parietal alpha modulation: an electroencephalographic study

Introduction: As a non-invasive neuromodulation technique, visual flicker entrainment has demonstrated considerable potential in enhancing basic visual perception; however, the neurophysiological mechanisms underlying these effects remain unclear. This study investigated whether rhythmic visual stimulation at individualized alpha frequencies can improve low-contrast visual search performance by selectively modulating alpha-band neural oscillations. Methods: Forty-three healthy male participants completed a low-contrast visual search task under two conditions: personalized rhythmic flicker and arrhythmic (random) flicker. Behavioral performance was evaluated using reaction time, accuracy, and perceptual sensitivity. Simultaneously, high-density electroencephalographic data were recorded. Neural activity was quantified using power spectral density analysis across delta, theta, and beta frequency bands. Neural oscillatory characteristics were compared across prefrontal, central, parietal, and temporal areas under different flicker conditions. Results: > 0.05). Conclusion: Individualized alpha-frequency visual flicker entrainment effectively enhances performance in male participants on complex visual search tasks, with the behavioral benefits mediated by selective modulation of neural oscillations in the parietal alpha band. These findings provide mechanistic electrophysiological evidence that rhythmic stimulation improves visual cognition by modulating frequency- and region-specific neural dynamics.