Prestimulus neural variability affects behavioral performances mediated by poststimulus-evoked responses at the intraindividual and interindividual levels

There are significant intra-individual and inter-individual variabilities in audiovisual temporal perception. Previous studies have shown that prestimulus neural variability could reflect behavioral variabilities. We aimed to investigate whether prestimulus neural variability can predict behavioral variability in audiovisual temporal perception. Furthermore, We also explored whether prestimulus neural variability directly influences behavioral responses or indirectly impacts perceptual decisions through post-stimulus-evoked responses. We analyzed the electroencephalography (EEG) data from a paradigm where the twenty-eight human subjects performed a simultaneity judgment (SJ) task in the beep-flash stimulus. The prestimulus weighted permutation entropy (WPE) was the indicator of neural variability in this study. We found that prestimulus frontal WPE could predict the individuals TBW in auditory- and visual-leading conditions. In addition, increased prestimulus parietal WPE was associated with more asynchronous responses. Prestimulus frontal WPE may be associated with top-down cognitive control, while parietal WPE may be related to bottom-up cortical excitability. Furthermore, poststimulus evoked responses could mediate the relation between prestimulus WPE and the individuals TBW or perceptual responses. These results suggested that prestimulus WPE was a marker in reflecting intra-individual and inter-individual variabilities in audiovisual temporal perception. Significantly, prestimulus WPE might influence perceptual responses by affecting poststimulus sensory representations.