The neurophysiological basis of short- and long-term ventriloquism aftereffects

Our senses often receive conflicting multisensory information, which our brain reconciles by adaptive recalibration. A classic example is the ventriloquist aftereffect, which emerges following both long-term and trial-wise exposure to spatially discrepant multisensory stimuli. Still, it remains debated whether the behavioral biases observed following short- and long-term exposure arise from largely the same or rather distinct neural origins, and hence reflect the same or distinct mechanisms. We address this question by probing EEG recordings for physiological processes predictive of the single-trial ventriloquism biases following the exposure to spatially offset audio-visual stimuli. Our results support the hypothesis that both short- and long-term aftereffects are mediated by common neurophysiological correlates, which likely arise from sensory and parietal regions involved in multisensory inference and memory, while prolonged exposure to consistent discrepancies additionally recruits prefrontal regions. These results posit a central role of parietal regions in mediating multisensory spatial recalibration and suggest that frontal regions contribute to increasing the behavioral bias when the perceived sensory discrepancy is consistent and persistent over time.