Effect of anticipatory multisensory integration on sensory-motor performance.

Multisensory integration (MSI) is a phenomenon that occurs in sensory areas after the presentation of multimodal stimuli. Nowadays, little is known about the anticipatory top-down processes taking place in the preparation stage of processing before the stimulus onset. Considering that the top-down modulation of modality-specific inputs might affect the MSI process, this study attempts to understand whether the direct modulation of the MSI process, beyond the well-known sensory effects, may lead to additional changes in multisensory processing also in non-sensory areas (i.e., those related to task preparation and anticipation). To this aim, event-related potentials (ERPs) were analyzed both before and after auditory and visual unisensory and multisensory stimuli during a discriminative response task (Go/No-go type). Results showed that MSI did not affect motor preparation in premotor areas, while cognitive preparation in the prefrontal cortex was increased and correlated with response accuracy. Early post-stimulus ERP activities were also affected by MSI and correlated with response time. Collectively, the present results point to the plasticity accommodating nature of the MSI processes, which are not limited to perception and extend to anticipatory cognitive preparation for task execution. Further, the enhanced cognitive control emerging during MSI is discussed in the context of Bayesian accounts of augmented predictive processing related to increased perceptual uncertainty.