Biological Motion as a Multisensory Signal: Predictive Integration of Space and Time

Everyday perception depends on the brain’s ability to integrate signals across the senses, yet how spatial and temporal alignment jointly shape multisensory perception remains unclear. Here, we investigated how audiovisual congruency influences the perception of biological motion, an ecologically and socially meaningful class of movement. Across two experiments, participants judged synchrony in point-light displays while auditory and visual cues varied in temporal and spatial alignment. Temporal congruency enhanced synchrony judgments, replicating prior work, but critically, spatial congruency also improved perceptual integration. This spatial advantage was strongest for biological motion, suggesting specialized sensitivity to socially relevant kinematics. These results extend predictive-processing accounts by showing that the brain’s expectations about both when and where sensory events co-occur guide perception of biological motion. Together, our findings highlight spatial congruency as an overlooked yet essential dimension of multisensory integration, revealing how predictive mechanisms link space and time in social perception.