Local and global influence of contextual information: insight from auditory and visual speed perception

Abstract Accurate perception of speed is essential for adaptive behaviour in dynamic environments, but it is systematically distorted across sensory modalities, making it subject to contextual effects. This study examines the influence of these effects, specifically central tendency and serial dependence, on speed estimation in vision and audition. Participants were asked to rate the speed of visual and auditory stimuli, allowing for a direct comparison of the magnitude of distortion and temporal dynamics across modalities. The results revealed three key findings: (i) central tendency effects were present in both modalities but significantly more pronounced in audition, consistent with greater sensory uncertainty; (ii) serial dependence manifested as an attractive bias towards the previous trial (n−1) in both modalities; (iii) the two effects did not correlate with each other in either modality, indicating distinct processes. Furthermore, the effects of central tendency were positively correlated across modalities, indicating a potential supramodal trait, which is not the case for serial dependence. These results might suggest a dual-process model of contextual integration in speed perception: one governed by long-term statistical learning and another by short-term temporal smoothing. This cross-modal investigation advances our understanding of how the brain stabilizes perceptual estimates under conditions of uncertainty.