Anticipating Multisensory Environments: Revealing Interactions in Predictions Across Sensory Modalities Unveils the Supra-modal Nature of the Predictive System

Our experience is generally framed in multisensory environments abundant in predictive information. Accordingly, previous research on statistical learning has shown that humans can learn regularities in different sensory modalities in parallel, but left open the question of whether participants also anticipated multisensory inputs. Across two experiments, we tested whether participants capitalized on prior expectations to facilitate perceptual processing of concurrent but independent multisensory stimuli. Participants were exposed to concurrent pairs of auditory and visual low-level stimuli (i.e., gratings and tones). In each experimental block, participants had to attend to one modality and discriminate whether the second stimulus of the attended pairs (targets) were deviant or standard, while ignoring stimuli from the other sensory modality (distractors). Orthogonal to the task goal, both the attended and unattended pairs followed transitional probabilities, so targets and distractors could be expected or unexpected. Participants performed better for expected compared to unexpected targets. This effect generalized to the distractors but only when targets were expected. Such interactive effects suggest that predictions may be gated by a supra-modal system with shared resources across sensory modalities that are distributed according to their respective behavioral relevance.