Neural effects of expectation violation generalize across sensory modalities

The brain receives more sensory information than it can usefully employ to control behaviour. This sensory overload can be reduced by exploiting regularities in the environment to predict future events. Previous work on the role of prediction in perception has focused on stimulus events within a single sensory modality. Here we asked whether expectation violations in one sensory modality (audition) can affect neural representations of stimuli in a separate modality (vision). Human observers viewed rapid sequences of randomly-oriented visual gratings together with a task-irrelevant stream of alternating high- and low-pitched tones. We verified a robust neural mismatch response to unexpected sounds, consistent with previous studies. Critically, using machine learning to extract neural orientation tuning to gratings, we observed stronger tuning following unexpected sounds suggesting that unimodal mismatches trigger cross-modal updating. The findings suggest that predictive coding theories of perception should incorporate cross-modal influences on internal models of the sensory environment.