Predicted Sensory Modality Determines the Timing and Topographies of Omitted Stimulus Potentials

It is thought that our brains actively predict what will happen next in the environment, but it remains unclear how specific the prediction of an upcoming event is. This study investigated whether the prediction about the sensory modality of the upcoming stimulus modulates neural responses to unexpected omissions of stimuli. Previous research has reported that the peak latencies of omitted stimulus potentials (OSPs) are shorter in the auditory modality than in the visual modality when tested in separate blocks. In this study, we presented auditory and visual stimuli in a fixed alternating pattern to examine whether modality-specific OSPs occur even within a single block. Participants (N = 33) were asked to press a mouse button at a constant interval of 1 s. Each button press triggered either an auditory or visual stimulus, and these were presented twice in an alternating pattern (A, A, V, V, A, A, etc.). The stimuli were omitted in 12% of the trials. This method ensured each type of omission (of either auditory or visual stimuli) to be preceded equally often by either an auditory or a visual stimulus, thereby controlling for late event-related potential components of the preceding stimulus, if any. The results showed that auditory OSPs had shorter peak latencies than visual OSPs and that their scalp topographies differed; auditory OSPs had more anterior and central distributions than visual OSPs. These findings suggest that OSPs occur in a modality-specific manner according to the predicted sensory modality of the upcoming stimulus.