Mismatch negativity (MMN) for sequences of auditory and visual stimuli: evidence for a mechanism specific to the auditory modality.

ERPs to sequences of standard and deviant sinusoidal 100 msec tone pips, high-contrast sinusoidal gratings and to their simultaneously presented combinations were recorded. Mismatch negativity (MMN), an ERP component elicited by deviant stimuli, was estimated for the different stimulus sequences in order to find out whether it reflects modality-specific processes or non-specific attentive phenomena. In addition to the auditory modality, we studied whether the mismatch response could be evoked by a deviant visual stimulus in a visual sequence or by a deviant stimulus in either modality. The results show that only auditory stimuli produced the mismatch response, suggesting that MMN is not a manifestation of a general attentional mechanism but is probably specific to the auditory modality.