An effect of attention on mismatch negativity in audiovisual visual modalities.

Abstract

It remains unclear whether there is an analogous automatic deviant-related negativity elicited outside the auditory modality even though the MMN can be elicited in auditory modality. The present study employed simultaneous audio-visual stimulus in the oddball paradigm to re-examine the effects of attention on visual mismatch negativity in audiovisual perception. The electrical brain activities were recorded from normal, from normal participants subjects. Stimuli consisted of a set of four audio-visual stimuli that are distinguished by frequencies (Hz) for audio and features for visual appearing on the computer screen. ANOVA showed statistically significant of the interaction between electrode site and modality. The difference waves with 100-200 msec latency at the anterior sites were markedly different to the posterior sites. The emergence of posterior negativity in the audio-visual modality might not be attributed to visual discrimination process as it did not appear in the visual modality.