The visual mismatch negativity (vMMN), deriving from the brain's response to stimulus deviance, is thought to be generated by the cortex that represents the stimulus. The vMMN response to visual speech stimuli was used in a study of the lateralization of visual speech processing. Previous research suggested that the right posterior temporal cortex has specialization for processing simple non-speech face gestures, and the left posterior temporal cortex has specialization for processing visual speech gestures. Here, visual speech consonant-vowel (CV) stimuli with controlled perceptual dissimilarities were presented in an electroencephalography (EEG) vMMN paradigm. The vMMNs were obtained using the comparison of event-related potentials (ERPs) for separate CVs in their roles as deviant vs. their roles as standard. Four separate vMMN contrasts were tested, two with the perceptually far deviants (i.e., “zha” or “fa”) and two with the near deviants (i.e., “zha” or “ta”). Only far deviants evoked the vMMN response over the left posterior temporal cortex. All four deviants evoked vMMNs over the right posterior temporal cortex. The results are interpreted as evidence that the left posterior temporal cortex represents speech contrasts that are perceived as different consonants, and the right posterior temporal cortex represents face gestures that may not be perceived as different CVs.
Keywords: speech perception, visual perception, lipreading, scalp electrophysiology, mismatch negativity (MMN), hemispheric laterazation for speech
Citation: Files BT, Auer ET Jr and Bernstein LE (2013) The visual mismatch negativity elicited with visual speech stimuli. Front. Hum. Neurosci. 7:371. doi: 10.3389/fnhum.2013.00371
Received: 25 April 2013; Accepted: 26 June 2013;
Published online: 16 July 2013.
Edited by:István Czigler, Hungarian Academy of Sciences, Hungary
Reviewed by:Erich Schröger, University of Leipzig, Germany
Copyright © 2013 Files, Auer and Bernstein. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc.
*Correspondence: Lynne E. Bernstein, Communication Neuroscience Laboratory, Department of Speech and Hearing Science, George Washington University, 550 Rome Hall, Washington, DC 20052, USA e-mail: firstname.lastname@example.org