MMN or no MMN: No magnitude of deviance effect on the MMN amplitude

Authors


  • We thank Gabriella Pálfy for assistance in data collection and Walter Ritter for valuable comments on the manuscript. The study was supported by the Hungarian National Science Research Fund (OTKA T048383), the Hungarian–German researcher exchange program (MÖB-DAAD 2006-2007, project 12), and the European Commission under the Marie Curie Intra-European Fellowship Program (MEIF-CT-2006-023924).

Address reprint requests to: János Horváth, Institute of Psychology I, University of Leipzig, Seeburgstr. 14-20, D-04103 Leipzig, Germany.
E-mail: horvath@cogpsyphy.hu

Abstract

Based on results showing that the “deviant-minus-standard” estimate of the mismatch negativity (MMN) amplitude increases with increasing amounts of deviance, it has been suggested that the MMN amplitude reflects the amount of difference between the neural representations of the standard and the deviant sound. However, the deviant-minus-standard waveform also includes an N1 difference. We tested the effects of the magnitude of deviance on MMN while minimizing this N1 confound. We found no significant magnitude of deviance effect on the genuine MMN amplitude. Thus we suggest that the average MMN amplitude does not reflect the difference between neural stimulus representations; rather it may index the percentage of detected deviants, each of which elicits an MMN response of uniform amplitude. These results are compatible with an explanation suggesting that MMN is involved in maintaining a neural representation of the auditory environment.

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