Horváth János, Czigler István, Jacobsen Thomas, Maess Burkhard, Schröger Erich, Winkler István
Institute of Psychology I, University of Leipzig, Leipzig, Germany.
Psychophysiology. 2008 Jan;45(1):60-9. doi: 10.1111/j.1469-8986.2007.00599.x. Epub 2007 Sep 14.
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.
基于研究结果显示失匹配负波（MMN）波幅的“偏差减标准”估计值会随着偏差量的增加而增大，有人提出MMN波幅反映了标准声音和偏差声音的神经表征之间的差异量。然而，偏差减标准波形还包括一个N1差异。我们在尽量减少这种N1混淆因素的同时，测试了偏差量对MMN的影响。我们发现，偏差量对真正的MMN波幅没有显著影响。因此我们认为，平均MMN波幅并不反映神经刺激表征之间的差异；相反，它可能指示了被检测到的偏差声音的百分比，每个偏差声音都会引发幅度一致的MMN反应。这些结果与一种解释相符，该解释认为MMN参与维持听觉环境的神经表征。
