Csépe V, Pantev C, Hoke M, Hampson S, Ross B
Institute of Experimental Audiology, University of Münster, Germany.
Electroencephalogr Clin Neurophysiol. 1992 Nov-Dec;84(6):538-48. doi: 10.1016/0168-5597(92)90043-b.
The neuromagnetic source localizations of the auditory M100 and the mismatch field (MMF) were studied using a large-array biomagnetometer. Standard tones of 1000 Hz and deviant tones of 1050 Hz were delivered with 90% and 10% probability, respectively. Wave forms of the derived MMF were computed by examining difference wave forms between the responses to the deviants and the responses to the standards preceding (D-P) and following (D-F) the deviants as well as to all remaining standards (D-A). The subset of standards preceding the deviants was used for a more realistic comparison with the set of deviants (having the same number of epochs and a similar signal-to-noise ratio), while the subset of standards following the deviants served to answer the question whether those standards also elicit an MMF. The MMF deflections were compared with each other, with the "native" MMF occurring in response to the deviants, and with wave M100. (The MMF as it appears in the unprocessed response to the deviants was termed "native" for an easy distinction from the "derived" MMF.) Our results demonstrate a distinct MMF deflection, corresponding in latency to the simultaneously recorded fronto-central electrical MMN. Source analysis, using a single moving dipole model, showed the same spatial localization for the native MMF and for the different derived MMFs. The MMF source location turned out to be significantly anterior, medial and inferior relative to the sources of the M100. The present data also demonstrate that a minor frequency deviation may not activate measurably different M100 generators, yet be sufficient to trigger the nearby but spatially distinct mismatch generator.
使用大型生物磁强计研究了听觉M100和失配场（MMF）的神经磁源定位。分别以90%和10%的概率呈现1000Hz的标准音和1050Hz的偏离音。通过检查对偏离音的反应与偏离音之前（D-P）和之后（D-F）以及所有其余标准音（D-A）的反应之间的差异波形，计算出导出的MMF的波形。偏离音之前的标准音子集用于与偏离音集进行更实际的比较（具有相同数量的epochs和相似的信噪比），而偏离音之后的标准音子集用于回答这些标准音是否也会引发MMF的问题。将MMF偏转相互比较，与对偏离音产生的“原始”MMF进行比较，并与M100波进行比较。（为了便于与“导出”的MMF区分，将对偏离音的未处理反应中出现的MMF称为“原始”MMF。）我们的结果表明存在明显的MMF偏转，其潜伏期与同时记录的额中央电MMN相对应。使用单移动偶极子模型的源分析表明，原始MMF和不同导出MMF的空间定位相同。结果表明，MMF源位置相对于M100源明显更靠前、更内侧和更低。目前的数据还表明，较小的频率偏差可能不会激活可测量的不同M100发生器，但足以触发附近但空间上不同的失配发生器。
