Winkler I, Paavilainen P, Näätänen R
Department of Psychology, University of Helsinki, Finland.
Psychophysiology. 1992 May;29(3):337-49. doi: 10.1111/j.1469-8986.1992.tb01707.x.
The mismatch negativity, a component of the event-related brain potential elicited by infrequent deviants in sequences of auditory stimuli, is presumably generated by an automatic mismatch process in a mechanism that compares the current stimulus to the trace of the previous one. The present study addressed the possible simultaneous existence of two such traces. Two equiprobable (45% each) frequent stimuli ("standards"), one of 600 Hz and the other of 700 Hz, were presented together with an infrequent (10%), "deviant" stimulus which was of different frequency in different blocks. These deviants elicited a mismatch negativity, though a smaller one than that obtained in corresponding blocks with only one standard stimulus. Two aspects of the present results from the blocks with two standard stimuli implicate two parallel stimulus traces in these blocks: 1) deviants elicited a mismatch negativity (MMN) of approximately the same amplitude when preceded by sequences of four identical standards as when preceded by sequences of four stimuli containing both standards; 2) in contrast to the one-standard condition, the magnitude of stimulus deviance did not affect the MMN component elicited by the different deviants.
失匹配负波是由听觉刺激序列中不常见的偏差引发的事件相关脑电位的一个成分，推测是由一种将当前刺激与前一个刺激痕迹进行比较的机制中的自动失匹配过程产生的。本研究探讨了两种这样的痕迹可能同时存在的情况。两个等概率（各45%）的频繁刺激（“标准刺激”），一个为600赫兹，另一个为700赫兹，与一个不常见的（10%）“偏差刺激”一起呈现，该偏差刺激在不同组块中具有不同频率。这些偏差刺激引发了失匹配负波，尽管其幅度比在相应组块中仅有一种标准刺激时获得的要小。来自具有两种标准刺激的组块的本研究结果的两个方面表明在这些组块中存在两条并行的刺激痕迹：1）当偏差刺激之前是四个相同标准刺激的序列时，与之前是包含两种标准刺激的四个刺激的序列时相比，引发的失匹配负波（MMN）幅度大致相同；2）与单标准条件相反，刺激偏差的大小并不影响不同偏差刺激引发的MMN成分。
