Näätänen R, Paavilainen P, Tiitinen H, Jiang D, Alho K
Department of Psychology, University of Helsinki, Finland.
Psychophysiology. 1993 Sep;30(5):436-50. doi: 10.1111/j.1469-8986.1993.tb02067.x.
The mismatch negativity (MMN) component of the auditory event-related potential (ERP) is elicited by infrequent, physically deviant stimuli in a sequence of frequent homogeneous stimuli (standards). It has been suggested that the MMN is generated by an automatic (attention-independent) neural mismatch process with a memory trace that encodes the physical features of the standard stimulus. The proposed MMN independence of attention was addressed in the present study. Standard stimuli and two types of deviant stimuli, differing from standards either in frequency or intensity, were dichotically presented in random order and at a rapid rate. The subject attended either to left- or right-ear stimuli, counting the number of a designated type of deviants in that ear. In the present conditions of very strongly focused attention, the MMN was elicited even by frequency change in the ignored input stream, and its amplitude was very similar to that of the MMN elicited by equivalent deviant stimuli (targets) in the attended input stream. In contrast, the MMN to intensity deviation was clearly attenuated in the absence of attention. This effect is, however, probably due to the attention effect on the MMN generator itself rather than the antecedent sensory-analysis and -storing functions.
听觉事件相关电位（ERP）的失匹配负波（MMN）成分，由频繁出现的同质刺激（标准刺激）序列中偶尔出现的、物理特征异常的刺激所诱发。有人提出，MMN是由一个自动的（与注意力无关的）神经失匹配过程产生的，该过程带有一个对标准刺激的物理特征进行编码的记忆痕迹。本研究探讨了所提出的MMN与注意力的独立性。标准刺激以及两种与标准刺激在频率或强度上不同的异常刺激，以随机顺序和快速速率进行双耳分听呈现。受试者只关注左耳或右耳的刺激，统计该耳中指定类型异常刺激的数量。在当前这种注意力高度集中的情况下，即使被忽视的输入流中的频率发生变化，也会诱发MMN，并且其波幅与在被关注的输入流中由等效异常刺激（目标）诱发的MMN波幅非常相似。相比之下，在没有注意力的情况下，对强度偏差的MMN明显减弱。然而，这种效应可能是由于注意力对MMN产生器本身的影响，而不是对先前的感觉分析和存储功能的影响。
