Sculthorpe Lauren D, Ouellet Daniel R, Campbell Kenneth B
School of Psychology, University of Ottawa, Ontario, Canada K1N 6N5.
Brain Res. 2009 Sep 22;1290:52-62. doi: 10.1016/j.brainres.2009.06.013. Epub 2009 Jun 13.
The mismatch negativity (MMN) ERP component is generally considered to reflect the outcome of a pre-conscious change detection mechanism. The manipulation of active task demands has typically demonstrated that the MMN operates relatively independently of inferred attention. It remains a possibility, however, that subjects are capable of covertly sampling, or "eavesdropping" on, the irrelevant auditory stimuli, even during the most demanding of diversion tasks. The presence of the MMN in an unconscious state, such as natural sleep, provides strong evidence that its operations take place at a pre-conscious level. There exists consistent evidence that the MMN can be elicited at least during REM sleep, but these MMNs were typically elicited using oddball paradigms in which the new physical properties of deviants may trigger fresh afferent activation. The current sleep study employed a standard pattern in which two pure tones alternated (e.g. ABABABAB). Deviants were repetitions (e.g., ABABBBAB), and therefore physically identical to the preceding standard. In different conditions, the tones of the pattern were separated by either 1 or 6 semitones. A clear MMN was elicited in the waking state in the 6 semitone condition. The MMN was also elicited in the 6 semitone condition during REM sleep. No MMN was apparent in REM sleep in the 1 semitone condition. The MMN was not apparent in either the 6 or 1 semitone condition during NREM sleep. These results confirm the operation of the MMN in REM sleep, and support the view that the MMN operates at a pre-conscious level of processing.
失匹配负波（MMN）这一事件相关电位成分通常被认为反映了一种前意识变化检测机制的结果。对主动任务需求的操控通常表明，MMN的运作相对独立于推断出的注意力。然而，仍有可能的是，即使在要求最高的分心任务期间，受试者也能够秘密地对无关听觉刺激进行采样或“窃听”。MMN在诸如自然睡眠等无意识状态下的存在，有力地证明了其运作发生在前意识水平。有一致的证据表明，至少在快速眼动睡眠期间可以诱发MMN，但这些MMN通常是使用异常刺激范式诱发的，在该范式中，偏差刺激的新物理特性可能会触发新的传入激活。当前的睡眠研究采用了一种标准模式，即两个纯音交替出现（例如ABABABAB）。偏差刺激是重复出现的（例如，ABABBBAB），因此在物理上与之前的标准刺激相同。在不同条件下，模式中的音调相隔1个或6个半音。在清醒状态下，6个半音条件下诱发了明显的MMN。在快速眼动睡眠期间，6个半音条件下也诱发了MMN。在快速眼动睡眠的1个半音条件下未出现明显的MMN。在非快速眼动睡眠期间，6个半音或1个半音条件下均未出现明显的MMN。这些结果证实了MMN在快速眼动睡眠中的运作，并支持了MMN在前意识加工水平上运作的观点。
