Cote Kimberly A
Psychology Department, Sleep Research Laboratory, Brock University, Ont, St Catharines, Canada L2S 3A1.
Int J Psychophysiol. 2002 Dec;46(3):227-41. doi: 10.1016/s0167-8760(02)00114-9.
During the waking state, a late component of the auditory event-related potential, P300, is elicited when subjects detect a rare 'target' stimulus. It is usually not elicited when subjects either ignore or fail to detect the stimulus. The presence of P300 is therefore thought to reflect conscious processing of the stimulus. Since P300 has been shown to be an attention-dependent cognitive component in wakefulness, one might suppose that it would be absent during sleep-a time in which information processing of external stimuli is commonly thought to be inhibited. This review examines the presence or absence of P300 in studies employing auditory odd-ball paradigms in sleep. Research to date indicates that P300 can be recorded during the transition to sleep and then reappears in REM sleep. Stimuli that are rare and intrusive are more likely to elicit the classic parietal P300 in REM sleep. There is, however, little or no positivity at frontal sites. This is consistent with brain imaging studies that show frontal deactivation is characteristic of REM sleep. These findings indicate that while sleepers may be able to detect stimulus deviance in stage 1 and REM, the frontal contribution to consciousness may be lost. In non-REM sleep, a later positive wave at 450 ms does not vary according to experimental manipulation in the same way as the waking and REM P300s. This non-REM sleep-related positivity may therefore underlie mechanism distinct from the waking P300.
在清醒状态下，当受试者检测到罕见的“目标”刺激时，会诱发听觉事件相关电位的晚期成分P300。当受试者忽略或未能检测到刺激时，通常不会诱发该电位。因此，P300的出现被认为反映了对刺激的有意识加工。由于P300已被证明是清醒状态下一种依赖于注意力的认知成分，人们可能会认为在睡眠期间它会消失，因为通常认为睡眠期间对外界刺激的信息加工受到抑制。这篇综述考察了在睡眠中采用听觉奇偶数范式的研究中P300的有无情况。迄今为止的研究表明，在睡眠过渡期间可以记录到P300，然后它会在快速眼动睡眠中再次出现。罕见且具有干扰性的刺激在快速眼动睡眠中更有可能诱发经典的顶叶P300。然而，额叶部位几乎没有或没有正波。这与脑成像研究结果一致，脑成像研究表明额叶失活是快速眼动睡眠的特征。这些发现表明，虽然睡眠者在第一阶段和快速眼动睡眠中可能能够检测到刺激偏差，但额叶对意识的贡献可能丧失了。在非快速眼动睡眠中，450毫秒时出现的较晚正波不会像清醒和快速眼动睡眠中的P300那样根据实验操作而变化。因此，这种与非快速眼动睡眠相关的正波可能是与清醒状态下的P300不同的机制的基础。
