Potter D D, Pickles C D, Roberts R C, Rugg M D
School of Psychology, University of St Andrews, St. Andrews, UK.
Biol Psychol. 2000 Feb;52(1):37-52. doi: 10.1016/s0301-0511(99)00023-x.
It has been suggested that the P3 event-related potential (ERP) may mark the operation of certain working or long-term memory processes. It has also been reported that cholinergic blockade by scopolamine induces significant memory impairment and is associated with an increased latency, as well as amplitude reduction or abolition of the auditory P3, thus supporting hypothesised links between P3 and long-term memory function. An intriguing anomaly is that, while visual P3 latency is also increased by scopolamine, amplitude is not changed. The aim of this study was to make a more detailed assessment of the effects of scopolamine on the visual P3 at a drug dose known to induce memory impairment. After drug administration, memory performance was significantly impaired and visual P3 latency was significantly increased. There was little evidence of parietal P3 amplitude reduction, but frontal P3 amplitude was significantly reduced in both target and non-target conditions. These findings, when considered in the light of a more recent study of the effects of scopolamine on auditory P3, suggest that cholinergic blockade produces a common effect in both visual and auditory modalities of significant frontal P3 amplitude reduction, but no significant parietal P3 amplitude reduction. These results are consistent with the view that there are modality-independent generators of the parietal and frontal P3. The finding of drug-induced memory impairment and modulations of frontal ERP deflections is also consistent with recent evidence of a significant role for regions of the frontal lobe in encoding and retrieval of long-term memories.
有人提出，P3事件相关电位（ERP）可能标志着某些工作记忆或长期记忆过程的运作。也有报道称，东莨菪碱引起的胆碱能阻滞会导致显著的记忆损害，并与听觉P3潜伏期延长以及波幅降低或消失有关，从而支持了P3与长期记忆功能之间的假设联系。一个有趣的异常现象是，虽然东莨菪碱也会使视觉P3潜伏期延长，但波幅并未改变。本研究的目的是在已知会引起记忆损害的药物剂量下，更详细地评估东莨菪碱对视觉P3的影响。给药后，记忆表现显著受损，视觉P3潜伏期显著延长。几乎没有证据表明顶叶P3波幅降低，但在目标和非目标条件下，额叶P3波幅均显著降低。这些发现，结合最近一项关于东莨菪碱对听觉P3影响的研究来看，表明胆碱能阻滞在视觉和听觉模态中都会产生共同的效应，即额叶P3波幅显著降低，但顶叶P3波幅无显著降低。这些结果与顶叶和额叶P3存在模态独立的发生器这一观点一致。药物诱导的记忆损害以及额叶ERP偏转的调制这一发现，也与最近关于额叶区域在长期记忆编码和提取中起重要作用的证据一致。
