Separating the FN400 and N400 potentials across recognition memory experiments.
Separating the FN400 and N400 potentials across recognition memory experiments.
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DOI：
10.1016/j.brainres.2016.01.015
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发表时间：
2016-03-15
期刊：
影响因子：
2.9
通讯作者：
Curran T
中科院分区：
文献类型：
--
作者：
Stróżak P;Abedzadeh D;Curran T
关于额叶分布的FN400电位是反映基于熟悉的再认，还是与反映语义加工的中央顶叶N400在功能上相同，存在着越来越多的争论。我们进行了两个实验，记录了与语义启动和再认相关的事件相关电位(ERPs)，或者当启动被嵌入到再认测试中时(实验1)，或者当这两个阶段分开时(实验2)。在实验一中，我们观察到启动和非启动旧词之间以及新旧启动词之间300-500ms的差异，但这两种效应在地形图上没有差异，都显示出中线中央最大值。在实验2中，仅在编码过程中记录到用于启动的N400，并再次显示中线中枢分布。识别的事件相关电位成分只存在于不相关的单词(在编码过程中没有被启动)，而且也显示出中线中央最大值，但除此之外，还存在于头皮的左额叶区域。反之，左额叶簇则不存在启动效应。这一结果模式表明，FN400和N400电位共享相似的神经生成器；但当启动和识别没有混淆时，这些电位在地形分布方面并不完全重叠，可能反映了不同的功能过程。
There is a growing debate as to whether frontally distributed FN400 potentials reflect familiarity-based recognition or are functionally identical to centro-parietal N400 reflecting semantic processing. We conducted two experiments in which event-related potentials (ERPs) associated with semantic priming and recognition were recorded, either when priming was embedded within a recognition test (Experiment 1), or when these two phases were separated (Experiment 2). In Experiment 1, we observed 300–500 ms differences between primed and unprimed old words as well as differences between old and new primed words, but these two effects did not differ topographically and both showed midline central maxima. In Experiment 2, the N400 for priming was recorded exclusively during encoding and again showed a midline central distribution. The ERP component of recognition was only found for unrelated words (not primed previously during encoding), and also showed a midline central maximum, but, in addition, was present in the left frontal area of the scalp. Conversely, the priming effect was absent in the left frontal cluster. This pattern of results indicate that FN400 and N400 potentials share similar neural generators; but when priming and recognition are not confounded, these potentials do not entirely overlap in terms of topographical distribution and presumably reflect functionally distinct processes.