Olivares-Carreño E I, Iglesias-Dorado J
Universidad Autónoma de Madrid, Facultad de Psicología, Madrid, España.
Rev Neurol. 2008;47(12):624-30.
Evoked potentials are real-time electrophysiological markers of cognitive operations and especially mnemonic processes. The N400 wave has traditionally been studied to characterise the processes involved in memorising verbal material. To investigate the existence of specific memory processes for each information domain, functional analogues of this wave were examined during the processing of non-verbal stimuli, such as faces.
Using an inter-subject design, the classic verbal N400 wave was compared with its functional analogue during the processing of faces in a contextual preactivation task adapted to the visual domain of faces.
After several sessions dedicated to learning a set of faces, another evoked potential recording session was held in order to analyse the effects of the existence of structural inconsistencies in these stimuli and to compare them, with regard to their topographic distribution and neural generators, with those observed in the classic verbal N400 task.
A verbal N400 wave was observed with a (slightly right) centro-parietal distribution, and this response was distinguished from another negative wave obtained during the processing of facial inconsistencies in the same group of participants, with a predominantly occipital localisation and differentiated neural generators.
These findings support the hypothesis of the specificity of the neural mechanisms involved in the mnemonic processing of faces and words, which is in line with the neurocognitive models that suggest the independence or modularity of memory processes in different domains of information.
诱发电位是认知操作尤其是记忆过程的实时电生理标记物。传统上，人们对N400波进行研究以表征记忆言语材料所涉及的过程。为了探究每个信息领域是否存在特定的记忆过程，在处理非言语刺激（如面孔）时对该波的功能类似物进行了检查。
采用被试间设计，在一个适用于面孔视觉领域的情境预激活任务中，将经典的言语N400波与其在处理面孔时的功能类似物进行比较。
在进行了几节专门用于学习一组面孔的课程后，又进行了一次诱发电位记录课程，以分析这些刺激中存在结构不一致的影响，并在地形图分布和神经发生器方面将其与经典言语N400任务中观察到的情况进行比较。
观察到一个具有（略偏右的）中央顶叶分布的言语N400波，并且该反应与同一组参与者在处理面孔不一致时获得的另一个负波不同，后者主要位于枕叶且神经发生器不同。
这些发现支持了面孔和单词记忆加工中所涉及神经机制具有特异性的假设，这与表明不同信息领域中记忆过程具有独立性或模块性的神经认知模型一致。
