Parametric analysis of event-related potentials in semantic comprehension: evidence for parallel brain mechanisms
Parametric analysis of event-related potentials in semantic comprehension: evidence for parallel brain mechanisms
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DOI：
10.1016/s0926-6410(02)00147-7
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发表时间：
2003-01-01
期刊：
影响因子：
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通讯作者：
Tucker, DM
中科院分区：
文献类型：
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作者：
Dien, J;Frishkoff, GA;Tucker, DM
认知过程的事件相关电位（ERP）研究。电生理反应通常在不同的实验条件下进行对比，这些条件被用来表示离散的类别（例如，有参与的与无参与的刺激，或真实的与无意义的单词）。由于分类变异不如连续或参数变异强大，因此更有效的方法可能是将认知过程中的连续变异与电生理反应中的匹配变异联系起来。我们通过让受试者沿着这两个维度对单词进行评分来评估不同句子语境中单词的期望和意义的持续变化。然后，通过对所有受试者对该单词的反应进行平均，得出每个单词的ERP平均值。然后通过将时间主成分分析的因子地形与每个评级参数的参数相关图相乘，进行参数主成分分析。分析表明，期望和意义在200毫秒左右开始影响词汇加工。期望N2（识别电位）的源定位指向左侧梭状回（视觉构词区）的一个源。意义性N2（意义识别电位）源定位提示右侧下后侧源，如右侧小脑或右侧梭状回区。通过对密集阵列erp的参数化分析，进一步研究可以阐明词识别的多种神经机制。(C) 2003 Elsevier Science B.V.版权所有
In event-related potential (ERP) Studies of cognitive processes. the electrophysiological responses are typically contrasted between experimental conditions that are taken to represent discrete categories (e.g. attended vs. unattended stimuli, or real vs. nonsense words). Because categorical variation is less powerful than continuous or parametric variation, a more effective method may be to relate continuous variation in the cognitive process with matching variation in the electrophysiological responses. We assessed continuous variation in the expectancy and meaningfulness of words in different sentence contexts by having subjects rate the words along these two dimensions. ERP averages were then created for each word by averaging the ERP across all subjects responses to that word. A parametric principal components analysis was then conducted by multiplying the factor topographies from the temporal PCA by the parameter correlation maps for each rating parameter. This analysis showed that both expectancy and meaningfulness begin to influence lexical processing around 200 ms. Source localization of the expectancy N2 (recognition potential) pointed to a source in the left fusiform gyrus region (visual word form area). Source localization of the meaningfulness N2 (meaning recognition potential) suggested a right inferior posterior source, such as in the right cerebellum or right fusiform area. Further research with parametric analysis of dense array ERPs may clarify the multiple neural mechanisms of word recognition. (C) 2003 Elsevier Science B.V. All rights reserved.