Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103, Leipzig, Germany.
Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103, Leipzig, Germany.
Neuroimage. 2018 Jul 15;175:286-296. doi: 10.1016/j.neuroimage.2018.04.008. Epub 2018 Apr 6.
Sentence comprehension requires the encoding of phrases and their relationships into working memory. To date, despite the importance of neural oscillations in language comprehension, the neural-oscillatory dynamics of sentence encoding are only sparsely understood. Although oscillations in a wide range of frequency bands have been reported both for the encoding of unstructured word lists and for working-memory intensive sentences, it is unclear to what extent these frequency bands subserve processes specific to the working-memory component of sentence comprehension or to general verbal working memory. In our auditory electroencephalography study, we isolated the working-memory component of sentence comprehension by adapting a subsequent memory paradigm to sentence comprehension and assessing oscillatory power changes during successful sentence encoding. Time-frequency analyses and source reconstruction revealed alpha-power desynchronization in left-hemispheric language-relevant regions during successful sentence encoding. We further showed that sentence encoding was more successful when source-level alpha-band desynchronization aligned with computational measures of syntactic-compared to lexical-semantic-difficulty. Our results are a preliminary indication of a domain-general mechanism of cortical disinhibition via alpha-band desynchronization superimposed onto the language-relevant cortex, which is beneficial for encoding sentences into working memory.
句子理解需要将短语及其关系编码到工作记忆中。迄今为止，尽管神经振荡在语言理解中很重要，但句子编码的神经振荡动力学仍知之甚少。虽然在编码非结构化单词列表和工作记忆密集型句子时都报告了广泛频带的振荡，但尚不清楚这些频带在多大程度上支持句子理解工作记忆成分的特定过程，或者支持一般的言语工作记忆。在我们的听觉脑电图研究中，我们通过适应后续记忆范式来分离句子理解的工作记忆成分，并在成功的句子编码期间评估振荡功率变化。时频分析和源重建显示，在成功的句子编码期间，左半球语言相关区域的 alpha 功率去同步。我们进一步表明，当源水平 alpha 频带去同步与句法相比词汇语义难度的计算测量对齐时，句子编码更成功。我们的结果初步表明，通过叠加在语言相关皮层上的 alpha 频带去同步，存在一种皮质去抑制的普遍机制，这有利于将句子编码到工作记忆中。
