Cognition and Brain Sciences Unit, Medical Research Council, Cambridge, UK.
Neuroimage. 2012 Feb 15;59(4):3502-13. doi: 10.1016/j.neuroimage.2011.11.011. Epub 2011 Nov 10.
We investigated the time-course of cortical activation during comprehension of literal and idiomatic sentences using MEG and anatomically guided distributed source analysis. Previous fMRI work had shown that the comprehension of sentences including action-related words elicits somatotopic semantic activation along the motor strip, reflecting meaning aspects of constituent words. Furthermore, idioms more strongly activated temporal pole and prefrontal cortex than literal sentences. Here we show that, compared to literal sentences, processing of idioms in a silent reading task modulates anterior fronto-temporal activity very early-on, already 150-250 ms after the sentences' critical disambiguating words ("kick the habit"). In parallel, the meaning of action words embedded in sentences is reflected by somatotopic activation of precentral motor systems. As neural reflections of constituent parts of idiomatic sentences are manifest at the same early latencies as brain indexes of idiomatic vs. literal meaning processing, we suggest that within ¼ of a second, compositional and abstract context-driven semantic processes in parallel contribute to the understanding of idiom meaning.
我们使用 MEG 和解剖导向的分布式源分析研究了在理解字面和惯用句子时皮质激活的时程。以前的 fMRI 研究表明，包含与动作相关的词的句子理解会沿着运动带引起躯体语义激活，反映出组成词的意义方面。此外，与字面句子相比，习语更强烈地激活了颞极和前额叶皮层。在这里，我们表明，与字面句子相比，在默读任务中处理习语会在句子关键的歧义消除词（“戒除习惯”）后 150-250 毫秒非常早地调节额前颞叶活动。同时，嵌入句子中的动作词的意义通过中央前运动系统的躯体定位激活来反映。由于习语句子组成部分的神经反射与习语与字面意义处理的大脑指标同时出现，我们认为在四分之一秒内，组合和抽象的上下文驱动的语义过程并行有助于理解习语的含义。
