晚期高熟练度汉英双语者名动加工的fMRI研究

An fM RI Study on Neural Substrates of Nouns and Verbs in Late High-proficient Chinese-English Bilinguals

运用f MRI技术,采用图片发声命名任务,以18名高熟练度汉英双语者为被试,研究汉英双语者名词和动词加工的神经机制。研究发现,两种语言的动词加工都比名词加工激活更大的脑区,汉语动词产出加工与汉语名词产出加工相比,大脑在右半球颞中回、左半球颞中回、左半球额下回和右半球枕上回有明显激活。英语动词产出加工与英语名词产出加工相比,大脑在左半球楔前叶、左半球颞中回、右半球颞下回、右半球颞中回和右半球枕中回有明显的激活。以上结果表明,汉英双语者一语和二语的名词和动词表征都是分离的,左颞中回是双语动词表征的普遍神经基础。

Nouns and Verbs are fundamental grammatical building blocks of all languages. Most of previous studies examining both monolingual speakers of Western languages and Western bilingual speakers have demonstrated that nouns and verbs are represen- ted in different brain circuits. However, it is still unclear about how nouns and verbs are represented in the brain of Chinese-Eng- lish bilinguals. This study investigates the neural substrates of these two grammatical categories in healthy, late high-proficient Chinese-English bilinguals using functional magnetic resonance imaging （fMRI） in a picture-naming task. Four regions show greater activity for verbs than for nouns in Chinese context： right middle temporal gyrns, left middle temporal gyms, left inferior frontal gyms and right superior occipital gyrns. Five regions show greater activity for verbs than for nouns in English context： left precuneus, left middle temporal gyrus, right inferior temporal gyrns, right middle temporal gyrus and right middle occipital gy- rus. These results suggest that nouns and verbs are separately represented in the brain of Chinese-English bilinguals, and left middle temporal gyrus is the neural substrate underlying verb-specific processing, which is independent of language in bilinguals.