The neural cost of the auditory perception of language switches: An event-related functional magnetic resonance imaging study in bilinguals
The neural cost of the auditory perception of language switches: An event-related functional magnetic resonance imaging study in bilinguals
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DOI：
10.1523/jneurosci.3294-07.2007
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发表时间：
2007-12-12
影响因子：
5.3
通讯作者：
Perani, Daniela
中科院分区：
文献类型：
--
作者：
Abutalebi, Jubin;Brambati, Simona M.;Perani, Daniela
双语者最显著的能力之一就是能够毫无困难地从一种语言转换到另一种语言。然而，一些心理语言学研究表明，产生、识别和整合不同于当前使用的语言代码可能会给说话者/听者带来处理成本。到目前为止，感知语言转换的潜在神经基质尚不清楚。本研究探讨了双语者听觉感知过程中语言转换的神经机制。研究人员对12名早期精通意大利语/法语的双语者进行了事件相关功能磁共振成像，这些人更多地接触第二语言。受试者必须听包含“转换段落”的叙述，这些段落可能尊重（即规则转换）或违反（即不规则转换）句子结构的成分。结果表明，转换涉及广泛的神经网络，包括双侧前额叶和颞叶相关区域。此外，还观察到开关类型的明显解离。规律的转换需要一种与词汇处理密切相关的大脑活动模式，而不规则的转换则涉及语言处理的句法和语音方面的大脑结构。值得注意的是，当切换到较少暴露的语言时，我们观察到皮质下结构和前扣带皮层的选择性参与，假设参与认知和执行控制。这表明转换到较少暴露的语言需要控制处理资源。这种大脑活动模式可能构成双语者语言优势的重要神经特征。
One of the most remarkable abilities of bilinguals is to produce and/or to perceive a switch from one language to the other without any apparent difficulty. However, several psycholinguistic studies indicate that producing, recognizing, and integrating a linguistic code different from the one in current use may entail a processing cost for the speaker/listener. Up to now, the underlying neural substrates of perceiving language switches are unknown. In the present study, we investigated the neural mechanisms of language switching during auditory perception in bilinguals. Event-related functional magnetic resonance imaging was performed in 12 early, highly proficient Italian/French bilinguals, who were more exposed to their second language. Subjects had to listen to narratives containing "switched passages" that could either respect (i.e., regular switches) or violate (i.e., irregular switches) the constituents of sentence structure. The results indicate that switching engages an extensive neural network, including bilateral prefrontal and temporal associative regions. Moreover, a clear dissociation is observed for the types of switches. Regular switches entail a pattern of brain activity closely related to lexical processing, whereas irregular switches engage brain structures involved in syntactic and phonological aspects of language processing. Noteworthy, when switching into the less-exposed language, we observed the selective engagement of subcortical structures and of the anterior cingulate cortex, putatively involved in cognitive and executive control. This suggests that switching into a less- exposed language requires controlled processing resources. This pattern of brain activity may constitute an important neural signature of language dominance in bilinguals.