Proverbio Alice Mado, Cok Barbara, Zani Alberto
Department of Psychology, University of Milano-Bicocca, Italy.
J Cogn Neurosci. 2002 Oct 1;14(7):994-1017. doi: 10.1162/089892902320474463.
The aim of the present study was to investigate how multiple languages are represented in the human brain. Event-related brain potentials (ERPs) were recorded from right-handed polyglots and monolinguals during a task involving silent reading. The participants in the experiment were nine Italian monolinguals and nine Italian/Slovenian bilinguals of a Slovenian minority in Trieste; the bilinguals, highly fluent in both languages, had spoken both languages since birth. The stimuli were terminal words that would correctly complete a short, meaningful, previously shown sentence, or else were semantically or syntactically incorrect. The task consisted in deciding whether the sentences were well formed or not, giving the response by pressing a button. Both groups read the same set of 200 Italian sentences to compare the linguistic processing, while the bilinguals also received a set of 200 Slovenian sentences, comparable in complexity and length, to compare the processing of the two languages within the group. For the bilinguals, the ERP results revealed a strong, left-sided activation, reflected by the N1 component, of the occipitotemporal regions dedicated to orthographic processing, with a latency of about 150 msec for Slovenian words, but bilateral activation of the same areas for Italian words, which was also displayed by topographical mapping. In monolinguals, semantic error produced a long-lasting negative response (N2 and N4) that was greater over the right hemisphere, whereas syntactic error activated mostly the left hemisphere. Conversely, in the bilinguals, semantic incongruence resulted in greater response over the left hemisphere than over the right. In this group, the P615 syntactical error responses were of equal amplitude on both hemispheres for Italian words and greater on the right side for Slovenian words. The present findings support the view that there are interand intrahemispheric brain activation asymmetries when monolingual and bilingual speakers comprehend written language. The fact that the bilingual speakers in the present study were highly fluent and had acquired both languages in early infancy suggests that the brain activation patterns do not depend on the age of acquisition or the fluency level, as in the case of late, not-so-proficient L2 language learners, but on the functional organization of the bilinguals' brain due to polyglotism and based on brain plasticity.
本研究的目的是调查多种语言在人脑中是如何表征的。在一项涉及默读的任务中，记录了右利手多语者和单语者的事件相关脑电位（ERP）。实验参与者包括9名意大利单语者和的里雅斯特一个斯洛文尼亚少数民族中的9名意大利语/斯洛文尼亚语双语者；这些双语者两种语言都非常流利，自出生起就会说这两种语言。刺激物是能够正确完成一个简短、有意义且先前已展示句子的结尾词，或者是语义或句法错误的词。任务是判断句子是否结构正确，通过按按钮给出回答。两组都阅读相同的200个意大利语句子以比较语言处理过程，而双语者还会收到一组200个复杂度和长度相当的斯洛文尼亚语句子，以比较组内两种语言的处理情况。对于双语者，ERP结果显示，枕颞区用于正字法处理的区域在左侧有强烈激活，由N1成分反映，斯洛文尼亚语单词的潜伏期约为150毫秒，但意大利语单词在相同区域有双侧激活，这也通过地形图显示出来。在单语者中，语义错误会产生持续时间较长的负向反应（N2和N4），在右半球更为明显，而句法错误主要激活左半球。相反，在双语者中，语义不一致在左半球产生的反应比右半球更大。在这组中，对于意大利语单词，P615句法错误反应在两个半球的幅度相等，而对于斯洛文尼亚语单词，右侧的反应更大。目前的研究结果支持这样一种观点，即单语者和双语者在理解书面语言时，脑内和脑间存在激活不对称。本研究中的双语者非常流利且在婴儿早期就掌握了两种语言，这一事实表明，脑激活模式并不像后期不太熟练的第二语言学习者那样取决于习得年龄或流利程度，而是由于多语能力和基于脑可塑性的双语者大脑功能组织。
