Neural systems of second language reading are shaped by native language

TLDR

Reading in a second language is a complex task involving interaction between L2 and L1, and the peak activation of the neural system is linked to Chinese characters’ square configuration mapping onto a monosyllabic unit. The study used fMRI to examine how Chinese–English bilinguals process phonology in logographic Chinese versus alphabetic English. fMRI was employed to map brain activity during phonological processing of Chinese characters and English words in bilinguals. Phonological processing of Chinese recruited a left middle frontal and posterior parietal network linked to spatial representation and executive control, whereas the same network was most active during English phonological tasks, while English monolinguals’ fine‑grained phonemic areas were weakly activated, indicating bilinguals applied their L1 system to L2 reading and supporting that language experience tunes the cortex. © 2003 Wiley‑Liss, Inc., Brain Mapping 18:158–166.

Abstract

Abstract Reading in a second language (L2) is a complex task that entails an interaction between L2 and the native language (L1). To study the underlying mechanisms, we used functional magnetic resonance imaging (fMRI) to visualize Chinese–English bilinguals' brain activity in phonological processing of logographic Chinese and alphabetic English, two written languages with a sharp contrast in phonology and orthography. In Experiment 1, we found that phonological processing of Chinese characters recruits a neural system involving left middle frontal and posterior parietal gyri, cortical regions that are known to contribute to spatial information representation, spatial working memory, and coordination of cognitive resources as a central executive system. We assume that the peak activation of this system is relevant to the unique feature of Chinese that a logographic character has a square configuration that maps onto a monosyllabic unit of speech. Equally important, when our bilingual subjects performed a phonological task on English words, this neural system was most active, whereas brain areas mediating English monolinguals' fine‐grained phonemic analysis, as demonstrated by Experiment 2, were only weakly activated. This suggests that our bilingual subjects were applying their L1 system to L2 reading and that the lack of letter‐to‐sound conversion rules in Chinese led Chinese readers to being less capable of processing English by recourse to an analytic reading system on which English monolinguals rely. Our brain imaging findings lend strongest support to the idea that language experience tunes the cortex. Hum. Brain Mapping 18:158–166, 2003. © 2003 Wiley‐Liss, Inc.