Neural systems of second language reading are shaped by native language.
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.
Tan
Li Hai
LH
Joint Laboratories for Language and Cognitive Neuroscience, University of Hong Kong, Hong Kong. tanlh@hkucc.hku.hk
Spinks
John A
JA
Feng
Ching-Mei
CM
Siok
Wai Ting
WT
Perfetti
Charles A
CA
Xiong
Jinhu
J
Fox
Peter T
PT
Gao
Jia-Hong
JH
D000328:Adult; D001921:Brain / Q000502:physiology; D001931:Brain Mapping; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D019303:Multilingualism; D010364:Pattern Recognition, Visual / Q000502:physiology; D010700:Phonetics; D011932:Reading