Chinese and Korean Characters Engage the Same Visual Word Form Area in Proficient Early Chinese-Korean Bilinguals

Jian'E Bai,Yi Jiang,Sheng He,Xuchu Weng,Jinfu Shi,Hans P Op De Beeck

doi:10.1371/journal.pone.0022765

Abstract

A number of recent studies consistently show an area, known as the visual word form area (VWFA), in the left fusiform gyrus that is selectively responsive for visual words in alphabetic scripts as well as in logographic scripts, such as Chinese characters. However, given the large difference between Chinese characters and alphabetic scripts in terms of their orthographic rules, it is not clear at a fine spatial scale, whether Chinese characters engage the same VWFA in the occipito-temporal cortex as alphabetic scripts. We specifically compared Chinese with Korean script, with Korean script serving as a good example of alphabetic writing system, but matched to Chinese in the overall square shape. Sixteen proficient early Chinese-Korean bilinguals took part in the fMRI experiment. Four types of stimuli (Chinese characters, Korean characters, line drawings and unfamiliar Chinese faces) were presented in a block-design paradigm. By contrasting characters (Chinese or Korean) to faces, presumed VWFAs could be identified for both Chinese and Korean characters in the left occipito-temporal sulcus in each subject. The location of peak response point in these two VWFAs were essentially the same. Further analysis revealed a substantial overlap between the VWFA identified for Chinese and that for Korean. At the group level, there was no significant difference in amplitude of response to Chinese and Korean characters. Spatial patterns of response to Chinese and Korean are similar. In addition to confirming that there is an area in the left occipito-temporal cortex that selectively responds to scripts in both Korean and Chinese in early Chinese-Korean bilinguals, our results show that these two scripts engage essentially the same VWFA, even at the level of fine spatial patterns of activation across voxels. These results suggest that similar populations of neurons are engaged in processing the different scripts within the same VWFA in early bilinguals.

Highlights

Reading is an important skill in modern society
We defined the selective area for Chinese characters as VCFA and the selective area for Korean characters as VKFA, and found that VCFA and VKFA had a high degree of overlap
Paired sample ttest showed that the beta value of the responses for Chinese characters and Korean characters had no significant differences (t(13) = 20.387, p = 0.705 in VCFA and t(13) = 20.271, p = 0.791 in VKFA)

Summary

Introduction

Reading is an important skill in modern society. There is evidence for an abstract representation of visual word form. Recent brain imaging studies have identified a region in the ventral occipito-temporal cortex that is consistently activated by words in normal readers, regardless of the position, size, color, font, or case used [1,2,3,4,5,6,7] and neuropsychological studies show that patients with lesions in this area are selectively impaired in reading letters and words [8,9,10,11,12,13,14] Cohen and his colleagues labeled this area in the left fusiform gyrus (Talairach coordinate: 243,254,212) the Visual Word Form Area (VWFA) and suggested that it is specialized in processing the abstract visual form of words [2,3]. Even though visual words from both alphabetic and non-alphabetic writing systems seem to be processed in the lateral fusiform region, at a fine spatial scale whether a non-alphabetic writing system, such as Chinese, engages the same VWFA as alphabetic writing systems is still unclear

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Conclusion