The Brain Connectome for Chinese Reading

Abstract

Chinese, as a logographic language, fundamentally differs from alphabetic languages like English. Previous neuroimaging studies have mainly focused on alphabetic languages, while the exploration of Chinese reading is still an emerging and fast-growing research field. Recently, a growing number of neuroimaging studies have explored the neural circuit of Chinese reading. Here, we summarize previous research on Chinese reading from a connectomic perspective. Converging evidence indicates that the left middle frontal gyrus is a specialized hub region that connects the ventral with dorsal pathways for Chinese reading. Notably, the orthography-to-phonology and orthography-to-semantics mapping, mainly processed in the ventral pathway, are more specific during Chinese reading. Besides, in addition to the left-lateralized language-related regions, reading pathways in the right hemisphere also play an important role in Chinese reading. Throughout, we comprehensively review prior findings and emphasize several challenging issues to be explored in future work.

Keywords: Brain connectome; Chinese reading; Functional connectivity; Reading comprehension; Structural connectivity; Word recognition.

Fig. 1

Identification of nodes for the Chinese reading connectome. The bilateral middle occipital gyrus (MOG) and ventral occipitotemporal cortex (vOT), right inferior parietal lobule (IPL), right superior parietal lobule (SPL), and right middle frontal gyrus (MFG) are involved in orthographic processing. The left angular gyrus (AG) and ventral part of the left inferior frontal gyrus (vIFG) are involved in semantic processing. The left middle temporal gyrus (MTG) and left anterior temporal lobe (ATL) are involved in syntactic processing. The left supramarginal gyrus (SMG), left superior temporal gyrus (STG), and dorsal part of the right inferior frontal gyrus are involved in orthographic and phonological processing. The dorsal part of the left inferior frontal gyrus (dIFG) is involved in phonological and syntactic processing. The left SPL and left IPL are involved in phonological and semantic processing. The left MFG is involved in orthographic, phonological, semantic, and syntactic processing. L, left hemisphere; R, right hemisphere.

Fig. 2

Structural connections for Chinese reading. The left arcuate fasciculus (AF) in the dorsal pathway, which connects the frontal lobe to the temporoparietal cortex, is associated with phonological processing. The bilateral inferior longitudinal fasciculus (ILF) is associated with orthographic processing which is language-specific for Chinese reading (bold italic). The left inferior fronto-occipital fasciculus (IFOF) is associated with semantic processing. The corpus callosum (CC) is proposed to integrate visual information generated from the bilateral occipital cortex.

Fig. 3

Functional connections for Chinese reading. The green arrows indicate the dorsal pathways. The orange arrows indicate the ventral pathways. vOT, ventral occipitotemporal cortex; TPC, temporoparietal cortex; STG, superior temporal gyrus; IFG, inferior frontal gyrus; MFG, middle frontal gyrus.