Cortical encoding during word reading in bilinguals: parallel interdigitated distributed networks support convergent linguistic functioning

Abstract

Word reading includes a series of cognitive processes that convert low-level visual characteristics to neural representations. However, the consistency of the neural mechanisms for processing these cognitive components across different writing systems in bilinguals remains inconclusive. Here, we explored this question by employing representational similarity analysis with a semantic access task involving Chinese words, English words and Chinese pinyin. Divergent spatial distribution patterns were detected for each type of brain representation across ideographic and alphabetic languages, resulting in 100% classification accuracy. Meanwhile, convergent cognitive components processing was found in the core language-related regions in left hemisphere, including the inferior frontal gyrus, temporal pole, superior and middle temporal gyrus, precentral gyrus and supplementary motor areas. Broadly, our findings indicated that the neural basis for word recognition of different writing systems in bilinguals was divergent in spatial locations of neural representations but convergent in functions, which supported and enriched the assimilation-accommodation hypothesis.TeaserCortical encoding of processing components across languages was divergent in fine spatial locations but convergent in cognitive functions.