Influence of high-level mathematical thinking on L2 phonological processing of Chinese EFL learners: Evidence from an fNIRS study

The contribution of language to the development of mathematical skills has been studied for several decades. However, how mathematical thinking influences language learning, especially second language (L2) learning, remains unknown. To approach this question, this study employed a control/experimental design to reveal the impacts of high-level mathematical thinking used in geometrical problems on the phonological processing of adult Chinese learners of English as a foreign language using a functional near-infrared spectroscopy (fNIRS) device. The results showed that high-level mathematical thinking in processing geometrical problems would not produce instant behavioural impacts on learners' L2 learning, although it inhibited learners' brain function activation and network functional connectivity (FC) for language processing. Nevertheless, it is presumed that high-level mathematical thinking may generate 'cognitive residue' in phonological processing of L2 as only learners with good phonics ability could reluctantly activate the brain regions necessary for English phonological decoding.