L1 Reading Experience Influences L2 Lexical Learning: Spanish Learning in Chinese Speakers and English Speakers

L2 processing is shaped by L1 experience; however, it is not completely understood whether L1 reading experience also influences how the brain learns L2 under different learning conditions. In this study, we compare brain mechanisms of Spanish word learning in Chinese and English speakers using two learning conditions: speech-based learning and handwriting-based learning. The behavioral data suggest an advantage for learning that uses handwriting over speech-based learning across all participants. Furthermore, brain imaging data reveal that English speakers show greater functional connectivity among phonological regions in the handwriting condition than the speech-based condition during a silent phonological recall task. This suggests that, for English speakers specifically, handwriting further enhanced the phonological network. Interestingly, Chinese speakers showed an opposite pattern, with greater functional connectivity among phonological regions in the speech-based condition than the handwriting condition. Moreover, it was found that Chinese speakers with higher reading skills in their native L1 tended to engage the right fusiform to a greater degree by connecting to phonological regions in the handwriting condition. Thus, the handwriting-based learning engaged visuo-orthographic regions to a greater degree in highly skilled Chinese speakers. In summary, the current findings suggest that handwriting facilitates lexical learning by enhancing orthographic involvement in Chinese speakers, while the handwriting condition enhanced phonological involvement in English speakers. This difference between Chinese and English speakers might be due to different L1 learning experience.