Previous research has utilized cognates and interlingual homographs to investigate the co-activation of the native (L1) and second language (L2) in the lexical processing of bilinguals. However, it remains unclear whether logographic script bilinguals, with distinct lexical access pathways from alphabetic script bilinguals, show variations in such co-activation.

In Experiment 1, Chinese–Japanese bilinguals performed an L2 (Japanese) lexical decision task. In Experiment 2, we used an eye-tracker to record participants’ reading of Japanese sentences containing cognates and interlingual homographs (Experiment 2A) and Chinese sentences (Experiment 2B).

The participants in Experiment 1 were 32 college students majoring in Japanese, and the data for Experiment 2 were collected from 25 college students majoring in Japanese.

In Experiment 1, we found a significant cognate interference effect and an interlingual homograph interference effect. During the Japanese sentence reading, we observed a facilitation effect of cognates and interlingual homographs compared to Japanese control words; however, during the Chinese sentence reading, we did not find any significant differences. We conclude that Chinese–Japanese bilinguals exhibit co-activation of L1 and L2 during lexical processing, but this co-activation differs from that in bilinguals reading alphabetic languages.

This study further explored the lexical recognition of Chinese–Japanese bilinguals using a lexical decision task and, for the first time, investigated their recognition during the natural reading of sentences. The results of this study demonstrate differences in bilinguals’ reading of alphabetic languages.

The findings indicate that the bilingual lexical recognition model based on alphabetic script bilinguals can be generalized to logographic script bilinguals, though certain differences in lexical recognition exist between the two groups.