Do semantic sentence constraint and L2 proficiency influence language selectivity of lexical access in native language listening?

We investigated whether language nonselective lexical access in bilingual auditory word recognition when listening in the native language (L1) is modulated by (a) the semantic constraint of the sentence and (b) the second language (L2) proficiency level. We report 2 experiments in which Dutch-English bilinguals with different proficiency levels completed an L1 auditory lexical-decision task on the last word of low- and high-constraining sentences. The critical stimuli were interlingual homophones (e.g., lief [sweet] - leaf /li:f/). Participants recognized homophones significantly slower than matched control words. Importantly, neither the semantic constraint of the sentence, nor the proficiency level of the bilinguals interacted with this interlingual homophone effect. However, when we compared the slow and fast reaction times (RTs), we observed a reduction in the homophone interference effect when listening to high-constraining sentences in L1 for the slow RTs, but not for the fast RTs. Taken together, this provides strong evidence for a language-nonselective account of lexical access when listening in L1, and suggests that even when low-proficient bilinguals are listening to high-constraint sentences in L1, both languages of a bilingual are still activated.