Beyond production conflict: evidence from bimodal bilinguals for language control across comprehension and production

This study examined whether bimodal bilinguals adopt shared language control mechanisms across comprehension and production. Twenty-nine hearing English-American Sign Language (ASL) bilinguals alternated between semantic categorisation (comprehension) and picture naming (production) tasks, when production was restricted to one language only. We examined language switch effects in mixed-language blocks and compared with a single-language block with no switch. Results revealed significant language switch costs (reactive control) and mixing costs (proactive control) in the dominant language (English), but no switch effects in ASL. Switch costs were more pronounced in late bilinguals with less balanced proficiency. The findings demonstrate that bimodal bilinguals at least reactively inhibit the dominant language, English, at the lexical level when alternating between comprehension and production. Proactive inhibition on English across comprehension and production is even more robust. Together, our findings provided evidence of shared reactive and proactive language control mechanisms between comprehension and production in bimodal bilinguals.