Abstract
When producing connected speech, bilinguals often select a default-language as the primary force driving the utterance. The present study investigated the cognitive mechanisms underlying default language selection. In three experiments, Spanish-English bilinguals named pictures out of context, or read aloud sentences with a single word replaced by a picture with a cognate (e.g., lemon-limón) or noncognate name (e.g., table-mesa). Cognates speeded naming and significantly reduced switching costs. Critically, cognate effects were not modulated by sentence context. However, switch costs were larger in sentence context, which also exhibited significant language dominance effects, asymmetrical switch costs, and asymmetrical cognate facilitation effects, which were absent or symmetrical respectively in bare picture naming. These results suggest that default-language selection is driven primarily by boosting activation of the default language, not by proactive inhibition of the nondefault language. However, relaxation of proactive control in production of connected speech leads to greater reliance on reactive control to produce language switches relative to out-of-context naming, a contextually driven dynamic tradeoff in language control mechanisms.