Voluntary language switching in English-Spanish bilingual children.

Although bilingual children frequently switch between languages, the psycholinguistic mechanisms underlying the emerging ability to control language choice are unknown. We examined the mechanisms of voluntary language switching in English-Spanish bilingual children during a picture-naming task under two conditions: 1) single-language naming in English and in Spanish; 2) either-language naming, when the children could use whichever language they wanted. The mechanism of inhibitory control was examined by analyzing local switching costs and global mixing costs. The mechanism of lexical accessibility was examined by analyzing the properties of the items children chose to name in their non-dominant language. The children exhibited significant switching costs across both languages and asymmetrical mixing costs; they also switched into their non-dominant language most frequently on highly accessible items. These findings suggest that both lexical accessibility and inhibition contribute to language choice during voluntary language switching in children.