The effect of lexical accessibility on Spanish-English intra-sentential codeswitching

Bilingual speakers sometimes codeswitch, or alternate between languages, in a single utterance. We investigated the effect of lexical accessibility of words, defined as the ease with which a speaker retrieves and produces a word, on codeswitching in Spanish-English bilinguals. We first developed a novel sentence-production paradigm to elicit naturalistic codeswitches in the lab. We then predicted items on which speakers were more or less likely to codeswitch as a consequence of the relative lexical accessibility of those items' labels across a speaker's two languages. In a Spanish sentence-production task, greater lexical accessibility in English was associated with an increased rate of codeswitching and longer speaking durations on trials on which speakers codeswitched, as well as on trials on which speakers did not codeswitch. Codeswitches were more frequent on trials where speakers likely experienced more competition from the other-language label, suggesting that codeswitching may be a tool that bilingual speakers use to alleviate difficulty associated with cross-language lexical competition. Given findings that comprehenders are able to learn lexical distributions and subtle acoustic cues to predict upcoming codeswitches, the present work suggests that demands on speakers during language production may play a role in explaining how those patterns come to exist in the language environment.