Is codeswitching easy or difficult? Testing processing cost through the prosodic structure of bilingual speech

A common practice often attested in bilingual and multilingual communities the world over is the combination of languages within a single utterance or conversation, a practice known as codeswitching. While sociolinguistic studies of spontaneous codeswitching have demonstrated its structure and systematicity, psycholinguistic approaches have focused on the cognitive mechanisms underlying language switching, most often at the lexical level. In the present study, we seek to investigate these mechanisms using spontaneous codeswitching from an established community of Spanish-English bilinguals in northern New Mexico. Focusing on the clausal rather than the lexical level, we find that global speech rates are fastest when bilinguals codeswitch compared to speaking only one language at a time. These results point to codeswitching as a unique discourse mode that these bilinguals use to facilitate production and suggests that what may appear costly at one level may be beneficial at another.