Production, processing, and prediction in bilingual codeswitching

Bilinguals in the presence of other bilinguals engage in codeswitching, the fluid and intentional alternation between languages during bilingual speech or text. Codeswitching has most prominently been studied from a theoretical and sociolinguistic perspective, but over the last 20 years, psycholinguists have increasingly turned their attention to understanding the cognitive and neural underpinnings of codeswitching. Despite its common use among bilinguals, understanding the production and comprehension of codeswitching presents unique challenges to current theories of sentence processing. We overview the planning, production, and comprehension of codeswitching, discussing the complex interaction between linguistic, cognitive, and social factors that modulate its use and its comprehension. This overview brings to the forefront an apparent paradox between measurable processing costs and the ease with which bilinguals engage in codeswitching, namely, that codeswitching introduces greater ambiguity into the linguistic signal yet does not lead to disruptive processing delays. To account for this contradiction, we propose the Adaptive Predictability hypothesis with two premises: bilinguals adapt predictive cues in sentence processing as a consequence of exposure to distributional regularities in production, and they recruit greater cognitive control in the service of rapidly integrating codeswitches in real time. We end the chapter by illustrating recent findings that support the Adaptive Predictability hypothesis and areas for future directions.