UC Irvine

Language brokering, the informal translation and interpretation that many heritage bilinguals perform for their families and communities, offers a rich context for understanding how early life experience shapes language processing. Past research has linked brokering to more integrated conceptual representations across bilinguals' two languages and cognitive flexibility, but little is known about how variability in brokering experiences relate to individual language use patterns. This dissertation examines how language brokering shapes bilingual language processing and regulation and proposes brokering as an experience that refines cross-language integration and the cognitive mechanisms that support it.Study 1 tested this across Spanish-English and Mandarin-English heritage bilinguals in California and Spanish-English sequential bilinguals in Mexico. Brokering was unrelated to picture naming, while childhood, not adulthood, brokering selectively predicted semantic interference resolution during translation recognition among Spanish-English heritage bilinguals. Study 2 used EEG with Spanish-English heritage bilingual brokers to localize this effect via the N400 and Late Positivity Component. Both showed robust semantic interference effects, but semantic-level brokering moderation was absent neurally. Instead, brokering reorganized neural responses to form-related distractors, more extensively for adulthood than childhood brokering. These findings indicate brokering exerts a selective influence on bilingual processing that is also determined by the developmental time frame in which brokering takes place.