Constraint sensitivity in L1 and L2: A within-subject investigation of non-local dependencies

This dissertation investigates how bilingual individuals interpret and process predictive non-local dependencies in their first (L1) and second (L2) languages, with a focus on the role of grammatical and extra-grammatical constraints in both real-time and offline sentence comprehension. Using a combination of behavioral and neurophysiological (ERP) methods, two empirical studies examined cataphoric pronoun resolution (CPR) and filler-gap dependency (FGD) formation in highly proficient L1 German–L2 English bilinguals. The research examined whether bilinguals apply the same linguistic constraints across their languages and to what extent individual variability patterns are shared across the L1 and the L2 within the same individuals. Study 1 focused on CPR and used offline antecedent judgments to assess sensitivity to structural and discourse-level constraints in the interpretation of cataphoric pronouns. At the group level, results showed largely consistent constraint application across the L1 and the L2. However, there were some sporadic modulations by language status (L1/L2) and L2 proficiency that affected both structural and discourse-level constraints. At the individual level, coreference preferences were highly correlated across the L1 and the L2, particularly with respect to the Condition C constraint, indicating consistent constraint sensitivity across languages. Study 2 examined FGD processing using ERP measures to track real-time responses to implausible filler conditions and filled-gap violations, alongside plausibility and grammaticality judgment tasks. Although effects of L2 proficiency were observed, the ERP responses elicited by filled-gap violations and semantic plausibility violations were qualitatively similar across both languages, reflecting consistent neural patterns associated with syntactic and semantic processing at the group level. Additionally, individual ERP responses to the syntactic properties of the examined violations were strongly correlated across languages and experiments, indicating consistent L1–L2 patterns of syntactic processing within the same individuals. Together, the findings demonstrate that bilinguals engage similar types of constraints across their two languages, but the strength and prioritization of these constraints in the L2 are modulated, in certain respects, by individual variability and L2 proficiency.