Grammatical Predictions in Spanish-English Bilinguals and Spanish-Language Learners

Although bilingual individuals know 2 languages, research suggests that the languages are not separate in the mind. This is especially evident when a bilingual individual switches languages midsentence, indicating that mental representations are, to some degree, overlapping or integrated across the 2 languages. In 2 eye-tracking experiments, we investigated the nature of this integration during reading to examine whether incremental grammatical predictions generated by Spanish-English bilinguals (Experiment 1, N = 50) and Spanish-as-a-second-language learners (Experiment 2, N = 50) are language-specific or language-independent. As participants in same-language and mixed-language pairs performed a 2-string lexical-decision task, we measured eye fixation times on nouns in grammatical (determiner-noun) and ungrammatical (adverb-noun) contexts. In Experiment 1, bilingual participants read nouns faster following determiners than they read adverbs in both same- and mixed-language pairs, indicating that grammatical predictability in this context is language-independent. Surface-string bigram frequencies are unlikely to account for the results because the grammatical predictability effect was just as large for mixed-language (very low bigram frequency) as same-language (higher bigram frequency) pairs, and the effect was not modulated by the code-switching experience of participants. Experiment 2 found a similar, though nonsignificant, pattern for Spanish-language learners. When the data for Experiments 1 and 2 were combined, the effect of grammaticality did not interact with language congruency, participant group, or language proficiency, suggesting that both bilingual participants and language learners generated language-independent predictions. Our results support a bilingual model in which language-independent syntactic representations are involved in word-by-word, incremental syntactic processing, even within the most basic grammatical constituents.