UC San Diego

This dissertation takes on an ambitious set of experiments to gain insight into the bilingual language processor. There are approximately 200 countries in the world and more than 4000 languages; you are in the minority if you speak only one language. Furthermore, approximately 55 million Americans are multilingual and that number is growing (census.gov, 2010). It would seem, then, that accounts of language processing should take into consideration these facts. Yet it is the case that very few accounts are sensitive to the issues that occur when participants are bilingual. Bilingual language research can be daunting because of the number of language and developmental factors that must be considered to accurately measure and interpret results. For example, bilinguals have demonstrated elevated cognitive skills when compared to their monolingual peers. As difficult as it is to account for language history and cognitive abilities in a language study, the benefits of such a study are well worth the effort. Monolingual language processing models are founded in studies that examine how and when information is integrated while comprehending sentences. The language studies presented in this dissertation find their origins in monolingual language processing literature. Pupillometry, however, provides time-course information that has been missing in past studies. We use the findings as a foundation for developing bilingual language processing models. A battery of non-linguistic tasks were selected to ensure any language differences were attributable to the language studies and not byproducts of differential cognitive abilities. The dissertation begins with an overview of both monolingual and bilingual language processing to illustrate the differences in language processing models between monolingual and multilingual individuals. This is followed by a description of the cognitive differences that have been observed between bilingual and monolingual individuals. The battery of non-linguistic assessment tools used include : N-Back (working memory), Attentional Network Test (conflict monitoring), Auditory Flanker Task (conflict monitoring), TONI IQ test, Picture naming tasks in Spanish and English and an extensive language questionnaire. The language studies examine tried and true sentence types from the monolingual processing literature including : Garden Path (temporarily ambiguous sentences), Filler-Gap constructions and antecedent-anaphor agreement. Pupillary responses were collected as a continuous index of processing demands. The combination of pupil data and non-linguistic tasks provide an interesting perspective on bilingual sentence processing. The results suggest that age of acquisition and conflict monitoring abilities are associated as both bilingual groups demonstrated reduced conflict monitoring costs. On the other hand, in the language studies sequential bilinguals demonstrated pupillary responses that resemble those of the monolingual control group in one sentential context and not so in others, while the simultaneous bilingual demonstrated unique patterns. Unsurprisingly, age of acquisition is associated with differential cognitive abilities as well as differential online language processing, but the cognitive advantages do not seem to penetrate language processing in the sequential bilinguals. The findings suggest the interaction of language and cognition may be age dependent