Hybrid model: investigating bilingual language production through code-switching
Bilingual language production is an area of psycholinguistic research that has received recent attention. Experimental evidence from bilingual word production tasks has shown that both languages share representation at the mental lexicon, meaning that concepts will lead to the activation of the target lemma from both languages. Investigations into how bilinguals organise two grammatical systems has largely come from cross-linguistic syntactic priming. Syntactic priming is a phenomenon in which speakers are likely to repeat a syntactic structure in which they have recently experienced: cross-linguistic syntactic priming is when a speaker uses a syntactic structure in one language because they have recently experienced that structure from the other language. Together, the study of the bilingual lexicon and syntactic representations have led to the development of models of bilingual language production. A more recent experimental paradigm is the forced code-switching task in which participants are required to code-switch in some experimental trials. The forced code-switching task is the experimental method used in this thesis. This thesis aims to use this experimental task to test my proposed model of bilingual language production, the Hybrid model. The Hybrid model proposes an architecture of the bilingual lemma stratum that differs from previous models of bilingual language production. The Hybrid model assumes that lexical items from one language can be produced using the syntactic structure of the other language. In this thesis I report seven experiments testing the proposed lemma stratum of the Hybrid model. Experiment 3.1 investigated the production of prenominal adjectives of English and postnominal adjectives of Spanish during code-switching between Spanish and English to see whether speakers would use the lexical items from one language with the word order of the other language. The results showed that speakers almost exclusively used the word order dictated by the language in which they produced the lexical items. This did not support the proposed lemma stratum of the Hybrid model. Experiments 4.1 and 4.2 investigated gender agreement of possessive pronouns during code-switching between Spanish and English to see if the possessive pronoun from one language could be produced using the gender agreement rules from the other language. The results showed that English-Spanish and Spanish-English bilinguals sometimes produced possessive pronouns in one language with the gender agreement rules from the other language. It was demonstrated that this effect was not due to a misunderstanding of the gender agreement rules of the participants’ second language. These results support the proposed lemma stratum of the Hybrid model. Experiments 5.1 and 5.2 investigated gender agreement of possessive determiners during code-switching between French and English to see if the possessive determiner from one language could be produced using the gender agreement rules from the other language. The results showed that English-French and French-English bilinguals sometimes produced possessive determiners in one language with the gender agreement rules from the other language. It was demonstrated that this effect was not due to a misunderstanding of the gender agreement rules of the participants’ second language. These results support the proposed lemma stratum of the Hybrid model. Experiments 6.1 and 6.2 investigated the production of determiners during code-switching between German and English. Of specific interest was whether English determiners would be produced more often than German determiners because German determiners hold case information whereas English determiners do not. In Experiment 6.1 participants were forced to code-switch before an accusative NP. The results showed that English determiners were sometimes produced within the German NPs, but German determiners were not used within the English NPs. In Experiment 6.2 participants were forced to code-switch before a dative NP. The results showed that participants almost exclusively produced the determiner in the same language as the target noun. Analysing the frequencies of the determiner used within the experimental session, the different pattern of results between Experiments 6.1 and 6.2 may be a result of a competition for selection between determiner forms. To conclude the thesis I discuss the implications of these findings, what they mean for the Hybrid model, and directions for future research.