Zawiszewski, A. , Erdocia, K. & Laka, I.
University of the Basque Country
Several Event-Related Potentials (ERPs) studies on native versus non-native language processing argue that native/non-native differences result either from language proficiency, age of acquisition (AoA) or transfer from L1, but the relative impact of these and other factors in bilingual language representation and processing are still not well understood (Kotz 2009). In order to investigate these issues, we conducted a series of experiments in Basque language with native Basque speakers and highly proficient Spanish/Basque bilinguals (AoA=3). The experimental conditions were (i) linearization (verb-before-object (VO) in Spanish and object-before-verb (OV) in Basque), (ii) verb agreement (only with subject in Spanish, with subject and object in Basque) and (iii) argument alignment (accusative in Spanish versus ergative in Basque). Our results show that both groups behaved differently with regard to (iii) ergative case, but similarly when dealing with (i) different linearizations (OV/VO) and with (ii) subject and object verb agreement violations. Spanish/Basque bilinguals displayed a smaller P600 component, and more errors in the grammaticality judgment task for ergative case compared to Basque/Spanish bilinguals. A similar ERP pattern and comparable behavioral measures obtained for non-canonical word-orders (frontal negativities+P600) and verb agreement violations (N400-P600) in both groups. These results indicate that some aspects of language-variation have a deeper impact in bilingual processing even at high proficiency and early AoA, than others. Our findings suggest that not all cross-linguistic differences are equivalent regarding bilingual processing (McLaughin et al. 2010), an issue that is relevant to fully understand the neural underpinnings of linguistic structure.