| Previous studies have suggested that late learning of a second language (L2) tends to be more difficult and less successful as compared to first language (L1) learning, especially with regard to grammatical/syntactic as compared to lexical/semantic aspects of language. However, the role of proficiency has not yet been fully elucidated. The current study sheds light on several interconnected issues that concern late-acquired second language, in particular: (a) the mechanisms underlying L2 acquisition and how these compare to those of first language (L1); (b) the effects of experience and proficiency on L2 performance and neural representation; and (c) the differential effects of the critical period and of experience and proficiency on different domains of language (i.e., grammar/syntax vs. lexicon/semantics). Two studies are discussed here. Study 1 examines the production of regular and irregular Spanish verbal morphology. Study 2 examines Event-Related Potentials (ERPs) in response to several lexical and grammatical aspects of Spanish: regular and irregular verbal morphology, noun and gender morpho-syntax, lexical-semantics, and syntactic phrase structure. Results reported here pertain to the examination in Study 2 of how Spanish semantic and syntactic knowledge are represented and processed by late L2 learners at different levels of experience and proficiency, as compared to L1 Spanish speakers, using evidence from ERPs. L2 Spanish participants were all late-acquirers (after the age of 17) of Spanish, and were at either a low or an advanced level of experience and proficiency in the L2. Participants were visually presented correct sentences as well as sentences containing either phrase structure or lexical semantic violations in Spanish. Results showed similar responses to semantic violations in L1 and both low and advanced experience/proficiency L2 (N400s). However, violations of phrase structure yielded similar responses in L1 and advanced experience/proficiency L2 (LANs + P600s), but not in lower experience L2. This pattern of results suggests that not only age of acquisition but also experience and proficiency do indeed play an important role in how late-acquired L2 grammar/syntax is processed. |
