Morphosyntactic processing in bilinguals-erp evidence

  1. Margaret Gillon Dowens
Supervised by:
  1. Manuel Francisco Carreiras Valiña Director
  2. Horacio A. Barber Friend Director

Defence university: Universidad de La Laguna

Year of defence: 2011

Committee:
  1. Sonia Kotz Chair
  2. Carlos Javier Álvarez González Secretary
  3. Antoni Rodríguez Fornells Committee member
  4. Alberto Domínguez Martínez Committee member
  5. María Teresa Bajo Molina Committee member
Department:
  1. Psicología Cognitiva, Social y Organizacional

Type: Thesis

Teseo: 311231 DIALNET

Abstract

The study of second language acquisition and particularly of how the brain acquires and processes a second language (L2) after childhood is a research area which has become increasingly important not only in its own right but also due to the significant social and educational implications of the findings from these studies. However, despite the recent increase in research in this area, little is still known about how an L2 acquired after childhood is represented, how it is processed and whether this is indeed qualitatively different to what happens in childhood L2 acquisition. There is a common assumption that L2 attainment is primarily or even exclusively a function of age and that native-like performance is not attainable unless the L2 is acquired during early childhood (Eubank & Gregg, 1999; Johnson & Newport, 1991). This idea of a maturationally-constrained critical or sensitive period for second language acquisition underlies, for example, the Failed Functional Features Hypothesis (Hawkins & Chan, 1997) and the Shallow Structure Hypothesis (Clahsen & Felser, 2006a), among other models of L2 acquisition and processing. However, recent experimental data do not unequivocally bear out this observation (Rossi, Gugler, Friederici, & Hahne, 2006, also see Birdsong, 2006 for an overview) and there is now a growing awareness that there is not one, but a number of different factors that can influence the processing of a second language acquired after childhood. These factors may include language proficiency (Ojima, Nakata, & Kakigi, 2005), similarity of the syntactic structures of the first language (L1) and the L2 (Jeong, Sugiura, Sassa, Yokoyama, et al., 2007) and limitations of general cognitive resources such as working memory (McDonald, 2006). There is, thus, a need for more detailed information and more empirical evidence about the nature of these different factors affecting adult L2 acquisition and processing, how they interact and how they apply to different language components. To answer these questions with precision, there is a particular need for on-line and neuro-imaging studies of late L2 processing, as most studies to date have provided behavioural data. While this has been very useful, it is also the case that behavioural results that indicate L1-L2 equivalence can in fact mask underlying processing differences. Thus, experimental data from online electrophysiological and neuroimaging studies is essential to clarify these issues. This is the aim of the present study. Using the Event Related Potentials (ERP) technique, which is particularly well suited to studying language processes due to its precise temporal resolution, the electrophysiological correlates of grammatical gender and number processing were examined in highly proficient late L2 learners of Spanish from different L1 backgrounds (English and Chinese), to explore the roles of age of acquisition, L2 proficiency and language transfer effects in L2 morphosyntax processing. Results from both studies indicate clear transfer effects and are more compatible with models such as Full Transfer Full Access (FTFA) and the Competition Model than with traditional models based on critical periods for second language acquisition. The results also indicate the importance of studying higher proficiency late L2 learners and of considering the length and nature of exposure to the L2. This dissertation is organized as follows: Chapter 1 presents a general introduction to the area of bilingualism and some important issues, concepts and definitions in this area. This is followed by a more detailed discussion of the key factors affecting L2 acquisition and processing that will be explored in the experimental study. Firstly, there is a discussion of the question of age of acquisition (AoA), the Critical Period Hypothesis (CPH) and some alternative accounts of age effects in L2 studies. The second key issue examined is L2 proficiency and results are discussed of some online and neuroimaging studies which have considered the role of L2 proficiency when comparing L1 and L2 processing. The third factor discussed is cross-linguistic influence, that is, the role of the L1 in L2 processing and the possibility of L1 feature transfer. Finally, some contrasting psycholinguistic models of L2 processing are outlined in terms of their predictions about the relative importance of these different factors in L2 acquisition and processing. Chapter 2 describes the contrasting features of Spanish, English and Chinese in terms of the morphosyntactic processing features examined in this study,specifically grammatical gender and number processing. This is followed by an introduction to the Event Related Potential (ERP) technique used in the experiments and a review of relevant ERP literature. Finally in this chapter are the predictions for the experiments according to the psycholinguistic models outlined in Chapter 2. Chapter 3 describes the first experiment with Chinese-Spanish late bilinguals and reports the results of this experiment.