Neurocognitive Correlates Of Syntactic Processing In Child And Adult Second Language Learners

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Author:
Abdollahi, Fatemeh A
Graduate Program:
Psychology
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
December 07, 2015
Committee Members:
  • Adriana Van Hell, Thesis Advisor
Keywords:
  • Second Language Learning; Bilingualism; Language Development; Co
Abstract:
Second languages (L2) are taught in millions of classrooms worldwide, and to almost all age groups. In spite of great efforts made to incorporate L2 teaching in classrooms, there are still fundamental questions of how the L2 is processed throughout learning, and what factors may affect this. The Competition and Proficiency-based Models describe how adult second language (L2) learning occurs. The Competition Model emphasizes the role of transfer of knowledge from the first language (L1) to L2 where grammatical structures are similar between languages, and competition between L1 and L2 in cases where grammatical structures are dissimilar. The Proficiency-based Model argues that as proficiency in the L2 changes, neurocognitive patterns of L2 processing will change, and learners will show increased sensitivity to L2 morphosyntax with increased proficiency. Neurocognitive and psycholinguistic studies on L2 learning have largely focused on highly proficient adult learners. Child L2 learners may differ fundamentally from adult L2 learners as children and adults are at different developmental stages, in terms of L1 development, as well as cognitively (e.g., smaller working memory span in children). In the present study, critical questions in second language acquisition were explored through electrophysiological and behavioral methods: 1) How is L2 learning influenced by the (dis)similarity between L1 and L2 structures, in children and adults? 2) How do individual differences in cognitive and affective variables associate with morphosyntactic processing, in children and in adults? Two groups of native English speaking participants at intermediate levels of proficiency in L2 Spanish completed a grammaticality judgment task to assess learned knowledge of Spanish morphosyntax. Adult learners were 18 years and older (late learners) and child learners were ages 9-11 years old (early learners). L2 learners were presented with Spanish sentences that have iii similar morphosyntactic structures in L1 and L2, have dissimilar morphosyntactic structures in L1 and L2, or have a unique morphosyntactic structure in the L2 that is not present in the L1. Building on the syntactic violation paradigm that is often used in ERP research, sentences were grammatically correct or incorrect. Participants read the sentences while electroencephalography (EEG) was recorded, and made a grammaticality judgment after having read the sentence. The manipulation of grammatically similar, dissimilar, or unique structures tested the predictions of the Competition Model; proficiency was held constant, and results were compared to ERP predictions across the L2-learning proficiency span (Steinhauer, White and Drury, 2009). In addition to the sentence reading experiment in the L2, sentence processing in the L1 was measured, and tasks were administered that measured working memory, executive functions, L1 proficiency, and attitude and motivation to learn an L2. Using correlations, I explored how variability in performance on these factors may be associated with sentence processing, in child and adult L2 learners. Adult learners demonstrated sensitivity to grammaticality through a P600 in the L2, but in only the dissimilar condition, suggesting both the Competition Model and Proficiency-based Model may not best represent L2 learning. In the L1 they demonstrated sensitivity as an AN+P600 in all three conditions. Measures of response dominance showed large variability in processing of both L1 and L2, within the learner group. This suggests that grand mean waveforms of traditional ERP can be misleading for actual processing patterns. In correlations of individual difference factors and language processing measures, only motivation and second language proficiency correlated, with increased proficiency with increased motivation. Child learners demonstrated no sensitivity to grammaticality in the L1. In the L2 there were no significant sensitivities, but emerging P600 patterns were present in processing sentences of iv structures similar between the L1-L2, and unique to the L2, though differential in topography from adult P600 processing. Within group variability was observed in response dominance, in both the L1 and L2. In correlations of individual difference factors and language processing measures, no factors correlated. Ultimately we conclude that 1) L2 learning is differentially influenced by (dis)similarity between L1-L2 in children (though only preliminary findings due to small sample), and adults. While children show emerging sensitivity based on (dis)similarity, adults did not show this effect. Again, due to large within group variation, we cannot conclude that these findings are not due to small child sample size. 2) Individual variation in working memory, cognitive control, L1 and L2 proficiency, and attitude/motivation to learn an L2 largely did not associate with language processing measures. Only motivation and L2 proficiency were found to have a positive association for adult L2 learners.