幼少期の第一、第二言語レキシコン処理と記憶における生物学的証拠に関する検証

Abstract

This study examines the brain’s biological evidence in L1 and L2 lexical acquisition and memory. By developing the theory of absence of vocabulary labels suggested by Lenneberg, the study clarified the relationship between language acquisition and biological states of brain areas and size according to latest observation data. To raise accuracy and to reconstruct the problem based on previous studies, the study emphasized the following five new points. They are; brain areas related to language information, its compatibility and parallel relations with acquisition, correlations with already learnt L1, early L2 and late L2 learners’ biological and neurological limitations, and comparisons of collateral effects. Significant findings include divergence in general memory mechanism and linguistic memory mechanism, temporal dynamics of linguistic memory, increase in brain size, acquisitional stabilization and development through reinforcement rather than augmentation, and dissimilarity in language processing mechanisms between early and late L2 learners. Linguistic information constructed from infancy to childhood is based on phonological binding. Linguistic knowledge before the critical period of age 12 to 13 is at a developmental stage in grammatical and semantic web of cognizance, and as information, processing is proven to be different from grammatical processing, in terms of neurological dimension. Also, the existence of the web of meaning is seen to be related to the reason for the existence of L2 critical period.