Modeling Second Language Lexical Development

The construct of lexical competence is a moot point in SLA research. This studyinvestigated the mental course of lexical development in a second language. Thenotion of "lexical unit", a coalition of a single lexical form and a solitary meaning, isadvocated. Considering the three practical restraints in an L2 learning environment:the lack of sufficient contextualized input, the limited opportunities forcomprehensible output and the presence of a prior conceptual and L1 lexical system,and on the basis of the analysis of the intra-lexical psycholinguistic determinants ofL2 vocabulary acquisition, the role of noticing in SLA and the features of lexicalrepresentation in the bilingual mental lexicon, a tentative six-stage psycholinguisticmodel monitoring lexical evolution is proposed: (1) the form-noticing stage when theformal specifications of an L2 lexical unit are temporarily stored in the verbalshort-term memory; (2) the form-meaning mapping stage when L2 lexical forms aremapped to the existing L1 lexical meanings and thus direct L2-L1 link is constructed;(3) the morpho/syntac growth stage when the acquired morphological and syntacticalspecifications of L2 lexical unit are stored in learners'episodic memory; (4) thenetwork building stage when the connections between L1/L2 lexical units in terms ofthe semantic, syntactic, morphological and phonological/orthographical features areset up; (5) the incorporation stage when all the L2 lexical information is integratedand a strong and direct L2-Concept linkage is built up; and optionally (6) the attritionstage when an L2 lexical unit is gradually deactivated, reflected by the weakenedlexical links due to a period of nonuse of the target language. The implications of thismodel, probing into issues such as the construct of lexical competence, the productiveL2 lexical errors and L2 vocabulary pedagogy, are also discussed.