How Words are Represented in Bilingual Memory

Abstract

This dissertation examines the Episodic L2 Hypothesis (Jiang & Forster, 2001), which postulates that first language (L1) words are represented in a specialized system that is devoted to one's L1, i.e., lexical memory, and second language (L2) words are represented in a more general memory system that is not specialized for language, i.e., episodic memory. This idea was based on a double dissociation found in masked translation priming studies - i.e., L2-L1 translation priming is obtained in episodic recognition but not lexical decision, whereas L1-L2 translation priming is obtained in lexical decision but not episodic recognition (Jiang & Forster, 2001; Finkbeiner, 2005). These results are interpreted to show that the decision systems are tuned to episodic memory during the performance of episodic recognition task. Hence, since L2 words are represented episodically, L2 primes assist the recognition of L1 targets, while L1 words are represented lexically, so L1 primes do not assist the recognition of L2 targets.A series of masked priming studies were conducted in this dissertation to further examines this Episodic L2 Hypothesis. Experiment 1 partially confirmed Jiang and Forster's (2001) results with highly-proficient L2 bilinguals, showing that these bilinguals indeed store their L2 words in episodic memory. Experiments 2 to 5 were conducted to examine the "episodic" nature of this memory system by showing that newly-learned L2-like words can be effective as masked translation primes for L1 targets in episodic recognition but not in lexical decision. Experiments 6 to 8 were conducted to eliminate other possible accounts as to why there is a dissociation of L2-L1 translation priming between these two tasks. Finally, Experiment 9 offers further evidence to the Episodic L2 Hypothesis by using masked repetition priming in episodic recognition.These studies, overall, lend support to the hypothesis that L2 words are indeed represented in episodic memory. The final chapter discusses the mechanisms behind masked translation priming, the nature of the memory system that L2 words are stored in, and generally on L2-L1 translation priming.