A fundamental aspect of second language vocabulary acquisition is the learning
of the spoken and written form of words. This thesis examined two aspects of the acquisition of second language word form. First, Experiments 1 to 4 investigated factors the that affect the development of automaticity of both native and second language word recognition. This question was examined using a repetition priming paradigm which entailed a visual or auditory search for words hidden among distracters. The modality in which words were presented and their frequency within the language were manipulated.
Within-modality repetition priming effects were found for both native language and second language words; that is, a single presentation of a word lead to a reduction in its recognition latency when subsequently re-presented in the same modality. A change in modality across repeated presentations (i.e., cross-modal priming) lead to an attenuation of repetition priming effects for native language words and an elimination of priming effects for second language words. Priming effects were greater for low frequency words as opposed to high frequency words. These findings suggest that the development of automaticity of second language word recognition is a modality specific process; and in addition, it is a function of frequency of exposure.
Second, Experiments 5 and 6 investigated the nature of the individual differences that affect the ability to learn second language word forms. Studies reviewed indicate that the capacity of the phonological short-term memory system constrains second language vocabulary development (e.g., Service, 1992). Further, phonological sequence learning ability (i.e., the ability to learn the phonological regularities of a language) also contributes to three facets of lexical development: short term retention of a novel word form; speech segmentation; and automaticity of word recognition. In Experiments 5 and
6, the phonological short-term memory competence of participants was measured using a nonword repetition task. Likewise, phonological sequence learning skill was measured using a test of sensitivity to patterns of phoneme/syllable co-occurrence. Experiment 5 ascertained that phonological short term memory competence and phonological sequence learning skill are both independently related to the ability to learn novel foreign language
vocabulary within the context of an experimental learning task. Experiment 6 established that both of these variables are related to the amount of second language vocabulary learnt by students taking a novice level Spanish course. Further, phonological sequence learning aptitude is particularly implicated in second language auditory perceptual skill; whereas, phonological short-term memory competence is most involved in productive skill. Moreover, the combined influence of these two psycholinguistic variables acts as a powerful constraint to vocabulary development. These findings carry implications for
both the student and the teacher of second languages, and the researcher of bilingual representation.