Vocabulary Size Is a Key Factor in Predicting Second Language Lexical Encoding Accuracy

Individual differences in attention control and the processing of phonological contrasts in a second language

This study investigated attention control in L2 phonological processing from a cognitive individual differences perspective, to determine its role in predicting phonological acquisition in adult L2 learning. Participants were 21 L1-Spanish learners of English, and 19 L1-English learners of Spanish. Attention control was measured through a novel speech-based attention-switching task. Phonological processing was assessed through a speeded ABX categorization task (perception) and a delayed sentence repetition task (production). Correlational analyses indicated that learners with more efficient attention switching skill and faster speed in correctly identifying the target phonetic features in the speech dimension under focus could perceptually discriminate L2 vowels at higher processing speed, but not at higher accuracy rates. Thus, attentional flexibility provided a processing advantage for difficult L2 contrasts but did not predict the extent to which precise representations for the target L2 vowels had been established. However, attention control was related to L2 learners' ability to distinguish the contrasting L2 vowels in production. In addition, L2 learners' accuracy in perceptually distinguishing between two contrasting vowels was significantly related to how much of a quality distinction between them they could make in production.

Difficulties in decoupling articulatory gestures in L2 phonemic sequences: the case of Mandarin listeners' perceptual deletion of English post-vocalic laterals

Nonnative or second language (L2) perception of segmental sequences is often characterised by perceptual modification processes, which may "repair" a nonnative sequence that is phonotactically illegal in the listeners' native language (L1) by transforming the sequence into a sequence that is phonotactically legal in the L1. Often repairs involve the insertion of phonetic materials (epenthesis), but we focus, here, on the less-studied phenomenon of perceptual deletion of nonnative phonemes by testing L1 Mandarin listeners' perception of post-vocalic laterals in L2 English using the triangulating methods of a cross-language goodness rating task, an AXB task, and an AX task. The data were analysed in the framework of the Perceptual Assimilation Model (PAM/PAM-L2), and we further investigated the role of L2 vocabulary size on task performance. The experiments indicate that perceptual deletion occurs when the post-vocalic lateral overlaps with the nucleus vowel in terms of tongue backness specification. In addition, Mandarin listeners' discrimination performance in some contexts was significantly correlated with their English vocabulary size, indicating that continuous growth of vocabulary knowledge can drive perceptual learning of novel L2 segmental sequences and phonotactic structures.

Fuzzy Lexical Representations in Adult Second Language Speakers

We propose the fuzzy lexical representations (FLRs) hypothesis that regards fuzziness as a core property of nonnative (L2) lexical representations (LRs). Fuzziness refers to imprecise encoding at different levels of LRs and interacts with input frequency during lexical processing and learning in adult L2 speakers. The FLR hypothesis primarily focuses on the encoding of spoken L2 words. We discuss the causes of fuzzy encoding of phonological form and meaning as well as fuzzy form-meaning mappings and the consequences of fuzzy encoding for word storage and retrieval. A central factor contributing to the fuzziness of L2 LRs is the fact that the L2 lexicon is acquired when the L1 lexicon is already in place. There are two immediate consequences of such sequential learning. First, L2 phonological categorization difficulties lead to fuzzy phonological form encoding. Second, the acquisition of L2 word forms subsequently to their meanings, which had already been acquired together with the L1 word forms, leads to weak L2 form-meaning mappings. The FLR hypothesis accounts for a range of phenomena observed in L2 lexical processing, including lexical confusions, slow lexical access, retrieval of incorrect lexical entries, weak lexical competition, reliance on sublexical rather than lexical heuristics in word recognition, the precedence of word form over meaning, and the prominence of detailed, even if imprecisely encoded, information about LRs in episodic memory. The main claim of the FLR hypothesis – that the quality of lexical encoding is a product of a complex interplay between fuzziness and input frequency – can contribute to increasing the efficiency of the existing models of LRs and lexical access.