Phrase parsing in a second language as indexed by the closure positive shift: The impact of language experience and acoustic cue salience.

Despite the importance of prosodic processing in utterance parsing, a majority of studies investigating boundary localization in a second language focus on word segmentation. The goal of the present study was to investigate the parsing of phrase boundaries in first and second languages from different prosodic typologies (stress-timed vs. syllable-timed). Fifty English-French bilingual adults who varied in native language (French or English) and second language proficiency listened to English and French utterances with different prosodic structures while event-related brain potentials were recorded. The utterances were built around target words presented either in phrase-final position (bearing phrase-final lengthening) or in penultimate position. Each participant listened to both English and French stimuli, providing data in their native language (used as reference) and their second language. Target words in phrase-final position elicited closure positive shifts across listeners in both languages, regardless of the language-specific acoustic cues associated with phrase-final lengthening (shorter phrase-final lengthening in English compared to French). Interestingly, directional effects were observed, where learning to parse English as a second language in a native-like manner seemed to require a higher proficiency level than learning to parse French as a second language. This pattern of results supports the idea that L2 listeners need to learn to recognize L2-specific phrase-final lengthening regardless of the apparent similarity across languages and that some language combinations might present greater challenges than others.