Poster C47, Wednesday, August 21, 2019, 10:45 am – 12:30 pm, Restaurant Hall
Phrase-Final Lengthening as a Word Segmentation Cue in French: A Bilingual ERP Investigation
Annie C. Gilbert1,2, Inbal Itzhak1,2, Max Wolpert1,2, Jasmine Lee1,2, Shari R. Baum1,2;1McGill University, 2Centre for Research on Brain, Language and Music, Canada
The literature on word segmentation has demonstrated that different languages rely on different strategies to isolate lexical items from the speech stream. For instance, English listeners tend to rely on lexical stress to locate word onsets, whereas French listeners tend to rely on phrase final lengthening to locate word offsets. Interestingly, later work demonstrated that English listeners also use phrase-final lengthening as a word offset cue in artificial language learning paradigms. Therefore, one might expect English-L1 listeners to use phrase-final lengthening to segment words in French, as French-L1 listeners do. To test this, we developed an EEG task involving a cross-modal (audiovisual) priming paradigm and tested 23 English-L1 / French-L2 (hereafter French-L2) listeners and 22 French-L1 listeners. The audio stimuli involved sentence pairs produced by a native speaker, built around syllable strings that can be interpreted as either two words (le vendeur d’or loge …) or as one bisyllabic word (le vendeur d’horloge …). Visual stimuli involved picture-prompts representing the interpretation of either the first syllable by itself (or), the two syllables as one word (horloge), or an unrelated word. Picture presentation was time-locked to the onset of the second syllable of the string, and each picture was presented with each sentence of a pair. EEG signals were pre-processed and artefact-free ERP trials were time-locked to the onset of picture presentation. Mean amplitude for electrodes Fz, FCz and Cz were extracted from a 100ms time window between 350ms to 450 ms after picture onset for each participant. Linear mixed effects models (LMEs) of N400 amplitudes triggered while listening to sentences from the two-word condition (or loge) revealed significant effects of picture type in both French-L1 and French-L2 listeners (although with slightly different magnitudes). Images of the first syllable alone (or) yielded the smallest N400s, followed by pictures of the two-syllable words (horloge); unrelated pictures yielded the largest N400s. These results suggest that both listener groups processed the lengthened first syllable as a marker of word offset, which impeded the activation of the bisyllabic interpretation, without blocking it completely. A picture type effect was also found in the one bisyllabic word condition (horloge), but here the picture of the first syllable (or) and the unrelated picture yielded similar N400 amplitudes, while the picture of the two-syllable word (horloge) yielded the smallest N400 amplitude. These results suggest that listeners had already parsed the two syllables as belonging to the same word, leading them to treat the other two pictures as unrelated to the sentence. Taken together, the results show that, as a group, these French-L2 listeners can rely on phrase-final lengthening to locate word offsets in French, leading to native-like segmentation patterns. Further analyses will investigate the impact of individual differences in language experience on performance.
Themes: Multilingualism, Speech Perception
Method: Electrophysiology (MEG/EEG/ECOG)