Distributional cues and the onset bias in early word segmentation.

Abstract

In previous infant studies on statistics-based word segmentation, the unit of statistical computation was always aligned with the syllabic edge, which had a consonant onset. The current study addressed whether the learning system imposes a constraint that favors word forms beginning with a consonant onset over those beginning with an onsetless sub-syllable, by examining infants' segmentation of vowel-initial non-words in French liaison. French-learning 20- and 24-month-old infants (N = 64) were familiarized with sentences containing variable liaison consonants preceding the same vowel-initial non-word (e.g., /n/onche, /z/onche, /r/onche, /t/onche), such that the distributional cues supported the sub-syllabic target (e.g., onche). After familiarization, we tested sub-syllabic statistical segmentation by presenting the vowel-initial target (e.g., onche) versus another non-familiarized vowel-initial word (e.g., èque). Another group of infants was tested with a consonant-initial mis-segmentation of the target (e.g., zonche) versus another non-familiarized consonant-initial word (e.g., zèque). Results showed that 20-month-olds failed to segment the vowel-initial targets, but they mis-segmented the targets as consonant-initial, indicating that the onset bias dominated over sub-syllabic statistics for word segmentation at this age. Twenty-four-month-olds showed ambiguous interpretations (i.e., both vowel-initial segmentation and consonant-initial mis-segmentation), suggesting that the use of statistics to segment sub-syllabic words was emerging while the onset bias continued to have an impact.

Development of Liaison Representation and its Top-Down Influence on Word Processing in Infants

“…For instance, they mis-segment the vowel-initial word ongle as consonant-initial (zongle) (e.g., Chevrot, Chabanal, & Dugua, 2007;Chevrot, Dugua, & Fayol, 2009) from liaison cases such as les ongles "the nails" and des ongles "some nails", in which the /z/ liaison consonant surfaces (i.e., les /z/ongles, des /z/ongles). Consonant-initial mis-segmentation has also been shown in perceptual studies with 20-and 24-month-old infants (Babineau & Shi, 2014). These findings are consistent with the onset bias in phonological theory (Kager, 1999), and with lexical access theories in psycholinguistics (Syllable Onset Segmentation Heuristic: Content, Dumay, & Frauenfelder, 2000;Possible Word Constraint: Norris, McQueen, Cutler, & Butterfield, 1997).…”

“…This success in finding the word boundary, even though it was misaligned with the syllabic edge, was likely guided by their top-down knowledge about the /z/ liaison consonant as unrelated to Word 2. These results are striking in comparison with the responses of younger infants in Babineau and Shi (2014), in which 20-month-olds showed a strong consonant-initial interpretation and ignored the disambiguating contexts of variable liaisons that supported the vowel-initial word boundary. Here the familiarization stimuli contained no such disambiguating cues, and 30-month-olds showed an adult-like vowel-initial bias.…”

“…The coexistence of two interpretations was found with 24-montholds in Babineau and Shi (2014). Hence, in Experiment 2b we tested the possibility that 30-month-olds may segment a consonant-initial form (i.e., zonche, zèque) upon hearing the unambiguous phrases (un zonche, un zèque).…”

“…It is interesting to note that in Babineau and Shi (2014) the 24-month-olds' interpretation of /z/ liaison cases was fully ambiguous: infants accepted both vowel-initial and consonant-initial interpretations, showing no stronger bias for either. This was unlike adults, who only showed a liaisondriven vowel-initial bias when the pivotal consonant was /z/ (Tremblay & Spinelli, 2013).…”

“…A recent study (Babineau & Shi, 2014) tested the hypothesis that infants may track distributional cues to correctly segment words in liaison phrases. In their experiments toddlers were presented with sentences containing a novel vowel-initial word preceded by different liaison consonants as the syllabic onset (e.g., ces /z/onches, petit /t/onche, mon /n/onche, premier /r/onche), providing distributional cues to vowel-initial word segmentation.…”