2018 Sat Poster 6505

Saturday, November 3, 2018 | Poster Session II, Metcalf Small | 3:15pm

Early consonant bias in recognizing segmented word forms in Japanese-learning infants
L. Nishibayashi, R. Mazuka

In order to build their lexicon, infants need the ability to recognize previously heard/stored word forms. Nespor et al. (2003) proposed that at the lexical level, consonants would be more important than vowels for identifying the lexical entities and thus would be preferentially used for word recognition. This is called the consonant bias (C-bias) hypothesis and is argued to facilitate early stages of language acquisition. Many studies on adult lexical tasks (Cutler et al., 2000; Carreiras & Price, 2008), word segmentation tasks (Bonatti et al., 2005), and on infant word learning (Nazzi, 2005; Hochmann et al., 2011) found results consistent with this hypothesis. To date, however, little is known about the origin of this C-bias and when it appears. Studies have found that while French- and Italian-learning infants seem to acquire the C-bias between 6 and 8/12 months of age (Nishibayashi & Nazzi, 2016; Hochmann et al., 2011, 2018), Danish-learning toddlers have an opposite vowel bias (V-bias, Højen & Nazzi, 2016). The fact that Danish has more vowels than consonants (Bleses et al., 2011) could be the reason for the V-bias. But could the frequency of vowel occurrences in speech, and not necessarily the richness of a vowel category, also lead to a V-bias? We tested this prediction using Japanese (23 consonants and 5 vowels) where vowels occur as frequently as consonants in speech, at a much higher rate than in French or in English, due to its limited syllable inventory (Tsuji et al., 2014).

The present study followed Nishibayashi & Nazzi (2016)’s experimental design to examine whether Japanese-learning 8-month-olds present a C-bias or a V-bias in recognizing previously segmented words. To do so, we first assessed infants’ segmentation abilities in Experiment 1 using the Headturn Preference Procedure: twenty infants were familiarized with passages containing two three-mora bisyllabic target words (e.g., KEIGI) and then tested on repetitions of the target words versus control words. Results (Figure 1, left panel) show that infants had a significant preference for target words over control words (p < .001), hence a familiarity preference suggesting that they were able to segment the target words. In Experiment 2, 32 infants were familiarized similarly to Experiment 1 and then were presented with both vowel and consonant mispronunciations of the target words (e.g., KOUGI vs. TEIGI). Results of Experiment 2 (Figure 1, right panel) show that, at 8 months, Japanese-learning infants oriented significantly longer to the vowel mispronunciations than to the consonant mispronunciations (p = .037). Since Experiment 1 showed a familiarity preference, this finding suggests that the infants considered the vowel mispronunciations as closer to the target words compared to the consonant mispronunciations, and consequently that they have a C-bias.

The results that Japanese-learning 8-month-olds have a C-bias indicate that it is not  the sheer quantity of vowels occurring in the input that leads infants to a V-bias. This is the first time such evidence is found in infants acquiring Japanese. However, future studies will have to determine whether such a phonological bias can be found earlier.

References

Bleses, D., Basbøll, H., & Vach, W. (2011). Is Danish difficult to acquire? Evidence from Nordic past-tense studies. Language and Cognitive Processes, 26(8), 1193–1231.

Bonatti, L. L., Pen, M., Nespor, M., & Mehler, J. (2005). Linguistic Constraints on Statistical Computations, 16(6), 451–459.

Carreiras, M., & Price, C. J. (2008). Brain activation for consonants and vowels. Cerebral Cortex, 18(7), 1727–35.

Cutler, A., Sebastián-Gallés, N., Soler-Vilageliu, O., & Van Ooijen, B. (2000). Constraints of vowels and consonants on lexical selection: Cross-linguistic comparisons. Memory & Cognition, 28(5), 746–755.

Hochmann, J.-R., Benavides-Varela, S., Nespor, M., & Mehler, J. (2011). Consonants and vowels: different roles in early language acquisition. Developmental Science, 14(6), 1445–1458.

Hochmann, J.-R., Benavides-Varela, S., Fló, A., Nespor, M., & Mehler, J. (2018). Bias for vocalic over consonantal information in 6-month-olds. Infancy, 23(1), 136–151.

Højen, A., & Nazzi, T. (2016). Vowel bias in Danish word-learning: Processing biases are language- specific. Developmental Science, 19(1), 41–49.

Nazzi, T. (2005). Use of phonetic specificity during the acquisition of new words: differences between consonants and vowels. Cognition, 98(1), 13–30.

Nespor, M., Peña, M., & Mehler, J. (2003). On the different roles of vowels and consonants in speech processing and language acquisition. Lingue E Linguaggio, 2(2), 203–229.

Nishibayashi, L. L., & Nazzi, T. (2016). Vowels, then consonants: Early bias switch in recognizing segmented word forms. Cognition, 155, 188–203.

Tsuji, S., Nishikawa, K., & Mazuka, R. (2014). Segmental distributions and consonant-vowel association patterns in Japanese infant- and adult-directed speech. Journal of Child Language, 41(6), 1276–1304.