Slide Slam H16
Speech perception slopes across the first year of life: Maturation of consonant perception, but not vowel perception, predicts lexical skills at 12 months
Gesa Schaadt1,2, Annika Werwach3, Hellmuth Obrig1,3, Angela D. Friederici1, Claudia Männel1,3,4; 1Max Planck Institute for Human Cognitive and Brain Sciences, 2Freie Universität Berlin, 3Medical Faculty, University Leipzig, 4Charité-Universitätsmedizin Berlin
Consonants and vowels differentially contribute to lexical acquisition across the first year of life, with a preferential role of consonants from around 8 months (Nishibayashi & Nazzi, 2016; Poltrock & Nazzi, 2015). Infants’ differential reliance on consonants versus vowels in word recognition has been shown to predict later lexical outcome (Von Holzen et al., 2018; Von Holzen & Nazzi, 2020). This predictive value, however, has not yet been evaluated for infants’ longitudinal trajectories of consonant and vowel perception. We here aimed to study brain markers that can capture perceptual changes before infants show vowel or consonant preferences in word recognition behaviorally. We examined longitudinally (at ages 2, 6, and 10 months) whether infants’ (n= 59) maturation trajectories of vowel and consonant discrimination differentially predict their later lexicon. At each age, we measured infants’ discrimination abilities in a multi-feature paradigm by means of the electrophysiological mismatch responses (MMR) to consonant and vowel deviants. At 12 months, we assessed infants’ lexical skills via the German version of the Communicative Development Inventories (parental questionnaire; Grimm & Doil, 2000). Using separate second-order latent growth curve models for each deviant type, we tested the maturational slopes of vowel and consonant MMRs between 2 and 10 months as predictors of word production and perception at 12 months, controlling for the effect of individual MMR amplitudes at each assessment. The consonant MMR slope significantly predicted word perception (p = .003) and production (p < .0001), whereas there were no effects for the vowel MMR slope for perception (p = .867) or production scores (p = .502). Note that only for consonants at 2 months, the single time point MMR predicted later receptive (p < .0001) and productive lexicon (p = .006), while the MMR’s maturational slope had an additive predictive value. These results confirm a prominent role of consonant, but not vowel, discrimination for word learning from early on. Given that a behavioral preference for consonants in word recognition only evolves towards the end of the first year (Nishibayashi & Nazzi, 2016; Poltrock & Nazzi, 2015; Von Holzen et al., 2018; Von Holzen & Nazzi, 2020), our study points to a much earlier predictive value of consonant perception and to a particular role of the longitudinal maturation of this perceptual skill in lexical acquisition. References: Grimm, H., & Doil, H. (2000). ELFRA - Elternfragebögen für die Früherkennung von Risikokindern. Hogrefe. Nishibayashi, L.-L., & Nazzi, T. (2016). Vowels, then consonants: Early bias switch in recognizing segmented word forms. Cognition, 155, 188–203. Poltrock, S., & Nazzi, T. (2015). Consonant/vowel asymmetry in early word form recognition. Journal of Experimental Child Psychology, 131, 135–148. Von Holzen, K., & Nazzi, T. (2020). Emergence of a consonant bias during the first year of life: New evidence from own‐name recognition. Infancy, 25(3), 319–346. Von Holzen, K., Nishibayashi, L.-L., & Nazzi, T. (2018). Consonant and Vowel Processing in Word Form Segmentation: An Infant ERP Study. Brain Sciences, 8(2), 24.