From Flexibility to Constraint: The Contrastive Use of Lexical Tone in Early Word Learning

Abstract

Infants must develop both flexibility and constraint in their interpretation of acceptable word forms. The current experiments examined the development of infants’ lexical interpretation of non-native variations in pitch contour. Fourteen, 17-, and 19-month-olds (Experiments 1 and 2, N = 72) heard labels for two novel objects; labels contained the same syllable produced with distinct pitch contours (Mandarin lexical tones). The youngest infants learned the label-object mappings, but the older groups did not, despite being able to discriminate pitch differences in an object-free task (Experiment 3, N = 14). Results indicate that 14-month-olds remain flexible regarding what sounds make meaningful distinctions between words. By 17–19 months, experience with a non-tonal native language constrains infants’ interpretation of lexical tone.

The Distribution of Talker Variability Impacts Infants’ Word Learning

“…These possibilities are potentially consistent with task-complexity explanations for early failures to learn minimal-pair words (e.g., the PRIMIR model; Werker & Curtin, 2005). Recent work by Hay et al (2015) indicates that 14-month-old English-learning infants will differentiate words using tones in the Switch paradigm, even though English does not use tone contrastively. This might suggest that infants at this age can learn words using dimensions that are contrastive cross-linguistically (even if not contrastive in their native language), but not dimensions that are never contrastive, like gender.…”

“…They are willing to treat pitch contour as lexically contrastive (Singh et al, 2014;Frota et al, 2012;Hay et al, 2015; see also Quam & Swingley, 2010). Until roughly 20 months of age, children are generally more willing than older learners to accept even non-word-like symbols, such as gestures, noise-maker sounds, and pictograms, as potential words (Namy, 2001;Namy & Waxman, 1998;Woodward & Hoyne, 1999).…”

“…At the same time, younger infants are more willing than older learners to attend to acoustic dimensions that are not contrastive in their language. For instance, before about 17 months, English-learning infants are willing to learn and differentiate words based on their pitch patterns (Singh et al, 2014;Hay et al, 2015; see also Quam & Swingley, 2010). Thus, even after the early "perceptual reorganization" for native-language sound discrimination, infants are still learning to attend to contrastive dimensions and listen through noncontrastive dimensions in word learning.…”

Finding patterns and learning words: Infant phonotactic knowledge is associated with vocabulary size

“…Testing infants at around 19 months of age allowed us to examine a range of productive vocabulary sizes and the association with phonotactic learning performance. The participants’ age range also overlaps with the age ranges of prior research investigating the development of early phonological representations (Graf Estes et al, 2011; Hay, Graf Estes, Wang, & Saffran, 2015; Mulak, Best, Tyler, Kitamura, & Irwin, 2013; White & Aslin, 2011). …”

Tone Attrition in Mandarin Speakers of Varying English Proficiency

“…Tone-language learners' tone discrimination is maintained within the first year of life, whereas intonation-language learners' tone discrimination worsens (Mattock & Burnham, 2006;Mattock, Molnar, Polka, & Burnham, 2008;Yeung, Chen, & Werker, 2013; see also Harrison, 2000). At the lexical level, language-specific pitch processing seems to develop by about 11 months for recognition of word forms (Singh & Foong, 2012) and by about 17 months for word learning (Hay, Graf Estes, Wang, & Saffran, 2014;Quam & Swingley, 2010;Singh, Hui, Chan, & Golinkoff, 2014).…”