Mandarin-learning Infants Research Articles

Perceptual asymmetry in lexical tone perception

Directional asymmetries have been documented in both infant and adult perception of lexical tones. For example, Tsao (2008) found that a stimulus change from the background mandarin T1 (55) to the target Mandarin T3 (213) was easier than the reverse among one-year-old Mandarin learning infants. Yeung et al. (2013) reported that 4- and 9-month-old Mandaring learning infants are better at Cantonese tone discrimination after being familiarized with T2 (25) than with T3 (33). Francis and Ciocca (2003) found that native Cantonese speakers’ tone discrimination was better when the first syllable was higher in frequency (about 4 Hz) than the second syllable. Finally, in an ERP study, Politzer-Ahles et al. (2016) found that Mismatch Negativity (MMN) was attenuated among both native and non-native Mandarin listeners when Mandarin T3 was the standard and another deviant in comparison to the reverse. In this talk, we will report results from two studies examining the effects of memory load and first language on perceptual asymmetry patterns in adult lexical tone perception among native English, Mandarin, and Cantonese speakers. Application of theoretical models including the perceptual magnet effects and perceptual assimilation will be discussed.Directional asymmetries have been documented in both infant and adult perception of lexical tones. For example, Tsao (2008) found that a stimulus change from the background mandarin T1 (55) to the target Mandarin T3 (213) was easier than the reverse among one-year-old Mandarin learning infants. Yeung et al. (2013) reported that 4- and 9-month-old Mandaring learning infants are better at Cantonese tone discrimination after being familiarized with T2 (25) than with T3 (33). Francis and Ciocca (2003) found that native Cantonese speakers’ tone discrimination was better when the first syllable was higher in frequency (about 4 Hz) than the second syllable. Finally, in an ERP study, Politzer-Ahles et al. (2016) found that Mismatch Negativity (MMN) was attenuated among both native and non-native Mandarin listeners when Mandarin T3 was the standard and another deviant in comparison to the reverse. In this talk, we will report results from two studies examining the effects of memory load and first language on perce...

Protracted Development on Native Tone Interpretation: Evidence From Mandarin-Learning Infants' Novel Word Learning.

Studies have shown that infants from cultures with tone languages develop categorical perception of their native lexical tone before their first birthday, but few studies have explored whether, and when, they interpret the phonemic function of lexical tone in word learning. Two habituation-switch experiments were conducted to explore whether Mandarin-learning infants could exploit tonal cues during their word learning, and detect a change when the association of two word-object pairs was switched. In Experiment 1, two words were solely differentiated by their lexical tones (/fāi/ vs. /făi/), and Mandarin-learning infants failed to detect the switch of tones at 14 months, but succeeded at 18 months. In Experiment 2, two words were markedly distinct (/fāi/ vs. /bǒu/), and infants could detect the change of words as early as 14 months. The results indicate that infants may not refer to the lexical function of tone during their novel word learning until 18 months, even though infants from birth are able to distinguish the Tone 1 vs. Tone 3 contrast. Given that lexical tone is expressed by variations of the pitch contours, which are also related to intonation, infants’ increasing knowledge of both tone and intonation may contribute to their misinterpretation of pitch contours in word learning at 14 months and, further, to their development of a sophisticated use of the phonemic function of lexical tone at 18 months of age.

Perceptual asymmetries in lexical tone perception

Perceptual asymmetric relations between two stimuli such as perceptual confusions where stimulus A is more frequently confused as stimulus B than the reverse has previously been accounted for in terms of response bias due to the prevalent assumption that perceptual space is Euclidean (Polka & Bohn, 2003). Perceptual asymmetries in lexical perception have been reported for both infants and adults. Tsao (2008) found that a stimulus change from the background mandarin T1 (55) to the target Mandarin T3 (213) was easier than the reverse among one-year-old Mandarin learning infants. Politzer-Ahles et al. (2016) found that mismatch negativity (MMN) was attenuated among both native and non-native Mandarin listeners when Mandarin T3 was the standard and another deviant in comparison to the reverse. This study examines the effects of memory load and first language (L1 background) on perceptual asymmetry patterns in adult lexical tone perception. All possible pairings in both orders of Mandarin tones produced on two open syllables [ma] and [ni] will be presented to native Mandarin and American English listeners in an AX categorial discrimination task. To examine the effects of auditory memory load, two different inter-stimulus-interval (ISI), 250 ms and 1,000 ms, will be used.

Perception and Representation of Lexical Tones in Native Mandarin-Learning Infants and Toddlers.

We investigated the perceptual development of lexical tones in native tone-learning infants during the first 2 years of life, focusing on two important stages of phonological acquisition: the preverbal and vocabulary explosion stages. Experiment 1 examined monolingual Mandarin-Chinese-learning 4- to 13-month-olds' discrimination of similar lexical tones in Mandarin, Tone 2 (T2, rising) vs. Tone 3 (T3, low-dipping). Infants were habituated to exemplars of one tone (either T2 or T3), and tested with new exemplars of the habituated tone vs. the contrasting tone. Results show that looking time increased for the contrasting tone, but not for new exemplars of the habituated tone, suggesting that infants discriminated the two tones as separate categories. Furthermore, infants' discrimination of the tones was comparable across ages. Experiment 2 tested whether tones are distinguished in toddlers' lexicon. Monolingual Mandarin-learning 19- to 26-month-olds were presented with pairs of objects while one was named. Targets were familiar words bearing T2 or T3, either correctly pronounced (CP) or mispronounced (MP) in tone. We found that word recognition was equally successful in CP and in MP trials when T2 was mispronounced as T3 and T3 as T2, indicating that T2 and T3 are confusable. In contrast, recognition failed when T2 and T3 words were mispronounced as Tone 4 (T4, falling), showing that T4 was represented as a distinct category. Results show that toddlers have difficulty encoding similar tones distinctly in known words. The T2-T3 contrast is particularly challenging because of Tone 3 Sandhi, which changes T3 to T2 when it precedes another T3. At the stage when toddlers track the meaning of T2 and T3 words and track the sandhi alternations, they seem to overgeneralize the two tones as variants of one functional category, reflecting perceptual organization at the level of phonemic learning.

Perceptual Improvement of Lexical Tones in Infants: Effects of Tone Language Experience.

To learn words in a tonal language, tone-language learners should not only develop better abilities for perceiving consonants and vowels, but also for lexical tones. The divergent trend of enhancing sensitivity to native phonetic contrasts and reduced sensitivity to non-native phonetic contrast is theoretically essential to evaluate effects of listening to an ambient language on speech perception development. The loss of sensitivity in discriminating lexical tones among non-tonal language-learning infants was apparent between 6 and 12 months of age, but only few studies examined trends of differentiating native lexical tones in infancy. The sensitivity in discriminating lexical tones among 6–8 and 10–12 month-old Mandarin-learning infants (n = 120) was tested in Experiment 1 using three lexical tone contrasts of Mandarin. Facilitation of linguistic experience was shown in the tonal contrast (Tone 1 vs. 3), but both age groups performed similar in the other two tonal contrasts (Tone 2 vs. 4; Tone 2 vs. 3). In Experiment 2, 6–8 and 10–12 month-old Mandarin-learning infants (n = 90) were tested with tonal contrasts that have pitch contours either similar to or inverse from lexical tones in Mandarin, and perceptual improvement was shown only in a tonal contrast with familiar pitch contours (i.e., Tone 1 vs. 3). In Experiment 3, 6–8 and 10–12 month-old English-learning infants (n = 40) were tested with Tone 1 vs. 3 contrast of Mandarin and showed an improvement in the perception of non-native lexical tones. This study reveals that tone-language learning infants develop more accurate representations of lexical tones around their first birthday, and the results of both tone and non-tone language-learning infants imply that the rate of development depends on listening experience and the acoustical salience of specific tone contrasts.

Novel Word Learning in Bilingual and Monolingual Infants: Evidence for a Bilingual Advantage.

Previous studies revealing that monolingual and bilingual infants learn similar sounding words with comparable success are largely based on prior investigations involving single-feature changes in the onset consonant of a word. There have been no investigations of bilingual infants' abilities to learn similar sounding words differentiated by vowels. In the current study, 18-month-old bilingual and monolingual infants (n=90) were compared on their sensitivity to a vowel change when learning the meanings of words. Bilingual infants learned similar sounding words differing by a vowel contrast, whereas monolingual English- and Mandarin-learning infants did not. Findings are discussed in terms of early constraints on novel word learning in bilingual and monolingual infants.

Limits on Monolingualism? A Comparison of Monolingual and Bilingual Infants' Abilities to Integrate Lexical Tone in Novel Word Learning.

To construct their first lexicon, infants must determine the relationship between native phonological variation and the meanings of words. This process is arguably more complex for bilingual learners who are often confronted with phonological conflict: phonological variation that is lexically relevant in one language may be lexically irrelevant in the other. In a series of four experiments, the present study investigated English–Mandarin bilingual infants’ abilities to negotiate phonological conflict introduced by learning both a tone and a non-tone language. In a novel word learning task, bilingual children were tested on their sensitivity to tone variation in English and Mandarin contexts. Their abilities to interpret tone variation in a language-dependent manner were compared to those of monolingual Mandarin learning infants. Results demonstrated that at 12–13 months, bilingual infants demonstrated the ability to bind tone to word meanings in Mandarin, but to disregard tone variation when learning new words in English. In contrast, monolingual learners of Mandarin did not show evidence of integrating tones into word meanings in Mandarin at the same age even though they were learning a tone language. However, a tone discrimination paradigm confirmed that monolingual Mandarin learning infants were able to tell these tones apart at 12–13 months under a different set of conditions. Later, at 17–18 months, monolingual Mandarin learners were able to bind tone variation to word meanings when learning new words. Our findings are discussed in terms of cognitive adaptations associated with bilingualism that may ease the negotiation of phonological conflict and facilitate precocious uptake of certain properties of each language.

English- and Mandarin-learning infants' discrimination of actions and objects in dynamic events.

The present studies examined the role of linguistic experience in directing English and Mandarin learners' attention to aspects of a visual scene. Specifically, they asked whether young language learners in these 2 cultures attend to differential aspects of a word-learning situation. Two groups of English and Mandarin learners, 6-8-month-olds (n = 65) and 17-19-month-olds (n = 91), participated in 2 studies, based on a habituation paradigm, designed to test infants' discrimination between actions and objects in dynamic events. In Study 1, these stimuli were presented in silence, whereas in Study 2, a verbal label accompanied videos. Results showed that 6-8-month-olds could discriminate action changes but not object changes, whereas 17-19-month-olds could discriminate both types of changes. However, there were only very subtle cross-linguistic differences in these patterns when the scenes were presented together with a verbal label. These findings show strong evidence for universal developmental trends in attention, with somewhat weaker evidence that the differences in the types of words Mandarin- versus English-learning children produce or are exposed to affect attention to different aspects of a scene in the first 2 years of life.

Pitch production of a Mandarin-learning infant with cerebral palsy

In this study, pitch production were investigated in two Mandarin-learning infants at 6 months of age, an infant with cerebral palsy (CP) and a typically developing (TD) infant. Words with distinct tones in Mandarin differ in meaning. In order to produce a correct tone, having good control of the respiratory and the laryngeal mechanisms are necessary. Thus, producing a correct tone and reaching intelligibility for children with CP is considered to be relatively difficult. In previous studies, Kent and Murray (1982) pointed out that falling contours predominated in infant vocalizations at 3, 6, and 9 months. A study by Chen et al (2013) with 4-year-old children indicated that the mean pitch duration of CP children is 1.3–1.8 times longer than TD counterparts. In adults, Jeng, Weismer, and Kent (2006) found that the pitch slopes of Mandarin in CP adults are smaller than in healthy adults. Three measures were employed in this current study and the major findings are: (1) Both TD and CP infants produced more falling than rising pitch; (2) The mean duration of pitch in CP is 2.3 times longer than that of TD; (3) The pitch slope in CP is smaller than that of TD.

English- and Chinese-learning infants map novel labels to objects and actions differently.

Research based on naturalistic and checklist methods has revealed differences between English and Chinese monolingual children in their trajectories of learning nouns and verbs. However, studies based on controlled laboratory designs (e.g., Imai et al., 2008) have yielded a more mixed picture. Guided by a multidimensional view of word learning (in which different mechanisms are weighted and recruited to different extents over development), we examined English- and Mandarin-learning infants' (n = 128) ability to map novel labels to unfamiliar actions and objects. Findings reveal cross-linguistic variations in the mapping of words to actions versus objects that are consistent with those found previously with naturalistic and checklist methods. Specifically, English learners were able to map novel labels to both actions and objects at 18 months but to neither actions nor objects at 14 months. In an identical experimental paradigm, Mandarin learners at both 14 and 18 months of age were able to map novel labels to actions but not to objects. Similar patterns were found when infants were grouped based on their vocabulary size. Combined results lend support for a dynamic view of word learning that take into account multiple mechanisms interacting across developmental time with important cultural constraints.

Segmental production in Mandarin-learning infants

The early development of vocalic and consonantal production in Mandarin-learning infants was studied at the transition from babbling to producing first words. Spontaneous vocalizations were recorded for 24 infants grouped by age: G1 (0 ; 7 to 1 ; 0) and G2 (1 ; 1 to 1 ; 6). Additionally, the infant-directed speech of 24 caregivers was recorded during natural infant-adult interactions to infer language-specific effects. Data were phonetically transcribed according to broad categories of vowels and consonants. Vocalic development, in comparison with reports for children of other linguistic environments, exhibited two universal patterns: the prominence of [symbol: see text] and [symbol: see text], and the predominance of low and mid vowels over high vowels. Language-specific patterns were also found, e.g. the early appearance and acquisition of low vowels [symbol: see text]. Vowel production was similar in G1 and G2, and a continuum of developmental changes brought infants' vocalization closer to the adult model. Consonantal development showed two universal patterns: labials and alveolars occurred more frequently than velars; and nasals developed earlier than fricatives, affricates and liquids. We also found two language-specific patterns: alveolars were more prominent than labials and affricates developed early. Universal and language-specific characteristics in G1 continued to be prominent in G2. These data indicate that infants are sensitive to the ambient language at an early age, and this sensitivity influences the nature of their vocalizations.

Development of prosodic patterns in Mandarin-learning infants

Early prosodic development (f0 variation) was systematically measured in Mandarin-learning infants at the transition from babbling to producing first words. Spontaneous vocalizations of twenty-four infants aged 0 ; 7 to 1 ; 6 were recorded in 45-minute sessions. The speech production of twenty-four caregivers was also audio-recorded during caregiver-infant natural daily interactions at home. All recordings were transcribed using broad prosodic patterns. Analysis revealed four major findings: (1) falling f0 contours were more prominently produced than level and rising contours; (2) high prosodic patterns occurred more frequently than mid and low prosodic patterns; (3) these distribution patterns of f0 contours showed significant similarities in babbling and early words; and (4) these distribution patterns were also similar in infants' and their caregivers' data.

Consonant–vowel co-occurrence patterns in Mandarin-learning infants

Most studies on CV co-occurrence patterns in early phonetic development have been based on Indo-European languages. Data from infants learning Mandarin, which has a substantially different phonological system from Indo-European languages, can confirm or refute the findings of previous studies, thus shedding further light on the theoretical bases of CV association. Spontaneous vocalizations were recorded in 45-minute sessions for each of 24 Mandarin-learning infants aged 0;7 to 1;6. In addition, the speech production of 24 caregivers was audio-recorded during their natural daily interactions with the infants at home. Both infants' vocalizations and adults' speech were transcribed and analysed for consonant-vowel co-occurrence patterns. These patterns were similar to those in other language groups, but language-specific patterns were evident by 1;0. Combinations of alveolars+front vowels and velars+back vowels confirm Davis & MacNeilage's (1990, 1995) frame-then-content theory and Clements's (1991) model of unified features for consonants and vowels. However, our finding of a language-specific pattern (labials+back vowels) suggests the need to reexamine the 'pure frame' of Davis & MacNeilage and Clements's grouping of labials and rounded vowels.