The interaction between acoustic salience and language experience in developmental speech perception: evidence from nasal place discrimination

Previous research suggests that infant speech perception reorganizes in the first year: young infants discriminate both native and non‐native phonetic contrasts, but by 10–12 months difficult non‐native contrasts are less discriminable whereas performance improves on native contrasts. In the current study, four experiments tested the hypothesis that, in addition to the influence of native language experience, acoustic salience also affects the perceptual reorganization that takes place in infancy. Using a visual habituation paradigm, two nasal place distinctions that differ in relative acoustic salience, acoustically robust labial‐alveolar [ma]–[na] and acoustically less salient alveolar‐velar [na]–[?a], were presented to infants in a cross‐language design. English‐learning infants at 6–8 and 10–12 months showed discrimination of the native and acoustically robust [ma]–[na] (Experiment 1), but not the non‐native (in initial position) and acoustically less salient [na]–[?a] (Experiment 2). Very young (4–5‐month‐old) English‐learning infants tested on the same native and non‐native contrasts also showed discrimination of only the [ma]–[na] distinction (Experiment 3). Filipino‐learning infants, whose ambient language includes the syllable‐initial alveolar (/n/)–velar (/?/) contrast, showed discrimination of native [na]–[?a] at 10–12 months, but not at 6–8 months (Experiment 4). These results support the hypothesis that acoustic salience affects speech perception in infancy, with native language experience facilitating discrimination of an acoustically similar phonetic distinction [na]–[?a]. We discuss the implications of this developmental profile for a comprehensive theory of speech perception in infancy.     

孤独症儿童潜在早期识别标志——发声异常及原因探析

孤独症谱系障碍(Autism Spectrum Disorder, ASD)儿童的早期识别及早期干预对其发育结果至关重要。发声是指儿童学会说话之前发出的声音。已有研究表明, 非类言语和类言语发声异常是ASD儿童2岁前的潜在识别标志。ASD儿童发声异常的理论解释主要有动机导向、神经运动导向、感知觉导向和社会反馈导向理论。未来研究可考虑探讨发声异常作为ASD儿童独特的早期识别标志的可能性, 加强哭声在ASD儿童早期筛查中的研究, 探索基于最具预测性声学参数集的自动学习分类模型, 探究内在动机与社会动机对ASD儿童类言语发声的影响和进一步探究ASD儿童类言语发声异常的神经机制。从而为ASD儿童的早期识别及早期干预提供更加客观的理论依据。     

Foundational Tuning: How Infants' Attention to Speech Predicts Language Development

Orienting biases for speech may provide a foundation for language development. Although human infants show a bias for listening to speech from birth, the relation of a speech bias to later language development has not been established. Here, we examine whether infants' attention to speech directly predicts expressive vocabulary. Infants listened to speech or non‐speech in a preferential listening procedure. Results show that infants' attention to speech at 12 months significantly predicted expressive vocabulary at 18 months, while indices of general development did not. No predictive relationships were found for infants' attention to non‐speech, or overall attention to sounds, suggesting that the relationship between speech and expressive vocabulary was not a function of infants' general attentiveness. Potentially ancient evolutionary perceptual capacities such as biases for conspecific vocalizations may provide a foundation for proficiency in formal systems such language, much like the approximate number sense may provide a foundation for formal mathematics.     

The neuroethology of primate vocal communication: substrates for the evolution of speech

In this article, we review behavioral and neurobiological studies of the perception and use of species-specific vocalizations by non-human primates. At the behavioral level, primate vocal perception shares many features with speech perception by humans. These features include a left-hemisphere bias towards conspecific vocalizations, the use of temporal features for identifying different calls, and the use of calls to refer to objects and events in the environment. The putative neural bases for some of these behaviors have been revealed by recent studies of the primate auditory and prefrontal cortices. These studies also suggest homologies with the human language circuitry. Thus, a synthesis of cognitive, ethological and neurobiological approaches to primate vocal behavior is likely to yield the richest understanding of the neural bases of speech perception, and might also shed light on the evolutionary precursors to language.     

Bilingual exposure influences infant VOT perception

Linking the discrimination of voice onset time (VOT) in infancy with infant language background, we examine the perceptual changes of two VOT contrasts (/b/-/p/ and /p^h/-/p/) by Dutch monolingual and bilingual infants from 8 to 15 months of age. Results showed that language exposure and language dominance had a strong impact on monolingual and bilingual infant VOT perceptual patterns. In addition, perceptual turbulence was found at 8–9 months for bilingual infants, and stabilized perception was presented for all infants from 11 months onwards. We thus report a general input-driven developmental VOT perception in both monolingual and bilingual infants, with perceptual turbulence for bilinguals in the second half of the first year of life.     

Examination of perceptual reorganization for nonnative speech contrasts: Zulu click discrimination by English-speaking adults and infants

The language environment modifies the speech perception abilities found in early development. In particular, adults have difficulty perceiving many nonnative contrasts that young infants discriminate. The underlying perceptual reorganization apparently occurs by 10-12 months. According to one view, it depends on experiential effects on psychoacoustic mechanisms. Alternatively, phonological development has been held responsible, with perception influenced by whether the nonnative sounds occur allophonically in the native language. We hypothesized that a phonemic process appears around 10-12 months that assimilates speech sounds to native categories whenever possible; otherwise, they are perceived in auditory or phonetic (articulatory) terms. We tested this with English-speaking listeners by using Zulu click contrasts. Adults discriminated the click contrasts; performance on the most difficult (80% correct) was not diminished even when the most obvious acoustic difference was eliminated. Infants showed good discrimination of the acoustically modified contrast even by 12-14 months. Together with earlier reports of developmental change in perception of nonnative contrasts, these findings support a phonological explanation of language-specific reorganization in speech perception.     

Infants’ vocalizations at 6 months predict their productive vocabulary at one year

Long before their first words, children communicate by using speech-like vocalizations. These protophones might be indicative of infants’ later language development. We here examined infants’ (n = 56) early vocalizations at 6 months (vocal reactivity scale of the IBQ-R) as a predictor of their expressive and receptive language at 12 months (German version of the CDI). Regression analyses revealed vocalizations to significantly predict expressive, but not receptive language. Our findings in German-learning 6-month-olds extend previous predictive evidence of early vocalizations reported for older infants. Together these findings are informative in light of early assessments monitoring typical and atypical language development.     

Cognitive influences on cross-language speech perception in infancy

Previous research has shown that young infants can discriminate both native and nonnative phonetic contrasts with ease. By 10 to 12 months of age, however, infants—like adults—typically have difficulty discriminating consonant contrasts that are not used to distinguish meaning in their native language. Although the timing of this change in speech perception has been firmly established, little is currently known about the processes or mechanisms involved in this selective and adaptive reorganization in nonnative phonetic discrimination. This study was designed to determine if there is a relation between age-related changes in speech perception performance and other developing cognitive abilities. A total of 40 8- to 10-month-old infants were tested on a nonnative consonant discrimination task and then on two additional tasks (a visual categorization task and an object search task) in an attempt to determine whether changes in nonnative consonant perception coincide with changes in these other areas of cognitive/perceptual functioning. The results indicate that changes in task performance occur in synchrony across all three tasks, and that this synchrony is not explained by simple age effects. These findings suggest that domain-general cognitive/perceptual competencies may influence developmental changes in speech perception by the end of the 1st year of life.     

汉语普通话声调感知的老年化效应：来自ERP的证据

研究考察汉语普通话老年人前注意阶段声调感知状况, 探究是否存在领域特殊的老年化。运用事件相关电位技术, 采用被动oddball范式诱发MMN回应, 控制领域一般性因素的影响。结果显示涉及范畴变化的声调和非语音音调诱发MMN强度衰减, 不涉及范畴变化的声调诱发MMN强度未衰退。研究结果表明在前注意阶段, 在特定汉语普通话声调范畴知识加工能力上存在领域特殊的衰退, 而不涉及母语音位知识的声调的感知存在领域特殊的一定程度的保留, 这一保留与时间维度上补偿机制的调用有关。受补偿机制调节, 语言加工呈现出衰退或保留等不同的老年化进程。     

Bilingual infants excel at foreign‐language talker recognition

Bilingual and monolingual infants differ in how they process linguistic aspects of the speech signal. But do they also differ in how they process non‐linguistic aspects of speech, such as who is talking? Here, we addressed this question by testing Canadian monolingual and bilingual 9‐month‐olds on their ability to learn to identify native Spanish‐speaking females in a face‐voice matching task. Importantly, neither group was familiar with Spanish prior to participating in the study. In line with our predictions, bilinguals succeeded in learning the face‐voice pairings, whereas monolinguals did not. We consider multiple explanations for this finding, including the possibility that simultaneous bilingualism enhances perceptual attentiveness to talker‐specific speech cues in infancy (even in unfamiliar languages), and that early bilingualism delays perceptual narrowing to language‐specific talker recognition cues. This work represents the first evidence that multilingualism in infancy affects the processing of non‐linguistic aspects of the speech signal, such as talker identity.     

Characterizing the influence of native language experience on adult speech perception.

Previous cross-language research has indicated that some speech contrasts present greater perceptual difficulty for adult non-native listeners than others do. It has been hypothesized that phonemic, phonetic, and acoustic factors contribute to this variability. Two experiments were conducted to evaluate systematically the role of phonemic status and phonetic familiarity in the perception of non-native speech contrasts and to test predictions derived from a model proposed by Best, McRoberts, and Sithole (1988). Experiment 1 showed that perception of an unfamiliar phonetic contrast was not less difficult for subjects who had experience with an analogous phonemic distinction in their native language than for subjects without such analogous experience. These results suggest that substantive phonetic experience influences the perception of non-native contrasts, and thus should contribute to a conceptualization of native language-processing skills. In Experiment 2, English listeners' perception of two related nonphonemic place contrasts was not consistently different as had been expected on the basis of phonetic familiarity. A clear order effect in the perceptual data suggests that interactions between different perceptual assimilation patterns or acoustic properties of the two contrasts, or interactions involving both of these factors, underlie the perception of the two contrasts in this experiment. It was concluded that both phonetic familiarity and acoustic factors are potentially important to the explanation of variability in perception of nonphonemic contrasts. The explanation of how linguistic experience shapes speech perception will require characterizing the relative contribution of these factors, as well as other factors, including individual differences and variables that influence a listener's orientation to speech stimuli.     

婴儿期母语音位范畴习得：来自言语知觉的证据

婴儿期言语知觉研究表明婴儿最初（1~4个月）可以分辨几乎所有的语音范畴对比;随母语经验增加,婴儿言语知觉逐渐表现出母语语音特征的影响,辅音知觉表现为对母语语音范畴界限敏感性的提高和对非母语范畴界限敏感性的下降,非母语范畴开始同化到母语音系中去,母语元音知觉表现出知觉磁体效应。这些证据表明婴儿逐渐习得母语音位范畴,音位范畴习得顺序可能依赖范畴例子本身的声学特征、发生频率等因素     

Infant speech perception and cognitive skills as predictors of later vocabulary

Research has identified bivariate correlations between speech perception and cognitive measures gathered during infancy as well as correlations between these individual measures and later language outcomes. However, these correlations have not all been explored together in prospective longitudinal studies. The goal of the current research was to compare how early speech perception and cognitive skills predict later language outcomes using a within-participant design. To achieve this goal, we tested 97 5- to 7-month-olds on two speech perception tasks (stress pattern preference, native vowel discrimination) and two cognitive tasks (visual recognition memory, A-not-B) and later assessed their vocabulary outcomes at 18 and 24 months. Frequentist statistical analyses showed that only native vowel discrimination significantly predicted vocabulary. However, Bayesian analyses suggested that evidence was ambiguous between null and alternative hypotheses for all infant predictors. These results highlight the importance of recognizing and addressing challenges related to infant data collection, interpretation, and replication in the developmental field, a roadblock in our route to understanding the contribution of domain-specific and domain-general skills for language acquisition. Future methodological development and research along similar lines is encouraged to assess individual differences in infant speech perception and cognitive skills and their predictability for language development.     

幼儿汉语口语感知特点及神经机制

口语感知是当前心理语言学的研究热点, 然而以往研究大多以婴儿和成人为被试, 缺乏对幼儿口语感知的研究。此外, 现有口语感知模型主要是基于非声调语言研究建立起来的, 对汉语并不完全适用。汉语是一种声调语言, 在语音构成上不同于非声调语言。本项目将立足于汉语口语特点, 以3~5岁幼儿为研究对象, 考察幼儿汉语口语感知特点及神经机制。综合使用眼动方法、ERP方法和LORETA源定位技术探讨以下问题：(1)幼儿在前注意阶段和注意阶段的听觉语音辨别特点; (2)幼儿汉语口语词汇识别过程中音段信息和超音段信息的作用; (3)幼儿汉语口语感知的神经机制。本项目研究结果将揭示幼儿汉语口语感知特点, 为完善现有的口语感知模型提供新的实验证据。     

Characterizing the influence of native language experience on adult speech perception

Previous cross-language research has indicated that some speech contrasts present greater perceptual difficulty for adult non-native listeners than others do. It has been hypothesized that phonemic, phonetic, and acoustic factors contribute to this variability. Two experiments were conducted to evaluate systematically the role of phonemic status and phonetic familiarity in the perception of non-native speech contrasts and to test predictions derived from a model proposed by Best, McRoberts, and Sithole (1988). Experiment 1 showed that perception of an unfamiliar phonetic contrast was not less difficult for subjects who had experience with an analogous phonemic distinction in their native language than for subjects without such analogous experience. These results suggest that substantive phonetic experience influences the perception of non-native contrasts, and thus should contribute to a conceptualization of native language-processing skills. In Experiment 2, English listeners’ perception of two related nonphonemic place contrasts was not consistently different as had been expected on the basis of phonetic familiarity. A clear order effect in the perceptual data suggests that interactions between different perceptual assimilation patterns or acoustic properties of the two contrasts, or interactions involving both of these factors, underlie the perception of the two contrasts in this experiment. It was concluded that both phonetic familiarity and acoustic factors are potentially important to the explanation of variability in perception of nonphonemic contrasts. The explanation of how linguistic experience shapes speech perception will require characterizing the relative contribution of these factors, as well as other factors, including individual differences and variables that influence a listener’s orientation to speech stimuli.     

The role of perception, language, and preference in the developmental acquisition of basic color terms

When learning basic color vocabulary, young children show a selective delay in the acquisition of brown and gray relative to other basic color terms. In this study, we first establish the robustness of this finding and then investigate the extent to which perception, language, and color preference may influence color conceptualization. Experimental tasks were designed to measure different aspects of perceptual color processing (discrimination and saliency), color preference and objective counts of color term frequency in preschool-directed language (books and mothers' speech) were used to compare the acquisition of three groups of colors: primary colors, secondary colors (orange, pink, and purple) that appear at the same time as the primary colors, and secondary colors (brown and gray) that appear late. Although our results suggest that perception does not directly shape young children's color term acquisition, we found that children prefer brown and gray significantly less than basic colors and that these color terms appear significantly less often in child-directed speech, suggesting that color preference, linguistic input, and developing color cognition may be linked.     

The developmental course of lexical tone perception in the first year of life

Perceptual reorganisation of infants' speech perception has been found from 6 months for consonants and earlier for vowels. Recently, similar reorganisation has been found for lexical tone between 6 and 9 months of age. Given that there is a close relationship between vowels and tones, this study investigates whether the perceptual reorganisation for tone begins earlier than 6 months. Non-tone language English and French infants were tested with the Thai low vs. rising lexical tone contrast, using the stimulus alternating preference procedure. Four- and 6-month-old infants discriminated the lexical tones, and there was no decline in discrimination performance across these ages. However, 9-month-olds failed to discriminate the lexical tones. This particular pattern of decline in nonnative tone discrimination over age indicates that perceptual reorganisation for tone does not parallel the developmentally prior decline observed in vowel perception. The findings converge with previous developmental cross-language findings on tone perception in English-language infants [Mattock, K., & Burnham, D. (2006). Chinese and English infants' tone perception: Evidence for perceptual reorganization. Infancy, 10(3)], and extend them by showing similar perceptual reorganisation for non-tone language infants learning rhythmically different non-tone languages (English and French).     

婴儿对语音和非语音的感知:认知和神经机制

婴儿听觉感知能力的发展对于他们未来的语言学习和社会化都具有重要意义。过去大量的研究主要关注语音感知方面,只有较少的研究将非语音感知纳入考虑之中,但了解非语音感知的特征和机制将有助于增加研究者对听觉加工以及儿童发育的认识。该文分别介绍了婴儿语音感知中的三种偏好——对语音、“婴儿语”和母语的偏好,并尝试着将非语音分为音乐、人类的非言语发声、环境声音三类进行阐述。通过对比这两大类声音的感知得到婴儿可能存在语音感知的左脑偏侧化和音乐感知的右脑偏侧化现象,但这也尚存争议,目前有特定领域模型、特定线索模型和脑网络模型三种理论对偏侧化现象的认知机制进行解释。