Child phonological responses to variegation in adult words: A cross-linguistic study.

Variegation - the presence of more than one supraglottal consonant per word - is a key challenge for children as they increase their expressive vocabulary toward the end of the single-word period. Here we consider the prosodic structures of target words and child forms in English, Finnish, French, Japanese and Mandarin to determine whether children learning these languages respond similarly to the challenge or instead differ in ways related to the phonological structure of the adult language. Based on proportional occurrence of each structure, we find that the word forms of children learning Mandarin and Japanese show more variegation than do those of children learning the European languages, although their target words do not; proportions of reduplication, consonant harmony and single-consonant words also differ by language. We conclude that experience with the structure of the language - and thus representation, as well as immature articulatory skills - shapes children's responses to variegation.

Infant looking preferences towards dynamic faces: A systematic review.

Although the pattern of visual attention towards the region of the eyes is now well-established for infants at an early stage of development, less is known about the extent to which the mouth attracts an infant's attention. Even less is known about the extent to which these specific looking behaviours towards different regions of the talking face (i.e., the eyes or the mouth) may impact on or account for aspects of language development. The aim of the present systematic review is to synthesize and analyse (i) which factors might determine different looking patterns in infants during audio-visual tasks using dynamic faces and (ii) how these patterns have been studied in relation to aspects of the baby's development. Four bibliographic databases were explored, and the records were selected following specified inclusion criteria. The search led to the identification of 19 papers (October 2021). Some studies have tried to clarify the role played by audio-visual support in speech perception and early production based on directly related factors such as the age or language background of the participants, while others have tested the child's competence in terms of linguistic or social skills. Several hypotheses have been advanced to explain the selective attention phenomenon. The results of the selected studies have led to different lines of interpretation. Some suggestions for future research are outlined.

The developmental origins of phonological memory.

Phonological memory, or the ability to remember a novel word string well enough to repeat it, has long been characterized as a time-limited store. An alternative embodiment model sees it as the product of the dynamic sensorimotor (perceptual and production) processes that inform responses to speech. Keren-Portnoy et al. (2010) demonstrated that this capacity, often tested through nonword repetition and found to predict lexical advance, is itself predicted by the first advances in babbling. Pursuing the idea that phonological memory develops through vocal production, we trace its development-drawing on illustrative data from children learning six languages-from the earliest adult-like vocalizations through to the first words and the consolidation of early words into an initial lexical network and more stable representational capacity. We suggest that it is the interaction of perceptual and production experience that mediates the mapping of new forms onto lexical representations. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Robust effects of stress on early lexical representation.

This study aims to elucidate the factors that affect the robustness of word form representations by exploring the relative influence of lexical stress and segmental identity (consonant vs. vowel) on infant word recognition. Our main question was which changes to the words may go unnoticed and which may lead the words to be unrecognizable. One-hundred 11-month-old Hebrew-learning infants were tested in two experiments using the Central Fixation Procedure. In Experiment 1, 20 infants were presented with iambic Familiar and Unfamiliar words. The infants listened longer to Familiar than to Unfamiliar words, indicating their recognition of frequently heard word forms. In Experiment 2, four groups of 20 infants each were tested in each of four conditions involving altered iambic Familiar words contrasted with iambic Unfamiliar nonwords. In each condition, one segment in the Familiar word was changed-either a consonant or a vowel, in either the first (unstressed) or the second (stressed) syllable. In each condition, recognition of the Familiar words despite the change indicates a less accurate or less well-specified representation. Infants recognized Familiar words despite changes to the weak (first) syllable, regardless of whether the change involved a consonant or a vowel (conditions 2a, 2c). However, a change of either consonant or vowel in the stressed (second) syllable blocked word recognition (conditions 2b, 2d). These findings support the proposal that stress pattern plays a key role in early word representation, regardless of segmental identity.

Vocal production and novel word learning in the first year.

Previous studies have demonstrated an effect of early vocal production on infants' speech processing and later vocabulary. This study focuses on the relationship between vocal production and new word learning. Thirty monolingual Italian-learning infants were recorded at about 11 months, to establish the extent of their consonant production. In parallel, the infants were trained on novel word-object pairs, two consisting of early learned consonants (ELC), two consisting of late learned consonants (LLC). Word learning was assessed through Preferential Looking. The results suggest that vocal production supports word learning: Only children with higher, consistent consonant production attended more to the trained ELC images.

Lexical access and competition in bilingual children: The role of proficiency and the lexical similarity of the two languages.

Using a picture-auditory word recognition task, we examined how early child bilinguals access their languages and how the languages affect one another. Accuracy and response times in "false friends" (i.e., words with similar form but unrelated meanings) and semantically related words were compared with control conditions within and across languages and grades. Study 1 tested the performance of school-age children with balanced versus unbalanced knowledge of first-language (L1) Italian and second-language (L2) German. Study 2 compared unbalanced bilingual children with L1 Italian and L2 French or German to investigate the effect of lexical similarity in the children's languages. Children were found to activate both languages on receiving an auditory stimulus; performance in each language was affected by proficiency in the other language, degree of between-language similarity, and length of experience with each language. The BLINCS (Bilingual Language Interactive Network for Comprehension of Speech) model was invoked as a plausible framework for conceptualizing the nature of bilingual phonolexical representation and its effect on word recognition.

In search of a learning model.

While the four commentaries reflect a range of different perspectives on my target paper (Vihman, 2017), all basically accept the overall approach, which has been central to my research for 30 years. Each commentary proposes ways of deepening aspects of the ideas expressed or points out limitations and potential areas in which elaboration would be useful. This response takes up each commentary in turn.

The role of geminates in infants' early word production and word-form recognition.

Infants learning languages with long consonants, or geminates, have been found to 'overselect' and 'overproduce' these consonants in early words and also to commonly omit the word-initial consonant. A production study with thirty Italian children recorded at 1;3 and 1;9 strongly confirmed both of these tendencies. To test the hypothesis that it is the salience of the medial geminate that detracts attention from the initial consonant we conducted three experiments with 11-month-old Italian infants. We first established baseline word-form recognition for untrained familiar trochaic disyllables and then tested for word-form recognition, separately for words with geminates and singletons, after changing the initial consonant to create nonwords from both familiar and rare forms. Familiar words with geminates were recognized despite the change, words with singletons were not. The findings indicate that a feature occurring later in the word affects initial consonant production and perception, which supports the whole-word phonology model.

How salient are onomatopoeia in the early input? A prosodic analysis of infant-directed speech.

Onomatopoeia are frequently identified amongst infants' earliest words (Menn & Vihman, 2011), yet few authors have considered why this might be, and even fewer have explored this phenomenon empirically. Here we analyze mothers' production of onomatopoeia in infant-directed speech (IDS) to provide an input-based perspective on these forms. Twelve mothers were recorded interacting with their 8-month-olds; onomatopoeic words (e.g. quack) were compared acoustically with their corresponding conventional words (duck). Onomatopoeia were more salient than conventional words across all features measured: mean pitch, pitch range, word duration, repetition, and pause length. Furthermore, a systematic pattern was observed in the production of onomatopoeia, suggesting a conventionalized approach to mothers' production of these words in IDS.

What Paves the Way to Conventional Language? The Predictive Value of Babble, Pointing, and Socioeconomic Status.

A child's first words mark the emergence of a uniquely human ability. Theories of the developmental steps that pave the way for word production have proposed that either vocal or gestural precursors are key. These accounts were tested by assessing the developmental synchrony in the onset of babbling, pointing, and word production for 46 infants observed monthly between the ages of 9 and 18 months. Babbling and pointing did not develop in tight synchrony and babble onset alone predicted first words. Pointing and maternal education emerged as predictors of lexical knowledge only in relation to a measure taken at 18 months. This suggests a far more important role for early phonological development in the creation of the lexicon than previously thought.

Learning words and learning sounds: Advances in language development.

Phonological development is sometimes seen as a process of learning sounds, or forming phonological categories, and then combining sounds to build words, with the evidence taken largely from studies demonstrating 'perceptual narrowing' in infant speech perception over the first year of life. In contrast, studies of early word production have long provided evidence that holistic word learning may precede the formation of phonological categories. In that account, children begin by matching their existing vocal patterns to adult words, with knowledge of the phonological system emerging from the network of related word forms. Here I review evidence from production and then consider how the implicit and explicit learning mechanisms assumed by the complementary memory systems model might be understood as reconciling the two approaches.

Making Sense of Infant Familiarity and Novelty Responses to Words at Lexical Onset.

This study suggests that familiarity and novelty preferences in infant experimental tasks can in some instances be interpreted together as a single indicator of language advance. We provide evidence to support this idea based on our use of the auditory headturn preference paradigm to record responses to words likely to be either familiar or unfamiliar to infants. Fifty-nine 10-month-old infants were tested. The task elicited mixed preferences: familiarity (longer average looks to the words likely to be familiar to the infants), novelty (longer average looks to the words likely to be unfamiliar) and no-preference (similar-length of looks to both type of words). The infants who exhibited either a familiarity or a novelty response were more advanced on independent indices of phonetic advance than the infants who showed no preference. In addition, infants exhibiting novelty responses were more lexically advanced than either the infants who exhibited familiarity or those who showed no-preference. The results provide partial support for Hunter and Ames' (1988) developmental model of attention in infancy and suggest caution when interpreting studies indexed to chronological age.

British English infants segment words only with exaggerated infant-directed speech stimuli.

The word segmentation paradigm originally designed by Jusczyk and Aslin (1995) has been widely used to examine how infants from the age of 7.5 months can extract novel words from continuous speech. Here we report a series of 13 studies conducted independently in two British laboratories, showing that British English-learning infants aged 8-10.5 months fail to show evidence of word segmentation when tested in this paradigm. In only one study did we find evidence of word segmentation at 10.5 months, when we used an exaggerated infant-directed speech style. We discuss the impact of variations in infant-directed style within and across languages in the course of language acquisition.

When do infants begin recognizing familiar words in sentences?

Previous studies have shown that by 11 but not by 10 months infants recognize words that have become familiar from everyday life independently of the experimental setting. This study explored the ability of 10-, 11-, and 12-month-old infants to recognize familiar words in sentential context, without experimental training. The headturn preference procedure was used to contrast passages containing words likely to be familiar to the infants with passages containing words unlikely to have been previously heard. Two stimulus words were inserted near the beginning and end of each of a set of simple sentence frames. The ability to recognize the familiar words within sentences emerged only at 12 months of age. The contrast between segmentation abilities as they emerge as a result of everyday exposure to language, as assessed here, and those abilities as measured in studies in which words are experimentally trained is discussed in terms of memory-based mechanisms.

The influence of babbling patterns on the processing of speech.

This study compared the preference of 27 British English- and 26 Welsh-learning infants for nonwords featuring consonants that occur with equal frequency in the input but that are produced either with equal frequency (Welsh) or with differing frequency (British English) in infant vocalizations. For the English infants a significant difference in looking times was related to the extent of production of the nonword consonants. The Welsh infants, who showed no production preference for either consonant, exhibited no such influence of production patterns on their response to the nonwords. The results are consistent with a previous study that suggested that pre-linguistic babbling helps shape the processing of input speech, serving as an articulatory filter that selectively makes production patterns more salient in the input.

Do production patterns influence the processing of speech in prelinguistic infants?

The headturn preference procedure was used to test 18 infants on their response to three different passages chosen to reflect their individual production patterns. The passages contained nonwords with consonants in one of three categories: (a) often produced by that infant ('own'), (b) rarely produced by that infant but common at that age ('other'), and (c) not generally produced by infants. Infants who had a single 'own' consonant showed no significant preference for either 'own' (a) or 'other' (b) passages. In contrast, infants' with two 'own' consonants exhibited greater attention to 'other' passages (b). Both groups attended equally to the passage featuring consonants rarely produced by infants of that age (c). An analysis of a sample of the infant-directed speech ruled out the mothers' speech as a source of the infant preferences. The production-based shift to a focus on the 'other' passage suggests that nascent production abilities combine with emergent perceptual experience to facilitate word learning.

The role of production practice in lexical and phonological development--a commentary on Stoel-Gammon's 'Relationships between lexical and phonological development in young children'.

Carol Stoel-Gammon has made a real contribution in bringing together two fields that are not generally jointly addressed. Like Stoel-Gammon, we have long focused on individual differences in phonological development (e.g. Vihman, Ferguson & Elbert, 1986; Vihman, Boysson-Bardies, Durand & Sundberg, 1994; Keren-Portnoy, Majorano & Vihman, 2008). And like her, we have been closely concerned with the relationship between lexical and phonological learning. Accordingly, we will focus our discussion on two areas covered by Stoel-Gammon (this issue) on which our current work may shed some additional light.

The role of vocal practice in constructing phonological working memory.

PURPOSE: In this study, the authors looked for effects of vocal practice on phonological working memory. METHOD: A longitudinal design was used, combining both naturalistic observations and a nonword repetition test. Fifteen 26-month-olds (12 of whom were followed from age 11 months) were administered a nonword test including real words, "standard" nonwords (identical for all children), and nonwords based on individual children's production inventory (in and out words). RESULTS: A strong relationship was found between (a) length of experience with consonant production and (b) nonword repetition and between (a) differential experience with specific consonants through production and (b) performance on the in versus out words. CONCLUSIONS: Performance depended on familiarity with words or their subunits and was strongest for real words, weaker for in words, and weakest for out words. The results demonstrate the important role of speech production in the construction of phonological working memory.

From phonetics to phonology: the emergence of first words in Italian.

This study assesses the extent of phonetic continuity between babble and words in four Italian children followed longitudinally from 0.9 or 0.10 to 2.0--two with relatively rapid and two with slower lexical growth. Prelinguistic phonetic characteristics, including both (a) consistent use of specific consonants and (b) age of onset and extent of consonant variegation in babble, are found to predict rate of lexical advance and to relate to the form of the early words. In addition, each child's lexical profile is analyzed to test the hypothesis of non-linearity in phonological development. All of the children show the expected pattern of phonological advance: Relatively accurate first word production is followed by lexical expansion, characterized by a decrease in accuracy and an increase of similarity between word forms. We interpret such a profile as reflecting the emergence of word templates, a first step in phonological organization.

Familiar words capture the attention of 11-month-olds in less than 250 ms.

The capacity of human infants to discriminate contrasting speech sounds specializes to the native language by the end of the first year of life, when the first signs of word recognition have also been found, using behavioural measures. The extent of voluntary attentional involvement in such word recognition has not been explored, however, nor do we know what its neural time-course may be. Here we demonstrate that 11-month-old children shift their attention automatically to familiar words within 250 ms of presentation onset by measuring event-related potentials elicited by familiar and unfamiliar words. A significant modulation of the first negative peak (N200), known to index implicit change detection in adults, was induced by word familiarity in the infants.