Errors of Omission in English-Speaking Children's Production of Plurals and the Past Tense: The Effects of Frequency, Phonology, and Competition

How do English‐speaking children inflect nouns for plurality and verbs for the past tense? We assess theoretical answers to this question by considering errors of omission, which occur when children produce a stem in place of its inflected counterpart (e.g., saying “dress” to refer to 5 dresses). A total of 307 children (aged 3;11–9;9) participated in 3 inflection studies. In Study 1, we show that errors of omission occur until the age of 7 and are more likely with both sibilant regular nouns (e.g., dress) and irregular nouns (e.g., man) than regular nouns (e.g., dog). Sibilant nouns are more likely to be inflected if they are high frequency. In Studies 2 and 3, we show that similar effects apply to the inflection of verbs and that there is an advantage for “regular‐like” irregulars whose inflected form, but not stem form, ends in d/t. The results imply that (a) stems and inflected forms compete for production and (b) children generalize both product‐oriented and source‐oriented schemas when learning about inflectional morphology.     

What Do North American Babies Hear? A large‐scale cross‐corpus analysis

A range of demographic variables influences how much speech young children hear. However, because studies have used vastly different sampling methods, quantitative comparison of interlocking demographic effects has been nearly impossible, across or within studies. We harnessed a unique collection of existing naturalistic, day‐long recordings from 61 homes across four North American cities to examine language input as a function of age, gender, and maternal education. We analyzed adult speech heard by 3‐ to 20‐month‐olds who wore audio recorders for an entire day. We annotated speaker gender and speech register (child‐directed or adult‐directed) for 10,861 utterances from female and male adults in these recordings. Examining age, gender, and maternal education collectively in this ecologically valid dataset, we find several key results. First, the speaker gender imbalance in the input is striking: children heard 2–3× more speech from females than males. Second, children in higher‐maternal education homes heard more child‐directed speech than those in lower‐maternal education homes. Finally, our analyses revealed a previously unreported effect: the proportion of child‐directed speech in the input increases with age, due to a decrease in adult‐directed speech with age. This large‐scale analysis is an important step forward in collectively examining demographic variables that influence early development, made possible by pooled, comparable, day‐long recordings of children's language environments. The audio recordings, annotations, and annotation software are readily available for reuse and reanalysis by other researchers.     

Processing of English inflectional morphology

The present paper explores the representation of inflectional morphology in the English lexicon. There has been a long-standing debate about how these inflectional relationships might be involved during on-line processing. Inflected forms may be derived from an uninflected base form by rule application; by contrast, both regular and irregular inflection may be treated in the same way, with morphological patterns emerging from mappings between base and inflected forms. The present series of experiments investigated these issues using a lexical decision task. The first experiment showed that response latencies to nouns were significantly shorter than those to verbs. A possible explanation for these results can be found in differences in inflectional structure between English nouns and verbs. Namely, the relative frequency of uninflected compared with inflected forms is greater for nouns than for verbs. Two additional experiments compared noun stimuli with different inflectional structures. In all cases, differences in response latencies were predicted by the frequency of the surface form, whether uninflected or inflected. The pattern of results lends support for a unitary associative system for processing regular inflection of nouns in English and argues against the view that regular inflected plurals are derived by rule from a single, uninflected lexical entry.     

The secret is in the sound: from unsegmented speech to lexical categories

When learning language, young children are faced with many seemingly formidable challenges, including discovering words embedded in a continuous stream of sounds and determining what role these words play in syntactic constructions. We suggest that knowledge of phoneme distributions may play a crucial part in helping children segment words and determine their lexical category, and we propose an integrated model of how children might go from unsegmented speech to lexical categories. We corroborated this theoretical model using a two‐stage computational analysis of a large corpus of English child‐directed speech. First, we used transition probabilities between phonemes to find words in unsegmented speech. Second, we used distributional information about word edges – the beginning and ending phonemes of words – to predict whether the segmented words from the first stage were nouns, verbs, or something else. The results indicate that discovering lexical units and their associated syntactic category in child‐directed speech is possible by attending to the statistics of single phoneme transitions and word‐initial and final phonemes. Thus, we suggest that a core computational principle in language acquisition is that the same source of information is used to learn about different aspects of linguistic structure.     

The moment‐to‐moment pitch dynamics of child‐directed speech shape toddlers’ attention and learning

Young children have an overall preference for child‐directed speech (CDS) over adult‐directed speech (ADS), and its structural features are thought to facilitate language learning. Many studies have supported these findings, but less is known about processing of CDS at short, sub‐second timescales. How do the moment‐to‐moment dynamics of CDS influence young children's attention and learning? In Study 1, we used hierarchical clustering to characterize patterns of pitch variability in a natural CDS corpus, which uncovered four main word‐level contour shapes: ‘fall’, ‘rise’, ‘hill’, and ‘valley’. In Study 2, we adapted a measure from adult attention research—pupil size synchrony—to quantify real‐time attention to speech across participants, and found that toddlers showed higher synchrony to the dynamics of CDS than to ADS. Importantly, there were consistent differences in toddlers’ attention when listening to the four word‐level contour types. In Study 3, we found that pupil size synchrony during exposure to novel words predicted toddlers’ learning at test. This suggests that the dynamics of pitch in CDS not only shape toddlers’ attention but guide their learning of new words. By revealing a physiological response to the real‐time dynamics of CDS, this investigation yields a new sub‐second framework for understanding young children's engagement with one of the most important signals in their environment.     

Productivity of Noun Slots in Verb Frames

Productivity is a central concept in the study of language and language acquisition. As a test case for exploring the notion of productivity, we focus on the noun slots of verb frames, such as __want__, __see__, and __get__. We develop a novel combination of measures designed to assess both the flexibility and creativity of use in these slots. We do so using a rigorously controlled sample of child speech and child directed speech from three English‐speaking children between the ages of 2–3 years and their caregivers. We find different levels of creativity and flexibility between the adult and child samples for some measures, for some slots, and for some developmental periods. We discuss these differences in the context of verb frame semantics, conventionality versus creativity and child errors, and draw some tentative conclusions regarding developmental changes in children's early grammatical representations.     

Rules versus statistics: insights from a highly inflected language

Inflectional morphology has been taken as a paradigmatic example of rule-governed grammatical knowledge (Pinker, 1999). The plausibility of this claim may be related to the fact that it is mainly based on studies of English, which has a very simple inflectional system. We examined the representation of inflectional morphology in Serbian, which encodes number, gender, and case for nouns. Linguists standardly characterize this system as a complex set of rules, with disagreements about their exact form. We present analyses of a large corpus of nouns which showed that, as in English, Serbian inflectional morphology is quasiregular: It exhibits numerous partial regularities creating neighborhoods that vary in size and consistency. We then asked whether a simple connectionist network could encode this statistical information in a manner that also supported generalization. A network trained on 3,244 Serbian nouns learned to produce correctly inflected phonological forms from a specification of a word's lemma, gender, number, and case, and generalized to untrained cases. The model's performance was sensitive to variables that also influence human performance, including surface and lemma frequency. It was also influenced by inflectional neighborhood size, a novel measure of the consistency of meaning to form mapping. A word-naming experiment with native Serbian speakers showed that this measure also affects human performance. The results suggest that, as in English, generating correctly inflected forms involves satisfying a small number of simultaneous probabilistic constraints relating form and meaning. Thus, common computational mechanisms may govern the representation and use of inflectional information across typologically diverse languages.     

Linguistic and prosodic aspects of child-directed speech: The role of maternal child-rearing experiences

This study explored if the quality of mothers’ reported child-rearing experiences influences the prosodic and linguistic features of maternal child-directed speech. Lexical, syntactic, functional and prosodic aspects of maternal speech directed towards their 24-month-old children were examined. Results showed that mothers with different child-rearing histories differed in the ways they talked to their children. Mothers who recalled the caregiving they received during childhood as characterized by high levels of care and low levels of control, used a lexically and syntactically more complex speech and expressed more positive emotions. This kind of input seems to be more attuned with the typical growing skills of two-year-old children. Implications for the study of mother–infant relationship as well as for the study of child language development are addressed.     

The inflected noun system in Serbo-Croatian: Lexical representation of morphological structure

Repetition priming is examined for alternating and nonalternating morphologically related inflected nouns. In Experiments I and 2, latencies to targets in nominative and dative/locative cases, respectively, were invariant over case of prime. In Experiment 3, latencies to nominative-case nouns were the same whether the nouns were primed by forms in which the spelling and pronunciation of the common stem were shared (nonalternating) or not (alternating) with the nominative form. Results are interpreted as reflecting lexical organization among the members of a noun system. In Experiments I and 2, the pattern of latencies to primes suggests a satellite organization in which nominative forms are more strongly linked to oblique forms than oblique forms are to each other. In Experiment 3, atypical cases of alternating forms showed a different pattern of prime latencies, suggesting that the organization within a noun system may differ for alternating and nonalternating forms.     

Are Words Easier to Learn From Infant‐ Than Adult‐Directed Speech? A Quantitative Corpus‐Based Investigation

We investigate whether infant‐directed speech (IDS) could facilitate word form learning when compared to adult‐directed speech (ADS). To study this, we examine the distribution of word forms at two levels, acoustic and phonological, using a large database of spontaneous speech in Japanese. At the acoustic level we show that, as has been documented before for phonemes, the realizations of words are more variable and less discriminable in IDS than in ADS. At the phonological level, we find an effect in the opposite direction: The IDS lexicon contains more distinctive words (such as onomatopoeias) than the ADS counterpart. Combining the acoustic and phonological metrics together in a global discriminability score reveals that the bigger separation of lexical categories in the phonological space does not compensate for the opposite effect observed at the acoustic level. As a result, IDS word forms are still globally less discriminable than ADS word forms, even though the effect is numerically small. We discuss the implication of these findings for the view that the functional role of IDS is to improve language learnability.     

Mothers speak differently to infants at‐risk for dyslexia

Dyslexia is a neurodevelopmental disorder manifested in deficits in reading and spelling skills that is consistently associated with difficulties in phonological processing. Dyslexia is genetically transmitted, but its manifestation in a particular individual is thought to depend on the interaction of epigenetic and environmental factors. We adopt a novel interactional perspective on early linguistic environment and dyslexia by simultaneously studying two pre‐existing factors, one maternal and one infant, that may contribute to these interactions; and two behaviours, one maternal and one infant, to index the effect of these factors. The maternal factor is whether mothers are themselves dyslexic or not (with/without dyslexia) and the infant factor is whether infants are at‐/not‐at family risk for dyslexia (due to their mother or father being dyslexic). The maternal behaviour is mothers’ infant‐directed speech (IDS), which typically involves vowel hyperarticulation, thought to benefit speech perception and language acquisition. The infant behaviour is auditory perception measured by infant sensitivity to amplitude envelope rise time, which has been found to be reduced in dyslexic children. Here, at‐risk infants showed significantly poorer acoustic sensitivity than not‐at‐risk infants and mothers only hyperarticulated vowels to infants who were not at‐risk for dyslexia. Mothers’ own dyslexia status had no effect on IDS quality. Parental speech input is thus affected by infant risk status, with likely consequences for later linguistic development.     

The impact of mothers' trait anxiety on their expectations of approach‐avoidance behaviour in anxious and non‐anxious children

This study investigated estimates of approach and avoidance behaviour in clinically anxious and non‐anxious children, and whether mothers' expectations of their children's avoidance differed as a function of high trait anxiety (HTA) versus low trait anxiety (LTA). Participants were 62 clinically anxious and 60 non‐anxious children aged 7–12 years and their mothers. Estimates of avoidance were obtained using an analogue task in which children and mothers were given threat and pleasant information about two novel animals and were asked to estimate children's avoidance of the threat animal's habitat when the threat animal was present (threat condition) and absent (safe condition) from the habitat and when its presence was uncertain (ambiguous condition). Contrary to expectation, anxious children did not differ from controls in estimates of avoidance in any condition. However, relative to HTA mothers of anxious children and LTA mothers of non‐anxious children, HTA mothers estimated greater approach behaviour by their non‐anxious children in the threat condition. Findings suggest that mothers' expectations of children's approach‐avoidance behaviour is influenced by both maternal and child factors.     

The competition–compensation account of developmental language disorder

Children with developmental language disorder (DLD) regularly use the bare form of verbs (e.g., dance) instead of inflected forms (e.g., danced). We propose an account of this behavior in which processing difficulties of children with DLD disproportionally affect processing novel inflected verbs in their input. Limited experience with inflection in novel contexts leads the inflection to face stronger competition from alternatives. Competition is resolved through a compensatory behavior that involves producing a more accessible alternative: in English, the bare form. We formalize this hypothesis within a probabilistic model that trades off context-dependent versus independent processing. Results show an over-reliance on preceding stem contexts when retrieving the inflection in a model that has difficulty with processing novel inflected forms. We further show that following the introduction of a bias to store and retrieve forms with preceding contexts, generalization in the typically developing (TD) models remains more or less stable, while the same bias in the DLD models exaggerates difficulties with generalization. Together, the results suggest that inconsistent use of inflectional morphemes by children with DLD could stem from inferences they make on the basis of data containing fewer novel inflected forms. Our account extends these findings to suggest that problems with detecting a form in novel contexts combined with a bias to rely on familiar contexts when retrieving a form could explain sequential planning difficulties in children with DLD.

Research Highlights

• Generalization difficulties with inflectional morphemes in children with Developmental Language Disorder arise from these children's limited experience with novel inflected forms.
• Limited experience with a form in novel contexts could lead to a storage bias where retrieving a form often requires relying on familiar preceding stems.
• While generalization in typically developing models remains stable across a range of model parameters, certain parameter values in the impaired models exaggerate difficulties with generalization.
• Children with DLD compensate for these retrieval difficulties through accessibility-driven language production: they produce the most accessible form among the alternatives.

     

Reminiscing and recounting in the preschool years

Talk about past events can be classified as either reminiscing (discussing shared experiences) or recounting (discussing unshared experiences). Reminiscing may have more of a social memory function whereas recounting may also be informational. This research focused on the form of mother–child reminiscing and recounting during the preschool years. Twenty 40‐month‐old and 20 58‐month‐old children reminisced and recounted past events with their mothers. Results showed that mothers who provided more memory information during reminiscing and requested more memory information during recounting had children who reported more unique information about the events. Regardless of maternal conversational style, however, children reported more unique memory information during recounting than reminiscing. We discuss these results in terms of the importance of both forms of remembering for autobiographical memory development. Copyright © 2000 John Wiley & Sons, Ltd.     

Gender and age differences in parent–child emotion talk

This study examined gender differences in emotion word use during mother–child and father–child conversations. Sixty‐five Spanish mothers and fathers and their 4‐ (M = 53.50, SD = 3.54) and 6‐year‐old (M = 77.07, SD = 3.94) children participated in this study. Emotion talk was examined during a play‐related storytelling task and a reminiscence task (conversation about past experiences). Mothers mentioned a higher proportion of emotion words than did fathers. During the play‐related storytelling task, mothers of 4‐year‐old daughters mentioned a higher proportion of emotion words than did mothers of 4‐year‐old sons, whereas fathers of 4‐year‐old daughters directed a higher proportion of emotion words than did fathers of 4‐year‐old sons during the reminiscence task. No gender differences were found with parents of 6‐year‐old children. During the reminiscence task daughters mentioned more emotion words with their fathers than with their mothers. Finally, mothers' use of emotion talk was related to whether children used emotion talk in both tasks. Fathers' use of emotion talk was only related to children's emotion talk during the reminiscence task.     

An Elicited‐Production Study of Inflectional Verb Morphology in Child Finnish

Many generativist accounts (e.g., Wexler, 1998) argue for very early knowledge of inflection on the basis of very low rates of person/number marking errors in young children's speech. However, studies of Spanish (Aguado‐Orea & Pine, 2015) and Brazilian Portuguese (Rubino & Pine, 1998) have revealed that these low overall error rates actually hide important differences across the verb paradigm. The present study investigated children's production of person/number marked verbs by eliciting present tense verb forms from 82 native Finnish‐speaking children aged 2;2–4;8 years. Four main findings were observed: (a) Rates of person/number marking errors were higher in low‐frequency person/number contexts, even excluding children who showed no evidence of having learned the relevant morpheme, (b) most errors involved the use of higher frequency forms in lower frequency person/number contexts, (c) error rates were predicted not only by the frequency of person/number contexts (e.g., 3sg > 2pl) but also by the frequency of individual “ready‐inflected” lexical target forms, and (d) for low‐frequency verbs, lower error rates were observed for verbs with high phonological neighborhood density. It is concluded that any successful account of the development of verb inflection will need to incorporate both (a) rote‐storage and retrieval of individual inflected forms and (b) phonological analogy across them.     

A construction based analysis of child directed speech

The child directed speech of twelve English‐speaking motherswas analyzed in terms of utterance‐level constructions. First, the mothers' utterances were categorized in terms of general constructional categories such as Wh‐questions, copulas and transitives. Second, mothers' utterances within these categories were further specified in terms of the initial words that framed the utterance, item‐based phrases such as Are you …, I'll …, It's …, Let's …, What did … The findings were: (i) overall, only about 15% of all maternal utterances had SVO form (most were questions, imperatives, copulas, and fragments); (ii) 51% of all maternal utterances began with one of 52 item‐based phrases, mostly consisting of two words or morphemes (45% began with one of just 17 words); and (iii) children used many of these same item‐based phrases, in some cases at a rate that correlated highly with their own mother's frequency of use. We suggest that analyses of adult–child linguistic interaction should take into account not just general constructional categories, but also the item‐based constructions that adults and children use and the frequency with which they use them.     

When infants talk,infants listen: pre‐babbling infants prefer listening to speech with infant vocal properties

To learn to produce speech, infants must effectively monitor and assess their own speech output. Yet very little is known about how infants perceive speech produced by an infant, which has higher voice pitch and formant frequencies compared to adult or child speech. Here, we tested whether pre‐babbling infants (at 4–6 months) prefer listening to vowel sounds with infant vocal properties over vowel sounds with adult vocal properties. A listening preference favoring infant vowels may derive from their higher voice pitch, which has been shown to attract infant attention in infant‐directed speech (IDS). In addition, infants' nascent articulatory abilities may induce a bias favoring infant speech given that 4‐ to 6‐month‐olds are beginning to produce vowel sounds. We created infant and adult /i/ (‘ee’) vowels using a production‐based synthesizer that simulates the act of speaking in talkers at different ages and then tested infants across four experiments using a sequential preferential listening task. The findings provide the first evidence that infants preferentially attend to vowel sounds with infant voice pitch and/or formants over vowel sounds with no infant‐like vocal properties, supporting the view that infants' production abilities influence how they process infant speech. The findings with respect to voice pitch also reveal parallels between IDS and infant speech, raising new questions about the role of this speech register in infant development. Research exploring the underpinnings and impact of this perceptual bias can expand our understanding of infant language development.     

成人言语输入对儿童早期单词获得影响的个案追踪

追踪观察一名婴儿(6~20个月), 分析其中看护者的言语输入特征及婴儿早期词汇获得的发展变化。主要对成人言语输入中动、名词比例、单词在句中的位置、具体环境等因素及婴儿早期动、名词理解和产生等方面进行探讨。结果显示, 成人言语输入中动词比例显著高于名词, 更多动词位于句首或句尾使得主语和宾语省略; 同时, 这种动词优势的输入特征促进儿童早期动词获得, 使得婴儿早期语言样本中动、名词理解相对比例与成人言语输入一致。这一结果表明, 婴儿词汇发展初期就已经利用言语或社会线索, 同时这种早期词汇组成中较高的动词比例进一步支持“名词优势”理论存在跨语言差异