Publications

Abstract

Introduction

Children's early language and communication skills are efficiently measured using parent report, for example, communicative development inventories (CDIs). These have scalable potential to determine risk of later language delay, and associations between delay and risk factors such as prematurity and poverty. However, there may be measurement difficulties in parent reports, including anomalous directions of association between child age/socioeconomic status and reported language. Findings vary on whether parents may report older infants as having smaller vocabularies than younger infants, for example.

Methods

We analysed data from the UK Communicative Development Inventory (Words and Gestures); UK-CDI (W&G) to determine whether anomalous associations would be replicated in this population, and/or with gesture. In total 1204 families of children aged 8–18 months (598 girls, matched to UK population for income, parental education and ethnicity as far as possible) completed Vocabulary and Gesture scales of the UK-CDI (W&G).

Results

Overall scores on the Gesture scale showed more significant relationships with biological risk factors including prematurity than did Vocabulary scores. Gesture also showed more straightforward relationships with social risk factors including income. Relationships between vocabulary and social risk factors were less straightforward; some at-risk groups reported higher vocabulary scores than other groups.

Discussion

We conclude that vocabulary report may be less accurate than gesture for this age. Parents have greater knowledge of language than gesture milestones, hence may report expectations for vocabulary, not observed vocabulary. We also conclude that gesture should be included in early language scales partly because of its greater, more straightforward association with many risk factors for language delay.

Abstract

A long-standing question in language development concerns the nature of the relationship between early lexical and grammatical knowledge. The very strong correlation between the two has led some to argue that lexical and grammatical knowledge may be inseparable, consistent with psycholinguistic theories that eschew a distinction between the two systems. However, little research has explicitly examined whether early lexical and grammatical knowledge are statistically separable. Moreover, there are two under-appreciated methodological challenges in such research. First, the relationship between lexical and grammatical knowledge may change during development. Second, non-linear mappings between true and observed scores on scales of lexical and grammatical knowledge could lead to spurious multidimensionality. In the present study, we overcome these challenges by using vocabulary and grammar data from several developmental time points and a statistical method robust to such non-linear mappings. In Study 1, we examined item-level vocabulary and grammar data from two American English samples from a large online repository of data from studies employing a commonly used language development scale. We found clear evidence that vocabulary and grammar were separable by two years of age. In Study 2, we combined data from two longitudinal studies of language acquisition that used the same scale (at 18/19, 21, 24 and 30 months) and found evidence that vocabulary and grammar were, under some conditions, separable by 18 months. Results indicate that, while there is clearly a very strong relationship between vocabulary and grammar knowledge in early language development, the two are separable. Implications for the mechanisms underlying language development are discussed.

Abstract

Preschoolers’ exposure to abstract language (i.e. talk beyond the here and now) during shared reading is associated with language development. This randomized intervention study tested whether preschoolers’ repeated exposure to simple and complex stories (as defined by the inferential demands of the story), and the extratextual talk associated with such stories, would lead to differences in language production during shared reading and to differential gains in vocabulary and narrative skills post intervention. An experimenter read scripted stories to 34 children (3;07–4;11) assigned to one of two story conditions (simple or complex) in small-groups, twice weekly over six weeks. Results showed that children in the complex story condition produced more complex language (as indexed by their mean length of utterance, use of mental and communication verbs, and use of subordinate clauses). However, post-intervention, children’s vocabulary and narrative skills did not differ between conditions. Specific kinds of stories and corresponding extratextual talk by adults may not only increase children’s exposure to rich and challenging input from the extratextual talk, but can also provide valuable opportunities for children to produce complex language. Theoretical and methodological implications are also discussed.

Abstract

We argue that language learning occurs in triadic interactions, where caregivers and children engage not only with each other but also with objects, actions and non-verbal cues that shape language acquisition. We illustrate this using two studies on real-time interactions in spoken and signed language. The first examines shared book reading, showing how caregivers use speech, gestures and gaze coordination to establish joint attention, facilitating word-object associations. The second study explores joint attention in spoken and signed interactions, demonstrating that signing dyads rely on a wider range of multimodal behaviours – such as touch, vibrations and peripheral gaze – compared to speaking dyads. Our data highlight how different language modalities shape attentional strategies. We advocate for research that fully incorporates the dynamic interplay between language, attention and environment.

Abstract

Language acquisition is multifaceted, relying on cognitive and social abilities in addition to language-specific skills. We hypothesized that executive function (EF) may assist language development by enabling children to revise misinterpretations during online processing, encode language input more accurately and/or learn non-canonical sentence structures like the passive better over time. One hundred and twenty Dutch preschoolers each completed three sessions of testing (pre-test, exposure and post-test). During pre-test and post-test, we measured their comprehension of passive sentences and performance in three EF tasks. In the exposure session, we tracked children’s eye movements as they listened to passive (and other) sentences. Each child was also assessed for short-term memory and receptive language. Multiple regression evaluated the relationship between EF and online processing and longer-term learning. EF predicted online revision accuracy, while controlling for receptive language, prior passive knowledge and short-term memory, consistent with theories linking EF to the revision of misinterpretations. EF was also associated with longer-term learning, but the results could not disentangle EF from receptive language. These findings broadly support a role for EF in language acquisition, including a specific role in revision during sentence processing and potentially other roles that depend on reciprocal interaction between EF and receptive language.

Abstract

We used eye-tracking to investigate if and when children show an incremental bias to assume that the first noun phrase in a sentence is the agent (first-NP-as-agent bias) while processing the meaning of English active and passive transitive sentences. We also investigated whether children can override this bias to successfully distinguish active from passive sentences, after processing the remainder of the sentence frame. For this second question we used eye-tracking (Study 1) and forced-choice pointing (Study 2). For both studies, we used a paradigm in which participants simultaneously saw two novel actions with reversed agent-patient relations while listening to active and passive sentences. We compared English-speaking 25-month-olds and 41-month-olds in between-subjects sentence structure conditions (Active Transitive Condition vs. Passive Condition). A permutation analysis found that both age groups showed a bias to incrementally map the first noun in a sentence onto an agent role. Regarding the second question, 25-month-olds showed some evidence of distinguishing the two structures in the eye-tracking study. However, the 25-month-olds did not distinguish active from passive sentences in the forced choice pointing task. In contrast, the 41-month-old children did reanalyse their initial first-NP-as-agent bias to the extent that they clearly distinguished between active and passive sentences both in the eye-tracking data and in the pointing task. The results are discussed in relation to the development of syntactic (re)parsing.

Abstract

Children who hear large amounts of diverse speech learn language more quickly than children who do not. However, high correlations between the amount and the diversity of the input in speech samples makes it difficult to isolate the influence of each. We overcame this problem by controlling the input to a computational model so that amount of exposure to linguistic input (quantity) and the quality of that input (lexical diversity) were independently manipulated. Sublexical, lexical, and multi-word knowledge were charted across development (Study 1), showing that while input quantity may be important early in learning, lexical diversity is ultimately more crucial, a prediction confirmed against children’s data (Study 2). The model trained on a lexically diverse input also performed better on nonword repetition and sentence recall tests (Study 3) and was quicker to learn new words over time (Study 4). A language input that is rich in lexical diversity outperforms equivalent richness in quantity for learned sublexical and lexical knowledge, for well-established language tests, and for acquiring words that have never been encountered before.

Abstract

Historically, first language acquisition research was a painstaking process of observation, requiring the laborious hand coding of children's linguistic productions, followed by the generation of abstract theoretical proposals for how the developmental process unfolds. Recently, the ability to collect large-scale corpora of children's language exposure has revolutionized the field. New techniques enable more precise measurements of children's actual language input, and these corpora constrain computational and cognitive theories of language development, which can then generate predictions about learning behavior. We describe several instances where corpus, computational, and experimental work have been productively combined to uncover the first language acquisition process and the richness of multimodal properties of the environment, highlighting how these methods can be extended to address related issues in second language research. Finally, we outline some of the difficulties that can be encountered when applying multimethod approaches and show how these difficulties can be obviated

Abstract

In developmental psycholinguistics, we have, for many years,
been generating and testing theories that propose both descriptions of
adult representations and explanations of how those representations
develop. We have learnt that restricting ourselves to any one
methodology yields only incomplete data about the nature of linguistic
representations. We argue that we need a multi-method approach to the
study of representation.

Abstract

This study investigated different accounts of children's acquisition of non-subject wh-questions. Questions using each of 4 wh-words (what, who, how and why), and 3 auxiliaries (BE, DO and CAN) in 3sg and 3pl form were elicited from 28 children aged 3;6–4;6. Rates of non-inversion error (Who she is hitting?) were found not to differ by wh-word, auxiliary or number alone, but by lexical auxiliary subtype and by wh-word+lexical auxiliary combination. This finding counts against simple rule-based accounts of question acquisition that include no role for the lexical subtype of the auxiliary, and suggests that children may initially acquire wh-word+lexical auxiliary combinations from the input. For DO questions, auxiliary-doubling errors (What does she does like?) were also observed, although previous research has found that such errors are virtually non-existent for positive questions. Possible reasons for this discrepancy are discussed.

Abstract

Studies based on naturalistic data are a core tool in the field of language acquisition research and have provided thorough descriptions of children's speech. However, these descriptions are inevitably confounded by differences in the relative frequency with which children use words and language structures. The purpose of the present work was to investigate the impact of sampling constraints on estimates of the productivity of children's utterances, and on the validity of error rates. Comparisons were made between five different sized samples of wh-question data produced by one child aged 2;8. First, we assessed whether sampling constraints undermined the claim (e.g. Tomasello, 2000) that the restricted nature of early child speech reflects a lack of adultlike grammatical knowledge. We demonstrated that small samples were equally likely to under- as overestimate lexical specificity in children's speech, and that the reliability of estimates varies according to sample size. We argued that reliable analyses require a comparison with a control sample, such as that from an adult speaker. Second, we investigated the validity of estimates of error rates based on small samples. The results showed that overall error rates underestimate the incidence of error in some rarely produced parts of the system and that analyses on small samples were likely to substantially over- or underestimate error rates in infrequently produced constructions. We concluded that caution must be used when basing arguments about the scope and nature of errors in children's early multi-word productions on analyses of samples of spontaneous speech.

Abstract

In our recent paper, ‘Semantic generality, input frequency and the acquisition of syntax’ (Journal of Child Language31, 61–99), we presented data from two-year-old children to examine the question of whether the semantic generality of verbs contributed to their ease and stage of acquisition over and above the effects of their typically high frequency in the language to which children are exposed. We adopted two different categorization schemes to determine whether individual verbs should be considered to be semantically general, or ‘light’, or whether they encoded more specific semantics. These categorization schemes were based on previous work in the literature on the role of semantically general verbs in early verb acquisition, and were designed, in the first case, to be a conservative estimate of semantic generality, including only verbs designated as semantically general by a number of other researchers (e.g. Clark, 1978; Pinker, 1989; Goldberg, 1998), and, in the second case, to be a more inclusive estimate of semantic generality based on Ninio's (1999a,b) suggestion that grammaticalizing verbs encode the semantics associated with semantically general verbs. Under this categorization scheme, a much larger number of verbs were included as semantically general verbs.