Publications

Abstract

We used a multi-method approach to investigate how children avoid (or retreat from) argument structure overgeneralisation errors (e.g., *You giggled me). Experiment 1 investigated how semantic and statistical constraints (preemption and entrenchment) influence children’s and adults’ judgments of the grammatical acceptability of 120 verbs in transitive and intransitive sentences. Experiment 2 used syntactic priming to elicit overgeneralisation errors from children (aged 5–6) to investigate whether the same constraints operate in production. For judgments, the data showed effects of preemption, entrenchment, and semantics for all ages. For production, only an effect of preemption was observed, and only for transitivisation errors with intransitive-only verbs (e.g., *The man laughed the girl). We conclude that preemption, entrenchment, and semantic effects are real, but are obscured by particular features of the present production task.

Abstract

Eye gaze is a ubiquitous cue in child-caregiver interactions and infants are highly attentive to eye gaze from very early on. However, the question of why infants show gaze-sensitive behavior, and what role this sensitivity to gaze plays in their language development, is not yet well-understood. To gain a better understanding of the role of eye gaze in infants’ language learning, we conducted a broad systematic review of the developmental literature for all studies that investigate the role of eye gaze in infants’ language development. Across 77 peer-reviewed articles containing data from typically-developing human infants (0-24 months) in the domain of language development we identified two broad themes. The first tracked the effect of eye gaze on four developmental domains: (1) vocabulary development, (2) word-object mapping, (3) object processing, and (4) speech processing. Overall, there is considerable evidence that infants learn more about objects and are more likely to form word-object mappings in the presence of eye gaze cues, both of which are necessary for learning words. In addition, there is good evidence for longitudinal relationships between infants’ gaze following abilities and later receptive and expressive vocabulary. However, many domains (e.g. speech processing) are understudied; further work is needed to decide whether gaze effects are specific to tasks such as word-object mapping, or whether they reflect a general learning enhancement mechanism. The second theme explored the reasons why eye gaze might be facilitative for learning, addressing the question of whether eye gaze is treated by infants as a specialized socio-cognitive cue. We concluded that the balance of evidence supports the idea that eye gaze facilitates infants’ learning by enhancing their arousal, memory and attentional capacities to a greater extent than other low-level attentional cues. However, as yet, there are too few studies that directly compare the effect of eye gaze cues and non-social, attentional cues for strong conclusions to be drawn. We also suggest there might be a developmental effect, with eye gaze, over the course of the first two years of life, developing into a truly ostensive cue that enhances language learning across the board.

Abstract

In the previous decade, dozens of studies involving thousands of children across several research disciplines have made use of a combined daylong audio-recorder and automated algorithmic analysis called the LENAⓇ system, which aims to assess children’s language environment. While the system’s prevalence in the language acquisition domain is steadily growing, there are only scattered validation efforts on only some of its key characteristics. Here, we assess the LENAⓇ system’s accuracy across all of its key measures: speaker classification, Child Vocalization Counts (CVC), Conversational Turn Counts (CTC), and Adult Word Counts (AWC). Our assessment is based on manual annotation of clips that have been randomly or periodically sampled out of daylong recordings, collected from (a) populations similar to the system’s original training data (North American English-learning children aged 3-36 months), (b) children learning another dialect of English (UK), and (c) slightly older children growing up in a different linguistic and socio-cultural setting (Tsimane’ learners in rural Bolivia). We find reasonably high accuracy in some measures (AWC, CVC), with more problematic levels of performance in others (CTC, precision of male adults and other children). Statistical analyses do not support the view that performance is worse for children who are dissimilar from the LENAⓇ original training set. Whether LENAⓇ results are accurate enough for a given research, educational, or clinical application depends largely on the specifics at hand. We therefore conclude with a set of recommendations to help researchers make this determination for their goals.

Abstract

Understanding the mechanisms that drive variation in children’s language acquisition requires large, population-representative datasets of children’s word learning across development. Parent report measures such as the MacArthur-Bates Communicative Development Inventories (CDI) are commonly used to collect such data, but the traditional paper-based forms make the curation of large datasets logistically challenging. Many CDI datasets are thus gathered using convenience samples, often recruited from communities in proximity to major research institutions. Here, we introduce Web-CDI, a web-based tool which allows researchers to collect CDI data online. Web-CDI contains functionality to collect and manage longitudinal data, share links to test administrations, and download vocabulary scores. To date, over 3,500 valid Web-CDI administrations have been completed. General trends found in past norming studies of the CDI are present in data collected from Web-CDI: scores of children’s productive vocabulary grow with age, female children show a slightly faster rate of vocabulary growth, and participants with higher levels of educational attainment report slightly higher vocabulary production scores than those with lower levels of education attainment. We also report results from an effort to oversample non-white, lower-education participants via online recruitment (N = 241). These data showed similar demographic trends to the full sample but this effort resulted in a high exclusion rate. We conclude by discussing implications and challenges for the collection of large, population-representative datasets.

Abstract

By the end of their first year, infants can interpret many different types of complex dynamic visual events, such as caused-motion, chasing, and goal-directed action. Infants of this age are also in the early stages of vocabulary development, producing their first words at around 12 months. The present work examined whether there are meaningful individual differences in infants’ ability to represent dynamic causal events in visual scenes, and whether these differences influence vocabulary development. As part of the longitudinal Language 0–5 Project, 78 10-month-old infants were tested on their ability to interpret three dynamic motion events, involving (a) caused-motion, (b) chasing behaviour, and (c) goal-directed movement. Planned analyses found that infants showed evidence of understanding the first two event types, but not the third. Looking behaviour in each task was not meaningfully related to vocabulary development, nor were there any correlations between the tasks. The results of additional exploratory analyses and simulations suggested that the infants’ understanding of each event may not be predictive of their vocabulary development, and that looking times in these tasks may not be reliably capturing any meaningful individual differences in their knowledge. This raises questions about how to convert experimental group designs to individual differences measures, and how to interpret infant looking time behaviour.

Abstract

A key omission from many accounts of children’s early word learning is the linguistic knowledge that the child has acquired up to the point when learning occurs. We simulate this knowledge using a computational model that learns phoneme and word sequence knowledge from naturalistic language corpora. We show how this simple model is able to account for effects of word length, word frequency, neighborhood density and phonotactic probability on children’s early word learning. Moreover, we show how effects of neighborhood density and phonotactic probability on word learning are largely influenced by word length, with our model being able to capture all effects. We then use predictions from the model to show how the ease by which a child learns a new word from maternal input is directly influenced by the phonological knowledge that the child has acquired from other words up to the point of encountering the new word. There are major implications of this work: models and theories of early word learning need to incorporate existing sublexical and lexical knowledge in explaining developmental change while well-established indices of word learning are rejected in favor of phonological knowledge of varying grain sizes.

Abstract

The purpose of this project was to investigate the effectiveness of a language-focused professional development programme on the knowledge and behaviour of preschool practitioners (sometimes called early years practitioners) in the UK. In Study 1 we determined whether the training received by practitioners is effective in improving their knowledge of how to support children’s language and communicative development. In Study 2 we tested whether trained practitioners, and practitioners from centres with embedded Language Champions, were able to implement the techniques they had been taught. For this, we video-recorded practitioners interacting, one to one, with 2- and 3–4-year-old children in their centres. We conclude that (1) practitioners retain the knowledge they have been taught, both about how children learn and about how to promote this learning, and that (2), in some respects, this knowledge translates well into practice; practitioners in centres with embedded Language Champions and trained practitioners used language-enriching behaviours when interacting with children more often than did untrained practitioners. We discuss how the translation of some techniques into overt behaviour could be made more effective

Abstract

Language users encounter words in at least two different modalities. Arguably, the most frequent encounters are in spoken or written form. Previous research has shown that – compared to the spoken modality – written language features more difficult words. Thus, frequent reading might have effects on word recognition. In the present study, we investigated 1) whether input modality (spoken, written, or bimodal) has an effect on word recognition accuracy, 2) whether this modality effect interacts with word difficulty, 3) whether the interaction of word difficulty and reading experience impacts word recognition accuracy, and 4) whether this interaction is influenced by input modality. To do so, we re-analysed a dataset that was collected in the context of a vocabulary test development to assess in which modality test words should be presented. Participants had carried out a word recognition task, where non-words and words of varying difficulty were presented in auditory, visual and audio-visual modalities. In addition to this main experiment, participants had completed a receptive vocabulary and an author recognition test to measure their reading experience. Our re-analyses did not reveal evidence for an effect of input modality on word recognition accuracy, nor for interactions with word difficulty or language experience. Word difficulty interacted with reading experience in that frequent readers were more accurate in recognizing difficult words than individuals who read less frequently. Practical implications are discussed.

Abstract

Previous studies have shown that children retreat from argument-structure overgeneralization errors (e.g., *Don’t giggle me) by inferring that frequently encountered verbs are unlikely to be grammatical in unattested constructions, and by making use of syntax-semantics correspondences (e.g., verbs denoting internally caused actions such as giggling cannot normally be used causatively). The present study tested a new account based on a unitary learning mechanism that combines both of these processes. Seventy-two participants (ages 5–6, 9–10, and adults) rated overgeneralization errors with higher (*The funny man’s joke giggled Bart) and lower (*The funny man giggled Bart) degrees of direct external causation. The errors with more-direct causation were rated as less unacceptable than those with less-direct causation. This finding is consistent with the new account, under which children acquire—in an incremental and probabilistic fashion—the meaning of particular constructions (e.g., transitive causative = direct external causation) and particular verbs, rejecting generalizations where the incompatibility between the two is too great.

Abstract

Positive and negative what, why and yes/no questions with the 3sg auxiliaries can and does were elicited from 50 children aged 3;3–4;3. In support of the constructivist “schema-combination” account, only children who produced a particular positive question type correctly (e.g., What does she want?) produced a characteristic “auxiliary-doubling” error (e.g., *What does she doesn't want?) for the corresponding negative question type. This suggests that these errors are formed by superimposing a positive question frame (e.g., What does THING PROCESS?) and an inappropriate negative frame (e.g., She doesn't PROCESS) learned from declarative utterances. In addition, a significant correlation between input frequency and correct production was observed for 11 of the 12 lexical frames (e.g., What does THING PROCESS?), although some negative question types showed higher rates of error than one might expect based on input frequency alone. Implications for constructivist and generativist theories of question-acquisition are discussed.

Abstract

A number of researchers have claimed that questions and other constructions with long distance dependencies (LDDs) are acquired relatively early, by age 4 or even earlier, in spite of their complexity. Analysis of LDD questions in the input available to children suggests that they are extremely stereotypical, raising the possibility that children learn lexically specific templates such as WH do you think S-GAP? rather than general rules of the kind postulated in traditional linguistic accounts of this construction. We describe three elicited imitation experiments with children aged from 4;6 to 6;9 and adult controls. Participants were asked to repeat prototypical questions (i.e., questions which match the hypothesised template), unprototypical questions (which depart from it in several respects) and declarative counterparts of both types of interrogative sentences. The children performed significantly better on the prototypical variants of both constructions, even when both variants contained exactly the same lexical material, while adults showed prototypicality e¤ects for LDD questions only. These results suggest that a general declarative complementation construction emerges quite late in development (after age 6), and that even adults rely on lexically specific templates for LDD questions.

Abstract

Purpose: The study of auxiliary acquisition is central to work on language development and has attracted theoretical work from both nativist and constructivist approaches. This study is part of a 2-part companion set that represents a unique attempt to trace the development of auxiliary syntax by using a longitudinal elicitation methodology. The aim of the research described in this part is to track the development of modal auxiliaries and auxiliary DO in questions and declaratives to provide a more complete picture of the development of the auxiliary system in English-speaking children. Method: Twelve English-speaking children participated in 2 tasks designed to elicit auxiliaries CAN, WILL, and DOES in declaratives and yes/no questions. They completed each task 6 times in total between the ages of 2;10 (years;months) and 3;6. Results: The children’s levels of correct use of the target auxiliaries differed in complex ways according to auxiliary, polarity, and sentence structure, and these relations changed over development. An analysis of the children’s errors also revealed complex interactions between these factors. Conclusions: These data cannot be explained in full by existing theories of auxiliary acquisition. Researchers working within both generativist and constructivist frameworks need to develop more detailed theories of acquisition that predict the pattern of acquisition observed.

Abstract

Purpose: The question of how and when English-speaking children acquire auxiliaries is the subject of extensive debate. Some researchers posit the existence of innately given Universal Grammar principles to guide acquisition, although some aspects of the auxiliary system must be learned from the input. Others suggest that auxiliaries can be learned without Universal Grammar, citing evidence of piecemeal learning in their support. This study represents a unique attempt to trace the development of auxiliary syntax by using a longitudinal elicitation methodology. Method: Twelve English-speaking children participated in 3 tasks designed to elicit auxiliary BE in declaratives and yes/no and wh-questions. They completed each task 6 times in total between the ages of 2;10 (years;months) and 3;6. Results: The children’s levels of correct use of 2 forms of BE (is,are) differed according to auxiliary form and sentence structure, and these relations changed over development. An analysis of the children’s errors also revealed complex interactions between these factors. Conclusion: These data are problematic for existing accounts of auxiliary acquisition and highlight the need for researchers working within both generativist and constructivist frameworks to develop more detailed theories of acquisition that directly predict the pattern of acquisition observed.

Abstract

According to Crain and Nakayama (1987), when forming complex yes/no questions, children do not make errors such as Is the boy who smoking is crazy? because they have innate knowledge of structure dependence and so will not move the auxiliary from the relative clause. However, simple recurrent networks are also able to avoid such errors, on the basis of surface distributional properties of the input (Lewis & Elman, 2001; Reali & Christiansen, 2005). Two new elicited production studies revealed that (a) children occasionally produce structure-dependence errors and (b) the pattern of children's auxiliary-doubling errors (Is the boy who is smoking is crazy?) suggests a sensitivity to surface co-occurrence patterns in the input. This article concludes that current data do not provide any support for the claim that structure dependence is an innate constraint, and that it is possible that children form a structure-dependent grammar on the basis of exposure to input that exhibits this property.

Abstract

Participants (aged 5–6 yrs, 9–10 yrs and adults) rated (using a five-point scale) grammatical (intransitive) and overgeneralized (transitive causative)1 uses of a high frequency, low frequency and novel intransitive verb from each of three semantic classes [Pinker, S. (1989a). Learnability and cognition: the acquisition of argument structure. Cambridge, MA: MIT Press]: “directed motion” (fall, tumble), “going out of existence” (disappear, vanish) and “semivoluntary expression of emotion” (laugh, giggle). In support of Pinker’s semantic verb class hypothesis, participants’ preference for grammatical over overgeneralized uses of novel (and English) verbs increased between 5–6 yrs and 9–10 yrs, and was greatest for the latter class, which is associated with the lowest degree of direct external causation (the prototypical meaning of the transitive causative construction). In support of Braine and Brooks’s [Braine, M.D.S., & Brooks, P.J. (1995). Verb argument strucure and the problem of avoiding an overgeneral grammar. In M. Tomasello & W. E. Merriman (Eds.), Beyond names for things: Young children’s acquisition of verbs (pp. 352–376). Hillsdale, NJ: Erlbaum] entrenchment hypothesis, all participants showed the greatest preference for grammatical over ungrammatical uses of high frequency verbs, with this preference smaller for low frequency verbs, and smaller again for novel verbs. We conclude that both the formation of semantic verb classes and entrenchment play a role in children’s retreat from argument-structure overgeneralization errors.