Publications

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

Our target paper argued for the ubiquity of frequency effects in acquisition, and that any comprehensive theory must take into account the multiplicity of ways that frequently occurring and co-occurring linguistic units affect the acquisition process. The commentaries on the paper provide a largely unanimous endorsement of this position, but raise additional issues likely to frame further discussion and theoretical development. Specifically, while most commentators did not deny the importance of frequency effects, all saw this as the tip of the theoretical iceberg. In this short response we discuss common themes raised in the commentaries, focusing on the broader issue of what frequency effects mean for language acquisition.

Abstract

Participants aged 5;2-6;8, 9;2-10;6 and 18;1-22;2 (72 at each age) rated verb argument structure overgeneralization errors (e.g., *Daddy giggled the baby) using a five-point scale. The study was designed to investigate the feasibility of two proposed construction-general solutions to the question of how children retreat from, or avoid, such errors. No support was found for the prediction of the preemption hypothesis that the greater the frequency of the verb in the single most nearly synonymous construction (for this example, the periphrastic causative; e.g., Daddy made the baby giggle), the lower the acceptability of the error. Support was found, however, for the prediction of the entrenchment hypothesis that the greater the overall frequency of the verb, regardless of construction, the lower the acceptability of the error, at least for the two older groups. Thus while entrenchment appears to be a robust solution to the problem of the retreat from error, and one that generalizes across different error types, we did not find evidence that this is the case for preemption. The implication is that the solution to the retreat from error lies not with specialized mechanisms, but rather in a probabilistic process of construction competition.

Abstract

This review article presents evidence for the claim that frequency effects are pervasive in children's first language acquisition, and hence constitute a phenomenon that any successful account must explain. The article is organized around four key domains of research: children's acquisition of single words, inflectional morphology, simple syntactic constructions, and more advanced constructions. In presenting this evidence, we develop five theses. (i) There exist different types of frequency effect, from effects at the level of concrete lexical strings to effects at the level of abstract cues to thematic-role assignment, as well as effects of both token and type, and absolute and relative, frequency. High-frequency forms are (ii) early acquired and (iii) prevent errors in contexts where they are the target, but also (iv) cause errors in contexts in which a competing lower-frequency form is the target. (v) Frequency effects interact with other factors (e.g. serial position, utterance length), and the patterning of these interactions is generally informative with regard to the nature of the learning mechanism. We conclude by arguing that any successful account of language acquisition, from whatever theoretical standpoint, must be frequency sensitive to the extent that it can explain the effects documented in this review, and outline some types of account that do and do not meet this criterion.

Abstract

In this study, we investigated when children develop adult-like verb–structure links, and examined two mechanisms, associative and error-based learning, that might explain how these verb–structure links are learned. Using structural priming, we tested children’s and adults’ ability to use verb–structure links in production in three ways; by manipulating: (1) verb overlap between prime and target, (2) target verb bias, and (3) prime verb bias. Children (aged 3–4 and 5–6 years old) and adults heard and produced double object dative (DOD) and prepositional object dative (PD) primes with DOD- and PD-biased verbs. Although all age groups showed significant evidence of structural priming, only adults showed increased priming when there was verb overlap between prime and target sentences (the lexical boost). The effect of target verb bias also grew with development. Critically, however, the effect of prime verb bias on the size of the priming effect (prime surprisal) was larger in children than in adults, suggesting that verb–structure links are present at the earliest age tested. Taken as a whole, the results suggest that children begin to acquire knowledge about verb-argument structure preferences early in acquisition, but that the ability to use adult-like verb bias in production gradually improves over development. We also argue that this pattern of results is best explained by a learning model that uses an error-based learning mechanism.

Abstract

This article reviews the some of the most widely used methods used for studying children's language acquisition including (1) spontaneous/naturalistic, diary, parental report data, (2) production methods (elicited production, repetition/elicited imitation, syntactic priming/weird word order), (3) comprehension methods (act-out, pointing, intermodal preferential looking, looking while listening, conditioned head turn preference procedure, functional neuroimaging) and (4) judgment methods (grammaticality/acceptability judgments, yes-no/truth-value judgments). The review outlines the types of studies and age-groups to which each method is most suited, as well as the advantage and disadvantages of each. We conclude by summarising the particular methodological considerations that apply to each paradigm and to experimental design more generally. These include (1) choosing an age-appropriate task that makes communicative sense (2) motivating children to co-operate, (3) choosing a between-/within-subjects design, (4) the use of novel items (e.g., novel verbs), (5) fillers, (6) blocked, counterbalanced and random presentation, (7) the appropriate number of trials and participants, (8) drop-out rates (9) the importance of control conditions, (10) choosing a sensitive dependent measure (11) classification of responses, and (12) using an appropriate statistical test. WIREs Cogn Sci 2013, 4:149–168. doi: 10.1002/wcs.1215

Abstract

This review investigates empirical evidence for different theoretical proposals regarding the retreat from overgeneralization errors in three domains: word learning (e.g., *doggie to refer to all animals), morphology [e.g., *spyer, *cooker (one who spies/cooks), *unhate, *unsqueeze, *sitted; *drawed], and verb argument structure [e.g., *Don't giggle me (c.f. Don't make me giggle); *Don't say me that (c.f. Don't say that to me)]. The evidence reviewed provides support for three proposals. First, in support of the pre-emption hypothesis, the acquisition of competing forms that express the desired meaning (e.g., spy for *spyer, sat for *sitted, and Don't make me giggle for *Don't giggle me) appears to block errors. Second, in support of the entrenchment hypothesis, repeated occurrence of particular items in particular constructions (e.g., giggle in the intransitive construction) appears to contribute to an ever strengthening probabilistic inference that non-attested uses (e.g., *Don't giggle me) are ungrammatical for adult speakers. That is, both the rated acceptability and production probability of particular errors decline with increasing frequency of pre-empting and entrenching forms in the input. Third, learners appear to acquire semantic and morphophonological constraints on particular constructions, conceptualized as properties of slots in constructions [e.g., the (VERB) slot in the morphological un-(VERB) construction or the transitive-causative (SUBJECT) (VERB) (OBJECT) argument-structure construction]. Errors occur as children acquire the fine-grained semantic and morphophonological properties of particular items and construction slots, and so become increasingly reluctant to use items in slots with which they are incompatible. Findings also suggest some role for adult feedback and conventionality; the principle that, for many given meanings, there is a conventional form that is used by all members of the speech community.

Abstract

Both children and adults predict the content of upcoming language, suggesting that prediction is useful for learning as well as processing. We present an alternative model which can explain prediction behaviour as a by-product of language learning. We suggest that a consideration of language acquisition places important constraints on Pickering & Garrod's (P&G's) theory.