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

The present study investigated how children learn that some verbs may appear in the figure-locative but not the ground-locative construction (e.g., Lisa poured water into the cup; *Lisa poured the cup with water), with some showing the opposite pattern (e.g., *Bart filled water into the cup; Bart filled the cup with water), and others appearing in both (Lisa sprayed water onto the flowers; Lisa sprayed the flowers with water). Grammatical acceptability judgments were obtained for the use of each of 142 locative verbs (60 for children) in each sentence type. Overall, and for each age group individually, the judgment data were best explained by a model that included ratings of the extent to which each verb exhibits both the broad- and narrow-range semantic properties of the figure- and ground-locative constructions (relating mainly to manner and end-state respectively; Pinker, 1989) and the statistical-learning measure of overall verb frequency (entrenchment; Braine & Brooks, 1995). A second statistical-learning measure, frequency in each of the two locative constructions (pre-emption; Goldberg, 1995), was found to have no additional dissociable effect. We conclude by drawing together various theoretical proposals to arrive at a possible account of how semantics and statistics interact in the retreat from overgeneralization.

Abstract

Children (aged five-to-six and nine-to-ten years) and adults rated the acceptability of well-formed sentences and argument-structure overgeneralization errors involving the prepositional-object and double-object dative constructions (e.g. Marge pulled the box to Homer/*Marge pulled Homer the box). In support of the entrenchment hypothesis, a negative correlation was observed between verb frequency and the acceptability of errors, across all age groups. Adults additionally displayed sensitivity to narrow-range semantic constraints on the alternation, rejecting double-object dative uses of novel verbs consistent with prepositional-dative-only classes and vice versa. Adults also provided evidence for the psychological validity of a proposed morphophonological constraint prohibiting Latinate verbs from appearing in the double-object dative. These findings are interpreted in the light of a recent account of argument-structure acquisition, under which children retreat from error by incrementally learning the semantic, phonological, and pragmatic properties associated with particular verbs and particular construction slots.*

Abstract

Structural priming paradigms have been influential in shaping theories of adult sentence processing and theories of syntactic development. However, until recently there have been few attempts to provide an integrated account that explains both adult and developmental data. The aim of the present paper was to begin the process of integration by taking a developmental approach to structural priming. Using a dialog comprehension-to-production paradigm, we primed participants (3–4 year olds, 5–6 year olds and adults) with double object datives (Wendy gave Bob a dog) and prepositional datives (Wendy gave a dog to Bob). Half the participants heard the same verb in prime and target (e.g. gave–gave) and half heard a different verb (e.g. sent–gave). The results revealed substantial differences in the magnitude of priming across development. First, there was a small but significant abstract structural priming effect across all age groups, but this effect was larger in younger children than in older children and adults. Second, adding verb overlap between prime and target prompted a large, significant increase in the priming effect in adults (a lexical boost), a small, marginally significant increase in the older children and no increase in the youngest children. The results support the idea that abstract syntactic knowledge can develop independently of verb-specific frames. They also support the idea that different mechanisms may be needed to explain abstract structural priming and lexical priming, as predicted by the implicit learning account (Bock, K., & Griffin, Z. M. (2000). The persistence of structural priming: Transient activation or implicit learning? Journal of Experimental Psychology – General, 129(2), 177–192). Finally, the results illustrate the value of an integrative developmental approach to both theories of adult sentence processing and theories of syntax acquisition.

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.