Publications

Abstract

Language processing is rapidly incremental, but evidence bearing upon this assumption comes from very few languages. In this paper we report on a study of incremental processing in Murrinhpatha, a polysynthetic Australian language, which expresses complex sentence-level meanings in a single verb, the full meaning of which is not clear until the final morph. Forty native Murrinhpatha speakers participated in a visual world eyetracking experiment in which they viewed two complex scenes as they heard a verb describing one of the scenes. The scenes were selected so that the verb describing the target scene had either no overlap with a possible description of the competitor image, or overlapped from the start (onset overlap) or at the end of the verb (rhyme overlap). The results showed that, despite meaning only being clear at the end of the verb, Murrinhpatha speakers made incremental predictions that differed across conditions. The findings demonstrate that processing in polysynthetic languages is rapid and incremental, yet unlike in commonly studied languages like English, speakers make parsing predictions based on information associated with bound morphs rather than discrete words.

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

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

Emergentist approaches to language acquisition identify a core role for language-specific experience and give primacy to other factors like function and domain-general learning mechanisms in syntactic development. This directly contrasts with a nativist structurally oriented approach, which predicts that grammatical development is guided by Universal Grammar and that structural factors constrain acquisition. Cantonese relative clauses (RCs) offer a good opportunity to test these perspectives because its typologically rare properties decouple the roles of frequency and complexity in subject- and object-RCs in a way not possible in European languages. Specifically, Cantonese object RCs of the classifier type are frequently attested in children’s linguistic experience and are isomorphic to frequent and early-acquired simple SVO transitive clauses, but according to formal grammatical analyses Cantonese subject RCs are computationally less demanding to process. Thus, the two opposing theories make different predictions: the emergentist approach predicts a specific preference for object RCs of the classifier type, whereas the structurally oriented approach predicts a subject advantage. In the current study we revisited this issue. Eighty-seven monolingual Cantonese children aged between 3;2 and 3;11 (Mage: 3;6) participated in an elicited production task designed to elicit production of subject- and object- RCs. The children were very young and most of them produced only noun phrases when RCs were elicited. Those (nine children) who did produce RCs produced overwhelmingly more object RCs than subject RCs, even when animacy cues were controlled. The majority of object RCs produced were the frequent classifier-type RCs. The findings concur with our hypothesis from the emergentist perspectives that input frequency and formal and functional similarity to known structures guide acquisition.

Abstract

In this study we test the hypothesis that symbolic play represents a fertile context for language acquisition because its inherent ambiguity elicits communicative behaviours that positively influence development. Infant-caregiver dyads (N = 54) participated in two 20-minute play sessions six months apart (Time 1 = 18 months, Time 2 = 24 months). During each session the dyads played with two sets of toys that elicited either symbolic or functional play. The sessions were transcribed and coded for several features of dyadic interaction and speech; infants’ linguistic proficiency was measured via parental report. The two play contexts resulted in different communicative and linguistic behaviour. Notably, the symbolic play condition resulted in significantly greater conversational turn-taking than functional play, and also resulted in the greater use of questions and mimetics in infant-directed speech (IDS). In contrast, caregivers used more imperative clauses in functional play. Regression analyses showed that unique properties of symbolic play (i.e., turn-taking, yes-no questions, mimetics) positively predicted children’s language proficiency, whereas unique features of functional play (i.e., imperatives in IDS) negatively predicted proficiency. The results provide evidence in support of the hypothesis that symbolic play is a fertile context for language development, driven by the need to negotiate meaning.

Abstract

There is consensus that the adult lexicon exhibits lexical competition. In particular, substantial evidence demonstrates that words with more phonologically similar neighbors are recognized less efficiently than words with fewer neighbors. How and when these effects emerge in the child's lexicon is less clear. In the current paper, we build on previous research by testing whether phonological onset density slows lexical access in a large sample of 100 English-acquiring 30-month-olds. The children participated in a visual world looking-while-listening task, in which their attention was directed to one of two objects on a computer screen while their eye movements were recorded. We found moderate evidence of inhibitory effects of onset neighborhood density on lexical access and clear evidence for an interaction between onset neighborhood density and vocabulary, with larger effects of onset neighborhood density for children with larger vocabularies. Results suggest the lexicons of 30-month-olds exhibit lexical-level competition, with competition increasing with vocabulary size.

Abstract

How children learn grammar is one of the most fundamental questions in cognitive science. Two theoretical accounts, namely, the Early Abstraction and Usage-Based accounts, propose competing answers to this question. To compare the predictions of these accounts, we tested the comprehension of 92 24-month old children of transitive sentences with novel verbs (e.g., “The boy is gorping the girl!”) with the Intermodal Preferential Looking (IMPL) task. We found very little evidence that children looked to the target video at above-chance levels. Using mixed and mixture models, we tested the predictions the two accounts make about: (i) the structure of individual differences in the IMPL task and (ii) the relationship between vocabulary knowledge, lexical processing, and performance in the IMPL task. However, the results did not strongly support either of the two accounts. The implications for theories on language acquisition and for tasks developed for examining individual differences are discussed.

Abstract

Children acquire language embedded within the rich social context of interaction. This paper reports on a longitudinal study investigating the developmental relationship between conversational turn‐taking and vocabulary growth in English‐acquiring children (N = 122) followed between 9 and 24 months. Daylong audio recordings obtained every 3 months provided several indices of the language environment, including the number of adult words children heard in their environment and their number of conversational turns. Vocabulary was measured independently via parental report. Growth curve analyses revealed a bidirectional relationship between conversational turns and vocabulary growth, controlling for the amount of words in children’s environments. The results are consistent with theoretical approaches that identify social interaction as a core component of early language acquisition.

Abstract

Children must necessarily process their input in order to learn it, yet the architecture of the developing parsing system and how it interfaces with acquisition is unclear. In the current paper we report experimental and corpus data investigating adult and children's use of morphosyntactic cues for making incremental online predictions of thematic roles in Tagalog, a verb-initial symmetrical voice language of the Philippines. In Study 1, Tagalog-speaking adults completed a visual world eye-tracking experiment in which they viewed pictures of causative actions that were described by transitive sentences manipulated for voice and word order. The pattern of results showed that adults process agent and patient voice differently, predicting the upcoming noun in the patient voice but not in the agent voice, consistent with the observation of a patient voice preference in adult sentence production. In Study 2, our analysis of a corpus of child-directed speech showed that children heard more patient voice- than agent voice-marked verbs. In Study 3, 5-, 7-, and 9-year-old children completed a similar eye-tracking task as used in Study 1. The overall pattern of results suggested that, like the adults in Study 1, children process agent and patient voice differently in a manner that reflects the input distributions, with children developing towards the adult state across early childhood. The results are most consistent with theoretical accounts that identify a key role for input distributions in acquisition and language processing

Abstract

This paper reports on an on-going project designed to collect comparable corpus data on child language and child-directed language in under-researched languages. Despite a long history of cross-linguistic research, there is a severe empirical bias within language acquisition research: Data is available for less than 2% of the world's languages, heavily skewed towards the larger and better-described languages. As a result, theories of language development tend to be grounded in a non-representative sample, and we know little about the acquisition of typologically-diverse languages from different families, regions, or sociocultural contexts. It is very likely that the reasons are to be found in the forbidding methodological challenges of constructing child language corpora under fieldwork conditions with their strict requirements on participant selection, sampling intervals, and amounts of data. There is thus an urgent need for proposals that facilitate and encourage language acquisition research across a wide variety of languages. Adopting a language documentation perspective, we illustrate an approach that combines the construction of manageable corpora of natural interaction with and between children with a sketch description of the corpus data – resulting in a set of comparable corpora and comparable sketches that form the basis for cross-linguistic comparisons.

Abstract

The current chapter discusses a structural priming experiment that investigated the on-line processing of English subject- and object- relative clauses. Sixty-one monolingual English-speaking adults participated in a self-paced reading experiment where they read prime-target pairs that fully crossed the relativised element within the relative clause (subject- versus object) across prime and target sentences. Following probabilistic theories of sentence processing, which predict that low frequency structures like object relatives are subject to greater priming effects due to their marked status, it was hypothesised that the normally-observed subject RC processing advantage would be eliminated following priming. The hypothesis was supported, identifying an important role for structural frequency in the processing of relative clause structures.

Abstract

In this paper we report on a visual world eye-tracking experiment that investigated the differing abilities of adults and children to use referential scene information during reanalysis to overcome lexical biases during sentence processing. The results showed that adults incorporated aspects of the referential scene into their parse as soon as it became apparent that a test sentence was syntactically ambiguous, suggesting they considered the two alternative analyses in parallel. In contrast, the children appeared not to reanalyze their initial analysis, even over shorter distances than have been investigated in prior research. We argue that this reflects the children's over-reliance on bottom-up, lexical cues to interpretation. The implications for the development of parsing routines are discussed

Abstract

This paper considers the use and representation of Australian hypocoristics (e.g., choccie → chocolate, arvo → afternoon). One-hundred-and-fifteen adult speakers of Australian English aged 17–84 years generated as many tokens of hypocoristics as they could in 10 min. The resulting corpus was analysed along a number of dimensions in an attempt to identify (i) general age- and gender-related trends in hypocoristic knowledge and use, and (ii) linguistic properties of each hypocoristic class. Following Bybee’s (1985, 1995) lexical network approach, we conclude that Australian hypocoristics are the product of the same linguistic processes that capture other inflectional morphological processes.

Abstract

The present paper reports on a study that investigated the role of procedural and declarative memory in the acquisition of Finnish past tense morphology. Two competing models were tested. Ullman's (2004) declarative/procedural model predicts that procedural memory supports the acquisition of regular morphology, whereas declarative memory supports the acquisition of irregular morphology. In contrast, single-route approaches predict that declarative memory should support lexical learning, which in turn should predict morphological acquisition. One-hundred and twenty-four (N=124) monolingual Finnish-speaking children aged 4;0–6;7 completed tests of procedural and declarative memory, tests of vocabulary knowledge and nonverbal ability, and a test of past test knowledge. The results best supported the single-route approach, suggesting that this account best extends to languages that possess greater morphological complexity than English.

Abstract

Educational tools claiming to use “right-brain techniques” are increasingly shaping school curricula. By implying a strong scientific basis, such approaches appeal to educators who rightly believe that knowledge of the brain should guide curriculum development. However, the notion of hemisphericity (idea that people are “left-brained” or “right-brained”) is a neuromyth that was debunked in the scientific literature 25 years ago. This article challenges the validity of “right-brain” teaching, highlighting the fact that neuroscientific research does not support its claims. Providing teachers with a basic understanding of neuroscience research as part of teacher training would enable more effective evaluation of brain-based claims and facilitate the adoption of tools validated by rigorous independent research rather than programs based on pseudoscience.

Abstract

The current study examined the acquisition of relative clauses (RCs) in Persian-speaking children. Persian is a relatively unique data point in crosslinguistic research in acquisition because it is a head-final language with post-nominal RCs. Children (N = 51) aged 2 to 7 years completed a picture-selection task that tested their comprehension of subject-, object-, and genitive-RCs. The results showed that the children experienced greater difficulty processing object and genitive RCs when compared to subject RCs, suggesting that the children have particular difficulty processing sentences with non-canonical word order. The results are discussed with reference to a number of theoretical accounts proposed to account for sentence difficulty.

Abstract

Aim and method: A comparison study of four six-year-old children attending a school with a play-based curriculum and a school with a traditionally structured classroom from low socioeconomic areas was conducted in Victoria, Australia. Children’s play, language and social skills were measured in February and again in August. At baseline assessment there was a combined sample of 31 children (mean age 5.5 years, SD 0.35 years; 13 females and 18 males). At follow-up there was a combined sample of 26 children (mean age 5.9 years, SD 0.35 years; 10 females, 16 males). Results: There was no significant difference between the school groups in play, language, social skills, age and sex at baseline assessment. Compared to norms on a standardised assessment, all the children were beginning school with delayed play ability. At follow-up assessment, children at the play-based curriculum school had made significant gains in all areas assessed (p values ranged from 0.000 to 0.05). Children at the school with the traditional structured classroom had made significant positive gains in use of symbols in play (p < 0.05) and semantic language (p < 0.05). At follow-up, there were significant differences between schools in elaborate play (p < 0.000), semantic language (p < 0.000), narrative language (p < 0.01) and social connection (p < 0.01), with children in the play-based curriculum school having significantly higher scores in play, narrative language and language and lower scores in social disconnection. Implications: Children from low SES areas begin school at risk of failure as skills in play, language and social skills are delayed. The school experience increases children’s skills, with children in the play-based curriculum showing significant improvements in all areas assessed. It is argued that a play-based curriculum meets children’s developmental and learning needs more effectively. More research is needed to replicate these results.