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

The present article reports on an investigation of one child's acquisition of the multiple senses of the preposition with from 2;0–4;0. Two competing claims regarding children's early representation and subsequent acquisition of with were investigated. The “multiple meanings” hypothesis predicts that children form individual form-meaning pairings for with as separate lexical entries. The “monosemy approach” (McKercher 2001) claims that children apply a unitary meaning by abstracting core features early in acquisition. The child's (“Brian”) speech and his input were coded according to eight distinguishable senses of with. The results showed that Brian first acquired the senses that were most frequent in the input (accompaniment, attribute, and instrument). Less common senses took much longer to emerge. A detailed analysis of the input showed that a variety of clues are available that potentially enable the child to distinguish among high frequency senses. The acquisition data suggested that the child initially applied a restricted one-to-one form-meaning mapping for with, which is argued to reflect the spatial properties of the preposition. On the basis of these results it is argued that neither the monosemy nor the multiple meanings approach can fully explain the data, but that the results are best explained by a combination of word learning principles and children's ability to categorize the contextual properties of each sense's use in the ambient language.

Abstract

Hartshorne and Ullman (2006) presented naturalistic language data from 25 children (15 boys, 10 girls) and showed that girls produced more past tense overregularization errors than did boys. In particular, girls were more likely to overregularize irregular verbs whose stems share phonological similarities with regular verbs. It was argued that the result supported the Declarative/Procedural model of language, a neuropsychological analogue of the dual-route approach to language. In the current study we present experimental data that are inconsistent with these naturalistic data. Eighty children (40 males, 40 females) aged 5;0–6;9 completed a past tense elicitation task, a test of declarative memory, and a test of non-verbal intelligence. The results revealed no sex differences on any of the measures. Instead, the best predictors of overregularization rates were item-level features of the test verbs. We discuss the results within the context of dual versus single route debate on past tense acquisition

Abstract

he present study investigated the referential communication skills of children with imaginary companions (ICs). Twenty-two children with ICs aged between 4 and 6 years were compared to 22 children without ICs (NICs). The children were matched for age, gender, birth order, number of siblings, and parental education. All children completed the Test of Referential Commu- nication (Camaioni, Ercolani & Lloyd, 1995). The results showed that the children with ICs performed better than the children without ICs on the speaker component of the task. In particular, the IC children were better able to identify a specific referen t to their interlocutor than were the NIC children. Furthermore, the IC children described less redundant features of the target picture than did the NIC children. The children did not differ in the listening comprehension component of the task. Overall, the results suggest that the IC children had a better understanding of their interlocutor’s information requirements in convers ation. The role of pretend play in the development of communicative competence is discussed in light of these results.