Letitia R. Naigles

Children use syntax to learn verb meanings

Verb learning is clearly a function of observation of real-world contingencies; however, it is argued that such observational information is insufficient to account fully for vocabulary acquisition. This paper provides an experimental validation of Landau & Gleitmans (1985) syntactic bootstrapping procedure; namely, that children may use syntactic information to learn new verbs. Pairs of actions were presented simultaneously with a nonsense verb in one of two syntactic structures. The actions were subsequently separated, and the children (MA = 2;1) were asked to select which action was the referent for the verb. The childrens choice of referent was found to be a function of the syntactic structure in which the verb had appeared.

How children use input to acquire a lexicon.

The contributions of social processes and computational processes to early lexical development were evaluated. A re-analysis and review of previous research cast doubt on the sufficiency of social approaches to word learning. An empirical investigation of the relation of social-pragmatic and data-providing features of input to the productive vocabulary of sixty-three 2-year-old children revealed benefits of data provided in mother-child conversation, but no effects of social aspects of those conversations. The findings further revealed that the properties of data that benefit lexical development in 2-year-olds are quantity, lexical richness, and syntactic complexity. The nature of the computational mechanisms implied by these findings is discussed. An integrated account of the roles of social and computational processes to lexical development is proposed.

Caregiver speech and children's use of nouns versus verbs: A comparison of English, Italian, and Mandarin

This paper examines naturalistic samples of adult-to-child speech to determine if variations in the input are consistent with reported variations in the proportions of nouns and verbs in childrens early vocabularies. It contrasts two PRO-DROP languages, Italian and Mandarin, with English. Naturalistic speech samples from six 2:0 English-, six 1:11 Italian-, and ten 1:10 Mandarin-speaking children and their caregivers were examined. Adult-to-child speech was coded for the type frequency, token frequency, utterance position, and morphological variation of nouns and verbs as well as the types and placements of syntactic subjects and the pragmatic focus of adult questions. Childrens spontaneous productions of nouns and verbs and their responses to adult questions were also examined. The results suggest a pattern consistent with the childrens spontaneous production data. Namely, the speech of English-speaking caregivers emphasized nouns over verbs, whereas that of Mandarin-speaking caregivers emphasized verbs over nouns. The data from the Italian-speaking caregivers were more equivocal, though still noun-oriented, across these various input measures.

Why are some verbs learned before other verbs? Effects of input frequency and structure on children's early verb use

This study investigated the extent to which the nature of verb input accounts for the order in which children acquire verbs. We assessed the nature of verb input using a combined sample of the speech of 57 mothers addressing their Stage I children. We assessed the order of verb acquisition using as our database a combined sample of those childrens speech 10 weeks later and using as our measure of order of acquisition the frequency of verb occurrence. The first set of analyses established the validity of this measure of acquisition order by comparing it with order of acquisition data obtained from checklist and diary data. The second set of analyses revealed that three properties of the input were significant predictors of the order of acquisition of the 25 verbs that were the focus of this study. The predictive properties of input were the total frequency, final position frequency, and diversity of syntactic environments in which the verbs appeared. These findings suggest that the way verbs appear in input influences their ease of acquisition. More specifically, the effect of syntactic diversity in input provides support for the syntactic bootstrapping account of how children use structural information to learn the meaning of new verbs.

The use of multiple frames in verb learning via syntactic bootstrapping

Following the original Syntactic Bootstrapping proposal of Landau and Gleitman (1985), this study investigated whether young 2-year-old children (mean age = 28 months) can use multiple syntactic frames, in addition to the extralinguistic scene, to help focus on the meaning of a novel verb. The multiple frames tested were combinations of transitive and intransitive frames in two alternation patterns, Causative and Omitted Object. By hypothesis, the Causative alternation would be more predictive of actions involving physical causation and the Omitted Object alternation more predictive of actions involving repeated physical contact without causation. Subjects were presented with videos depicting both actions, together with a novel verb. The actions were subsequently separated, and the children were asked to select which action was the referent of the novel verb. The novel verb was presented either in transitive and intransitive frames in the Causative alternation (CS: The duck is sebbing the frog, the frog is sebbing) or the Omitted Object alternation (OO: The duck is sebbing the frog, the duck is sebbing), or in intransitive frames only (IO: The duck is sebbing), or without a frame (FF: Sebbing!). In the CS, IO, and FF conditions, children preferred the causative action as the referent of the verb. However, the girls in the OO condition showed a significantly different preference, and looked more toward the contact actions than their peers in the other conditions did. This study thus provides the first experimental evidence that young 2-year-old children can use multiple syntactic frames to help determine the meaning of a novel verb.

Motion-Verb Generalizations in English and Spanish: Influences of Language and Syntax

English and Spanish speakers differ in the ways they talk about motion events, but how have these different modes of expression become instantiated as differing generalizations—as syntactic rules, lexical patterns, or both? In two studies, we asked English- and Spanish-speaking adults to interpret novel motion verbs presented in three types of sentence frames. Overall, English speakers expected novel verbs to encode the manner of motion, whereas Spanish speakers expected the verbs to encode the path of motion. The sentence frames also significantly affected how the speakers interpreted the novel verbs. We conclude that speakers of different languages represent their different generalizations about the composition of motion verbs both lexically and syntactically, and discuss how these generalizations might be important for issues of language acquisition and linguistic relativity.

Form is easy, meaning is hard: resolving a paradox in early child language

A developmental paradox is discussed: studies of infant processing of language and language-like stimuli indicate considerable ability to abstract patterns over specific items and to distinguish natural from unnatural English sentences. In contrast, studies of toddler language production find little ability to generalize patterns over specific English words or constructions. Thus, infants appear to be abstract auditory or language processors whereas toddlers appear to be non-abstract, item-specific language users. Three resolutions are offered to this paradox. The first, that no resolution is necessary because only the toddler findings come from language use in a communicative context and so only the toddler findings are relevant to linguistic knowledge, is rejected. The second, that the contradictions are rooted in the differing methodologies of the two sets of studies (comprehension vs. production), is found to explain important aspects of the contradictory findings. The third, that the contractions come from the differing content of the stimuli in the studies, is also found to be explanatory and is argued to carry greater weight. Resolution 3 suggests that the patterns that infants extract from their linguistic input are not yet tied to meaning; thus, toddlers do not lose these earlier-abstracted forms but their use of them is limited until they have been integrated with meaning. It is argued that in language acquisition, learning form is easy but learning meaning, and especially linking meanings and forms, is hard.

Flexibility in early verb use : evidence from a multiple-n diary study

Flexibility and productivity are hallmarks of human language use. Competent speakers have the capacity to use the words they know to serve a variety of communicative functions, to refer to new and varied exemplars of the categories to which words refer, and in new and varied combinations with other words. When and how children achieve this flexibility and when they are truly productive language users--are central issues among accounts of language acquisition. The current study tests competing hypotheses of the achievement of flexibility and some kinds of productivity against data on childrens first uses of their first-acquired verbs. Eight mothers recorded their childrens first 10 uses of 34 early acquired verbs, if those verbs were produced within the window of the study. The children were between 16 and 20 months when the study began (depending on when the children started to produce verbs), were followed for between 3 and 12 months, and produced between 13 and 31 of the target verbs. These diary records provided the basis for a description of the pragmatic, semantic, and syntactic properties of early verb use. The data revealed that within this early, initial period of verb use, children use their verbs both to command and describe, they use their verbs in reference to a variety of appropriate actions enacted by variety of actors and with a variety of affected objects, and they use their verbs in a variety of syntactic structures. All 8 children displayed semantic and grammatical flexibility before 24 months of age. These findings are more consistent with a model of the language-learning child as an avid generalizer than as a conservative language user. Childrens early verb use suggests abilities and inclinations to abstract from experience that may indeed begin in infancy.

Do children with autism spectrum disorders show a shape bias in word learning

Many children with autism spectrum disorders (ASD) acquire a sizeable lexicon. However, these children also seem to understand and/or store the meanings of words differently from typically developing children. One of the mechanisms that helps typically developing children learn novel words is the shape bias, in which the referent of a noun is mapped onto the shape of an object, rather than onto its color, texture, or size. We hypothesized that children with autistic disorder would show reduced or absent shape bias. Using the intermodal preferential looking paradigm , we compared the performance of young children with ASD and typically developing children (TYP), across four time points, in their use of shape bias. Neither group showed a shape bias at Visit 1, when half of the children in both groups produced fewer than 50 count nouns. Only the TYP group showed a shape bias at Visits 2, 3, and 4. According to the growth curve analyses, the rate of increase in the shape bias scores over time was significant for the TYP children. The fact that the TYP group showed a shape bias at 24 months of age, whereas children with ASD did not demonstrate a shape bias despite a sizeable vocabulary, supports a dissociation between vocabulary size and principles governing acquisition in ASD children from early in language development.

Intervention for optimal outcome in children and adolescents with a history of autism.

Objective: Autism spectrum disorders (ASDs) were once considered lifelong disorders, but recent findings indicate that some children with ASDs no longer meet diagnostic criteria for any ASD and reach normal cognitive function. These children are considered to have achieved “optimal outcomes” (OO). The present study aimed to retrospectively examine group differences in the intervention history of children and adolescents with OO and those with high-functioning autism (HFA). Method: The current study examined intervention histories in 25 individuals with OO and 34 individuals with HFA (current age, 8–21 years), who did not differ on age, sex, nonverbal intelligence, or family income. Intervention history was collected through detailed parent questionnaires. Results: Children in the OO group had earlier parental concern, received earlier referrals to specialists, and had earlier and more intensive intervention than those in the HFA group. Substantially more children with OO than HFA received applied behavior analysis (ABA) therapy, although for children who received ABA, the intensity did not differ between the groups. Children in the HFA group were more likely to have received medication, especially antipsychotics and antidepressants. There were no group differences in the percent of children receiving special diets or supplements. Conclusion: These data suggest that OO individuals generally receive earlier, more intense interventions, and more ABA, whereas HFA individuals receive more pharmacologic treatments. Although the use of retrospective data is a clear limitation to the current study, the substantial differences in the reported provision of early intervention, and ABA in particular, is highly suggestive and should be replicated in prospective studies.