Upon hearing a novel label, listeners tend to assume that it refers to a novel, rather than a familiar object. While this disambiguation or mutual exclusivity (ME) effect has been robustly shown across development, it is unclear what it involves. Do listeners use their pragmatic and lexical knowledge to exclude the familiar object and thus select…

This study investigates the influence of semantic maturation on early lexical development by examining the impact of contextual diversity--known to influence semantic development--on word promotion from receptive to productive vocabularies (i.e., comprehension-expression gap). Study 1 compares the vocabularies of 3685 American-English-speaking…

Successful word recognition requires that listeners attend to differences that are phonemic in the language while also remaining flexible to the variation introduced by different voices and accents. Previous work has demonstrated that American-English-learning 19-month-olds are able to balance these demands: although one-off one-feature…

When learning a language, typically-developing infants face the daunting task of learning both the sounds and the meanings of words. In this dissertation, we focus on a source of variability that complicates the one-to-one relationship between words and their meanings: wordform variability. In Chapter 1 we make a distinction between the micro…

Purpose: This study investigates how the variables of culture and hearing status might influence the amount of parent-child talk families engage in throughout an average day. Method: Seventeen Vietnamese and 8 Canadian families of children with hearing loss and 17 Vietnamese and 13 Canadian families with typically hearing children between the ages…

Although the size of a child's vocabulary associates with language-processing skills, little is understood regarding how this relation emerges. This investigation asks whether and how the structure of vocabulary knowledge affects language processing in English-learning 24-month-old children (N = 32; 18 F, 14 M). Parental vocabulary report was used…

To better understand how toddlers integrate multiple learning strategies to acquire verbs, we compared sensorimotor recruitment and comparison learning because both strategies are thought to boost children's access to scene-level information. For sensorimotor recruitment, we tested having toddlers use dolls as agents and compared this strategy…

This mixed two-way experimental, cross-sectional study investigated fast-mapping (FM) of novel nouns and verbs in 63 Persian-speaking toddlers aged 30 months, including 31 late-talking (LT) and 32 typically developing (TD) matched with respect to age and maternal education. Toddlers were classified as LT if they had limited expressive vocabulary…

We report on an analysis of spontaneous gesture production in 2-year-old children who come from three countries (Italy, United Kingdom, Australia) and who speak two languages (Italian, English), in an attempt to tease apart the influence of language and culture when comparing children from different cultural and linguistic environments.…

Purpose: Despite the apparent primacy of syntactic deficits, children with developmental language disorder (DLD) often also evidence lexical impairments. In particular, it has been argued that this population have difficulty forming lexical representations that are detailed enough to support effective spoken word processing. In order to better…

When children hear a novel word in a context presenting a novel object and a familiar one, they usually assume that the novel word refers to the novel object. In a series of experiments, we tested whether this behavior would be found when 2-year-olds interpreted novel words that differed phonologically from familiar words in only 1 sound, either a…

The first years of life represent a unique window of opportunity for foreign language learning. However, key questions are: How much and what kind of foreign language exposure is needed to ignite learning? We conducted a foreign language (English) intervention in four public Infant Education Centers in Madrid, Spain. Intervention children (N =…

To explore how being at high risk for autism spectrum disorder (ASD), based on having an older sibling diagnosed with ASD, affects word comprehension and language processing speed, 18-, 24- and 36-month-old children, at high and low risk for ASD were tested in a cross-sectional study, on an eye gaze measure of receptive language that measured how…

Children up to school age have been reported to perform poorly when interpreting sentences containing restrictive and additive focus particles by treating sentences with a focus particle in the same way as sentences without it. Careful comparisons between results of previous studies indicate that this phenomenon is less pronounced for restrictive…

This study tested the theory that future poor comprehenders would show modest but pervasive deficits in both language comprehension and production during early childhood as compared with future poor decoders and typical readers. Using an existing database (NICHD ECCRN), fifth-grade students were identified as having poor comprehension skills…