Purpose: Late talkers (LTs) are a group of children who exhibit delays in language development without a known cause. Although a hallmark of LTs is a reduced expressive vocabulary, little is known about LTs' processing of semantic relations among words in their emerging vocabularies. This study uses an eye-tracking task to compare 2-year-old LTs'…

This project explores how children disambiguate and retain novel object-label mappings in the face of semantic similarity. Burgeoning evidence suggests that semantic structure in the developing lexicon promotes word learning in ostensive contexts, whereas other findings indicate that semantic similarity interferes with and temporarily slows…

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…

Toddlerhood is marked by advances in several lexico-semantic skills, including improvements in the size and structure of the lexicon and increased efficiency in lexical processing. This project seeks to delineate how early changes in vocabulary size and vocabulary structure support lexical processing (Experiment 1), and how these three skills…

Purpose: Children come to understand many words by the end of their 1st year of life, and yet, generally by 12 months, only a few words are said. In this study, we investigated which linguistic factors contribute to this comprehension-expression gap the most. Specifically, we asked the following: Are phonological neighborhood density, semantic…

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…

There is a debate as to whether topic structures in Chinese involve A'-movement or result from base-generation of the topic in the left periphery. If Chinese topicalization was derived by movement, under the assumptions of Friedmann et al.'s Relativized Minimality (Lingua 119:67-88, 2009), we would expect children's comprehension of object…

Previous studies report that children use color words haphazardly before acquiring conventional, adult-like meanings. The most common explanation for this is that children do not abstract color as a domain of linguistic meaning until several months after they begin producing color words, resulting in a stage during which they produce but do not…

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…

A substantial body of evidence demonstrates that infants understand the meaning of spoken words from as early as 6 months. Yet little is known about their ability to do so in the absence of any visual referent, which would offer diagnostic evidence for an adult-like, symbolic interpretation of words and their use in language mediated thought. We…

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…

It is by now well established that toddlers use the linguistic context in which a new word--and particularly a new verb--appears to discover aspects of its meaning. But what aspects of the linguistic context are most useful? To begin to investigate this, we ask how 2-year-olds use two sources of linguistic information that are known to be useful…

Syntactic bootstrapping facilitates children's initial learning of verb meanings based on syntactic information. A challenging case is the argument-drop languages, where the number of argument NPs is not a reliable cue for distinguishing between transitive and intransitive verbs. Despite this fact, the availability of syntactic bootstrapping in…

What is the relative salience of different aspects of word meaning in the developing lexicon? The current study examines the time-course of retrieval of semantic and color knowledge associated with words during toddler word recognition: At what point do toddlers orient toward an image of a yellow cup upon hearing color-matching words such as…

This study investigated whether vocabulary delays in toddlers with autism spectrum disorders (ASD) can be explained by a cognitive style that prioritizes processing of detailed, local features of input over global contextual integration--as claimed by the weak central coherence (WCC) theory. Thirty toddlers with ASD and 30 younger,…