Why do infants learn some words earlier than others? Many theories of early word learning focus on explaining how infants map labels onto concrete objects. However, words that are more abstract than object nouns, such as "uh-oh," "hi," "more," "up," and "all-gone," are typically among the first to…

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…

To learn a language infants must learn to link arbitrary sounds to their meaning. While words are the clearest example of this link, they are not the only component of language; morphological regularities (e.g., the plural -s suffix in English) carry meaning as well. Comprehensive theories of language acquisition must account for how infants build…

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…

The ability to map similar sounding words to different meanings alone is far from enough for successful speech processing. To overcome variability in the speech signal, young learners must also recognize words across surface variations. Previous studies have shown that infants at 14 months are able to use variations in word-internal cues (i.e.,…

We investigated toddlers' phonological representations of common vowel-initial words that can take on multiple surface forms in the input. In French, liaison consonants are inserted and are syllabified as onsets in subsequent vowel-initial words, for example, petit /t/ éléphant [little elephant]. We aimed to better understand the impact on…

Contrastive focus, conveyed by prosodic cues, marks important information. Studies have shown that 6-year-olds learning English and Japanese can use contrastive focus during online sentence comprehension: focus used in a "contrastive context" facilitates the identification of a target referent (speeding up processing), whereas focus used…

Although research suggests that responsive interactions are imperative for language development, the advent of mobile technology means that parent-child exchanges are often fraught with unpredictable interruptions. Less clear is how these momentary breaks in responsiveness affect word learning. In this within-subjects design, 38 mothers taught…

Although an abundant literature documents preliterate children's word learning success from shared storybook reading, a full synthesis of the factors which moderate these word learning effects has been largely neglected. This meta-analysis included 38 studies with 2,455 children, reflecting 110 effect sizes, investigating how reading styles, story…

Previous studies using direct forms of vocabulary instruction have shown that newly learned words are integrated with existing lexical knowledge only "after" off-line consolidation (as measured by competition between new and existing words during spoken word recognition). However, the bulk of vocabulary acquisition during childhood…

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…

We explored 12-month-olds' flexibility in accepting phonotactically illegal or ill-formed word forms in a modified associative-learning task. Sixty-four English-learning infants were presented with a training phase that either clarified the purpose of a sound--object association task or left the task ambiguous. Infants were then habituated to sets…

Language is rife with ambiguity. Do children and adults meet this challenge in similar ways? Recent work suggests that while adults resolve syntactic ambiguities by integrating a variety of cues, children are less sensitive to top-down evidence. We test whether this top-down insensitivity is specific to syntax or a general feature of children's…

Four word-learning studies exposed 2-year olds to novel verbs and nouns. Found that knowledge of what action or object was impending was not necessary for learning the words; children learned a novel verb for an intentional but not an accidental action; and children learned a novel noun for an object being sought, but not ones rejected while…

Two studies examined relationships between infants' early speech processing performance and later language and cognitive outcomes. Study 1 found that performance on speech segmentation tasks before 12 months of age related to expressive vocabulary at 24 months. However, performance on other tasks was not related to 2-year vocabulary. Study 2…