The goal of this project is to understand how children (and older second-language learners) discover the meanings of words and their semantic roles in sentences. Even for simple words like "dog" it is not easy to glean what they mean from observing (as one usually will) that there is a dog in sight. For after all, when a dog is in sight, so is his fur, and his ear, and the joyous wagging of his tail. To which of these factors or properties does the pointing finger refer when an adult says "Look at that doggie!" Things get even harder when the child has to learn the meanings of words like "idea" or "think" because in these cases there's nothing so obvious to point to out there in the world. Yet children of three and four years of age understand and utter such apparently "abstract" words. Our projects take off from the observation that not all words occur in the same places in sentences, for instance one can say "I think (or see) that you're cute" but not "I jump that you're cute." Strikingly, children as young as two- and three-years of age are sensitive to these "positional privileges," which in turn give clues to word meaning. Because it is hard to get information about children's word meanings or their learning by asking them for definitions or the like, we use implicit methods such as tracking children's eye gaze direction and responsiveness to queries that place words into different visuo-social environments and into different syntactic structures to find out about their evolving word knowledge. These issues are of much more than academic interest. No tested property of child cognition or behavior is a better predictor of school and work-place success than vocabulary growth in the first few years of life. Vocabulary scores diverge for children of higher or lower socio-economic status as early as the second birthday, and these differences increase throughout the school years, influencing all the child's subsequent learning. So our work extends to discovering ways that actual home and early school environments can maximize the supportive environment for vocabulary and syntax acquisition. Our past work gives strong indications of what these favorable learning environments are, and the present proposal inquires more deeply into these factors.

Public Health Relevance

The ability to speak and understand language fluently is a basic requirement for economic and social well- being in 21st Century American life. Yet language skills are unequally distributed across the citizenry with differences appearing before the second birthday and persisting through school years. Our findings, pertaining particularly to the growth of vocabulary, are uncovering the properties that foster high vocabulary attainment.

National Institute of Health (NIH)
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Research Project (R01)
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Language and Communication Study Section (LCOM)
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Miller, Brett
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University of Pennsylvania
Schools of Arts and Sciences
United States
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Cartmill, Erica A; Armstrong 3rd, Benjamin F; Gleitman, Lila R et al. (2013) Quality of early parent input predicts child vocabulary 3 years later. Proc Natl Acad Sci U S A 110:11278-83
Trueswell, John C; Medina, Tamara Nicol; Hafri, Alon et al. (2013) Propose but verify: fast mapping meets cross-situational word learning. Cogn Psychol 66:126-56
Medina, Tamara Nicol; Snedeker, Jesse; Trueswell, John C et al. (2011) How words can and cannot be learned by observation. Proc Natl Acad Sci U S A 108:9014-9
Li, Peggy; Abarbanell, Linda; Gleitman, Lila et al. (2011) Spatial reasoning in Tenejapan Mayans. Cognition 120:33-53
Choi, Youngon; Trueswell, John C (2010) Children's (in)ability to recover from garden paths in a verb-final language: evidence for developing control in sentence processing. J Exp Child Psychol 106:41-61
Novick, Jared M; Kan, Irene P; Trueswell, John C et al. (2009) A case for conflict across multiple domains: memory and language impairments following damage to ventrolateral prefrontal cortex. Cogn Neuropsychol 26:527-67
Papafragou, Anna; Hulbert, Justin; Trueswell, John (2008) Does language guide event perception? Evidence from eye movements. Cognition 108:155-84
Novick, Jared M; Thompson-Schill, Sharon L; Trueswell, John C (2008) Putting lexical constraints in context into the visual-world paradigm. Cognition 107:850-903
Snedeker, Jesse (2008) Effects of prosodic and lexical constraints on parsing in young children (and adults). J Mem Lang 58:574-608
Papafragou, Anna; Cassidy, Kimberly; Gleitman, Lila (2007) When we think about thinking: the acquisition of belief verbs. Cognition 105:125-65

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