Date on Master's Thesis/Doctoral Dissertation


Document Type

Doctoral Dissertation

Degree Name

Ph. D.


Psychological and Brain Sciences

Committee Chair

Cashon, Cara Helen

Author's Keywords

Infants; Language development; Williams syndrome; Information processing; Word learning; Infant development


Language acquisition; Children with disabilities--Language; Williams syndrome--Patients


The ability to form associations between words and objects rapidly with a short amount of exposure is a marker of more proficient word learners in typically developing (TD) infants. Investigating the underlying mechanisms for how words are associated with objects is necessary for understanding early word learning in the TD population as well as in people with Williams syndrome (WS), a rare neurogenetic developmental disorder characterized by language delay in early development. The findings in the present study showed a developmental difference in the ability to form word–object associations between 12 and 14 months of age in TD infants. It was indicated that whereas TD 12-month-old infants predominantly processed objects, TD 14-month-old infants processed objects, words, and word–object associations. The developmental pattern found with the participants with WS was very similar to that found in the TD infants. The findings indicated that toddlers with WS develop the ability to rapidly learn word-object associations as early as 2 years of age. Whereas 1-year-olds with WS processed objects and words, 2-year-olds with WS processed objects, words, and word–object associations. These patterns suggested that infants and toddlers with WS may go through similar developmental changes in learning word–object associations as TD population, though their language development is delayed. The findings provided evidence of underlying mechanisms of early word learning in both TD infants and infants and toddlers with WS. In the present study on learning word–object associations, a domain-general developmental progression from an independent to an integrated level of processing was found. In both TD infants and infants and toddlers with WS, novice word learners, who were in the independent processing phase, mainly processed the word and/or object information, but processed them independently of one another. In contrast, intermediate word learners processed associative information between words and objects, as well as the word and object information. This developmental progression was consistent with Cohen’s information processing approach to infant cognitive and perceptual development.