6-month-olds' segmentation and representation of morphologically complex words

One of the issues in infants’ language acquisition is - how do infants findword-like forms from fluent speech. Previous literature on infants word segmentationhas mostly focused on understanding the bottom-up cues, i.e., cuesin the input such as acoustic/prosodic cues, that infants utilize in pulling outnouns. This dissertation asks whether infants can use top-down cues in pullingout verbs. Verb segmentation has been reported to be delayed as compared tonoun segmentation and these results have been used to explain the delay in itsacquisition of verbs. This dissertation argues otherwise, demonstrating that infact at the beginning of word segmentation, i.e., at 6-months, infants can pullout verbs with the help of a known word mommy (a paradigm used in Bortfeld,Morgan, Golinkoff, & Rathbun, 2005).The current dissertation goes further and asks how these verbs are represented.To be specific, this dissertation looks at 6-month-olds’ segmentation ofmorphologically complex verbs, such as walking, walks, and walked, and askswhether preverbal infants can relate these forms to the root form walk. Themain focus of this research is to understand how prelexical infants, who cannotrely on semantics, relate complex forms to the root forms.This dissertation expands our understanding of the role of the functionalmorphemes (such as -ing, -ed, -s) in this process by conducting a corpus analysisas well as behavioral experiments. In this dissertation, I locate the beginningstage of this complex form acquisition and show that at 6-months, infants startsegmenting complex verbs, and based on the frequency and the characteristicsof the functional morphemes, infants begin to relate complex forms to rootforms. The findings of this dissertation highlight the importance of top-downcues in early language development and have crucial implications for verb acquisition.Also, these results provide evidence for morpheme-based processingmodels and acquisition models such as prosody-functor models, arguing forearly representation of functional elements and their facilitatory influence onword segmentation and representation