Abstract:

To acquire the rules by which words are combined to form phrases and sentences, infants must first learn to assign words to grammatical categories such as nouns, prepositions, etc. This study is based on the assumption that infants initially derive the binary, superordinate lexical and functional categories from perceptual cues in the input. These two categories are present in all human languages, and recent work reveals similar distinctive acoustic and phonological cues across languages [R. Shi, J. Morgan, and P. Allopenna, J. Child Language (in press)]. For this study it was therefore proposed that there exists an innate mechanism leading to initial sensitivity to cues separating the two universal categories. Newborns were tested using the high-amplitude sucking paradigm. Stimuli were multiple lexical and function word tokens randomly selected and sliced from natural infant-directed utterances of an English-speaking mother. After being habituated to a word set of one category, infants were tested on either words of the other category or new words from the same category. The results showed that infants' recovery was significantly greater to words of the other category. This evidence supports a predisposed sensitivity which may serve as an initial foundation for the formation of early grammatical categories.