Young infants encode lexical stress in newly encountered words.

In this study, we examined the nature of infants' representations of newly encountered word forms. Using a word-object association task, we taught 14-month-olds novel three-syllable words differing in segments and stress patterns. At test, we manipulated the stress pattern of the word or the position of the stressed syllable in the word. Our findings reveal that young infants store the stress information about the word, including the position in which the stressed syllable occurs, suggesting that infants form prosodically rich lexical representations of newly encountered words.