INFANTS PREFERENCE FOR THE PREDOMINANT STRESS PATTERNS OF ENGLISH WORDS

One critical aspect of language acquisition is the development of a le xicon that associates sounds and meanings; but developing a lexicon fi rst requires that the infant segment utterances into individual words. How might the infant begin this process? The present study was design ed to examine the potential role that sensitivity to predominant stres s patterns of words might play in lexical development. In English, by far the majority of words have stressed (strong) initial syllables. Ex periment 1 of our study demonstrated that by 9 months of age American infants listen significantly longer to words with strong/weak stress p atterns than to words with weak/strong stress patterns. However, Exper iment 2 showed that no significant preferences for the predominant str ess pattern appear with 6-month-old infants, which suggests that the p reference develops as a result of increasing familiarity with the pros odic features of the native language. In a third experiment, 9-month-o lds showed a preference for strong/weak patterns even when the speech input was low-pass filtered, which suggests that their preference is s pecifically for the prosodic structure of the words. Together the resu lts suggest that attention to predominant stress patterns in the nativ e language may form an important part of the infant's process of devel oping a lexicon.