Phonotactic probability and neighborhood density effects in the perception and production of speech in adults

Abstract

Phonotactic probability refers to the frequency with which phonological segments and sequences of segments occur in a language. Neighborhood density refers to the number of words that sound similar to a given word. Awareness to phonotactic probability and neighborhood density occurs early in life and seems to influence lexical development. Recent research in our lab suggests that these two variables also influence the on-line processing of spoken words in adults. In the case of spoken word recognition, when sub-lexical representations dominate processing, high probability stimuli are responded to more quickly than low probability stimuli. However, when lexical representations dominate processing, stimuli with sparse neighborhoods are responded to more quickly than stimuli with dense neighborhoods. Similarly, in speech production, pictures of high probability words are named more quickly than pictures of low probability words. However, in contrast to speech perception, pictures of words with dense neighborhoods are produced more quickly than pictures of words with sparse neighborhoods, suggesting that statistical regularities in the language may be used differently depending on the demands imposed by a given process or task.