Influences of the Mental Lexicon on the Perception of Speech
James R., Sawusch, Department of Psychology, University at Buffalo
December 1, 1998
The perception of speech reflects both a stimulus driven process and influences from the mental lexicon. Some of the lexical influences, such as phoneme restoration, are well known. The focus of this presentation will be on understanding how form based properties of the lexicon interact with perception. The influences of the mental lexicon on perception could include lexical status (is the item a word), lexical neighborhood (how many words is the item similar to), phonotactics (how often does the phoneme sequence occur in the language), and phoneme frequency (how often does the phoneme occur in the language).
We have explored the role of these sources of information in perception using phoneme identification and lexical decision tasks. All of these factors influence perception. Furthermore, the time course of these influences can be used to understand the nature of the processing operations in auditory word recognition. Based on results that show we can separately manipulate phoneme frequency, lexical neighborhood, and lexical status, an interactive model with effects at different levels or representations will be outlined. In essence, the perception of speech is the result of a continuous interaction between the auditory to phonetic coding of the sound and the knowledge of the individual about the words of their language.