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A THEORY OF LEXICAL ACCESS IN SPEECH PRODUCTION

Levelt, Willem J.M., Roelofs, Ardi and Meyer, Antje S. A THEORY OF LEXICAL ACCESS IN SPEECH PRODUCTION.

Short Abstract:

Preparing words in speech production is, normally, a fast and accurate process. We generate them two or three per second in fluent conversation, and overtly naming a clear picture of an object can easily be initiated within 600 ms after picture onset. The underlying process, however, is exceedingly complex. The theory reviewed in this target article analyzes this process as staged and feedforward. After a first stage of conceptual preparation, word generation proceeds through lexical selection, morphological and phonological encoding, phonetic encoding and articulation itself. In addition, the speaker exerts some degree of output control, by monitoring of self-produced internal and overt speech. The core of the theory, ranging from lexical selection to the initiation of phonetic encoding, is captured in a computational model, called WEAVER++. Both the theory and the computational model have been developed in interaction with reaction time experiments, particularly in picture naming or related word production paradigms with the aim of accounting for the real-time processing in normal word production. A comprehensive review of theory, model and experiments are presented. The model can handle some of the main observations in the domain of speech errors (the major empirical domain for most other theories of lexical access), and the theory also opens new ways of approaching the cerebral organization of speech production by way of high-resolution temporal imaging.

Long Abstract:

Preparing words in speech production is, normally, a fast and accurate process. We generate them two or three per second in fluent conversation, and overtly naming a clear picture of an object can easily be initiated within 600 ms after picture onset. The underlying process, however, is exceedingly complex. The theory reviewed in this target article analyzes this process as staged and feedforward. After a first stage of conceptual preparation, word generation proceeds through lexical selection, morphological and phonological encoding, phonetic encoding and articulation itself. In addition, the speaker exerts some degree of output control, by monitoring of self-produced internal and overt speech. The core of the theory, ranging from lexical selection to the initiation of phonetic encoding, is captured in a computational model, called WEAVER++. Both the theory and the computational model have been developed in interaction with reaction time experiments, particularly in picture naming or related word production paradigms with the aim of accounting for the real-time processing in normal word production. A comprehensive review of theory, model and experiments are presented. The model can handle some of the main observations in the domain of speech errors (the major empirical domain for most other theories of lexical access), and the theory also opens new ways of approaching the cerebral organization of speech production by way of high-resolution temporal imaging.

Keywords:	speaking, lexical access, conceptual preparation, lexical selection, morphological encoding, phonological encoding, syllabification, articulation, self-monitoring, lemma, morpheme, phoneme, speech error, magnetic encephalography, readiness potential, brain imaging.
Subjects:	Neuroscience: EEG and Brain Imaging Linguistics: Learnability Psychology: Psycholinguistics
ID code:	bbs00000526
Deposited by:	Willem Levelt on 02 May 2001