Levels of representation in the electrophysiology of speech perception

Mapping from acoustic signals to lexical representations is a complex proce ss mediated by a number of different levels of representation. This paper r eviews properties of the phonetic and phonological levels, and hypotheses a bout how category structure is represented at each of these levels, and eva luates these hypotheses in light of relevant electrophysiological studies o f phonetics and phonology. The paper examines evidence for two alternative views of how infant phonetic representations develop into adult representat ions, a structure-changing view and a structure-adding view, and suggests t hat each may be better suited to different kinds of phonetic categories. El ectrophysiological results are beginning to provide information about phono logical representations, but less is known about how the more abstract repr esentations at this level could be coded in the brain. (C) 2001 Cognitive S cience Society, Inc. All rights reserved.