Respostas evocadas de incongruência a categorias na percepção da fala.

Abstract

Speech perception involves categorization operations in which acoustic events that compose the speech stream are grouped into equivalence classes, i. e., categories whose members are treated by speakers as functionally equivalent. Several lines of evidence indicate effects of speech sound categories on perception. In this context, measures of neural activity related to perceptual processing at the level of the cerebral cortex are of great relevance. Psychophysiological studies show that the Mismatch Negativity (MMN) component of the auditory evoked responses, which has been regarded as an index of auditory sensory memoryand discrimination, is sensitive not only to the physical attributes of the speech sounds but also to the way those sounds are categorized by the speakers of a language. The present work offers a critical retrospective review of the use of the MMN response in research on speech sound categorization and an appreciation of its contributions to the comprehension of the perceptual aspects of speech communication.