Speech production: Motor programming of phonetic features

Abstract

Three experiments are reported on the role of phonetic features in motor programs for speech production. Each experiment involved a type of response-priming procedure. The procedure required subjects to prepare a specified primary vocal response that contained one or two vowel-consonant syllables (e.g., “up,” “ub,” “ut,” and “ud”). After the preparation interval, the subjects either produced the primary response upon command or else switched to produce another specified secondary response instead. Response latency and accuracy were measured as a function of the relationship between the phonetic features of the primary and secondary responses. Longer latencies and more errors occurred when the secondary response had place-of-articulation or voicing features identical to those of the primary response. The results may be interpreted in terms of an interactive-activation model. It appears that phonetic features play a significant role during the compilation of articulatory motor programs, and that preparation to produce an utterance inhibits the programming of other utterances with similar features. This outcome complements and extends conclusions derived from analyzing naturalistic slips of the tongue and coarticulation phenomena. The interactive-activation model of speech production provides a link with theoretical accounts of speech perception, word recognition, and manual movement.