Effects of syllable stress on articulatory planning observed in a stop-signal experiment

This paper presents experimental evidence that gestural planning systems associated with stressed syllables are more highly activated than ones associated with unstressed syllables. A stop-signal experiment was conducted to investigate how syllable stress and metrical structure influence the ability to halt speech in mid-utterance. Subjects produced three sentences with controlled metrical patterns, and on 75% of trials were given a randomly timed signal to stop speaking as quickly as possible. The presence of syllable stress in the immediately upcoming speech plan increased the amount of time it took for speakers to halt their speech in response to the stop-signal. This finding is interpreted in the context of a dynamical model which incorporates activation and inhibition. Gestural systems associated with stressed syllables are more highly activated and hence take longer to inhibit. An additional contribution of this paper is the resurrection of the stop-signal paradigm in speech research. This paradigm has the potential to reveal new phenomena of theoretical import in a variety of