The effect of syntactic structure upon speech initiation times of stuttering and nonstuttering speakers.

Abstract Past research has shown that adults who stutter tend to be slower than adults who do not stutter at initiating various speech-like movements, nonsense syllables, words, short phrases, and simple sentences. The present study sought to extend this research by examining the effect that syntactic structure has upon stutterers’ and nonstutterers’ ability to initiate sentences. Eleven persons who stutter (mean age=22.2 years) and 11 nonstuttering controls (mean age=23.3 years) read, rehearsed, and then reproduced a series of 96 sentences within a simple reaction time paradigm. The sentences were presented in four blocks of 24 sentences, and each block contained one version of each of the 24 base sentences. Versions of the base sentences varied, from simple to complex, along four levels of syntactic complexity. Results indicated that speech initiation times (SITs) were significantly longer for participants who stutter than they were for nonstuttering controls for three of the four sentence types. There was no significant difference in SITs across the four sentence types for either group. Among the stuttering participants, there was no significant correlation between stuttering severity and overall initiation time for the sentences. Consistent with other studies, the present findings suggest that persons who stutter are slower than persons who do not stutter at planning and/or initiating motor movements associated with speech production. Educational objectives: The reader will be able to (1) describe how persons who stutter typically perform during various reaction time tasks, (2) explain the rationale for examining the effect of syntactic complexity upon speech initiation time, (3) discuss how the speech initiation times of persons who stutter compare to those of persons who do not stutter during the production of various types of sentences, (4) identify future research needs in this area.