Autonomic arousal in adults who stutter prior to various reading tasks intended to elicit changes in stuttering frequency

This study examined relationships between anticipatory autonomic arousal and stuttering in four reading tasks. 13 adult persons who stutter (PWS) reported their ‘feared’ (expected to elicit more stuttering) sounds. They read phrases initiated by feared (F) and neutral (N) phonemes. Both stimuli sets were read solo (S) and with choral accompaniment (C), creating FS, FC, NS, and NC conditions. Skin conductance (SC) and heart rate (HR) measures were made during a 9 s window that followed stimulus presentation and preceded speaking. Only SC measures produced significant differences across conditions. Choral conditions produced decreases in SC measures and stuttered trials. Feared conditions produced increases in SC but not stuttering. HR measures were variable, undifferentiated by condition, but produced a gradually increasing triphasic response pattern. No differences in anticipatory SC or HR measures were found in stuttered versus fluent trial comparisons. However, the NC condition, which eliminated stuttering, produced significantly lower SC measures than the fluent utterances in the other conditions (FS, FC, NS). Furthermore, SC measures from the fluent and stuttered trials were similar in these three conditions. These findings suggest that anticipatory autonomic arousal is better differentiated by the possibility of stuttering than by a fluent/stuttered speech outcome. Trials that produced anticipatory SC responses showed greater final HR deceleration, suggesting autonomic coactivation, a response pattern that is associated with aversive stimuli and herein, likely indicative of speech-related state anxiety. However, these physiological markers of anxiety appear to be neither necessary nor sufficient to induce observable stuttering.