Phonatory and manual reaction times of stuttering and nonstuttering children.

This investigation compared the simple reaction times of 13 stuttering and 13 nonstuttering children matched individually for age, sex, and handedness. The reaction time stimulus in all response conditions was the offset of a 1000-Hz pure tone. Two of the experimental conditions required button-pressing responses, one using the left forefinger and the other the right. The remaining four experimental conditions required phonatory responses. The nonspeech phonatory responses consisted of inspiratory phonation and expiratory throat clearing; the speech-like phonatory responses required abrupt initiation of the isolated vowel and the word upper. The stuttering children were slower and more variable than the normal children only during phonatory initiation of throat clearing and. The results are compared to previous reaction time investigations with both children and adults and related to certain factors which potentially can influence sensorimotor pathways prior to and during speech.