Reaction Time of the Tongue to Auditory and Tactile Stimulation

Measures of reaction time of the tongue to tactile stimulation on the lips and to a 1000-cps tone at sensation levels of 10, 50, and 70 db were obtained from 26 normal young adults. Results revealed that tactile stimulation evoked the shortest reaction time (M = .123 sec.); 70 db elicited slightly longer reaction time (M = .129 sec.); 50 db still longer reaction time (M = .137 sec.); and 10 db the longest (M = .209 sec.). The 10-db tone reaction time was significantly longer than that of any other stimulus condition, while tactile stimulus reaction time was significantly shorter than both the 10- and 50-db tonal stimuli, but not than the 70-db stimulus. Among the auditory conditions, 50 and 70 db were not significantly different from one another, but both were different from 10 db. The findings support the role played by tactual feedback in the oral region for monitoring speech. It is hypothesized that a speech mechanism which operates on a servosystem principle is likely to utilize the most efficient sensory channels available in monitoring speech output, with time of response being one important measure of efficiency.