Subvocal motor activity and contextual processing

Twenty male and female subjects listened for mispronounced words while minimizing either subvocal or frontalis electromyographic activity. Stimuli were varied on size of the distortion, lexical constraint, and contextual constraint, all known to influence detections. Analysis of both the reaction time and detection data indicated that the minimization of subvocal EMG activity reduced or eliminated the effect of contextual constraint, while minimization of frontalis EMG activity resulted in the typically observed contextual constraint effect. Results indicate that subvocal activity is related to contextual processing. Additionally, reaction time data are reported that indicate that although low contextual constraint greatly slows the decision process, detectability is actually superior. A possible underlying mechanism for this reversal of the speed-accuracy trade-off is discussed.This article is partially based on the first author's Wayne State University doctoral dissertation. Special thanks go to Cathy Gross Ward, Cris Foster, and Bob Beattie for their valuable assistance during the collection of data. A preliminary version of this paper was presented at the Eastern Psychological Association meeting in Baltimore, 1982.