Heart Rate and Blink Rate Responses During Mental Arithmetic With and Without Continuous Verbalization of Results

ABSTRACT The purpose of this study was to investigate the effect of speech motor activity during the performance of mental arithmetic tasks on the cardiac‐eyelid motor relationship. In 29 subjects, heart rate and blink rate responses were analyzed during the performance of tasks with and without continuous verbalization of results. Heart rate and blink rate were differentially affected by the experimental conditions. Significant heart rate increases were observed under both test conditions with responses being largest during verbalization. Significant blink rate increases, in contrast, occurred only when verbalization of results was required. The interactions between verbalization vs no‐verbalization and both the order of tasks and task type were significant only for heart rate. Furthermore, neither between‐subject nor within‐subject correlations provided evidence for a close positive relationship between heart rate and blink rate under either the verbalization or the no‐verbalization condition. The present results support the suggestion that heart rate and concomitant somatic activity may be “uncoupled” under certain stimulus conditions.