Heart rate response to touch.

The effect of tactile stimulation on heart rate (HR) in humans was investigated under three conditions: 1) Experimenter outside of room in which subject is sitting; 2) experimenter in the room with the subject; 3) experimenter in the room while touching the subject's right wrist. Nonsignificant increases in HR were observed when the experimenter entered the room (X = 0.64 beats per minute (bpm)). Conversely, large decreases occurred when the experimenter placed his hand on the subject's wrist (X = 9.16 bpm, p is less than 0.05). To determine if tactile stimulation alone accounts for these differences three comparisons were made in a second experiment: 1) Experimenter out of test room, subject touches own wrist; 2) experimenter in room standing near subject; 3) experimenter touching subject's wrist. Subjects showed slightly elevated HR during the self-touch condition (X = 1.26 bpm, not significant). Although no change was noted with the experimenter standing beside the subject, there were decreases, as in Experiment I, when the experimenter touched the subject's wrist (X = 1.75 bpm, p is less than 0.05). These results suggest that the observed decreases in HR were contingent upon another person's touch. While self-tactile stimulation produced a slight increase in HR, tactile stimulation by another caused bradycardia.