Facial Vibrotactile Stimulation Activates the Parasympathetic Nervous System: Study of Salivary Secretion, Heart Rate, Pupillary Reflex, and Functional Near-Infrared Spectroscopy Activity

Figure 1

Experimental pattern diagrams. (a) Recording of fNIRS and heart beat during vibrotactile stimulation. (b) Recording of pupillary reflex during vibrotactile stimulation. (c) Cotton-roll method for recording of salivation.