Facial Vibrotactile Stimulation Activates the Parasympathetic Nervous System: Study of Salivary Secretion, Heart Rate, Pupillary Reflex, and Functional Near-Infrared Spectroscopy Activity
Figure 3
(a) Changes in pulse frequency during 89 Hz-S on the face (89 Hz-face), 114 Hz-S on the face (114 Hz-face), and resting stage. We assessed changes in pulse frequencies for five typical subjects. Note that all subjects showed decreased pulse frequency during 89 Hz-face. (b) HRV module analysis. Method used to measure RR intervals (, , , , etc.) on ECG recordings (B-a) and frequency spectrum based on RR interval length over 3 min during 89 Hz-face (B-b). Horizontal line indicates RR interval (ms), and vertical line indicates number. Note that the peak frequency spectrum was 1000 ms in this experiment, as shown in B-b. (c) Changes in peak frequency spectra of HRV modulation during various stimuli. We indicate 89 Hz-face, Mozart, Mozart + 89 Hz-face, 89 Hz-neck, and Noise, respectively. There were significant differences between RS and 89 Hz-face (paired t-test, ), between RS and Mozart + 89 Hz-face (paired t-test, ), and between RS and noise (paired t-test, ).
