Abstract
The influence of a 20Hz periodically flashing light stimulation on heartbeat fluctuation and ryodoraku electrodermal activities was determined, where ryodoraku means a meridian defined from the viewpoint of electrodermal activities. Subjects were healthy males aged from 22 to 23. None of the subjects felt any pain with this stimulation and their heartbeat was unchanged. Also, there were no significant changes in the low frequency component LF and the high frequency component HF of the power spectra of the heartbeat fluctuation. However, LF/HF decreased significantly during stimulation and 4 minutes after stimulation. This suggested that the stimulation induced suppression of sympathetic nerve activities. The electric resistance of the ryodoraku increased during and after stimulation. The changes in LF/HF and the ryodoraku electrodermal activities showed that the effect of the stimulation continued 4 and 8 minutes after stimulation, respectively.
