Evaluation of the effect of visual stimulation on humans by simultaneous experiment with multiple subjects.

To evaluate the biological effects of visual stimulation on multiple subjects watching a same image, a more compact and low-cost device measuring both ECG and photo-plethysmogram was developed. On the basis of these physiological parameters, the maximum cross-correlation coefficient, &#961;<inf>max</inf>, from pulse wave transmission time to heart rate could be calculated. This index reflects the activity of the autonomic nervous system and is considered as a good index for evaluating the effect of visual stimulation on humans. The result of simultaneous experiment with 6 subjects watching a video image taken by an intentionally swaying handy camera has shown that &#961;<inf>max</inf>of almost all subjects decreased in the latter part of the video image and that &#961;<inf>max</inf>of the subjects who felt motion sickness strongly decreased after watching the video image at a time.