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, ρmax, 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 ρmaxof almost all subjects decreased in the latter part of the video image and that ρmaxof the subjects who felt motion sickness strongly decreased after watching the video image at a time.