Time–frequency structure of image motion vectors around cybersickness intervals determined with biosignals

Vection-inducing or shaky video images sometimes cause visually induced motion sickness (cybersickness). We determined potential cybersickness intervals and trigger points with biosignals and analyzed video images with the motion vectors. For video images that strongly induced cybersickness, zone intervals with a high correlation coefficient between local and global motion vectors were located at the peaks of trigger points in the time-distribution obtained from 25 subjects. Around the trigger points, the time–frequency structure of global motion vectors included temporal frequencies ranging from 0.3 to 2.5 Hz. This approach will be useful for predicting trigger points in video images from only motion vectors.