The VU Network Institute has recently been asked by the VU Department of Human Movement Sciences for help with the development of two VR based tests to measure “visual dependency” in relation to motion sickness susceptibility. Motion sickness is gaining interest due an anticipated increase of carsickness in automated vehicles (drivers rarely get sick, while passengers do), and an already observed increase of visually induced motion sickness in VR, also referred to as cybersickness. Visual dependency refers to the weighting by the brain of visual and physical self-motion cues. Susceptibility to these types of motion sickness varies largely between people, and a predictive test possibly based on visual dependency, would be helpful to find appropriate and personalised countermeasures.
Two tests might be helpful in this respect: a rod-and-frame test, and a rod-and-roll test. In both tests a subject is asked to adjust a rod to what (s)he deems Earth-vertical. At the same time, either a static titled frame (rectangle) is shown, or a pattern with dots rotating in roll. Rod adjustments are affected by a variety of image parameters that can now be easily manipulated and studied in the virtual environment, and vary between people as well. Because both imageries are known to be perceptually controlled by different neural structures, these two tests are complementary, hence allowing for a more complete answer to the question posed.
Thanks to the help of the Network Institute, a PhD and a number of Human Movement Sciences students has recently started using these tests in the quest for a less sickening future for automated vehicles and virtual reality, based on a better understanding of the underlaying mechanisms.