Visual information is a key aspect of human perception that facilitates successful interaction with the environment. When moving, we experience the perception of self-motion adapting our velocity and body posture to space. In part, this is possible because of the close link between two brain systems: the visual cortex and the vestibular cortex. The main assumption is that both systems contribute to distinguishing between self-motion and motion of the environment. However, sometimes these two systems are in conflict like when we experience self-motion when actually is the scene that moves and not us as happens in a simulator or virtual reality settings. This phenomenon of illusory self-motion is called “vection” and has been well investigated during the last decades.
An illusion for you but a conflict in your brain
Have you ever been seating on a stationary train before departing when the train on the neighboring track begins to move? You will probably feel like the train you are sitting in is starting to move instead of the train on the next track. This is a real-life situation that perfectly illustrates the experience of illusory self-motion perception. The good news is that there is a scientific explanation.