You can experience somatogravic illusions in a sim just as you can in an aircraft in flight. In fact, when you think about it, a full-motion sim uses somatagravic illusions in combination with its visuals to create realistic sensations of motion.
When you let off the brakes and put up the power it's not that the sim cab goes scooting across the room; it just tips back to create a similar feeling to positive acceleration, using a shift in the direction of gravitational acceleration that goes misread because of where the visuals and the flight displays put the horizon. Step on the brakes and it tips forward to give you the feeling of negative acceleration.
In fact, you can experience somatagravic illusions anywhere. One cheap and easy way of producing them is with a so-called Bárány chair, one that simply rotates the subject in the horizontal plane for a while, after which he usually experiences disorientation. (Bárány won the Nobel prize for this invention and for his research into this aspect of human physiology: the role of the inner ear in maintaining balance.) Try this with a common or garden-variety office chair, putting on a blindfold and then having someone whirl you around. Stopping the chair usually results in the blindfolded subject being certain that he's now whirling around in the opposite direction, because that's what the fluid in part of his vestibular system is telling him.
Another easy way to induce disorientation is to use this childish trick of having the subject put his forehead on a baseball bat and then shuffle in a circle around it, afterwards trying to stand up and walk straight, when hilarity ensues.
We had a sim with a small problem with the visuals, when starting to taxy made the horizon bob up and down just a few degrees before settling down. That always hit me right in the pit of the stomach. My ears were arguing with my eyes then about who was correct: minor disorientation.
Another sort of disorientation is looking at a single-point light source in a darkened room, when the point of light will begin to move after a while. There your ears are not telling you that it's your head, not the point of light, that's moving.
It's good to know that most people do experience disorientation, that it's a normal human experience. I suppose that some people might think that it's some sort of weakness or defect that can't happen to them, so that when it does happen then it goes ignored, along with whatever the flight instruments are trying to tell him.
Last edited by chuks; 12th Apr 2016 at 10:17.