ABSTRACT
Why do these sensory conflicts lead to motion sickness? Reason (1978) suggests that the conflicts that arise between the sensory signals of the body, eye and image as compared with those conditioned by past experiences are an inherent characteristic of all forms of motion sickness. The degree of sickness experienced is generally proportional to the severity of the sensory discordance. Through continued exposure to, and particularly interaction with, a displaced environment the plasticity of the human sensory system allows humans to adapt to the new stimuli. This adaptation will then allow the individual to perform effectively in the displaced environment. This can, in turn, lead to after effects when an individual returns to normal conditions, such as on terminating exposure to a virtual environment. In this case the individual, whose functioning was modified to accommodate the virtual world, may be compromised for a period of time when returning to the “real” world. These after effects, which can take the form of balance and visual disturbances or displaced hand-eye coordination, can present safety concerns.
