Sensory conflict
Short definition
Sensory conflict is the mismatch between information from the eyes and from the vestibular (balance) system, the most widely cited explanation for motion sickness and cybersickness.
In plain language
When the image shows movement but the body is still, or vice versa, the brain receives contradictory signals and may react with nausea or dizziness. The theory was formulated in the 1970s, in relation to motion sickness in general, by Reason and Brand. In VR, avoiding camera movements the person does not control is one way of reducing this conflict.