Motion sickness (ZT)
"The most common theory for the cause of motion sickness is that it evolved as a defense mechanism against neurotoxins.[4] The area postrema in the brain is responsible for inducing vomiting when poisons are detected, and for resolving conflicts between vision and balance. When feeling motion but not seeing it (for example, in a ship with no windows), the inner ear transmits to the brain that it senses motion, but the eyes tell the brain that everything is still. The area postrema will always believe the inner ear signal over the eyes, as the eyes are more susceptible to trickery (see optical illusion). As a result, the brain will come to the conclusion that one is hallucinating and further conclude that the hallucination is due to poison ingestion. The brain responds by inducing vomiting, to clear the supposed toxin.'