How does a mismatch between visual and vestibular signals contribute to motion sickness?

Motion sickness occurs due to a sensory conflict within the brain when it receives contradictory information regarding the body's orientation and movement.12

The vestibular system—located in the inner ear—detects changes in linear and angular acceleration through the semicircular canals and otolith organs. Simultaneously, the eyes provide visual input about the body's position relative to the external environment.324

When these signals mismatch, the brain becomes confused. For example, if a person is below deck on a ship, their vestibular system senses the vessel's rocking motion, but their eyes register a relatively stable cabin, signaling no movement. The cerebellum and other brain centers attempt to process these conflicting inputs, leading to the release of stress hormones like epinephrine and norepinephrine. This physiological response often results in symptoms such as dizziness, nausea, and vomiting.124