This comprises three fluid-filled chambers, or labyrinths, situated in the bony temporal area that are concerned with identifying a person's position in space. Each chamber lies in a different plane, and movement of fluid within it is picked up by sensory cells that transmit the information to the brain. Disease or damage to the inner ear upsets the sense of balance and causes vertigo. MOTION SICKNESS is caused by the inner ear being unable to accommodate the changes in position resulting from motion. (See EAR.)