Why might a fixed base flight simulator cause motion sickness?

A fixed base flight simulator can cause motion sickness primarily due to the discrepancy between visual and vestibular cues. In a simulated environment, pilots experience visual stimuli that suggest motion, but since the simulator is stationary, the body does not feel the corresponding movements that would occur in actual flight. This mismatch leads to confusion in the brain, as it processes conflicting information from the eyes and the inner ear.

The sensory conflict theory explains that the brain relies on integrated signals from multiple sensory systems to determine body position and movement. When visual cues indicate motion, but the vestibular system, which detects movement through the fluid in the inner ear, signals that the body is still, it creates a sensory conflict. This disconnect can trigger symptoms of motion sickness, such as dizziness, nausea, and disorientation.