Which term describes the misperception of pitch attitude during rapid acceleration when external cues are limited?

• A. Vestibular illusion
• B. Somatogravic illusion
• C. Spatial disorientation
• D. Visual illusion

Answer: (B)

During rapid acceleration with limited external cues, the inner-ear organs that sense motion can misread your pitch. The otoliths detect linear acceleration and gravity but can’t distinguish forward acceleration from a tilt of the aircraft. As you speed up, this can create a false sense of nose-up attitude, a misperception known as somatogravic illusion. It’s most likely to occur when you don’t have reliable visual references (such as in clouds or at night), so you must rely on the flight instruments to maintain the correct pitch. This term specifically captures the acceleration-related pitch illusion described in the scenario, whereas broader terms like vestibular illusion or spatial disorientation cover wider or different types of perceptual errors.