Human tilt perception in a dynamic environment.

This study examines the perception of tilt and linear acceleration as sensed through the utricular otolith of the vestibular system. Any sensation derived from the otolith is a consequence of the displacement of the otolith parallel to its own plane. This leads, naturally, to the definition of a sensation plane. A model is presented which defines this sensation plane. It assumes that the sacular otolith contribution is negligible, an assumption substantiated by correlation with experimental data by Schöne. Applying this model to perceived pitch angle, a simple equation is presented which relates the number of Gs and actual pitch angle to the perceived pitch angle. Experimental data are needed to develop perceived sensation curves for the sensation plane. The model implies that a state of confusion exists outside the realm of our prior experiences. Disorientation or motion sickness may be related to this confused state. In addition, new avenues of inquiry are introduced.