Related Experiment Video
Updated: Feb 18, 2026

Using Eye-tracking to Assess the Relative Importance of Visual and Vestibular Input to Subcortical Motion Processing in the Roll Plane
Published on: August 22, 2025
Perceived direction of gravity and the body-axis during static whole body roll-tilt in healthy subjects
Atsushi Tamura1, Yoshiro Wada2, Takuo Inui3
1a Department of Otolaryngology - Head and Neck Surgery , National Defense Medical College , Tokorozawa , Japan.
Objective:
We used the subjective visual vertical (SVV) and two different subjective visual body axis (SVBA) methods to quantify roll-tilt perception under gravity, and investigated the characteristics of these methods during static roll-tilt. In addition, we independently developed a compact device to facilitate evaluation of SVBA in different gravitational environments.
Methods:
Ten male volunteers participated in this study. We created a roll-tilt environment using a flight simulator in a dark room. The cockpit of the simulator was tilted leftward or rightward (-30°, -20°, -10°, 0°, 10°, 20° and 30°) in each randomly ordered trial. We quantified roll-tilt perception such that the experiment was conducted under 21 different conditions per participant.
Results:
We found no significant differences among the SVV error and the two types of SVBA error.
Conclusions:
The SVV and the SVBA methods may be useful for evaluating subjective roll-tilt perception.
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