Affiliations: [a] Department of Mathematics, Colby College, Waterville, ME 04901, USA | [b] Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA | [c] Department of Psychiatry, Massachusetts General Hospital, Charlestown, MA 02129, USA
Correspondence:
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Corresponding author: Jan E. Holly, Department of Mathematics, Colby College, 5845 Mayflower Hill, Waterville, ME 04901, USA. Tel.: +1 207 859 5845; Fax: +1 207 859 5846; E-mail: [email protected]
Abstract: Illusory perceptions of motion and orientation arise during human centrifuge runs without vision. Asymmetries have been found between acceleration and deceleration, and between forward-facing and backward-facing runs. Perceived roll tilt has been studied extensively during upright fixed-carriage centrifuge runs, and other components have been studied to a lesser extent. Certain, but not all, perceptual asymmetries in acceleration-vs-deceleration and forward-vs-backward motion can be explained by existing analyses. The immediate acceleration-deceleration roll-tilt asymmetry can be explained by the three-dimensional physics of the external stimulus; in addition, longer-term data has been modeled in a standard way using physiological time constants. However, the standard modeling approach is shown in the present research to predict forward-vs-backward-facing symmetry in perceived roll tilt, contradicting experimental data, and to predict perceived sideways motion, rather than forward or backward motion, around a curve. The present work develops a different whole-motion-based model taking into account the three-dimensional form of perceived motion and orientation. This model predicts perceived forward or backward motion around a curve, and predicts additional asymmetries such as the forward-backward difference in roll tilt. This model is based upon many of the same principles as the standard model, but includes an additional concept of familiarity of motions as a whole.
Keywords: Perception, self-motion, model, centrifuge, VOR
