Affiliations: [a] Man-Vehicle Lab, Massachusetts Institute of Technology, Cambridge, MA, USA | [b] Universität Mainz, Mainz, Germany
Correspondence:
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Corresponding author: Heiko Hecht, MIT Man-Vehicle Lab, 77 Mass Ave., Bldg. 37-219, Cambridge, MA 02139, USA. Tel.: +1 617 253 0017; Fax: +1 617 258 8111; E-mail: hecht@mit.edu
Abstract: Short-radius centrifugation offers a promising and affordable countermeasure to the adverse effects of prolonged weightlessness. However, head movements made in a fast rotating environment elicit Coriolis effects, which seriously compromise sensory and motor processes. We found that participants can adapt to these Coriolis effects when exposed intermittently to high rotation rates and, at the same time, can maintain their perceptual-motor coordination in stationary environments. In this paper, we explore the role of inter-sensory conflict in this adaptation process. Different measures (vertical nystagmus, illusory body tilt, motion sickness) react differently to visual-vestibular conflict and adapt differently. In particular, proprioceptive-vestibular conflict sufficed to adapt subjective parameters and the time constant of nystagmus decay, while retinal slip was required for VOR gain adaptation. A simple correlation between the strength of intersensory conflict and the efficacy of adaptation fails to explain the data. Implications of these findings, which differ from existing data for low rotation rates, are discussed.
Keywords: coriolis effects, artificial gravity, orientation illusions, motion sickness, classical conditioning, control theory, sensory conflict, space sickness, vestibulo-ocular reflex
