Format

Send to

Choose Destination
See comment in PubMed Commons below
J Vestib Res. 2013;23(1):13-22. doi: 10.3233/VES-130471.

Eye movements and motion perception during off-vertical axis rotation after spaceflight.

Author information

1
International Space University, Strasbourg, France. clement@isu.isunet.edu

Abstract

Constant velocity off-vertical axis rotation (OVAR) provides dynamic linear acceleration stimuli that can be used to assess otolith function. Eight astronauts were rotated in darkness about their longitudinal axis 20° off vertical at low (0.125 Hz) and high (0.5 Hz) frequencies and their responses were compared before and after spaceflight. Eye movements were recorded using infrared videography and perceived motion was evaluated using a joystick with four degrees of freedom - pitch and roll tilt, front-back and lateral translation. Low-frequency OVAR generates tilt otolith-induced responses - modulation of ocular counter-roll and counter-pitch with perceived conical motion path - whereas high-frequency OVAR generates translational otolith-induced responses - modulation of horizontal and vergence slow phase velocity with perceived cylindrical motion path. While there were transient changes in the amplitude of the translational ocular responses on landing day, there were no major changes in the tilt ocular reflexes after adaptation to weightlessness. However, there was an increase in sensitivity to motion perception after spaceflight. Direct comparisons of pre- and postflight stimuli suggested that OVAR on landing day was less provocative of motion sickness than before spaceflight. These results confirm that some otolith reflexes elicited during passive motion may not be altered by short-duration spaceflight - or may readapt very quickly - and that the resolution of sensory conflict associated with postflight recovery involves higher-order neural processes.

PMID:
23549051
DOI:
10.3233/VES-130471
[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for IOS Press
    Loading ...
    Support Center