Effects of Weightlessness on Eye-Head Coordination during Target Acquisition Task
- Paper number
IAC-07-A1.2.01
- Author
Mrs. Elena Tomilovskaya, Institute of Biomedical Problems (IBMP), Russia
- Coauthor
Prof. Mainhard Berger, Austria
- Coauthor
Prof. Franz Gerstenbrand, Austria
- Coauthor
Dr. Inessa Kozlovskaya, Institute for Biomedical Problems, Russia
- Year
2007
- Abstract
Introduction. The purpose of the studies was to explore effects of long-duration SF on characteristics of the horizontal gaze fixation reaction (hGFR). Methods. The study was provided with 3 cosmonauts –- members of 180-d Mir missions. Test sessions were performed 4 times before launch, on flight days 5, 24, 53, 88, 105 and 135, and twice after landing (R+2 and R+5). During the test sessions, the human subjects were to perform the target acquisition task in the horizontal plane on targets that appeared at a distance of 16 angular degrees in a random order right- and leftwards from the center. Characteristics of eye and head movements were recorded with the MONIMIR system (Austria). Results. Time of gaze fixation amounted to 520-650 ms in all the members of the group before space flight (SF). Within the time of recording equal 1200 ms in gaze fixation on the target was successful in 97-99% of cases. In flight, the mean velocity of head movements decreased in the first month and showed a significant increase (by 35-52%, p<0,05) to the 4d month of flight. The velocities of eye counterrotation during SFs sharply increased on the 1st month. Maximal changes in this characteristic recorded in FD-105 reaching 85-110% and being smoothed over by month 5 to 5-12%. Time of gaze fixation in flight extended by 900-1000 ms and more being the longest on FD-105. The number of hGFR completed in 1200 ms reduced considerably in SF amounting by month 4 only 68-72%. After landing, most GFR characteristics returned to baseline values, however, on R+2 the time of gaze fixation was still 680-730 ms at most, regaining the preflight values only on R+5. Conclusions. Changes in the GFR characteristics recorded in the course of long-duration SF point out to serious disturbances within the VOR system due to, apparently, an altered vestibular activity. The studies represent a part of the joint Russian-Austrian Program (Austromir RLF) performed in SFs on the MIR Station. Authors express their gratitude to Dr. Silvia Lechner-Steinleitner and Dr. Engelbert Gruber for their help in processing of the data. Special thanks to Mag. Martin Schlaff for his financial support.
- Abstract document