Abstract
Postural stability is critical for our ability to engage in other behaviors and can be influenced by several factors, including changes in optic flow. In situations where postural stability is degraded for prolonged periods of time, motion sickness commonly results. The current research examined how the complexity of a motion stimulus and the coupling of a motion stimulus to the actions of the participant influenced postural sway and motion sickness. Differences in incidence of motion sickness and postural sway characteristics emerged across conditions. In particular, postural sway of participants who became motion sick was characterized by increases in magnitude and spatial complexity but by a decrease in temporal complexity compared with participants who remained well.
ACKNOWLEDGMENTS
This work is based in part on the dissertation research of Edward W. Otten (CitationOtten, 2008; CitationOtten & Smart, 2009) and was partially presented at the 15th International Conference on Perception and Action (2009), Minneapolis, MN, and Progress in Motor Control VIII (2011), Cincinnati, OH.
FUNDING
Support for Henry E. Cook IV was provided by the National Science Foundation Graduate Research Fellowship program.
Notes
1 Given that the maximum range of AP head movement during quiet stance is approximately 4 cm, that small a change at a distance of 3.3 m would have been very difficult to detect in a computer-generated stimulus such as this. Therefore the motion of the participant was amplified by 15 (1 cm of change in the participant's motion resulted in the star field moving 15 cm) to ensure that the motion was observable to the participant.
2 SEn parameters M (vector length) and r (tolerance) were set at 3 and 0.1, respectively, following a selection procedure described by CitationRamdani, Seigle, Lagarde, Bouchara, and Bernard (2009).