On land, body sway during stance becomes coupled with imposed oscillations of the illuminated environment or of the support surface. This coupling appears to have the function of stabilizing the body relative to the illuminated or inertial environment. In previous research, the stimulus has been limited to motion in a single axis. Little is known about our ability to couple postural activity with complex, multi-axis oscillations. On a ship at sea, we evaluated postural activity using measures of body movement, as such, and we separately evaluated a direct measure of coupling between body movement and ship motion. Participants were tested while facing fore-aft and athwartship. We compared postural activity between participants who had been seasick at the beginning of the voyage and those who had not. Coupling of postural activity with ship motion differed between body axes as a function of body orientation relative to the ship. In addition, coupling differed between participants who had been seasick at the beginning of the voyage and those who had not. We discuss the results in terms of implications for general theories of postural control, and for prediction of susceptibility to seasickness in individuals.
Bibliographical noteFunding Information:
This research was supported by a Grant from the Institut Universitaire de France. We thank the Institute for Shipboard Education, Mike Zoll and the staff of the Semester at Sea program, and the captain and crew of the M/V Explorer. We also thank Marcos Duarte, whose support made possible the participation of Cristina Alcantara. Finally, we thank Jean-Paul Micallef for his helpful support with data collection.
© 2015, Springer-Verlag Berlin Heidelberg.
- Postural coordination
- Spontaneous coordination
- Vehicular travel