Affiliations: Harvard-MIT Division of Health Sciences and Technology and Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
Note: [1] Reprint address: Thomas J. Mullen, Harvard-MIT, Division of Health Sciences and Technology, Massachusetts Institute of Technology, Room E25-335b, Cambridge, MA 02139. Tel: (617)253-7430; Fax: (617)253-3019; E-mail: tjm@atrium.mit.edu
Abstract: In a study of 18 human subjects, we applied a new technique, estimation of the transfer function between instantaneous lung volume (ILV) and instantaneous heart rate (HR), to assess autonomic activity during motion sickness. Two control recordings of ILV and electrocardiogram (ECG) were made prior to the development of motion sickness. During the first, subjects were seated motionless, and during the second they were seated rotating sinusoidally about an earth vertical axis. Subjects then wore prism goggles that reverse the left-right visual field and performed manual tasks until they developed moderate motion sickness. Finally, ILV and ECG were recorded while subjects maintained a relatively constant level of sickness by intermittent eye closure during rotation with the goggles. Based on analyses of ILV to HR transfer functions from the three conditions, we were unable to demonstrate a change in autonomic control of heart rate due to rotation alone or due to motion sickness. These findings do not support the notion that moderate motion sickness is manifested as a generalized autonomic response.
Keywords: nausea and vomiting syndromes, parasympathetic, sympathetic, autonomic nervous system, transfer function estimation
