Mechanism of Motion Sickness

Abstract

SEASICKNESS is a serious inconvenience to many people in times of peace. In times of war, however, motion sickness in its various forms may be a very real threat to the success of operations in the air and on the sea. Army personnel are apt to be affected in very large numbers, when airborne or in landing craft, since they have little opportunity to become acclimatized, as does the sailor or the airman.The literature on motion sickness up to 1942 has been reviewed elsewhere.1 Since that time a large amount of important work has been done, but publication has been in restricted reports. It is hoped that various workers will soon write up their results for open publication.The present paper is a summary of studies carried out during the recent war by a group of workers in Montreal of which we were a part. These experiments on the mechanism of motion sickness were made at an early stage of the investigation in the hope that they might give a lead to specific therapy. Later, through urgency, all our attention was devoted to therapeutic experiments. It is probable, however, that if worth while advances are to be made in therapy more must be known of the fundamental mechanism of motion sickness. MATERIALS AND METHODSMany hundreds of human volunteers were subjected to various types of motion.The majority were naval ratings from H.M.C.S. Montreal, but University students and members of the staff of the Montreal Neurological Institute also volunteered.The device first used was designed to reproduce the wayward movements of a ship at sea.

Intravestibular Balance and Motion Sickness

“…VIMS can even be stronger than MS caused by actual rotation because visually induced stimulation of canal projection areas in the brain never ceases, unlike an actual sustained rotation in which the canal output declines after the initial acceleration with a time constant of 10-15 s. Numerous studies have shown that MS susceptibility in various situations is positively correlated with the duration and magnitude of canal-ocular reflexes, 52,62,87 although other studies have shown no relationship. 13,60,68 No study to date has shown a negative relationship between the strength of canal outputs and MS susceptibility, however.…”

“…Nor is increased loading of the otoliths provocative, as moving from a microgravity to a 1-G environment does not generate substantial MS, despite a wide variety of sensory conflicts. 92 Indeed, anecdotal reports suggest the return to a 1-G environment following spaceflight may confer later immunity to terrestrial MS. 92 The beneficial effects of normal graviception is further illustrated by the fact that roll oscillation is not very provocative in the erect position, 46,68 when otolith shearing would be present, but is highly provocative when supine, 43 when otolith graviceptor signals do not accompany the movement of the head.…”

Perceived Motion Sickness and Effects on Shooting Performance Following Combat Vehicle Transportation

“…For as long as people have been exposed to motion, the occurrence of motion sickness has affected personal well being (Morton, Cipriani, & McEachern, 1947). However, perceiving motion sickness does not require exposure to actual motion.…”

Motion Sickness Literature Search

“…Canadian wartime investigators made some of the most significant contributions toward motion sickness prevention and understanding. The "roll-pitch rocker" was used in these studies to simulate vehicle motion (Morton et al, 1947). Later, the two-and four-pole swings became the primary research tools (Manning, 1943;Manning & Stewart, 1949).…”