Artificial horizon effects on motion sickness and performance.
OBJECTIVE
To investigate whether the projection of Earth-referenced scenes during provocative motion can alleviate motion sickness severity and prevent motion sickness-induced degradation of performance.


BACKGROUND
Exposure to unfamiliar motion patterns commonly results in motion sickness and decreased performance.


METHODS
Thirty subjects with moderate-to-severe motion sickness susceptibility were exposed to the recorded motion profile of a missile boat under moderate sea conditions in a 3-degrees-of-freedom ship motion simulator. During a 120-minute simulated voyage, the study participants were repeatedly put through a performance test battery and completed a motion sickness susceptibility questionnaire, while self-referenced and Earth-referenced visual scenes were projected inside the closed simulator cabin.


RESULTS
A significant decrease was found in the maximal motion sickness severity score, from 9.83 ± 9.77 (mean ± standard deviation) to 7.23 ± 7.14 (p < 0.03), when the visual display better approximated the full scale of the roll, pitch, and heave movements of the simulator. Although there was a significant decrease in sickness severity, substantial symptoms still persisted. Decision making, vision, concentration, memory, simple reasoning, and psychomotor skills all deteriorated under the motion conditions. However, no significant differences between the projection conditions could be found in the scores of any of the performance tests.


CONCLUSIONS
Visual information regarding the vessel's movement provided by an artificial horizon device might decrease motion sickness symptoms. However, although this device might be suitable for passive transportation, the continued deterioration in performance measures indicates that it provides no significant advantage for personnel engaged in the active operation of modern vessels.
The Motion Sickness and Human Performance Laboratory, The Israel Naval Medical Institute, Haifa, Israel.
Dror
D
Tal
Adi
A
Gonen
Guy
G
Wiener
Ronen
R
Bar
Amnon
A
Gil
Zohar
Z
Nachum
Avi
A
Shupak
D000222:Adaptation, Physiological / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D006801:Humans; D008297:Male; D009038:Motion; D009041:Motion Sickness / Q000503:physiopathology / Q000517:prevention & control*; D009068:Movement; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology*; D012720:Severity of Illness Index; D014796:Visual Perception / Q000502:physiology*