Nausogenic properties of various dynamic and static force environments

Area of Science:

• Neuroscience
• Human Physiology
• Aerospace Medicine

Background:

• Motion sickness, including space sickness, has both dynamic and static causes.
• Dynamic sickness involves vestibular system sensitivity, while static sickness relates to otolith system compensation in altered gravity.
• Previous research indicates varying susceptibility to motion sickness across different body axes.

Purpose of the Study:

• To differentiate between dynamic and static causes of motion sickness.
• To explore the specific characteristics of space sickness in microgravity.
• To identify factors influencing susceptibility to motion sickness, particularly acceleration direction.

Main Methods:

• Analysis of motion sickness triggers, including changing acceleration and constant force fields.
• Distinguishing between dynamic and static causes of sickness.
• Review of experiments conducted in airplanes, cars, and on a vestibular sled.

Main Results:

• Motion sickness can be triggered by dynamic (changing acceleration) and static (altered gravity) factors.
• Space sickness exhibits both dynamic and static components.
• Susceptibility to motion sickness is greatest for acceleration changes along the negative X-axis.
• The peripheral vestibular apparatus cannot accurately detect true motion or standstill during reciprocating linear accelerations.

Conclusions:

• Understanding the distinct dynamic and static elements of motion sickness is crucial.
• Space sickness mechanisms require further investigation, particularly concerning otolith system function in microgravity.
• The directional sensitivity of the human body to acceleration impacts motion sickness, highlighting limitations in vestibular motion detection.