Every individual is aware of changes in his body position even when they are not the result of conscious effort or muscular contraction. An astronaut experiencing weightlessness will know every time his head changes position, even though he may not have moved it himself. In this post, we’ll go a little deeper into Environmental Psychology and Labyrinthine Sense.
The receptors involved in giving you a cue to body position when no muscular activity is involved are located in the labyrinth, or inner ear. Within the bony labyrinthine are the semicircular canals–three loops extending in three different planes.
These receptors are called the labyrinthine or vestibular receptors, and their function is to keep you informed of your position in space–whether you are moving up or down, right or left, backward or forward. When your body’s motion in space is accelerating or decelerating, hair calls in the ampullae–swellings at the base of the semicircular canals–are the chief receptors stimulated.
These hairs are activated by movement of the liquid in the canals; their bending, in turn, stimulates associated nerve fibers. Similar receptors in the saccule and utricle, two saclike chambers in the vestibule at the base of the canals, respond to the static force of gravity and to straight-line motion.
The sense of movement in space is related to the unpleasant phenomenon of “motion sickness.” We know that the labyrinthine is the organ involved in motion sickness, for people and animals with no vestibular sensitivity do not experience it. For many people, however, the sensation is a common one, occurring most frequently in airplanes, ships, autos, streetcars, and trains, in that order.
Effective physiological stimuli for producing motion sickness are: rotation (especially in more than one plane), vertical movements, change of head position in relation to body position, and certain visual stimuli during motion. We’ve also found that it plays a key role in memory and language after brain injury. Read more here.
Wavelike motions are particularly nauseating when they are of an intermediate size and frequency; large or small waves, or very quick or slow ones, are not so likely to make us feel sick. There are many other causes or nausea, of course, such as certain drugs, physical illnesses, and unpleasant odors, which do not involve the semicircular canals.
Perhaps the most interesting psychological cause of motion sickness is the experiencing of incongruous sets of sensations. The labyrinthine sense is stimulated only when the body stops or starts in space. On a quiet day, an airplane (even when flying close to the earth) gives the passenger no labyrinthine or kinesthetic stimulation.
He might just as well be sitting in a comfortable chair at home as far as sense of movement is concerned, and no nausea will occur if he either closes his eyes or confines his visual field to the interior of the plane. But if he looks out of the window at the earth rushing past at 300 miles per hour, he may very well get sick, for he is not accustomed to seeing the earth move past him when he has no sensation of movement.
If the plane is bouncing around, on the other hand, it is best for the passenger to close his eyes. If he looks at the interior of the plane, he will feel the sensation of falling without seeing himself falling past anything. This is another incongruous sensation and will tend to produce nausea. To prevent motion sickness, an individual must be able to organize his sensations into a meaningful and consistent pattern.
Other psychological factors in motion sickness are suggestion, emotional condition, and conditioning by past experience. CBT might be helpful is this appears to be problematic. Reduction of motion sickness occurs by habituation to the stimuli causing sickness, by lying down, or by taking certain drugs.