Postural behavior and motion sickness.

(1) An interesting style of acting was demonstrated on a stage of a Kyogen, a classic comedy of Japan, titled "Funawatashimuko", i.e., "A boatman and a bridgegroom in a boat". Antagonistic postures which move toward the opposite direction were displayed by a boatman who is pulling an oar and a passenger who is being moved by the rolling of a boat. (2) Why doesn't one suffer from motion sickness when he drives a car but may suffer from it when he is a passenger? This question was answered, from the standpoint of human postures, by observing the antagonistic postures exhibited by a bus-driver and a passenger, and also by the findings in postrotatory eye nystagmus (an indication of artificial motion sickness) which was varied according to the three different positions of the head. (3) Learning postural adjustment against motion sickness, developing through repetitively traveling in vehicles, was also objectively shown in a posture of an experienced lady bus-conductor whose body inclined in the same direction as that of the driver. Its similarity to the establishment of a kinetic labyrinthine reflex in chickens was explained.